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Background: NATALEE assessed efficacy and tolerability of 3 years of adjuvant ribociclib plus a nonsteroidal aromatase inhibitor (NSAI) compared with an NSAI alone in a broad population of patients with hormone receptor (HR)-positive/human epidermal growth factor 2 (HER2)-negative early breast cancer, including a select group without nodal involvement. This is the final preplanned analysis of invasive disease-free survival (iDFS)., Patients and Methods: Premenopausal/postmenopausal women and men were randomized 1 : 1 to ribociclib (n = 2549; 400 mg/day, 3 weeks on/1 week off for 36 months) plus NSAI (letrozole 2.5 mg/day or anastrozole 1 mg/day for 60 months) or NSAI alone (n = 2552). Men and premenopausal women also received goserelin (3.6 mg once every 28 days). Patients had anatomical stage IIA (N0 with additional risk factors or N1), IIB, or III disease. The primary endpoint was iDFS. Secondary efficacy endpoints were recurrence-free survival (RFS), distant DFS, and overall survival. This final iDFS analysis was planned after ∼500 events., Results: At data cut-off (21 July 2023), ribociclib was stopped for 1996 patients (78.3%); 1091 (42.8%) completed 3 years of ribociclib, and ribociclib treatment was ongoing for 528 (20.7%). Median follow-up for iDFS was 33.3 months. Overall, 226 and 283 iDFS events occurred with ribociclib plus NSAI versus NSAI alone, respectively. Ribociclib plus NSAI demonstrated significant iDFS benefit over NSAI alone [hazard ratio 0.749, 95% confidence interval (CI) 0.628-0.892; P = 0.0012]. The 3-year iDFS rates were 90.7% (95% CI 89.3% to 91.8%) versus 87.6% (95% CI 86.1% to 88.9%). A consistent benefit was observed across prespecified subgroups, including stage (II/III) and nodal status (positive/negative). Distant DFS and RFS favored ribociclib plus NSAI. Overall survival data were immature. No new safety signals were observed., Conclusions: With longer follow-up and most patients off ribociclib, NATALEE continues to demonstrate iDFS benefit with ribociclib plus NSAI over NSAI alone in the overall population and across key subgroups. Observed adverse events remained stable., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Leptomeningeal disease (LMD) is associated with poor survival and diminished quality of life. Trastuzumab deruxtecan (T-DXd) has shown remarkable intracranial and extracranial activity in human epidermal growth factor receptor 2 (HER2)-positive and HER2-low advanced breast cancer (ABC). The DEBBRAH trial was designed to evaluate its efficacy and safety in patients with HER2-positive and HER2-low ABC with a history of brain metastases (BMs) and/or LMD. Here, we report results from cohort 5, which specifically included patients with pathologically confirmed LMD., Methods: This single-arm, open-label, five-cohort, phase 2 trial enrolled seven patients in cohort 5 who received 5.4 mg/kg T-DXd intravenously every 21 days until disease progression or unacceptable toxicity. The primary endpoint was overall survival (OS). Key secondary endpoints included progression-free survival (PFS) and safety profile., Findings: At data cutoff (April 4, 2023), the median duration of follow-up was 12.0 months (range, 2.5-18.6). The median OS was 13.3 months (95% confidence interval [CI], 5.7-NA, p < 0.001), meeting the primary endpoint. The median PFS was 8.9 months (95% CI, 2.1-NA). Two (28.6%) of seven patients remained on treatment after 18.6 and 11.9 months, respectively. Of the five patients who progressed and died, none had intracranial progression or clinical worsening of leptomeningeal symptoms. Notably, 71.4% (95% CI, 29.0-96.3) achieved prolonged stabilization (≥24 weeks) by response evaluation criteria in solid tumors (RECIST) v.1.1. No unexpected safety signals and no treatment-related deaths were observed., Conclusions: T-DXd showed promising antitumor activity in patients with HER2-positive and HER2-low ABC with previously untreated, pathologically confirmed LMD. These encouraging data warrant further investigation to address the unmet need in this difficult-to-treat condition., Funding: This work was funded by Daiichi Sankyo/AstraZeneca. This trial is registered with ClinicalTrials.gov: NCT04420598., Competing Interests: Declaration of interests M.V.B. reports participating in a consulting/advisory board for AstraZeneca; participating as an invited speaker for Daiichi Sankyo and Nutricia; and receiving travel fees from AstraZeneca, Daiichi Sankyo, Pfizer, and GSK. J.M.P.-G. reports having a consulting or advisory role for Lilly, Roche, Eisai, Daiichi Sankyo, AstraZeneca, and Seattle Genetics; receiving travel compensation from Roche; and employment at MEDSIR. J.A.G.-S. declares consultative and advisory services for Seagen, AstraZeneca, Daiichi Sankyo, Novaris, Gilead, and Menarini; consultancy/speaker fees from Celgene, Eli Lilly, EISAI, MSD, Exact Sciences, Tecnofarma, Nolver (Adium), Asofarma, and Roche; institution and research funding from AstraZeneca; and travel support from Gilead, AstraZeneca, and Daiichi Sankyo. M.R.-B. reports serving as a consultant to Roche and Puma and receiving honoraria from Roche/Genentech, Pfizer, and Novartis. M.F.-A. reports participating in an advisory board for Seagen and Daiichi Sankyo-AstraZeneca and speakers’ bureau from Novartis and Lilly. M.G. reports receiving honoraria from Roche, Novartis, Gilead, and Daiichi Sankyo and travel compensation from Roche, Pfizer, and Daiichi Sankyo. G.M. is a full-time employee at MEDSIR. D.A.-L. is a full-time employee at MEDSIR. J.P.-E. is a full-time employee at MEDSIR. M.S.-C. reports participating in an advisory board for Optimapharm, Ability Pharma, and MD Anderson and is a full-time employee at MEDSIR. A.L.-C. reports receiving research support from Roche, Agendia, Lilly, Pfizer, Novartis, Merck Sharp & Dohme, Gilead, and Daiichi Sanyo; consulting or advisory roles for Lilly, Roche, Pfizer, and Novartis; speakers’ bureaus from Lilly, AstraZeneca, and Merck Sharp & Dohme; travel support from Roche, Pfizer, and AstraZeneca; and stock or other ownership of MEDSIR and Initia-Research. S.B. reports participating in a consulting/advisory board for Daiichi Sankyo, AstraZeneca, Novartis, and Roche; participating as an invited speaker for Daiichi Sankyo, AstraZeneca, Novartis, and Roche; and receiving travel fees from Daiichi Sankyo, AstraZeneca, Novartis, and Roche. J.C. reports serving as a consultant/advisor to Roche, Celgene, Cellestia, AstraZeneca, Seattle Genetics, Daiichi Sankyo, Erytech, Athenex, Polyphor, Lilly, Merck Sharp & Dohme, GSK, Leuko, Bioasis, Clovis Oncology, Boehringer Ingelheim, Ellipses, Hibercell, BioInvent, Gemoab, Gilead, Menarini, Zymeworks, Reveal Genomics, and Expres2ion Biotechnologies; receiving honoraria from Roche, Novartis, Celgene, Eisai, Pfizer, Samsung Bioepis, Lilly, Merck Sharp & Dohme, and Daiichi Sankyo; research funding to the Institution from Roche, Ariad Pharmaceuticals, AstraZeneca, Baxalta GMBH/Servier Affaires, Bayer Healthcare, Eisai, F. Hoffman-La Roche, Guardant Health, Merck Sharp & Dohme, Pfizer, Piqur Therapeutics, Puma C, and Queen Mary University of London; stock of MEDSIR, Nektar Pharmaceuticals, and Leuko (relative); travel, accommodations, and expenses from Roche, Novartis, Eisai, Pfizer, Daiichi Sankyo, AstraZeneca, and Gilead; and the following patents: (1) “Pharmaceutical Combinations of A Pi3k Inhibitor And A Microtubule Destabilizing Agent,” Javier Cortés Castán, Alejandro Piris Giménez, Violeta Serra Elizalde, WO 2014/199294 A, ISSUED; and (2) “Her2 as a predictor of response to dual HER2 blockade in the absence of cytotoxic therapy,” Aleix Prat, Antonio Llombart, Javier Cortés, US 2019/0338368 A1, LICENSED., (Copyright © 2024. Published by Elsevier Inc.)

Background: Concomitant intake of proton pump inhibitors (PPIs) may create drug-drug interactions, potentially impacting efficacy of anticancer agents. In the phase III PALLAS trial, the addition of palbociclib capsules to standard adjuvant endocrine therapy in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative early breast cancer did not improve invasive disease-free survival (iDFS). We explored whether concomitant use of PPIs affected survival outcomes in patients treated with palbociclib in PALLAS., Methods: This is an exploratory analysis of PALLAS including patients who received at least one dose of palbociclib capsules. We aimed to determine the association of concomitant PPI use with iDFS, distant relapse-free survival and overall survival. Uni- and multivariable Cox models with time-dependent PPI were used. The association between PPI use and neutropenia was also investigated., Results: Of 2840 patients treated with palbociclib + endocrine therapy, 525 (18.5%) had concomitant PPI and palbociclib intake. PPI intake was significantly associated with older age, post-menopausal status, use of aromatase inhibitors, higher body mass index, and worse Eastern Cooperative Oncology Group status (all P < 0.001). Concomitant PPI intake was not significantly associated with survival outcomes (iDFS, distant relapse-free survival, overall survival). All-grade neutropenia rates were numerically lower in patients who initiated a PPI before study start compared with patients never initiating PPIs (adjusted odds ratio 0.81, 95% confidence interval 0.60-1.09)., Conclusions: Our exploratory analysis did not demonstrate worse survival outcomes in patients receiving concomitant palbociclib and PPIs in PALLAS. Nonetheless, careful consideration of possible drug-drug interactions is important, especially when studying novel agents in the early breast cancer setting., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Complete pathological response to neoadjuvant treatment (NAT) in breast cancer is associated with prolonged survival. Compared to other breast cancer immunophenotypes, luminal tumors are the least chemosensitive with low rates of pathological response within this molecular subtype. Thus, finding predictors of response in this subset remains challenging. The emerging concept of low human epidermal growth factor receptor 2 (HER2) expression has led to a repurpose of the current prognostic system. Little is known about its correlation with response to NAT., Objectives: This study aims to evaluate predictors of response in early-stage luminal breast cancer receiving neoadjuvant chemotherapy., Design: A total of 252 luminal patients who received NAT were retrospectively assessed in this cohort study., Methods: We analyzed the correlation of ki67 and HER2 low expression with the rate of pathologic response. Using ki67 as a continuous variable and applying the receiver operating characteristic curves method., Results: We identified that in patients with a ki67 expression level >37%, the probability of having a complete pathological response was 4.80 times higher (odds ratio = 4.80, 95% confidence interval: 1.92-12.04). In Her2-low breast cancer patients, Her2 expression did not correlate with a better response rate., Conclusion: In our study, a ki67 expression value greater than 37% constitutes a predictive biomarker of pathological complete response in the subgroup of patients with luminal B tumors and could be considered, therefore, an indicator for treatment decisions in this subgroup., Competing Interests: M.B.: Ipsen, Novartis, Pfizer, Roche (C/A, H); M.R.-B.: Pfizer, Novartis, Daichi, Pierre Fabre (C/A), Novartis, Pfizer, AstraZeneca, Eisai, Roche (H); A.F.: Roche, Pfizer, Novartis, Lilly, Seagen, Grunenthal (H), Roche, Pfizer, Novartis, Seagen (C/A); J.S.-B.: Pfizer, Novartis, Daichi, Pierre Fabre, Lilly (C/A), Novartis, Pfizer, AstraZeneca, Eisai, Roche, and Lilly (H). The other authors indicated no financial relationships., (© The Author(s), 2024.)

Background: Alpelisib, a PI3Kα-selective inhibitor and degrader, plus fulvestrant showed efficacy in hormone receptor-positive, HER2-negative, PIK3CA-mutated advanced breast cancer in SOLAR-1; limited data are available in the post-cyclin-dependent kinase 4/6 inhibitor setting. BYLieve aimed to assess alpelisib plus endocrine therapy in this setting in three cohorts defined by immediate previous treatment; here, we report results from cohort A., Methods: This ongoing, phase 2, multicentre, open-label, non-comparative study enrolled patients with hormone receptor-positive, HER2-negative, advanced breast cancer with tumour PIK3CA mutation, following progression on or after previous therapy, including CDK4/6 inhibitors, from 114 study locations (cancer centres, medical centres, university hospitals, and hospitals) in 18 countries worldwide. Participants aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 2 or less, with no more than two previous anticancer treatments and no more than one previous chemotherapy regimen, were enrolled in three cohorts. In cohort A, patients must have had progression on or after a CDK4/6 inhibitor plus an aromatase inhibitor as the immediate previous treatment. Patients received oral alpelisib 300 mg/day (continuously) plus fulvestrant 500 mg intramuscularly on day 1 of each 28-day cycle and on day 15 of cycle 1. The primary endpoint was the proportion of patients alive without disease progression at 6 months per local assessment using Response Evaluation Criteria in Solid Tumors, version 1.1, in patients with a centrally confirmed PIK3CA mutation. This trial is registered with ClinicalTrials.gov, NCT03056755., Findings: Between Aug 14, 2017, and Jul 29, 2022 (data cutoff), 127 patients with at least 18 months' follow-up were enrolled into cohort A. 119 patients had a centrally confirmed PIK3CA mutation. At data cutoff, median follow-up was 21·8 months (IQR 10·8-37·6). 64 (53·8%; 95% CI 44·4-63·0) of 119 patients were alive without disease progression at 6 months. The most frequent grade 3 or worse adverse events were hyperglycaemia (37 [29%] of 127 patients), rash (13 [10%]), and rash maculopapular (11 [9%]). Serious adverse events occurred in 37 (29%) of 127 patients. No treatment-related deaths were reported., Interpretation: BYLieve showed activity of alpelisib plus fulvestrant with manageable toxicity in patients with PIK3CA-mutated, hormone receptor-positive, HER2-negative advanced breast cancer, after progression on a CDK4/6 inhibitor plus an aromatase inhibitor., Funding: Novartis Pharmaceuticals., Competing Interests: Declaration of interests HSR reports research support to the University of California San Francisco from Pfizer, Merck, Novartis, Eli Lilly, Genentech, OBI, Odonate, Daiichi, Eisai, Seattle Genetics, MacroGenics, Sermonix, and Immunomedics; a limited consulting role with Samsung; honoraria from Puma and Mylan; and travel support from Daiichi, Mylan, Pfizer, Merck, AstraZeneca, Novartis, and MacroGenics. FL reports consulting for AstraZeneca, Eisai, Genomic Health, and Eli Lilly; and travel support from Eli Lilly, Novartis, Pfizer, Roche, and Laboratories Pierre Fabre. EC reports honoraria, and consulting and paid speakers’ bureaus for Novartis, Pfizer, Eli Lilly, and Roche; and travel support from Roche and Pfizer. PD reports research funding from Roche and Novartis. YHP reports grants from Novartis, during the conduct of the study; personal fees from AstraZeneca, Pfizer, Daiichi Sankyo, and Eli Lilly; grants and personal fees from Merck, AstraZeneca, Eisai, and Novartis; grants and non-financial support from Pfizer; and personal fees and non-financial support from Roche, outside the submitted work. AP reports immediate family member employee of Novartis; personal honoraria from Pfizer, Novartis, Roche, MSD Oncology, Eli Lilly, Daiichi Sankyo, and Amgen; consultant for Amgen, Roche, Novartis, Pfizer, Bristol-Myers Squibb, Boehringer, Puma, Oncolytics Biotech, Daiichi Sankyo, and AbbVie; institutional honorarium from Nanostring Technologies; institutional research funding from Roche, Novartis, Incyte, and Puma; patents on HER2 and chemoendocrine score predictors; travel support from Daiichi Sankyo; an advisory role with Oncolytics and consultancy for Peptomyc; and is the founder of Reveal Genomics. TB reports personal fees and non-financial support from Roche; and grants, personal fees, and non-financial support from Novartis, AstraZeneca, and Pfizer, outside the submitted work. DJ reports personal fees from Novartis, Genentech, Eisai, Ipsen, and EMD Serono, during the conduct of the study. NT reports advisory board honoraria from AstraZeneca, Bristol-Myers Squibb, Lilly, Merck Sharpe & Dohme, Novartis, Pfizer, Roche/Genentech, Bicycle Therapeutics, Taiho, Zeno Pharmaceuticals, Repare Therapeutics; and research funding from AstraZeneca, BioRad, Pfizer, Roche/Genentech, Clovis, Merck Sharpe & Dohme, and Guardant Health. NS reports employment at Novartis. JPZ reports employment at and stock ownership in Novartis. JPZ's wife is employed by Johnson & Johnson. CA and Y-MS report employment at Novartis. ST reports employment at and stock ownership in Novartis. HK and W-CH reports consulting agreements and research funding for the conduct of this study from Novartis. SC reports grants and personal fees from Novartis and Pfizer; and personal fees from Eli Lilly, during the conduct of the study; and grants and personal fees from Hoffmann LaRoche, AstraZeneca, and Genomic Health, outside the submitted work. MR-B and PN declare no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: The effect of the addition of cyclin-dependent kinases 4 and 6 inhibitors to endocrine therapy in terms of molecular downstaging remains undetermined. Switching from a high-risk to a low risk Recurrence Score (RS) group could provide useful information to identify patients who might not require chemotherapy. The purpose of this study was to assess the biological and clinical activity of letrozole plus palbociclib as neoadjuvant treatment for patients with hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative early breast cancer with an initial Oncotype DX RS ≥18., Patients and Methods: Participants were women aged ≥18 years with HR-positive/HER2-negative, Ki67 ≥ 20%, stage II-IIIB early breast cancer with a baseline RS ≥18. Eligible patients with a pretreatment RS 18-25 (cohort A) and 26-100 (cohort B) received six 28-day cycles of letrozole (2.5 mg per day; plus goserelin if pre- or perimenopausal) plus palbociclib (125 mg per day; 3/1 schedule) before surgery. The primary endpoint for both cohorts was the proportion of patients who achieved an RS ≤25 at surgery or a pathological complete response (pCR)., Results: A total of 67 patients were enrolled, among which 65 were assessable for the primary endpoint (32 patients in cohort A and 33 in cohort B). At surgery, 22 (68.8%) patients in cohort A and 18 (54.5%) patients in cohort B had an RS ≤25 or a pCR [only 1 (3.0%) patient in cohort B], meeting the primary endpoint in cohort B (P < 0.01), but not in cohort A (P = 0.98). No new safety signals were identified., Conclusions: The efficacy of neoadjuvant treatment with letrozole plus palbociclib does not seem to depend on pretreatment RS for patients with RS ≥18. However, around half of patients with HR-positive/HER2-negative early breast cancer with an RS 26-100 at baseline achieved molecular downstaging with this regimen., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Trastuzumab deruxtecan (T-DXd) is approved for human epidermal growth factor receptor 2 (HER2)-positive and HER2-low advanced breast cancer (ABC). T-DXd has shown encouraging intracranial activity in HER2-positive ABC patients with stable or active brain metastases (BMs); however, its efficacy in patients with HER2-low ABC with BMs is not well established yet., Methods: DEBBRAH is a single-arm, five-cohort, phase II study evaluating T-DXd in patients with central nervous system involvement from HER2-positive and HER2-low ABC. Here, we report results from patients with heavily pretreated HER2-low ABC and active BMs, enrolled in cohorts 2 (n = 6, asymptomatic untreated BMs) and 4 (n = 6, progressing BMs after local therapy). Patients received 5.4 mg/kg T-DXd intravenously once every 21 days. The primary endpoint was intracranial objective response rate per Response Assessment in Neuro-Oncology Brain Metastases (RANO-BM) for both cohorts., Results: Intracranial objective response rate per RANO-BM was 50.0% [3/6 patients; 95% confidence interval (CI) 11.8% to 88.2%] and 33.3% [2/6 patients; 95% CI 4.3% to 77.7%; P = 0.033 (one-sided)] in cohorts 2 and 4, respectively. All responders had partial responses. Median time to intracranial response was 2.3 months (range, 1.5-4.0 months) and median duration of intracranial response was 7.2 months (range, 2.8-16.8 months). Median progression-free survival per RECIST v.1.1. was 5.4 months (95% CI 4.1-10.0 months). Treatment-emergent adverse events occurred in all patients included (16.7% grade 3). Three patients (25.0%) had grade 1 interstitial lung disease/pneumonitis., Conclusions: T-DXd demonstrated promising intracranial activity in pretreated HER2-low ABC patients with active BMs. Further studies are needed to validate these results in larger cohorts. This trial is registered with ClinicalTrials.gov, NCT04420598., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Purpose: HER2-targeted therapies have dramatically improved outcomes of patients with HER2-positive breast cancer (BC), as demonstrated in neoadjuvant trials. This study aims to provide real-world evidence on the use and effectiveness of combined pertuzumab, trastuzumab and chemotherapy (CT) in early-stage HER2-positive BC., Methods: A retrospective, multicentre study was conducted on patients diagnosed with HER2-positive early BC treated with neoadjuvant pertuzumab and trastuzumab plus CT at 13 Spanish sites. The primary endpoint was pathological complete response (pCR)., Results: A total of 310 patients were included. Pertuzumab and trastuzumab were combined with anthracyclines and taxanes, carboplatin and docetaxel, and taxane-based CT in 77.1%, 16.5%, and 6.5% of patients, respectively. Overall, the pCR rate was 62.2%. The pCR was higher amongst patients with hormone receptor-negative tumours and with tumours expressing higher levels of Ki-67 (> 20%). After postoperative adjuvant treatment, 13.9% of patients relapsed. Those patients who did not achieve pCR, with tumours at advanced stages (III), and with node-positive disease were more likely to experience distant relapse. Median overall survival (OS) and distant disease-free survival (D-DFS) were not reached at the study end. The estimated mean OS and D-DFS times were 7.5 (95% CI 7.3-7.7) and 7.3 (95% CI 7.1-7.5) years, respectively (both were significantly longer amongst patients who achieved pCR). Grade 3-4 anti-HER2 related toxicities were reported in six (1.9%) patients., Conclusion: Neoadjuvant pertuzumab and trastuzumab plus CT achieve high pCR rates in real-life patients with HER2-positive early BC, showing an acceptable safety profile. Innovative adjuvant strategies are essential in patients at high risk of distant disease recurrence., (© 2024. The Author(s).)

Background: The capsule formulation of CDK4/6 inhibitor palbociclib has reduced solubility at gastric pH > 4.5 and may have decreased activity when used with proton-pump inhibitors (PPI). Herein, we report the effect of PPI on palbociclib capsule activity and safety in the PARSIFAL study., Methods: First-line endocrine-sensitive, hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) patients received palbociclib capsules plus fulvestrant or letrozole. The primary endpoint was progression-free survival (PFS). This post-hoc analysis compared PPI use. Patients were PPI-naïve (N-PPI) if not on PPI during the study, and either early (E-PPI) or long-term PPI (LT-PPI) if on PPI at study entry or for at least ≥⅔ of treatment, respectively. PPI groups were not mutually exclusive., Results: Among 486 patients, 66.9 % were N-PPI, 13.2 % E-PPI, 18.7 % LT-PPI, and 11.5 % of the PPI users were defined as neither. Median PFS (mPFS) was 29.6 months in the study population, 28.7 months in N-PPI, 23.0 months in E-PPI (Hazard Ratio [HR] 1.5; 95%Confidence Interval [CI] 1.1-2.2; p = 0.024), and 23.0 months in LT-PPI (HR 1.4; 95%CI 1.0-1.9; p = 0.035). By landmark analysis, PPI use was associated with poorer mPFS at 3 and 12 months. Grade ≥3 hematological adverse events occurred in 71.7 % of N-PPI, 57.8 % of E-PPI (p = 0.021), and 54.9 % of LT-PPI (p = 0.003). Dose reductions and dosing delays due to hematological toxicity occurred in 70.8 % of N-PPI, 56.3 % of E-PPI (p = 0.018), and 52.7 % of LT-PPI (p = 0.002)., Conclusions: PPI use may reduce palbociclib capsule toxicity, dose modifications, and clinical activity in HR+/HER2- ABC., Competing Interests: Declaration of competing interest SDC reports consulting for MEDSIR and IQVIA and honoraria from Pierre-Fabre, Novartis, and AstraZeneca. JMPG reports consulting for Roche, Eiasi, Daichii Sankyo, AstraZeneca, Gilead, MSD and Seagen and travel expenses from Roche. MB reports consulting fees from Pfizer, Novartis, Lilly, and Steamline-Menarini; honoraria from Pfizer, Novartis, and Lilly; and trave support from Pfizer. FD reports travel grants for Daichii, Novartis, and Pfizer, and participation in monitor/advisory boards for Daiichi, Seagen, Novartis, Gilead, Lilly, and MSD. MGG reports honoraria from Pfizer, Novartis, and AstraZeneca, travel grants from Lilly, Daiichi-Sankyo, and Pfizer, and participation in monitoring/advisory boards for AstraZeneca, Seagen, and Gilead. MRB reports honoraria from Pfizer, Novartis, AstraZenca, and Daiichi Sankyo. JG reports consulting fees from Novartis, Pfizer, AstraZeneca; honoraria from Novartis; and travel support from Roche and AstraZeneca. EAO reports consulting for AstraZeneca, Daichii, Gilead, MSD, and Seagen; honoraria from AstraZeneca, Daichii, Lilly, MSD, and Seagen; travel support from Daichii, Lilly, Gilead, and AstraZeneca; and participation in monitor/advisory boards for Gilead, AstraZeneca, Seagen, and Dachii. PS reports honoraria from Pfizer, AstraZeneca, Novartis, Roche, Merck, and Boehringer Ingelheim; a consulting role for Pfizer, AstraZeneca, Novartis, Roche, Merck, Boehringer Ingelheim, Bayer, Eisai, Celgene, and Puma; and institutional grants from Roche, Genentech, Oncogenex, and Novartis. FM reports grants from Roche, Novartis, AstraZeneca, GSK, MSD, Clovis, Vaccibody, Gilead Sciences, and Esai; consulting fees from AstraZeneca, GSK, and Roche; honoraria from AstraZeneca, MSD, Lilly, Pfizer, Novartis, GSK, Clovis, Myriad, Daiich Sankyo, Seagen, Pierre-Fabre, and Agendia; travel support from AstraZeneca, GSK, Pfizer, and Roche; and participation in advisory boards for Palleos and Amgen. JG reports grant/research support from Roche, Eiasi, and Exact Science; honoraria or consultation fees from AstraZeneca, Daiichi, Eisai, Exact Science, Evapharm, GE Healthcare, Gilead, Lilly, MSD, Novartis, Pfizer, Pierre Fabre, Roche, Seagen, Sothema and participation in company sponsored speaker's bureaus for Exact Science, Lilly, and Novartis. AS reports grants from Celgene, Roche, Abbvie; travel grants from Celgene, Roche, Pfizer, AstraZeneca, and honoraria from Roche, Celgene, Pfizer, AstraZeneca, Novartis, MSD, Tesaro, Lilly, Seagen, Gilead, GSK, Bayer, Amgen, Pierre Fabre. JA reports trial funding from MEDSIR and consulting for Pfizer, Lilly, and Novartis. PZ reports honoraria from Pfizer, Novartis, Roche, and Pierre Fabre; and travel support from Pfizer, Novartis, Roche, and Lilly. DW reports honoraria from Pfizer, Novartis, AstraZeneca and travel grants from Roche, and Novartis. JC reports consulting for Roche, Celgene, Cellestia, AstraZeneca, Seattle Genetics, Daiichi Sankyo, Erytech, Athenex, Polyphor, Lilly, Merck Sharp&Dohme, GSK, Leuko, Bioasis, Clovis Oncology, Boehringer Ingelheim, Ellipses, Hibercell, BioInvent, Gemoab, Gilead, Menarini, Zymeworks, Reveal Genomics, Expres2ion Biotechnologies; honoraria from Roche, Novartis, Celgene, Eisai, Pfizer, Samsung Bioepis, Lilly, Merck Sharp&Dohme, Daiichi Sankyo.; research funding to the Institution from Roche, Ariad pharmaceuticals, AstraZeneca, Baxalta GMBH/Servier Affaires, Bayer healthcare, Eisai, F. Hoffman-La Roche, Guardanth health, Merck Sharp&Dohme, Pfizer, Piqur Therapeutics, Puma C, Queen Mary University of London; stock shares for MEDSIR, Nektar Pharmaceuticals, Leuko (relative); Travel, accommodation, expenses from Roche, Novartis, Eisai, Pfizer, Daiichi Sankyo, Astrazeneca, Gilead; and Patents: Pharmaceutical Combinations of A Pi3k Inhibitor And A Microtubule Destabilizing Agent. Javier Cortés Castán, Alejandro Piris Giménez, Violeta Serra Elizalde. WO 2014/199294 A. ISSUED Her2 as a predictor of response to dual HER2 blockade in the absence of cytotoxic therapy. Aleix Prat, Antonio Llombart, Javier Cortés. US 2019/0338368 A1. LICENSED. ALC reports research support from Roche, Agendia, Lilly, Pfizer, Novartis, Merck Sharp & Dohme, Gilead, and Daichii-Sanyo; consulting for Lilly, Roche, Pfizer, and Novartis; participation in speakers' bureaus for Lilly, AstraZeneca, Merck Sharp & Dohme; travel support from Roche, Pfizer, AstraZeneca; and stock or other ownership in MEDSIR and Initia-Research. The remaining authors declare no conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: SERENA-1 (NCT03616587) is a phase I, multi-part, open-label study of camizestrant in pre- and post-menopausal women with estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer. Parts A and B aim to determine the safety and tolerability of camizestrant monotherapy and define doses for clinical evaluation., Patients and Methods: Women aged ≥18 years with metastatic or recurrent ER+, HER2- breast cancer, refractory (or intolerant) to therapy, were assigned 25 mg up to 450 mg once daily (QD; escalation) or 75, 150, or 300 mg QD (expansion). Safety and tolerability, antitumor efficacy, pharmacokinetics, and impact on mutations in the estrogen receptor gene (ESR1m) circulating tumor (ct)DNA levels were assessed., Results: By 9 March 2021, 108 patients received camizestrant monotherapy at 25-450 mg doses. Of these, 93 (86.1%) experienced treatment-related adverse events (TRAEs), 82.4% of which were grade 1 or 2. The most common TRAEs were visual effects (56%), (sinus) bradycardia (44%), fatigue (26%), and nausea (15%). There were no TRAEs grade 3 or higher, or treatment-related serious adverse events at doses ≤150 mg. Median t max was achieved ∼2-4 h post-dose at all doses investigated, with an estimated half-life of 20-23 h. Efficacy was observed at all doses investigated, including in patients with prior cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) and/or fulvestrant treatment, with and without baseline ESR1 mutations, and with visceral disease, including liver metastases., Conclusions: Camizestrant is a next-generation oral selective ER antagonist and degrader (SERD) and pure ER antagonist with a tolerable safety profile. The pharmacokinetics profile supports once-daily dosing, with evidence of pharmacodynamic and clinical efficacy in heavily pre-treated patients, regardless of ESR1m. This study established 75-, 150-, and 300-mg QD doses for phase II testing (SERENA-2, NCT04214288 and SERENA-3, NCT04588298)., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: The PHERGain study (NCT03161353) is assessing early metabolic responses to neoadjuvant treatment with trastuzumab-pertuzumab and chemotherapy de-escalation using a [ 18 Fluorine]fluorodeoxyglucose-positron emission tomography ([ 18 F]FDG-PET) and a pathological complete response-adapted strategy in HER2-positive (HER2+) early breast cancer (EBC). Herein, we present RESPONSE, a PHERGain substudy, where clinicopathological and molecular predictors of [ 18 F]FDG-PET disease detection were evaluated., Methods: A total of 500 patients with HER2 + EBC screened in the PHERGain trial with a tumor size > 1.5 cm by magnetic resonance imaging (MRI) were included in the RESPONSE substudy. PET[-] criteria entailed the absence of  ≥ 1 breast lesion with maximum standardized uptake value (SUVmax) ≥ 1.5 × SUVmean liver + 2 standard deviation. Among 75 PET[-] patients screened, 21 with SUVmax levels < 2.5 were randomly selected and matched with 21 PET[+] patients with SUVmax levels ≥ 2.5 based on patient characteristics associated with [ 18 F]FDG-PET status. The association between baseline SUVmax and [ 18 F]FDG-PET status ([-] or [+]) with clinicopathological characteristics was assessed. In addition, evaluation of stromal tumor-infiltrating lymphocytes (sTILs) and gene expression analysis using PAM50 and Vantage 3D™ Cancer Metabolism Panel were specifically compared in a matched cohort of excluded and enrolled patients based on the [ 18 F]FDG-PET eligibility criteria., Results: Median SUVmax at baseline was 7.2 (range, 1-39.3). Among all analyzed patients, a higher SUVmax was associated with a higher tumor stage, larger tumor size, lymph node involvement, hormone receptor-negative status, higher HER2 protein expression, increased Ki67 proliferation index, and higher histological grade (p < 0.05). [ 18 F]FDG-PET [-] criteria patients had smaller tumor size (p = 0.014) along with the absence of lymph node involvement and lower histological grade than [ 18 F]FDG-PET [+] patients (p < 0.01). Although no difference in the levels of sTILs was found among 42 matched [ 18 F]FDG-PET [-]/[+] criteria patients (p = 0.73), [ 18 F]FDG-PET [-] criteria patients showed a decreased risk of recurrence (ROR) and a lower proportion of PAM50 HER2-enriched subtype than [ 18 F]FDG-PET[+] patients (p < 0.05). Differences in the expression of genes involved in cancer metabolism were observed between [ 18 F]FDG-PET [-] and [ 18 F]FDG-PET[+] criteria patients., Conclusions: These results highlight the clinical, biological, and metabolic heterogeneity of HER2+ breast cancer, which may facilitate the selection of HER2+ EBC patients likely to benefit from [ 18 F]FDG-PET imaging as a tool to guide therapy., Trial Registration: Clinicaltrials.gov; NCT03161353; registration date: May 15, 2017., (© 2024. The Author(s).)

Purpose: The prognostic and predictive role of trophoblast cell-surface antigen-2 (Trop-2) overexpression in human epidermal growth factor receptor 2-positive (HER2-positive) breast cancer is currently unknown. We retrospectively analyzed Trop-2 expression and its correlation with clinicopathologic features and pathological complete response (pCR) in HER2-positive early breast cancer (EBC) patients treated with neoadjuvant docetaxel, carboplatin, trastuzumab, and pertuzumab in the PHERGain study., Methods: Trop-2 expression at baseline was determined in formalin-fixed, paraffin-embedded primary tumor biopsies by immunohistochemistry and was first classified into expressing (Trop-2-positive) or not-expressing (Trop-2-negative) tumors. Then, it was classified by histochemical score (H-score) according to its intensity into low (0-9), intermediate (10-49), and high (≥ 50). The association between clinicopathologic features, pCR, and Trop-2 expression was performed with Fisher's exact test., Results: Forty-one patients with tissue evaluable for Trop-2 expression were included, with 28 (68.3%) Trop-2-positive tumors. Overall, 17 (41.46%), 14 (34.15%), and 10 (24.40%) tumors were classified as low, intermediate, and high, respectively. Trop-2 expression was significantly associated with decreased pCR rates (50.0% vs. 92.3%; odds ratio [OR] 0.05; 95% CI, 0.002-0.360]; p adjusted = 0.01) but was not correlated with any clinicopathologic features (p ≥ 0.05). Tumors with the highest Trop-2 H-score were less likely to obtain a pCR (OR 0.03; 95% CI, 0.001-0.290, p adjusted < 0.01). This association was confirmed in univariate and multivariate regression analyses., Conclusion: These findings suggest a potential role of Trop-2 expression as a biomarker of resistance to neoadjuvant chemotherapy plus dual HER2 blockade and may become a strategic target for future combinations in HER2-positive EBC patients., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The PHERGain trial investigated the potential of metabolic imaging to identify candidates for chemotherapy deescalation in human epidermal growth factor receptor 2 (HER2)-positive, invasive, operable breast cancer with at least 1 breast lesion evaluable by [ 18 F]FDG PET/CT. [ 18 F]FDG PET/CT responders were defined as patients with an SUV max reduction (ΔSUV max ) of at least 40% in all of their target lesions after 2 cycles of trastuzumab and pertuzumab (HP) (with or without endocrine therapy). In total, 227 of 285 patients (80%) included in the HP arm showed a predefined metabolic response and received a total of 8 cycles of HP (with or without endocrine therapy). Pathologic complete response (pCR), defined as ypT0/isN0, was achieved in 37.9% of the patients. Here, we describe the secondary preplanned analysis of the best cutoff of ΔSUV max for pCR prediction. Methods: Receiver-operating-characteristic analysis was applied to look for the most appropriate ΔSUV max cutoff in HER2-positive early breast cancer patients treated exclusively with neoadjuvant HP (with or without endocrine therapy). Results: The ΔSUV max capability of predicting pCR in terms of the area under the receiver-operating-characteristic curve was 72.1% (95% CI, 65.1-79.2%). The optimal ΔSUV max cutoff was found to be 77.0%, with a 51.2% sensitivity and a 78.7% specificity. With this cutoff, 74 of 285 patients (26%) would be classified as metabolic responders, increasing the pCR rate from 37.9% (cutoff ≥ 40%) to 59.5% (44/74 patients) ( P < 0.01). With this optimized cutoff, 44 of 285 patients (15.4%) would avoid chemotherapy in either the neoadjuvant or the adjuvant setting compared with 86 of 285 patients (30.2%) using the original cutoff ( P < 0.001). Conclusion: In the PHERGain trial, an increased SUV max cutoff (≥77%) after 2 cycles of exclusive HP (with or without endocrine therapy) achieves a pCR in the range of the control arm with chemotherapy plus HP (59.5% vs. 57.7%, respectively), further identifying a subgroup of patients with HER2-addicted tumors. However, the original cutoff (≥40%) maximizes the number of patients who could avoid chemotherapy., (© 2024 by the Society of Nuclear Medicine and Molecular Imaging.)

Background: PHERGain was designed to assess the feasibility, safety, and efficacy of a chemotherapy-free treatment based on a dual human epidermal growth factor receptor 2 (HER2) blockade with trastuzumab and pertuzumab in patients with HER2-positive early breast cancer (EBC). It used an 18 fluorine-fluorodeoxyglucose-PET-based, pathological complete response (pCR)-adapted strategy., Methods: PHERGain was a randomised, open-label, phase 2 trial that took place in 45 hospitals in seven European countries. It randomly allocated patients in a 1:4 ratio with centrally confirmed, HER2-positive, stage I-IIIA invasive, operable breast cancer with at least one PET-evaluable lesion to either group A, where patients received docetaxel (75 mg/m 2 , intravenous), carboplatin (area under the curve 6 mg/mL per min, intravenous), trastuzumab (600 mg fixed dose, subcutaneous), and pertuzumab (840 mg loading dose followed by 420 mg maintenance doses, intravenous; TCHP), or group B, where patients received trastuzumab and pertuzumab with or without endocrine therapy, every 3 weeks. Random allocation was stratified by hormone receptor status. Centrally reviewed PET was conducted at baseline and after two treatment cycles. Patients in group B were treated according to on-treatment PET results. Patients in group B who were PET-responders continued with trastuzumab and pertuzumab with or without endocrine therapy for six cycles, while PET-non-responders were switched to receive six cycles of TCHP. After surgery, patients in group B who were PET-responders who did not achieve a pCR received six cycles of TCHP, and all patients completed up to 18 cycles of trastuzumab and pertuzumab. The primary endpoints were pCR in patients who were group B PET-responders after two treatment cycles (the results for which have been reported previously) and 3-year invasive disease-free survival (iDFS) in patients in group B. The study is registered with ClinicalTrials.gov (NCT03161353) and is ongoing., Findings: Between June 26, 2017, and April 24, 2019, a total of 356 patients were randomly allocated (71 patients in group A and 285 patients in group B), and 63 (89%) and 267 (94%) patients proceeded to surgery in groups A and B, respectively. At this second analysis (data cutoff: Nov 4, 2022), the median duration of follow-up was 43·3 months (range 0·0-63·0). In group B, the 3-year iDFS rate was 94·8% (95% CI 91·4-97·1; p=0·001), meeting the primary endpoint. No new safety signals were identified. Treatment-related adverse events and serious adverse events (SAEs) were numerically higher in patients allocated to group A than to group B (grade ≥3 62% vs 33%; SAEs 28% vs 14%). Group B PET-responders with pCR presented the lowest incidence of treatment-related grade 3 or higher adverse events (1%) without any SAEs., Interpretation: Among HER2-positive EBC patients, a PET-based, pCR-adapted strategy was associated with an excellent 3-year iDFS. This strategy identified about a third of patients who had HER2-positive EBC who could safely omit chemotherapy., Funding: F Hoffmann-La Roche., Competing Interests: Declaration of interests JMP-G reports consulting roles for Roche, Lilly, Eisai, Daiichi Sankyo, AstraZeneca, Gilead, MSD, and Seattle Genetics and travel expenses from Roche. JC reports consulting roles for Roche, Celgene, Cellestia, AstraZeneca, Biothera Phgroupaceutical, Merus, Seattle Genetics, Daiichi Sankyo, Erytech, Athenex, Polyphor, Lilly, Servier, MSD, GSK, Leuko, Bioasis, and Clovis Oncology; honoraria from Roche, Novartis, Celgene, Eisai, Pfizer, Samsung Bioepis, Lilly, MSD, and Daiichi Sankyo; research funding to their institution from Roche, Ariad pharmaceuticals, AstraZeneca, Baxalta GMBH/Servier Affaires, Bayer healthcare, Eisai, F Hoffman-La Roche, Guardanth health, MSD, Pfizer, Piqur Therapeutics, Puma C, and Queen Mary University of London; and intellectual property for Medica Scientia Innovation Research (MEDSIR). MR-B reports membership of a speaker bureau and advisory board for Novartis. MC reports a research grant to their institution from Roche and the role of co-chair of the scientific committee of the International Breast Cancer Study Group. AS reports consulting roles for Roche, AstraZeneca, Seagen, Novartis, and Boehringer Ingelheim; to be part of a speaker bureau for Daiichi Sankyo, Roche, and Novartis; and travel expenses from Pfizer, Novartis, and Eisai. BB reports receiving fees for medical education in a consulting or advisory role with MSD, Roche, Pierre Fabre, Novartis, AstraZeneca, and Seagen; participating in a speakers bureau for Pfizer, Roche, MSD, Palex, Eisai, Daichii Sankyo, AstraZeneca, and Seagen. SE-d-R reports consulting roles for Daiichi Sankyo/AstraZeneca, Seagen, and Pierre Fabre; to be part of a speaker bureau for Daiichi Sankyo/AstraZeneca, Pfizer, Novartis, Seagen; to have received research funding from Roche, Synthon, Byondis, MEDSIR, SOLTI, Zymeworks, and Daiichi Sankyo/AstraZeneca; and travel, accommodation, or expenses from Pfizer, Kern Pharma, and Daiichi Sankyo/AstraZeneca. NR reports research funding from Pfizer; and to be part of speaker bureau for Novartis, Pfizer, Gilead, and Daiichi Sankyo/AstraZeneca. FM reports grants from Roche, Novartis, AstraZeneca, GSK, MSD, Clovis, Vaccibody, Gilead Sciences, and Esai; consulting fees from AstraZeneca, GSK, and Roche; honoraria from AstraZeneca, MSD, Lilly, Pfizer, Novartis, GSK, Clovis, Myriad, Daiichi Sankyo, Seagen, Pierre Fabre, and Agendia; travel support from AstraZeneca, GSK, Pfizer, and Roche; and participation in advisory boards for Palleos and Amgen. AC reports consulting or advisory roles for Daiichi Sankyo/AstraZeneca, Seagen, and Pierre Fabre; being part of a speakers bureau for Daiichi Sankyo/AstraZeneca, Pfizer, Novartis, and Seagen; institutional research funding from Roche, Synthon, Byondis, MEDSIR, SOLTI, Zymeworks, and Daiichi Sankyo/AstraZeneca; and expert testimony and travel or accommodations expenses from Pfizer, Kern Pharma, and Daiichi Sankyo/AstraZeneca. AP reports honoraria from Pfizer, Novartis, Roche, MSD Oncology, Lilly, Daiichi Sankyo, and Amgen; to have consulting roles for Roche, AstraZeneca, Peptomyc, Novartis, and Daiichi Sankyo; research funding to their institution from Roche, AstraZeneca, Novartis, and Reveal Genomics; to have intellectual property (ERBB2 and HER2DX patents); travel expenses from Daiichi Sankyo; and a share in ownership at Reveal Genomics. PS reports honoraria from Pfizer, AstraZeneca, Novartis, Roche, Merck, and Boehringer Ingelheim; a consulting role in Pfizer, AstraZeneca, Novartis, Roche, Merck, Boehringer Ingelheim, Bayer, Eisai, Celgene, and Puma; and grants to their institution from Roche, Genentech, Oncogenex, and Novartis. SB reports a consulting or advisory board role at Daiichi Sankyo, AstraZeneca, Novartis, and Roche; speaker or conference fees from Daiichi Sankyo, AstraZeneca, Novartis, and Roche; and travel fees from Daiichi Sankyo, AstraZeneca, Novartis, and Roche. SDC reports receiving fees for medical education from Novartis, Pierre Fabre, and IQVIA; institutional grant IG 20774 of Fondazione AIRC per la Ricerca sul Cancro; Cancer Can.Heal European EU4 Health Programme 101080009–European Commission; and serving as an ad hoc medical advisor for MEDSIR. MG reports honoraria from Roche, Novartis, Gilead, and AstraZeneca; travel grants and accommodation from Roche, Pfizer, and AstraZeneca; and an advisory role at Gilead. GA reports honoraria from MEDSIR. AL-C reports leadership roles at Eisai, Celgene, Lilly, Pfizer, Roche, Novartis, and MSD; intellectual property for MEDSIR and Initia Research; to have consulting roles for Lilly, Roche, Pfizer, Novartis, Pierre Fabre, GenomicHealth, and GSK; to be part of a speakers bureau for Lilly, AstraZeneca, and MSD; research funding from Roche, Foundation Medicine, Pierre Fabre, and Agendia; and travel expenses from Roche, Lilly, Novartis, Pfizer, and AstraZeneca. CP, ES, DA-L, PG, JR-M, LM, and MS-C are employees of MEDSIR. All other authors declare no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Hyperglycaemia is an early and frequent adverse event during alpelisib treatment. METALLICA aimed to evaluate prophylactic metformin to prevent or reduce hyperglycaemia occurrence in patients with HR+/HER2-/ PIK3CA -mutated advanced breast cancer (ABC)., Methods: Between August 13th, 2020 and March 23rd, 2022, this 2-cohort, phase 2, multicentre, single-arm trial (NCT04300790) enrolled patients with HR+/HER2-/PIK3CA-mutated ABC: cohort A, normal glycaemia (fasting plasma glucose <100 mg/dL [<5.6 mmol/L] and HbA1c <5.7%), and cohort B, prediabetes (fasting plasma glucose 100-140 mg/dL [5.6-7.8 mmol/L] and/or haemoglobin A1C [HbA1c] 5.7-6.4%). Participants were at least 18 years old, with Eastern Cooperative Oncology Group performance status of 0-1, and up to two prior lines of endocrine therapy (ET) for ABC. Alpelisib plus ET were administered in 28-day cycles after initiation of prophylactic metformin plus ET. Primary endpoint was the incidence of grade 3-4 hyperglycaemia over the first 8 weeks. Secondary endpoints included safety, progression-free survival (PFS), objective response rate (ORR), and clinical benefit rate (CBR). The primary objective for cohort A and B is met with ≤7 (14.6%) and ≤4 (20%) patients with grade 3-4 hyperglycaemia over the first 8 weeks, respectively., Findings: 233 patients were screened, and 68 (20.2%) patients were enrolled in cohorts A (n = 48) and B (n = 20). Median follow-up was 7.8 months (IQR 1.4-19.6). Over the first 8 weeks, one (2.1%) of 48 patients in cohort A (95% CI: 0.5-11.1; P  < 0.0001), and three (15.0%) of 20 patients in cohort B (95% CI: 5.6-37.8; P  = 0.016) had grade 3-4 hyperglycaemia. Serious treatment-related adverse events occurred in seven patients (10.3%). The most common were rash (two [2.9%]), vomiting (two [2.9%]), and diarrhoea (two [2.9%]). Discontinuation of alpelisib caused by AEs was reported in nine patients (13.2%), none caused by hyperglycaemia. At data cutoff (15 June, 2022), no treatment-related deaths were observed. In the full analysis set, median PFS was 7.3 months (95% CI: 5.9-not reached), ORR was 20.6% (95% CI: 11.7-32.1%), and CBR was 52.9% (95% CI: 40.4-65.2)., Interpretation: In HR+/HER2-/ PIK3CA -mutated ABC, prophylactic metformin before alpelisib plus endocrine treatment has low incidence and severity of alpelicib-induced hyperglycaemia., Funding: Novartis Pharmaceuticals., Competing Interests: ALC reports research support from Roche, Agendia, Lilly, Pfizer, Novartis, Merck Sharp & Dohme, Gilead, and Daichii-Sanyo; a consulting or advisory role with Lilly, Roche, Pfizer, and Novartis. Speakers’ bureaus for Lilly, AstraZeneca, Merck Sharp & Dohme; travel support from Roche, Pfizer, AstraZeneca; and stock or other ownership in MEDSIR and Initia-Research. JMPG reports a consulting or advisory role with Lilly, Roche, Eisai, Daichii Sankyo, AstraZeneca, Seattle Genetics; and employment at MEDSIR. MRB reports research support and participating in an advisory board of Novartis. PT reports a consulting or advisory role with AstraZeneca, Daiichi-Sankyo, Novartis and Seagen. Speakers’ bureaus for Pfizer, Novartis, Lilly, AstraZeneca, Daiichi-Sankyo and Seagen. IB reports grants and research support to the Institution: AstraZeneca, Lilly, Pfizer and Roche; honoraria and advisor colaboration: AstraZeneca, Roche, Novartis, Eisai, Celgene, Pfizer, Lilly, Pierre-Fabre, Bristol-Myers Squibb, Daiichi Sankyo, Grünenthal, Seagen and Veracyte and support for attending meetings and/or travel: AstraZeneca, Roche, Novartis, Pfizer, Lilly, Pierre-Fabre, Bristol-Myers Squibb and Daiichi Sankyo. BR reports travel support from Roche and Lilly. AFO reports travel support from Novartis. CS reports research support, consulting or advisory role from Genentech, AstraZeneca, Aragon Pharmaceuticals, Bayer Pharma, Byondis, Boehringer Ingelheim, Bristol-Myers Squibb, Cytomx Therapeutics, Daiichi Sankyo, F. Hoffmann-La Roche, Eisai, Genomic Health, GlaxoSmithKline, Innoup Farma, Eli Lilly, Macrogenics, Menarini Ricerche, Merck Sharp & Dohme, Merus, Millennium Pharmaceuticals, Novartis, Pfizer, Pierre Fabre, PintPharma, Puma Biotechnology, Sanofi, Seattle Genetics, Zymeworks. JPL reports honoraria from Seagen, Novartis, Pfizer, AstraZeneca/Daiichi Sankyo, Eli Lilly, Roche; and a consulting or advisory role with Seagen, Novartis, AstraZeneca/Daiichi Sankyo, Roche. EL reports honoraria from Ipsen, MSD, Pfizer, AstraZeneca/Daiichi Sankyo and Roche. EG reports honoraria from Roche/Genentech, Pfizer, Novartis, AstraZeneca, Seagen; a consulting or advisory role with AstraZeneca, Seagen, PharmaMar, Gilead Sciences; and speakers’ bureaus for Pfizer, Novartis, Roche. SGS reports honoraria for speaking from Novartis and GSK; Advisory role from Lilly, Seagen and Astra Zeneca; and travel expenses from Clovis and Pfizer outside the submitted work. EC reports consultancy and speakers’ bureaus for Novartis, Pfizer, Roche, Lilly, Celgene; and personal fees from Novartis, Pfizer, Roche, Lilly, Celgene, during the conduct of the study. JFC reports honoraria from Roche, AstraZeneca, Teva, Celgene, Pfizer, GSK, Novartis; and a consulting or advisory role with Roche, AstraZeneca, Pfizer, GSK, Novartis. MSC reports advisory Board of MEDSIR, Optimapharm; Speaker's Bureau in MEDSIR, Optimapharm; and Funding from MEDSIR, Optimapharm, FGP has taken part in advisory panels for Sanofi and Novo Nordisk; has received research support from Sanofi, Novo Nordisk, Boehringer Ingelheim Pharmaceuticals and Lilly; and has acted as a speaker for Sanofi, Novo Nordisk, Boehringer Ingelheim Pharmaceuticals, AstraZeneca Pharmaceuticals LP, Bristol-Myers Squibb Co. and Lilly. JC reports research support from ARIAD, Astrazeneca, Baxalta GMBH/Servier Affaires, Bayer, Eisai, Guardanth health, Merck Sharp & Dohme, Pfizer, Puma, Queen Mary University of London, Roche, Piqur; honoraria from Novartis, Eisai, Celgene, Pfizer, Roche, Samsung, Eli Lilly, Merck Sharp & Dohme Daiichi Sankyo; a consulting or advisory role with Celgene, Cellestia Biotech, AstraZeneca, Roche, Seattle Genetics, Daiichi Sankyo, ERYTECH Pharma, Polyphor, Athenex, Lilly, SERVIER, Merck Sharp & Dohme, GlaxoSmithKline, Leuko, Clovis Oncology, Bioasis, Boehringer Ingelheim, Ellipses Pharma, HiberCell, Bioinven, GEMoaB, Gilead Sciences, Menarini, Zymeworks, Reveal Genomics; stock or other ownership in Leuko, MEDSIR, Nektar; and travel support from Roche, Pfizer, Eisai, Novartis, Daiichi Sankyo. AU, EMD, SB, BB, MGC, PCC, AL, JLAR report no competing interests. JMPG, GM, PG, DAL, and MSC are employed by MEDSIR., (© 2024 Published by Elsevier Ltd.)

Background: Ribociclib has been shown to have a significant overall survival benefit in patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer. Whether this benefit in advanced breast cancer extends to early breast cancer is unclear., Methods: In this international, open-label, randomized, phase 3 trial, we randomly assigned patients with HR-positive, HER2-negative early breast cancer in a 1:1 ratio to receive ribociclib (at a dose of 400 mg per day for 3 weeks, followed by 1 week off, for 3 years) plus a nonsteroidal aromatase inhibitor (NSAI; letrozole at a dose of 2.5 mg per day or anastrozole at a dose of 1 mg per day for ≥5 years) or an NSAI alone. Premenopausal women and men also received goserelin every 28 days. Eligible patients had anatomical stage II or III breast cancer. Here we report the results of a prespecified interim analysis of invasive disease-free survival, the primary end point; other efficacy and safety results are also reported. Invasive disease-free survival was evaluated with the use of the Kaplan-Meier method. The statistical comparison was made with the use of a stratified log-rank test, with a protocol-specified stopping boundary of a one-sided P-value threshold of 0.0128 for superior efficacy., Results: As of the data-cutoff date for this prespecified interim analysis (January 11, 2023), a total of 426 patients had had invasive disease, recurrence, or death. A significant invasive disease-free survival benefit was seen with ribociclib plus an NSAI as compared with an NSAI alone. At 3 years, invasive disease-free survival was 90.4% with ribociclib plus an NSAI and 87.1% with an NSAI alone (hazard ratio for invasive disease, recurrence, or death, 0.75; 95% confidence interval, 0.62 to 0.91; P = 0.003). Secondary end points - distant disease-free survival and recurrence-free survival - also favored ribociclib plus an NSAI. The 3-year regimen of ribociclib at a 400-mg starting dose plus an NSAI was not associated with any new safety signals., Conclusions: Ribociclib plus an NSAI significantly improved invasive disease-free survival among patients with HR-positive, HER2-negative stage II or III early breast cancer. (Funded by Novartis; NATALEE ClinicalTrials.gov number, NCT03701334.)., (Copyright © 2024 Massachusetts Medical Society.)

Background: Preclinical data suggest synergistic activity with the combination of programmed death-1 and cyclin-dependent kinase 4/6 blockade in oestrogen receptor-positive/human epidermal growth factor 2-negative (ER+/HER2-) breast cancer. The noncomparative phase 1b/2 CheckMate 7A8 study (NCT04075604) evaluated neoadjuvant treatment with nivolumab, palbociclib, and anastrozole in patients with ER+/HER2- breast cancer. Here, we report outcomes from the safety run-in phase., Methods: Patients with histologically confirmed, untreated ER+/HER2- breast cancer, primary tumour ≥2 cm, ECOG performance status ≤1, and eligible for post-treatment surgery received nivolumab 480 mg intravenously every 4 weeks, palbociclib 125 mg or 100 mg orally once daily for 3 weeks per cycle, and anastrozole 1 mg orally once daily for five 4-week cycles, or until disease progression. The primary endpoint was the proportion of patients with dose-limiting toxicities (DLTs) within 4 weeks of treatment initiation., Results: At safety data review, 21 patients were treated (palbociclib 125-mg group: n = 9; palbociclib 100-mg group: n = 12). DLTs were reported in 2 (22.2%) and 0 patients in the palbociclib 125-mg and 100-mg groups, respectively. Across both groups, 9 patients discontinued treatment due to toxicity (grade 3/4 hepatic adverse events [n = 6], grade 3 febrile neutropaenia [n = 1], grade 1 pneumonitis [n = 1], and grade 3 rash and grade 2 immune-mediated pneumonitis [n = 1]). Consequently, the study was closed early., Conclusions: Neoadjuvant treatment with nivolumab, palbociclib, and anastrozole showed a high incidence of grade 3/4 hepatotoxicity and treatment discontinuation, indicating that this combination should not be further pursued for treatment of primary ER+/HER2- breast cancer., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: G. Jerusalem declares acting in a consultancy or advisory role for AbbVie, Amgen, AstraZeneca, Bristol Myers Squibb, Daiichi Sankyo, Lilly, Novartis, Pfizer, Roche; receiving honoraria from Amgen, AstraZeneca, Bristol Myers Squibb, Lilly, Novartis, Pfizer, Roche, Seagen; research funding from Novartis, Pfizer, Roche; travel and accommodation expenses from Amgen, AstraZeneca, Bristol Myers Squibb, Lilly, Novartis, Pfizer, Roche; and medical writing support from Amgen, AstraZeneca, Bristol Myers Squibb, Lilly, Medimmune, Merck Sharp and Dohme Corp, Novartis, Roche. A. Prat declares acting in a consultancy or advisory role for AbbVie, Amgen, AstraZeneca, Boehringer Ingelheim, Bristol Myers Squibb, Daiichi Sankyo, NanoString Technologies, Novartis, Oncolytics Biotech, Pfizer, Puma, Roche; receiving honoraria from Amgen, Daiichi Sankyo, Guardant Health, Lilly, Merck Sharp and Dohme Corp, Novartis, Pfizer, Roche; research funding from Incyte, Novartis, Puma, Roche; travel and accommodation expenses from Daiichi Sankyo; an employee of Novartis; and a stockholder of Reveal Genomics. R. Salgado declares acting in a consultancy or advisory role for Bristol Myers Squibb and Roche; and travel and accommodation expenses from Merck Sharp and Dohme Corp, Puma, and Roche. M. Reinisch declares acting in a consultancy or advisory role for Daiichi Sankyo, Somatex, and Roche; receiving honoraria from AstraZeneca, Daiichi Sankyo, Lilly, Merck Sharp and Dohme Corp, Novartis, Pfizer, Roche, Seagen, Somatex; and travel and accommodation expenses from Novartis and Pfizer. C. Saura declares acting in a consultancy or advisory role for AstraZeneca, Ax's Consulting, Byondis, Daiichi Sankyo, Eisai, Exact Sciences, Exeter, F. Hoffmann-La Roche Ltd., International Society for the Study and Exchange of evidence from Clinical research And Medical experience (ISSECAM), Medical Statistics Consulting, MediTech, Merck Sharp and Dohme Corp, Novartis, Pfizer, Philips, Pierre Fabre, PintPharma, Puma, Roche, Sanofi, Seagen, Zymeworks, and research funding from Aragon, AstraZeneca, Bayer, Boehringer Ingelheim, Bristol Myers Squibb, Byondis, CytomX, Daiichi Sankyo, F. Hoffmann-La Roche Ltd., Genentech, German Breast Group Forchungs, GlaxoSmithKline, Immunomedics, Innoup, International Breast Cancer Study Group (IBCSG), Lilly, Macrogenics, Medica Scientia Innovation Research, Menarini Ricerche, Merck Sharp and Dohme Corp, Merus, Millennium, Novartis, Pfizer, Piqur, Puma, Roche, Sanofi, Seagen, Synthon, and Zenith. F. Ades, J. Filian, and N. Huang are employees and stockholders of Bristol Myers Squibb. A. Mazzei-Abba is an employee of Bristol Myers Squibb. S.M. Tolaney declares honoraria or consultation fees from 4D Pharma, AstraZeneca, Athenex, Blueprint Medicines, Bristol Myers Squibb, CytomX, Daiichi Sankyo, Eisai, Eli Lilly, Ellipses Pharma, Genentech/Roche, G1 Therapeutics, Gilead, Merck, Mersana Therapeutics, Novartis, Odonate, OncoPep, OncoSec, OncXerna, Pfizer, Puma, Reveal Genomics, Sanofi, Seagen, Zentalis, Zymeworks; presented at a public event organised by Chugai Pharma; and received grants/research supports from AstraZeneca, Bristol Myers Squibb, Certara, Cyclacel, Eisai, Eli Lilly, Exelixis, Genentech/Roche, Gilead, Merck, Nanostring, Nektar, Novartis, Odonate, Pfizer, Sanofi, and Seagen. M. Ruiz-Borrego and P. Nikolinakos have no conflicts of interest to disclose., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Purpose: Prognostic and predictive biomarkers to cyclin-dependent kinases 4 and 6 inhibitors are lacking. Circulating tumor DNA (ctDNA) can be used to profile these patients and dynamic changes in ctDNA could be an early predictor of treatment efficacy. Here, we conducted plasma ctDNA profiling in patients from the PEARL trial comparing palbociclib+fulvestrant versus capecitabine to investigate associations between baseline genomic landscape and on-treatment ctDNA dynamics with treatment efficacy., Experimental Design: Correlative blood samples were collected at baseline [cycle 1-day 1 (C1D1)] and prior to treatment [cycle 1-day 15 (C1D15)]. Plasma ctDNA was sequenced with a custom error-corrected capture panel, with both univariate and multivariate Cox models used for treatment efficacy associations. A prespecified methodology measuring ctDNA changes in clonal mutations between C1D1 and C1D15 was used for the on-treatment ctDNA dynamic model., Results: 201 patients were profiled at baseline, with ctDNA detection associated with worse progression-free survival (PFS)/overall survival (OS). Detectable TP53 mutation showed worse PFS and OS in both treatment arms, even after restricting population to baseline ctDNA detection. ESR1 mutations were associated with worse OS overall, which was lost when restricting population to baseline ctDNA detection. PIK3CA mutations confer worse OS only to patients on the palbociclib+fulvestrant treatment arm. ctDNA dynamics analysis (n = 120) showed higher ctDNA suppression in the capecitabine arm. Patients without ctDNA suppression showed worse PFS in both treatment arms., Conclusions: We show impaired survival irrespective of endocrine or chemotherapy-based treatments for patients with hormone receptor-positive/HER2-negative metastatic breast cancer harboring plasma TP53 mutations. Early ctDNA suppression may provide treatment efficacy predictions. Further validation to fully demonstrate clinical utility of ctDNA dynamics is warranted., (©2023 The Authors; Published by the American Association for Cancer Research.)

Purpose: The monarchE trial showed that the addition of abemaciclib improves efficacy in patients with high-risk early breast cancer (EBC). We analyzed the long-term outcomes of a population similar to the monarchE trial to put into context the potential benefit of abemaciclib., Methods: HR-positive/HER2-negative EBC patients eligible for the monarchE study were selected from 3 adjuvant clinical trials and a breast cancer registry. Patients with ≥ 4 positive axillary lymph nodes (N +) or 1-3 N + with tumor size ≥ 5 cm and/or histologic grade 3 and/or Ki67 ≥ 20%, who had undergone surgery with curative intent and had received anthracyclines ± taxanes and endocrine therapy in the neoadjuvant and /or adjuvant setting were included. We performed analysis of Invasive Disease-Free Survival (iDFS), Distant Disease-Free Survival (dDFS) and Overall Survival (OS) at 5 and 10 years, as well as yearly (up to 10) of Invasive Relapse Rate (IRR), Distant Relapse Rate (DRR) and Death Rate (DR)., Results: A total of 1,617 patients were analyzed from the GEICAM-9906 (312), GEICAM-2003-10 (210), and GEICAM-2006-10 (160) trials plus 935 from El Álamo IV. With a median follow-up of 10.1 years, the 5 and 10 years iDFS rates were 75.2% and 57.0%, respectively. The dDFS and OS rates at 5 years were 77.4% and 88.8% and the respective figures at 10 years were 59.7% and 70.9%., Conclusions: This data points out the need for new therapies for those patients. A longer follow-up of the monarchE study to see the real final benefit with abemaciclib is warranted., Trial Registration: ClinTrials.gov: GEICAM/9906: NCT00129922; GEICAM/ 2003-10: NCT00129935 and GEICAM/ 2006-10: NCT00543127., (© 2023. The Author(s).)

Background: In the single-arm, phase 2 DESTINY-Breast01 trial, trastuzumab deruxtecan showed robust activity in patients with HER2-positive metastatic breast cancer who were refractory or resistant to trastuzumab emtansine; a population with scarce effective treatments. In DESTINY-Breast02, we aimed to compare the efficacy and safety of trastuzumab deruxtecan with treatment of physician's choice in this patient population., Methods: This randomised, open-label, multicentre, phase 3 trial was conducted at 227 sites (hospitals, university hospitals, clinics, community centres, and private oncology centres) in North America, Europe, Asia, Australia, Brazil, Israel, and Türkiye. Eligible patients were aged 18 years or older, had unresectable or HER2-positive metastatic breast cancer, previously received trastuzumab emtansine, disease progression, an Eastern Cooperative Oncology Group performance status of 0 or 1, and adequate renal and hepatic function. Patients were randomly assigned (2:1) to receive trastuzumab deruxtecan (intravenously at 5·4 mg/kg once every 3 weeks) or treatment of physician's choice using block randomisation. Treatment of physician's choice was either capecitabine (1250 mg/m 2 ; orally twice per day on days 1-14) plus trastuzumab (8 mg/kg intravenously on day 1 then 6 mg/kg once per day) or capecitabine (1000 mg/m 2 ) plus lapatinib (1250 mg orally once per day on days 1-21), with a 21-day schedule. The primary endpoint was progression-free survival based on blinded independent central review in the full analysis set. This study is registered with ClinicalTrials.gov, NCT03523585., Findings: Between Sept 6, 2018, and Dec 31, 2020, 608 patients were randomly assigned to receive trastuzumab deruxtecan (n=406; two did not receive treatment) or treatment of physician's choice (n=202; seven did not receive treatment). 608 (100%) patients were included in the full analysis set. The median age was 54·2 years (IQR 45·5-63·4) in the trastuzumab deruxtecan group and 54·7 years (48·0-63·0) in the treatment of physician's choice group. 384 (63%) patients were White, 603 (99%) were female, and five (<1%) were male. The median follow-up was 21·5 months (IQR 15·2-28·4) in the trastuzumab deruxtecan group and 18·6 months (8·8-26·0) in the treatment of physician's choice group. Median progression-free survival by blinded independent central review was 17·8 months (95% CI 14·3-20·8) in the trastuzumab deruxtecan group versus 6·9 months (5·5-8·4) in the treatment of physician's choice group (HR 0·36 [0·28-0·45]; p<0·0001). The most common treatment-emergent adverse events were nausea (293 [73%] of 404 with trastuzumab deruxtecan vs 73 [37%] of 195 with treatment of physician's choice), vomiting (152 [38%] vs 25 [13%]), alopecia (150 [37%] vs eight [4%]), fatigue (147 [36%] vs 52 [27%]), diarrhoea (109 [27%] vs 105 [54%]), and palmar-plantar erythrodysaesthesia (seven [2%] vs 100 [51%]). Grade 3 or higher treatment-emergent adverse events occurred in 213 (53%) patients receiving trastuzumab deruxtecan versus 86 (44%) receiving treatment of physician's choice; whereas drug-related interstitial lung disease occurred in 42 (10%; including two grade 5 death events) versus one (<1%)., Interpretation: DESTINY-Breast02 shows the favourable benefit-risk profile of trastuzumab deruxtecan in patients with HER2 positive metastatic breast cancer, as previously reported in DESTINY-Breast01, and is the first randomised study to show that one antibody-drug conjugate can overcome resistance to a previous one., Funding: Daiichi Sankyo and AstraZeneca., Competing Interests: Declaration of interests FA reports grants or speaker compensation or advisory board participation for Sanofi, Novartis, Pfizer, Lilly, AstraZeneca, Daiichi Sankyo, and Roche. YHP reports grants from MSD, Pfizer, AstraZeneca, and Roche; consulting fees from AstraZeneca, MSD, Pfizer, Eisai, Lilly, Roche, Bixink, Daiichi Sankyo, Menarini, Everest, and Novartis; honoraria from AstraZeneca, Pfizer, Lilly, MSD, Roche, Daiichi-Sankyo, and Novartis; and advisory board participation for AstraZeneca, Pfizer, Roche, Novartis, and Menarini. S-BK reports grants from Novartis, Sanofi-Aventis, Dongkook Pharmaceutical; payment for expert testimony from Novartis, AstraZeneca, Lilly, Dae Hwa Pharmaceuticals, ISU Abxis, and Daiichi Sankyo; meeting or travel support (or both) from Novartis, AstraZeneca, and Lilly; advisory board participation for Novartis, AstraZeneca, Lilly, and Daiichi Sankyo; and stock in Genopeaks and Neogene Therapeutics. TT reports honoraria for lectures from Daiichi Sankyo, Chugai, Eisai, Eli Lilly, and Celltrion Healthcare. S-AI reports grants from AstraZeneca, Eisai, Daewoong Pharmaceutical, Daiichi Sankyo, Pfizer, Roche, and Boryung Pharmaceutical; and consulting fees from AstraZeneca, Hanmi, Eisai, Lilly, MSD, Idience, Novartis, Pfizer, Roche, GSK, Daiichi Sankyo, and Bertis. JPL reports grants from MSD, Bristol Myers Squibb, Taiho, Janssen, Mink, Agenus, Daiichi Sankyo, AstraZeneca, Roche, and Seagen; payment or honoraria from Bristol Myers Squibb, AstraZeneca, and Daiichi Sankyo; meeting or travel support (or both) from MSD, Bristol Myers Squibb, and AstraZeneca; and stock in Janssen. SA reports honoraria and consulting compensation from AstraZeneca, Bristol Myers Squibb, Lilly, Merck, Novartis, and Pfizer. JGG reports payment or honoraria, meeting or travel support (or both), and advisory board participation for AstraZeneca, Daiichi Sankyo, Novartis, Roche, Lilly, Seagen, and Pfizer. MDL reports payment or honoraria, meeting or travel support (or both), and advisory board participation for AstraZeneca, Eli Lilly, Novartis, Roche, Pfizer, Seagen, Daiichi Sankyo, MSD, GSK, and Sanofi; and payment or honoraria from Celltrion and Organon. FPD reports grants from Fondation Belge Contre le Cancer; consulting fees from Roche, Pfizer, AstraZeneca, Lilly, Novartis, Amgen, Daiichi Sankyo, Pierre Fabre, Gilead Sciences, and Seagen; and meeting or travel support (or both) from Amgen, Roche, Teva, Pfizer, Daiichi Sankyo, and AstraZeneca. GBi reports consulting fees from Roche, AstraZeneca, MSD, Daiichi Sankyo, Gilead, Sanofi, and Seagen; payment or honoraria from Roche, AstraZeneca, Daiichi Sankyo, Lilly, MSD, Chugai, Eisai, Gilead, and Seagen; meeting or travel support (or both) from Roche, Pfizer, MSD, Chugai, Novartis, and AstraZeneca; and advisory board participation for Roche, Pfizer, AstraZeneca, Lilly, Novartis, Amgen, MSD, Chugai, Daiichi Sankyo, Eisai, Gilead, Seagen, Exact Science, and Agendia. RR reports grants from National Institute for Health and Care Research; consulting fees from IQVIA, Eli Lilly, G1 Therapeutics, Daiichi Sankyo, and AstraZeneca; payment or honoraria from Daiichi Sankyo and AstraZeneca; meeting or travel support (or both) from G1 Therapeutics, Roche, Daiichi Sankyo, and Bristol Myers Squibb; and advisory board participation for Pfizer. YM reports grants from Daiichi Sankyo, Eisai, Chugai, MSD, Kyowa-Kirin, Eli Lilly, and Taiho; consulting fees from Daiichi Sankyo; and payment or honoraria from Daiichi Sankyo, Chugai, Eisai, Eli Lilly, AstraZeneca, Pfizer, Taiho, and Kyowa-Kirin. AA reports grants or contracts from AstraZeneca; meeting or travel support (or both) from MSD and Novartis; advisory board participation for MSD; a leadership role for the Royal College of Obstetricians and Gynaecologists Pregnancy and Breast Cancer Guidelines; and stock or stock options with AstraZeneca. EL reports consulting fees from Ellipses; speaker compensation from AstraZeneca, Lilly, Pfizer, Roche, Novartis, and Gilead; meeting or travel support (or both) from AstraZeneca, Novartis, and Gilead; advisory board participation for AstraZeneca, Lilly, Pfizer, Roche, Novartis, Gilead, and Eisai; leadership or fiduciary roles in the Breast Cancer Trials Scientific Advisory Board and University of New South Wales Medicine Faculty Advisory Board; and research support from Novartis and Pfizer. JE reports consulting fees, honoraria, meeting or travel support (or both), and advisory board participation for Daiichi Sankyo, Lilly, Roche, Pfizer, Novartis, Gilead, Seagen, and AstraZeneca. RY reports a research grant from Roche; and consulting fees and honoraria from Roche, Pfizer, Eli Lilly, Novartis, Gilead, Medison, MSD, and AstraZeneca. FZ reports grants, consulting fees, payment or honoraria, advisory board participation for, research support, leadership or fiduciary roles, and stock or stock options in AstraZeneca, Daiichi Sankyo, Eli Lilly, Merck, Novartis, Pfizer, Genesis Pharmaceuticals, and Roche. TF reports advisory board participation for Daiichi Sankyo, Novartis, Roche, Pfizer, MSD, and Teva Pharmaceuticals. CW was an employee of Daiichi Sankyo during the study. DG, JC, CC, and AE report employment by Daiichi Sankyo. AE reports stock in Daiichi Sankyo. IK reports grants from Pfizer, MacroGenics, Genentech (Roche); consulting fees from AstraZeneca, Daiichi Sankyo, Genentech (Roche), Bristol Myers Squibb, MacroGenics, Taiho Oncology, and Seagen; payment or honoraria from AstraZeneca; advisory board participation for Novartis and Merck; and leadership, fiduciary roles, and stock in Puretech. GBo, RS, and MRB declare no competing interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

By the end of 2020, there were more than 8 million women alive who had received a breast cancer diagnosis in the previous 5 years, making it the most prevalent neoplasia in the world. About 70% of breast-cancer cases present positivity for estrogen and/or progesterone receptors and a lack of HER-2 overexpression. Endocrine therapy has traditionally been the standard of care for ER-positive and HER-2-negative metastatic breast cancer. In the last 8 years, the advent of CDK4/6 inhibitors has shown that adding them to endocrine therapy doubles PFS. As a result, this combination has become the gold standard in this setting. Three CDK4/6 inhibitors have been approved by the EMA and the FDA: abemaciclib, palbociclib, and ribociclib. They all have the same indications, and it is at each physician's discretion to choose one or the other. The aim of our study was to perform a comparative efficacy analysis of the three CDK4/6i using real-world data. We selected patients diagnosed with endocrine-receptor-positive and HER2-negative breast cancer who were treated with all three CDK4/6i as first-line therapy at a reference center. After 42 months of retrospective follow up, abemaciclib was associated with a significant benefit in terms of progression-free survival in endocrine-resistant patients and in the population without visceral involvement. In our real-world cohort, we found no other statistically significant differences among the three CDK4/6 inhibitors.

Purpose: In hormone receptor-positive (HR+)/HER2- metastatic breast cancer (MBC), it is imperative to identify patients who respond poorly to cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) and to discover therapeutic targets to reverse this resistance. Non-luminal breast cancer subtype and high levels of CCNE1 are candidate biomarkers in this setting, but further validation is needed., Experimental Design: We performed mRNA gene expression profiling and correlation with progression-free survival (PFS) on 455 tumor samples included in the phase III PEARL study, which assigned patients with HR+/HER2- MBC to receive palbociclib+endocrine therapy (ET) versus capecitabine. Estrogen receptor-positive (ER+)/HER2- breast cancer cell lines were used to generate and characterize resistance to palbociclib+ET., Results: Non-luminal subtype was more prevalent in metastatic (14%) than in primary tumor samples (4%). Patients with non-luminal tumors had median PFS of 2.4 months with palbociclib+ET and 9.3 months with capecitabine; HR 4.16, adjusted P value < 0.0001. Tumors with high CCNE1 expression (above median) also had worse median PFS with palbociclib+ET (6.2 months) than with capecitabine (9.3 months); HR 1.55, adjusted P value = 0.0036. In patients refractory to palbociclib+ET (PFS in the lower quartile), we found higher levels of Polo-like kinase 1 (PLK1). In an independent data set (PALOMA3), tumors with high PLK1 show worse median PFS than those with low PLK1 expression under palbociclib+ET treatment. In ER+/HER2- cell line models, we show that PLK1 inhibition reverses resistance to palbociclib+ET., Conclusions: We confirm the association of non-luminal subtype and CCNE1 with resistance to CDK4/6i+ET in HR+ MBC. High levels of PLK1 mRNA identify patients with poor response to palbociclib, suggesting PLK1 could also play a role in the setting of resistance to CDK4/6i., (©2023 The Authors; Published by the American Association for Cancer Research.)

Background: We aimed to determine the effect of dual anti-HER2 blockade compared to monotherapy on clinically important outcomes., Methods: We carried out a systematic review updated until July 2022. The outcomes included pathological complete response (pCR), clinical response, event-free survival, and overall survival., Results: We identified eleven randomized clinical trials (2836 patients). When comparing paclitaxel plus dual treatment versus paclitaxel plus trastuzumab or lapatinib, dual treatment was associated with a higher probability of achieving a pathological complete response (OR 2.88, 95% CI 2.02-4.10). Addition of a taxane to an anthracycline plus cyclophosphamide and fluorouracil, plus lapatinib or trastuzumab, showed that the dual treatment was better than lapatinib alone (OR 2.47, 95% CI 1.41-4.34), or trastuzumab alone (OR 1.89, 95% CI 1.13-3.16). Dual treatment may result in an increase in survival outcomes and tumour clinical response, although such benefits are not consistent for all the combinations studied., Conclusions: The use of dual blockade with combinations of trastuzumab and pertuzumab can be recommended for the neoadjuvant treatment of women with HER2-positive breast cancer. PROSPERO Registration number: CRD42018110273., (© 2022. The Author(s), under exclusive licence to Federación de Sociedades Españolas de Oncología (FESEO).)

Background: The 21-gene Oncotype DX Breast Recurrence Score ® assay is prognostic and predictive of chemotherapy benefit for patients with estrogen receptor-positive, HER2- early breast cancer (EBC). The KARMA Dx study evaluated the impact of the Recurrence Score ® results (RS) on the treatment decision for patients with EBC and high-risk clinicopathological characteristics for whom chemotherapy (CT) was considered., Methods: Eligible patients with EBC were candidates for the study if CT was considered standard recommendation by local guidelines. Three high-risk EBC cohorts were predefined: (A) pT1-2, pN0/N1mi, and grade 3; (B) pT1-2, pN1, and grades 1-2; and (C) neoadjuvant cT2-3, cN0, and Ki67 ≤ 30%. Treatment recommendations before and after 21-gene testing were registered, as well as treatment received and physicians' confidence levels in their final recommendations., Results: A total of 219 consecutive patients were included from eight Spanish centers: 30 in cohort A, 158 in cohort B, and 31 in cohort C. Ten patients were excluded from the final analysis as CT was not initially recommended. After 21-gene testing, treatment decisions changed from CT + endocrine therapy (ET) to ET alone for 67% of the whole group. In total, 30% (95% confidence interval [CI] 15% to 49%), 73% (95% CI 65% to 80%), and 76% (95% CI 56% to 90%) of patients ultimately received ET alone in cohorts A, B, and C, respectively. Physicians' confidence in their final recommendations increased in 34% of cases., Conclusions: Use of the 21-gene test resulted in an overall 67% reduction in CT recommendation in patients considered candidates for CT. Our findings indicate the substantial potential of the 21-gene test to guide CT recommendations in patients with EBC considered to be at high risk of recurrence based on clinicopathological parameters, regardless of nodal status or treatment setting.

Background: Neratinib is an irreversible pan-HER tyrosine kinase inhibitor approved for HER2-positive early-stage and metastatic breast cancer. Diarrhea is the most frequent side effect and the most common reason for early discontinuation. The phase II CONTROL trial investigated antidiarrheal prophylaxis or neratinib dose escalation (DE) for prevention of diarrhea. We present complete study results including final data for two DE strategies., Methods: Patients who completed trastuzumab-based adjuvant therapy received neratinib 240 mg/day for 1 year. Early cohorts investigated mandatory prophylaxis with loperamide, then additional budesonide or colestipol. Final cohorts assessed neratinib DE over the first 2 (DE1) or 4 weeks (DE2). The primary endpoint was incidence of grade ≥3 diarrhea. Health-related quality of life (HRQoL) was assessed using FACT-B and EQ-5D-5L., Results: 563 patients were enrolled into six cohorts. All strategies reduced grade ≥3 diarrhea with the lowest incidence in DE1 (DE1 13%; colestipol + loperamide [CL] 21%, DE2 27%; budesonide + loperamide [BL] 28%; loperamide [L] 31%; colestipol + loperamide as needed [CL-PRN] 33%). Diarrhea-related discontinuations occurred early and were lowest in DE1 (DE1 3%; CL 4%; DE2 6%; CL-PRN 8%; BL 11%; L 20%). More patients stayed on neratinib for the prescribed period versus historical controls. Prior pertuzumab use did not affect rates of grade ≥3 diarrhea, diarrhea-related discontinuations, or treatment duration. Early transient reductions in HRQoL scores were observed., Conclusions: These complete results from CONTROL show improved neratinib tolerability with proactive management at the start of therapy. Two-week neratinib DE with loperamide as needed was particularly effective., Gov Registration Number: NCT02400476., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Arlene Chan: no competing interests to declare. Manuel Ruiz-Borrego: no competing interests to declare. Gavin Marx: no competing interests to declare. A. Jo Chien: Contracted research (personal) from Puma Biotechnology Inc. Hope S. Rugo: Research support for clinical trials through the University of California: Pfizer, Merck, Novartis, Lilly, Roche, Daiichi, Seattle Genetics, Macrogenics, Sermonix, Boehringer Ingelheim, Polyphor, AstraZeneca, Astellas, and Gilead. Honoraria from: Puma, Samsung, Chugai, Blueprint, and NAPO. Travel: GE Healthcare. Adam Brufsky: Consulting fees (personal) from Puma Biotechnology Inc. Michael Thirlwell: no competing interests to declare. Maureen Trudeau: no competing interests to declare. Ron Bose: Research grant from Puma Biotechnology, and consulting from Genentech. José A. García-Sáenz: consultative and advisory services for Seagen, Gilead, and Sanofi; consultancy/speaker fees from Novartis, Celgene, Eli Lilly, EISAI, AstraZeneca, Daiichi Sankyo, MSD, and Pierre Fabre; institution research funding from AstraZeneca; travel support from Novartis, Roche, and Pfizer. Daniel Egle: advisory services for AstraZeneca, Daiichi Sankyo, MSD, Seagen, Gilead, Novartis, Roche, Pfizer, and Lilly; consultancy/speaker fees from Roche, Pfizer, Novartis, Lilly, AstraZeneca, Daiichi Sankyo, MSD, Seagen, and Gilead; travel support from AstraZeneca and Pfizer. Barbara Pistilli: Consulting fees (personal) from Puma Biotechnology Inc., Pierre Fabre. Contracted research (personal) for Puma Biotechnology Inc. Johanna Wassermann: no competing interests to declare. Kerry A. Cheong: no competing interests to declare. Benjamin Schnappauf: no competing interests to declare. Dieter Semsek: no competing interests to declare. Christian F. Singer: no competing interests to declare. Navid Foruzan: Full-time employment Puma Biotechnology Inc. Ownership interest (stock, stock options) Puma Biotechnology Inc. Daniel DiPrimeo: Full-time employment Puma Biotechnology Inc. Ownership interest (stock, stock options) Puma Biotechnology Inc. Leanne McCulloch: Full-time employment Puma Biotechnology Inc. Ownership interest (stock, stock options) Puma Biotechnology Inc. Sara A. Hurvitz: Contracted research paid to institution: Ambrx, Amgen, Arvinas, AstraZeneca, Bayer, Cytomx, Daiichi Sankyo, Dantari, Dignitana, Genentech/Roche, G1-Therapeutics, Gilead, GSK, Immunomedics, Eli Lilly, Macrogenics, Novartis, OBI Pharma, Orinove, Pfizer, Phoenix Molecular Designs, Ltd., Pieris, PUMA, Radius, Samumed, Sanofi, Seattle Genetics/Seagen, Zymeworks; Travel expenses paid to SAH: Lilly (2019); speaking: Daiichi Sankyo (2021). Carlos H. Barcenas: no competing interests to declare., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Palbociclib has gained a central role in the treatment of hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC). Despite its manageable toxicity profile, venous thromboembolism (VTE) or interstitial lung disease (ILD)/pneumonitis may infrequently occur. Therefore, we provide a comprehensive summary of the safety and tolerability of the combination of endocrine therapy and palbociclib among patients included in the randomized phase 2 PARSIFAL study., Materials and Methods: Patients with endocrine-sensitive HR+/HER2- ABC and no prior therapy in an advanced setting (n = 486) were randomly assigned 1:1 to receive fulvestrant-palbociclib (FP) or letrozole-palbociclib (LP). Laboratory tests and the incidence of adverse events (AEs) were recorded at baseline and day 1 of each cycle. Progression-free survival (PFS) was estimated for patients with and without VTE., Results: A total of 483 patients were analyzed. Neutropenia, leukopenia, anemia, asthenia, arthralgia, fatigue, and diarrhea were the most frequent AEs in both groups. Febrile neutropenia occurred in 3 (1.2%) patients of the FP group and in 1 (0.4%) patient in the LP group. Six (2.5%; 0.4% grade 3) patients in the FP group and 6 patients (2.5%; 0.4% grade 3) in the LP group experienced ILD/pneumonitis. Pulmonary embolism was reported in 12 (5.0%) patients in the FP group and 6 (2.5%) patients in the LP group. Advanced age at baseline was the only factor significantly associated with an increased risk of pulmonary embolism (P < .01)., Conclusion: The PARSIFAL data confirmed the favorable safety profile of both palbociclib regimens. VTE and ILD/pneumonitis were occasionally reported, and their early detection allowed patients to continue treatment effectively without detriment to efficacy., Clinicaltrials.gov Identifier: NCT02491983; https://clinicaltrials.gov/ct2/show/NCT02491983)., (© The Author(s) 2022. Published by Oxford University Press.)

Purpose: Predictive biomarkers for capecitabine benefit in triple-negative breast cancer (TNBC) have been recently proposed using samples from phase III clinical trials, including non-basal phenotype and biomarkers related to angiogenesis, stroma, and capecitabine activation genes. We aimed to validate these findings on the larger phase III GEICAM/CIBOMA clinical trial., Experimental Design: Tumor tissues from patients with TNBC randomized to standard (neo)adjuvant chemotherapy followed by capecitabine versus observation were analyzed using a 164-gene NanoString custom nCounter codeset measuring mRNA expression. A prespecified statistical plan sought to verify the predictive capacity of PAM50 non-basal molecular subtype and tested the hypotheses that breast tumors with increased expression of (meta)genes for cytotoxic cells, mast cells, endothelial cells, PDL2, and 38 individual genes benefit from adjuvant capecitabine for distant recurrence-free survival (DRFS; primary endpoint) and overall survival., Results: Of the 876 women enrolled in the GEICAM/CIBOMA trial, 658 (75%) were evaluable for analysis (337 with capecitabine and 321 without). Of these cases, 553 (84%) were profiled as PAM50 basal-like whereas 105 (16%) were PAM50 non-basal. Non-basal subtype was the most significant predictor for capecitabine benefit [HRcapecitabine, 0.19; 95% confidence interval (CI), 0.07-0.54; P < 0.001] when compared with PAM50 basal-like (HRcapecitabine, 0.9; 95% CI, 0.63-1.28; P = 0.55; Pinteraction<0.001, adjusted P value = 0.01). Analysis of biological processes related to PAM50 non-basal subtype revealed its enrichment for mast cells, extracellular matrix, angiogenesis, and features of mesenchymal stem-like TNBC subtype., Conclusions: In this prespecified correlative analysis of the GEICAM/CIBOMA trial, PAM50 non-basal status identified patients with early-stage TNBC most likely to benefit from capecitabine., (©2022 The Authors; Published by the American Association for Cancer Research.)

Background: Trastuzumab deruxtecan (T-DXd) has shown durable antitumor activity in pretreated patients with HER2-positive advanced breast cancer (ABC), but its efficacy has not yet been evaluated in patients with active brain metastases (BMs). DEBBRAH aims to assess T-DXd in patients with HER2-positive or HER2-low ABC and central nervous system involvement., Methods: This ongoing, five-cohort, phase II study (NCT04420598) enrolled patients with pretreated HER2-positive or HER2-low ABC with stable, untreated, or progressing BMs, and/or leptomeningeal carcinomatosis. Here, we report findings from HER2-positive ABC patients with non-progressing BMs after local therapy (n = 8; cohort 1), asymptomatic untreated BMs (n = 4; cohort 2), or progressing BMs after local therapy (n = 9; cohort 3). Patients received 5.4 mg/kg T-DXd intravenously once every 21 days. The primary endpoint was 16-week progression-free survival (PFS) for cohort 1 and intracranial objective response rate (ORR-IC) for cohorts 2 and 3., Results: As of October 20, 2021, 21 patients received T-DXd. In cohort 1, 16-week PFS rate was 87.5% (95%CI, 47.3-99.7; P < .001). ORR-IC was 50.0% (95%CI, 6.7-93.2) in cohort 2 and 44.4% (95%CI, 13.7-78.8; P < .001) in cohort 3. Overall, the ORR-IC in patients with active BMs was 46.2% (95%CI, 19.2-74.9). Among patients with measurable intracranial or extracranial lesions at baseline, the ORR was 66.7% (12 out of 18 patients; 95%CI, 41.0-86.7), 80.0% (95%CI, 28.4-99.5) in cohort 1, 50.0% (95%CI, 6.7-93.2) in cohort 2, and 66.7% (95%CI, 29.9-92.5) in cohort 3. All responders had partial responses. The most common adverse events included fatigue (52.4%; 4.8% grade ≥3), nausea (42.9%; 0% grade ≥3), neutropenia (28.6%; 19% grade ≥3), and constipation (28.6%; 0% grade ≥3). Two (9.5%) patients suffered grade 1 interstitial lung disease/pneumonitis., Conclusions: T-DXd showed intracranial activity with manageable toxicity and maintained the quality of life in pretreated HER2-positive ABC patients with stable, untreated, or progressing BMs. Further studies are needed to validate these results in larger cohorts., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Neuro-Oncology.)

Most cancer-related deaths in breast cancer patients are associated with metastasis, a multistep, intricate process that requires the cooperation of tumour cells, tumour microenvironment and metastasis target tissues. It is accepted that metastasis does not depend on the tumour characteristics but the host's genetic makeup. However, there has been limited success in determining the germline genetic variants that influence metastasis development, mainly because of the limitations of traditional genome-wide association studies to detect the relevant genetic polymorphisms underlying complex phenotypes. In this work, we leveraged the extreme discordant phenotypes approach and the epistasis networks to analyse the genotypes of 97 breast cancer patients. We found that the host's genetic makeup facilitates metastases by the dysregulation of gene expression that can promote the dispersion of metastatic seeds and help establish the metastatic niche-providing a congenial soil for the metastatic seeds., Competing Interests: CONFLICTS OF INTEREST The authors declare no conflict of interest. The funders had no role in the design of the study, in the collection, analyses, or interpretation of data, in the writing of the manuscript, or in the decision to publish the results., (Copyright: © 2022 Santonja et al.)

Background: An earlier analysis of the PEARL phase III study showed that palbociclib plus endocrine therapy (ET) does not improve progression-free survival (PFS) over capecitabine in aromatase inhibitor-resistant, hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer (MBC) patients. Here, we report the final overall survival (OS) analysis., Methods: Postmenopausal patients (N = 601) were randomized 1:1 to capecitabine or palbociclib plus ET (exemestane, Cohort 1; fulvestrant, Cohort 2). OS was analysed in Cohort 2, the wild-type ESR1 population and the overall population. Additionally, we analysed subsequent systemic therapies and explored PFS2 (time from randomization to the end of the first subsequent therapy/death)., Results: OS was 31.1 months for palbociclib plus fulvestrant and 32.8 months for capecitabine (adjusted hazard ratio [aHR] 1.10, 95% confidence interval [CI] 0.81-1.50, P = 0.550). In the wild-type ESR1 population, OS was 37.2 months for palbociclib plus ET and 34.8 months for capecitabine (aHR 1.06, 95% CI 0.81-1.37, P = 0.683). In OS analyses, no subgroup showed superiority for palbociclib plus ET over capecitabine. OS in the overall population was 32.6 months for palbociclib plus ET and 30.9 months for capecitabine (P = 0.995). Subsequent systemic therapy was given to 79.8% and 82.9% of patients with palbociclib plus ET and capecitabine, respectively. Median PFS2 was similar between study arms (Cohort 2, P = 0.941; wild-type ESR1 population, P = 0.827). No new safety findings were observed., Conclusions: Palbociclib plus ET did not show a statistically superior OS compared to capecitabine in MBC patients progressing on aromatase inhibitors., Trial Registration: NCT02028507 (ClinTrials.gov), 2013-003170-27 (EudraCT)., Competing Interests: Conflict of interest statement The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: M. Martín has received consulting fees from AstraZeneca, Amgen, Taiho Oncology, Roche/Genentech, Novartis, PharmaMar, Eli Lilly, PUMA, Taiho Oncology and Pfizer; speakers' honoraria from AstraZeneca, Amgen, Roche/Genentech, Novartis, Daiichi-Sankyo and Pfizer; contracted research fees from Roche, Novartis and PUMA. C. Zielinski has received consulting fees and speaker's honoraria from Roche, Novartis, Bristol-Myers Squibb, Merck Sharp & Dohme, Imugene, Ariad, Pfizer, Merrimack, Merck KGaA, Fibrogen, AstraZeneca, Tesaro, Gilead, Servier, Shire, Eli Lilly and Athenex. His institution, Central European Cancer Center, Wiener Privatklinik Hospital, has received fees from Bristol-Myers Squibb, Merck Sharp & Dohme, Pfizer, AstraZeneca and Merck KGaA. M. Ruiz-Borrego has received speaker fees and advisory grants from Pfizer, Novartis and Lilly. E. Carrasco, who has a stock and other ownership interests from Lilly, has received travel and accommodation support from Roche, and her husband, who has participated in consulting and advisory board activities with Bristol-Myers Squibb, Novartis, Celgene, Roche Pharma, Janssen, Amgen, Incyte, Abbvie and Pfizer, has received travel and accommodation support from Celgene, Novartis and Bristol-Myers Squibb. His institution has received research funding from Celgene, Janssen, Bristol-Myers Squibb, Novartis, Celgene, Roche/Genentech, Amgen, Pfizer and Abbvie. GEICAM has received research funding from Roche/Genentech, Bristol-Myers Squibb, Novartis, Pfizer, Celgene, AstraZeneca, Merck Sharp & Dohme, Pierre Fabre and Takeda. E. M. Ciruelos has received advisory board honoraria from Lilly, Novartis, MSD, AstraZeneca, Pfizer and Roche; speakers' honoraria from Roche, Lilly and Pfizer; travel and congress assistance support from Pfizer and Roche. M. Muñoz has received advisory board honoraria from Pierre Favre and Seagen; honoraria for expert testimony from Novartis, Roche and Eisai; travel and congress assistance support from Roche, Novartis, Pfizer and Eisai. B. Bermejo has received advisory board honoraria from Roche, Novartis and MSD; speakers' honoraria from Roche, Novartis, MSD, Pfizer and Pierfabre; travel and congress assistance support from Pfizer. M. Margelí has received advisory board fees from Roche, Novartis, Pfizer and Eisai. Her institution, ICO-Badalona. B-ARGO (Badalona Applied Research Group in Oncology) Hospital Universitari Germans Trias i Pujol, Badalona, has received funding research from Roche, Pfizer, Novartis, Lilly, AstraZeneca, Eisai and Kern, and she has received travel and congress assistance support from Roche. A. Antón has received advisory board fees from Bayer Spain, Lilly and Gilead. N. Turner has received advisory board honoraria from Astra Zeneca, Bristol-Myers Squibb, Lilly, Merck Sharp & Dohme, Novartis, Pfizer, Roche/Genentech, Bicycle Therapeutics, Taiho, Zeno pharmaceuticals and Repare; therapeutics and research funding from Astra Zeneca, BioRad, Pfizer, Roche/Genentech, Clovis, Merck Sharp & Dohme and Guardant Health. E. Alba has received advisory board fees from Roche, Novartis, Pfizer, Lilly, Bristol-Myers Squibb, Genomic Health and Nanostring. He has received travel support from Celgene. His institution, Hospitales Regional y Virgen de la Victoria, Málaga, has received funding research from Roche, Pfizer, Sysmex, Merck Sharp & Dohme and Nanostring. J. de la Haba-Rodríguez has received speaker's honoraria from AstraZeneca, Pfizer, Novartis and Lilly. M. Ramos has received honoraria from Novartis, Roche and Pfizer. M. Corsaro is employed by Pfizer and has company stock options. X. Huang is employed by Pfizer and has company stock options. Z. Kahan has participated in advisory boards of and received speaker fees or travel support from Pfizer, Roche, AstraZeneca and Novartis. M. Gil-Gil has received honoraria from Pfizer, Ferrer International and Esteve Pharma. All remaining authors have declared no conflicts of interest. A complete list of the PEARL trial collaborators is provided in the Supplementary Appendix., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: The recurrence score based on the 21-gene breast-cancer assay has been clinically useful in predicting a chemotherapy benefit in hormone-receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative, axillary lymph-node-negative breast cancer. In women with positive lymph-node disease, the role of the recurrence score with respect to predicting a benefit of adjuvant chemotherapy is unclear., Methods: In a prospective trial, we randomly assigned women with hormone-receptor-positive, HER2-negative breast cancer, one to three positive axillary lymph nodes, and a recurrence score of 25 or lower (scores range from 0 to 100, with higher scores indicating a worse prognosis) to endocrine therapy only or to chemotherapy plus endocrine (chemoendocrine) therapy. The primary objective was to determine the effect of chemotherapy on invasive disease-free survival and whether the effect was influenced by the recurrence score. Secondary end points included distant relapse-free survival., Results: A total of 5083 women (33.2% premenopausal and 66.8% postmenopausal) underwent randomization, and 5018 participated in the trial. At the prespecified third interim analysis, the chemotherapy benefit with respect to increasing invasive disease-free survival differed according to menopausal status (P = 0.008 for the comparison of chemotherapy benefit in premenopausal and postmenopausal participants), and separate prespecified analyses were conducted. Among postmenopausal women, invasive disease-free survival at 5 years was 91.9% in the endocrine-only group and 91.3% in the chemoendocrine group, with no chemotherapy benefit (hazard ratio for invasive disease recurrence, new primary cancer [breast cancer or another type], or death, 1.02; 95% confidence interval [CI], 0.82 to 1.26; P = 0.89). Among premenopausal women, invasive disease-free survival at 5 years was 89.0% with endocrine-only therapy and 93.9% with chemoendocrine therapy (hazard ratio, 0.60; 95% CI, 0.43 to 0.83; P = 0.002), with a similar increase in distant relapse-free survival (hazard ratio, 0.58; 95% CI, 0.39 to 0.87; P = 0.009). The relative chemotherapy benefit did not increase as the recurrence score increased., Conclusions: Among premenopausal women with one to three positive lymph nodes and a recurrence score of 25 or lower, those who received chemoendocrine therapy had longer invasive disease-free survival and distant relapse-free survival than those who received endocrine-only therapy, whereas postmenopausal women with similar characteristics did not benefit from adjuvant chemotherapy. (Funded by the National Cancer Institute and others; RxPONDER ClinicalTrials.gov number, NCT01272037.)., (Copyright © 2021 Massachusetts Medical Society.)

Neratinib is an irreversible, pan-human epidermal growth factor inhibitor that has shown efficacy across human epidermal growth factor receptor 2 (HER2)-positive breast cancer settings. Neratinib is indicated for use as extended adjuvant therapy for HER2-positive early-stage breast cancer or, in combination with capecitabine, in the treatment of HER2-positive metastatic breast cancer. The primary tolerability concern with neratinib is diarrhea, and severe diarrhea early in treatment can lead to a substantial proportion of patients discontinuing neratinib, which may lead to reduced or nonexistent efficacy. In order to establish a set of treatment recommendations for use of neratinib, on May 12, 2020, an expert panel of oncologists and gastroenterologists met virtually to discuss the role of neratinib in the treatment of patients with HER2-positive breast cancer. The panel reviewed the current data on neratinib, including efficacy across settings and diarrhea management strategies. Based on these data and their clinical experience, the panelists developed a set of recommendations to guide selection of patients for neratinib, implement weekly dose escalation at initiation of therapy, and prophylactically manage diarrhea., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The PEARL study showed that palbociclib plus endocrine therapy (palbociclib/ET) was not superior to capecitabine in improving progression-free survival in postmenopausal patients with metastatic breast cancer resistant to aromatase inhibitors, but was better tolerated. This analysis compared patient-reported outcomes., Patients and Methods: The PEARL quality of life (QoL) population comprised 537 patients, 268 randomised to palbociclib/ET (exemestane or fulvestrant) and 269 to capecitabine. Patients completed the European Organisation for Research and Treatment of Cancer QLQ-C30 and QLQ-BR23 and EQ-5D-3L questionnaires. Changes from the baseline and time to deterioration (TTD) were analysed using linear mixed-effect and stratified Cox regression models, respectively., Results: Questionnaire completion rate was high and similar between treatment arms. Significant differences were observed in the mean change in global health status (GHS)/QoL scores from the baseline to cycle 3 (2.9 for palbociclib/ET vs. -2.1 for capecitabine (95% confidence interval [CI], 1.4-8.6; P = 0.007). The median TTD in GHS/QoL was 8.3 months for palbociclib/ET versus 5.3 months for capecitabine (adjusted hazard ratio, 0.70; 95% CI, 0.55-0.89; P = 0.003). Similar improvements for palbociclib/ET were also seen for other scales as physical, role, cognitive, social functioning, fatigue, nausea/vomiting and appetite loss. No differences were observed between the treatment arms in change from the baseline in any item of the EQ-5D-L3 questionnaire as per the overall index score and visual analogue scale., Conclusion: Patients receiving palbociclib/ET experienced a significant delay in deterioration of GHS/QoL and several functional and symptom scales compared with capecitabine, providing additional evidence that palbociclib/ET is better tolerated., Trial Registration Number: NCT02028507 (ClinTrials.gov)., Eudract Study Number: 2013-003170-27., Competing Interests: Conflict of interest statement Z.K. has participated in advisory boards of and received speaker fees or travel support from Pfizer, Roche, AstraZeneca and Novartis. M.G-G.- has received honoraria from Pfizer and Eisai and has participated in advisory boards of Genentech and Daiichi Sankyo. He has received travel support from Pfizer, Novartis, Daiichi Sankyo, Roche and Kern. M.R.B. has received speaker fees and advisory grants from Pfizer, Novartis and Lilly. E.Ca., who has a stock and other ownership interests from Lilly, has received travel and accommodation support from Roche, and her husband, who has participated in consulting and advisory board activities with Bristol Myers Squibb, Novartis, Celgene, Roche Pharma, Janssen, Amgen, Incyte, AbbVie and Pfizer, has received travel and accommodation support from Celgene, Novartis and Bristol Myers Squibb. His institution has received research funding from Celgene, Janssen, Bristol Myers Squibb, Novartis, Roche/Genentech, Amgen, Pfizer and AbbVie. GEICAM has received research funding from Roche/Genentech, Bristol Myers Squibb, Novartis, Pfizer, Celgene, AstraZeneca, Merck Sharp & Dohme, Pierre Fabre and Takeda. E.Ci. has received advisory board honoraria from Lilly, Novartis, MSD, AstraZeneca, Pfizer and Roche and speakers' honoraria from Roche, Lilly and Pfizer, and she has received travel and congress assistance support from Pfizer and Roche. M.Mu. has received travel and congress assistance support from Roche, Novartis, Pfizer and Eisai. B.B. has received advisory board honoraria from Roche, Novartis and MSD and speakers' honoraria from Roche, Novartis, MSD, Pfizer and Pierre Fabre, and she has received travel and congress assistance support from Pfizer. M.Marg. has received advisory board fees from Roche, Novartis, Pfizer and Eisai. Her institution, ICO-Badalona. B-ARGO (Badalona Applied Research Group in Oncology) Hospital Universitari Germans Trias i Pujol, Badalona, has received research funding from Roche, Pfizer, Novartis, Lilly, AstraZeneca, Eisai and Kern, and she has received travel and congress assistance support from Roche. A.A. has received advisory board fees from Bayer, Spain. E.A. has received advisory board fees from Roche, Novartis, Pfizer, Lilly, Bristol Myers Squibb, Genomic Health and Nanostring. He has received travel support from Celgene. His institution, Hospitales Regional y Virgen de la Victoria, Málaga, has received research funding from Roche, Pfizer, Sysmex, Merck Sharp & Dohme and Nanostring. J.d.l.H-R. has received speaker's honoraria from AstraZeneca, Pfizer, Novartis and Lilly. M.R. has received honoraria from Novartis, Roche and Pfizer. I.M.A-L. has received consulting or advisory board honoraria from AstraZeneca, Pfizer, Novartis, Palex and Roche; speakers' honoraria from AstraZeneca, Pfizer, Novartis, Roche and Eisai; travel and congress assistance support from AstraZeneca, Pfizer, Roche and Eisai and research funding from Pfizer, Novartis, AstraZeneca and Roche. E.G-Y. has received honoraria and travel support and has participated in advisory boards for Pfizer, Roche, Novartis and Eli Lilly. S.G-S. has received consulting or advisory board honoraria from Pfizer, MSD, GSK and Roche and speakers' honoraria from AstraZeneca, Pfizer and Novartis. C.A.R. has received consulting or advisory board honoraria from AstraZeneca, Pfizer, Novartis, SeaGen, DaiiChi Sankyo and Roche and speakers' honoraria from MSD, Pfizer, Novartis, Roche, Nanostring, Amgen and Eisai. S.S. has received consulting or advisory board or speakers' honoraria from Roche, Eisai, Daiichi Sankyo, AstraZeneca, MSD and Genomic Health. M.C. is employed by Pfizer and has the company's stock options. X.H. is employed by Pfizer and has the company's stock options. C.Z. has received consulting fees and speaker's honoraria from Roche, Novartis, Bristol Myers Squibb, Merck Sharp & Dohme, Imugene, Ariad, Pfizer, Merrimack, Merck KGaA, FibroGen, AstraZeneca, Tesaro, Gilead, Servier, Shire, Eli Lilly and Athenex. His institution, Central European Cancer Center, Wiener Privatklinik Hospital, has received fees from Bristol Myers Squibb, Merck Sharp & Dohme, Pfizer, AstraZeneca and Merck KGaA. M.Mart. has received consulting fees from AstraZeneca, Amgen, Taiho Oncology, Roche/Genentech, Novartis, PharmaMar, Eli Lilly, PUMA, Taiho Oncology and Pfizer; speakers' honoraria from AstraZeneca, Amgen, Roche/Genentech, Novartis, Daiichi Sankyo and Pfizer and contracted research fees from Roche, Novartis and PUMA. All remaining authors have declared no conflicts of interest. A complete list of the PEARL trial collaborators is provided in the Supplementary Appendix., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Several de-escalation approaches are under investigation in patients with HER2-positive, early-stage breast cancer. We assessed early metabolic responses to neoadjuvant trastuzumab and pertuzumab using 18 F-fluorodeoxyglucose ( 18 F-FDG)-PET ( 18 F-FDG-PET) and the possibility of chemotherapy de-escalation using a pathological response-adapted strategy., Methods: We did a multicentre, randomised, open-label, non-comparative, phase 2 trial in 45 hospitals in Spain, France, Belgium, Germany, the UK, Italy, and Portugal. Eligible participants were women aged 18 years or older with centrally confirmed, HER2-positive, stage I-IIIA, invasive, operable breast cancer (≥1·5 cm tumour size) with at least one breast lesion evaluable by 18 F-FDG-PET, an Eastern Cooperative Oncology Group performance status of 0 or 1, and a baseline left ventricular ejection fraction of at least 55%. We randomly assigned participants (1:4), via an interactive response system using central block randomisation with block sizes of five, stratified by hormone receptor status, to either docetaxel (75 mg/m 2 intravenous), carboplatin (area under the concentration-time curve 6 mg/mL  per  min intravenous), trastuzumab (subcutaneous 600 mg fixed dose), and pertuzumab (intravenous 840 mg loading dose, 420 mg maintenance doses; group A); or trastuzumab and pertuzumab (group B). Hormone receptor-positive patients allocated to group B were additionally given letrozole if postmenopausal (2·5 mg/day orally) or tamoxifen if premenopausal (20 mg/day orally). Centrally reviewed 18 F-FDG-PET scans were done before randomisation and after two treatment cycles. Patients assigned to group A completed six cycles of treatment (every 3 weeks) regardless of 18 F-FDG-PET results. All patients assigned to group B initially received two cycles of trastuzumab and pertuzumab. 18 F-FDG-PET responders in group B continued this treatment for six further cycles; 18 F-FDG-PET non-responders in this group were switched to six cycles of docetaxel, carboplatin, trastuzumab, and pertuzumab. Surgery was done 2-6 weeks after the last dose of study treatment. Adjuvant treatment was selected according to the neoadjuvant treatment administered, pathological response, hormone receptor status, and clinical stage at diagnosis. The coprimary endpoints were the proportion of 18 F-FDG-PET responders in group B with a pathological complete response in the breast and axilla (ypT0/is ypN0) as determined by a local pathologist after surgery after eight cycles of treatment, and 3-year invasive disease-free survival of patients in group B, both assessed by intention to treat. The definitive assessment of pathological complete response was done at this primary analysis; follow-up to assess invasive disease-free survival is continuing, hence these data are not included in this Article. Safety was assessed in all participants who received at least one dose of study drug. Health-related quality-of-life was assessed with EORTC QLQ-C30 and QLQ-BR23 questionnaires at baseline, after two cycles of treatment, and before surgery. This trial is registered with EudraCT (2016-002676-27) and ClinicalTrials.gov (NCT03161353), and is ongoing., Findings: Between June 26, 2017, and April 24, 2019, we randomly assigned 71 patients to group A and 285 to group B. Median follow-up was 5·7 months (IQR 5·3-6·0). 227 (80%) of 285 patients in group B were 18 F-FDG-PET responders, of whom 86 (37·9%, 95% CI 31·6-44·5; p<0·0001 compared with the historical rate) of 227 had a pathological complete response. The most common haematological grade 3-4 adverse events were anaemia (six [9%] of 68 patients in group A vs four [1%] of 283 patients in group B), neutropenia (16 [24%] vs ten [4%]), and febrile neutropenia (14 [21%] vs 11 [4%]). Serious adverse events occurred in 20 (29%) of 68 patients in group A versus 13 (5%) of 283 patients in group B. No deaths were reported during neoadjuvant treatment. Global health status declined by at least 10% in 65·0% (95% CI 46·5-72·4) and 35·5% (29·7-41·7) of patients in groups A and B, respectively INTERPRETATION: 18 F-FDG-PET identified patients with HER2-positive, early-stage breast cancer who were likely to benefit from chemotherapy-free dual HER2 blockade with trastuzumab and pertuzumab, and a reduced impact on global health status. Depending on the forthcoming results for the 3-year invasive disease-free survival endpoint, this strategy might be a valid approach to select patients not requiring chemotherapy., Funding: F Hoffmann-La Roche., Competing Interests: Declaration of interests JMP-G reports a consulting role for Roche and Lilly, travel expenses from Roche, and is a part-time employee of Medica Scientia Innovation Research. GG reports research funding from Roche paid to their institution and that an immediate family member received personal fees from Roche. MRB reports a consulting role for Novartis, Pfizer, and Merck-Sharpe & Dohme (MSD), and being part of the speaker bureau for Pfizer, Novartis, Roche, Lilly, and AstraZeneca. AS reports a consulting role for Roche and Eisai, being part of the speaker bureau for Roche and Eisai, and reports expert testimony for Eisai and Roche, and travel expenses from Roche and Pfizer. BB reports a consulting role for Genentech and MSD, being part of the speaker bureau for Genentech, and travel expenses from Pfizer. PS reports honoraria from Pfizer, AstraZeneca, Novartis, Roche, Merck, and Boehringer Ingelheim; a consulting role for Pfizer, AstraZeneca, Novartis, Roche, Merck, Boehringer Ingelheim, Bayer, Eisai, Celgene, and Puma; and a grant to their institution from Roche, Genentech, Oncogenex, and Novartis. FM reports honoraria from Roche–Genentech, Novartis, Pfizer, AstraZeneca, Tesaro, Clovis Oncology, Eisai, Celgene, Genomic Health, PharmaMar, Amgen, CureVac, MSD Oncology, Janssen-Cilag, and ImmunoMedics (to their institution); research funding to their institution from Roche–Genentech, Novartis, AstraZeneca, Eisai, Tesaro, Clovis, MSD Oncology, and Vaccibody; travel compensations from Roche, Pfizer, Novartis, PharmaMar, and AstraZeneca; and a consulting role for Tesaro, Pfizer, Novartis, GenomicHealth, CureVac, Amgen, Celgene, Eisai, Janssen-Cilag, AstraZeneca (to their institution), Roche (to their institution), Vaccibody (to their institution), and Immunomedics (to their institution) during this study. SE-d-R reports a consulting role for Roche, Pierre-Fabre, and Eisai; research funding from Synthon and Roche; and travel expenses from Roche, Pierre-Fabre, and Daiichi Sankyo. AP reports honoraria from Pfizer, Novartis, Roche, MSD Oncology, Lilly, Daiichi Sankyo, and Amgen; a consulting role for Amgen, Roche, Novartis, Pfizer, Bristol-Myers-Squibb, Boehringer, PUMA Biotechnology, Oncolytics Biotech, Daiichi Sankyo, Abbvie, and NanoString Technologies; research funding to their institution from Roche, Novartis, Incyte, and PUMA Biotechnology; intellectual property (PCT/EP2016/080056: HER2 as a predictor of response to dual HER2 blockade in the absence of cytotoxic therapy; WO/2018/096191: Chemoendocrine score based on PAM50 for breast cancer with positive hormone receptors with an intermediate risk of recurrence); travel expenses from Daiichi Sankyo; other funding from Oncolytics, and Peptomyc; and that an immediate family member is an employee of Novartis. MC reports a consulting role for Pierre-Fabre, Pfizer, OBI Pharma, Celldex, and AstraZeneca; and honoraria from Novartis. NA reports a consulting role for Pfizer, Novartis, Roche, AstraZeneca, and Lilly; and travel expenses from Pfizer, Novartis, Roche, and AstraZeneca. SDC reports fees for medical education from Novartis and Pierre-Fabre; being a recipient of the IG20774 grant from Fondazione Associazione Italiana Ricerca contro il Cancro), and is a part-time employee of MEDSIR during this study. MS-C reports honoraria and a consulting role for from MEDSIR, Syntax for Science, and Nestlé; being part of the speaker bureau for MEDSIR, Syntax for Science, and Roche; research funding from MEDSIR, Syntax for Science, and Roche; travel expenses from MEDSIR, Syntax for Science, and Roche; and is a part-time employee of MEDSIR during this study. AM is a full-time employee of MEDSIR. JC reports a consulting role for Roche, Celgene, Cellestia, AstraZeneca, Biothera Pharmaceutical, Merus, Seattle Genetics, Daiichi Sankyo, Erytech, Athenex, Polyphor, Lilly, Servier, MSD, GlaxoSmithKline (GSK), Leuko, Bioasis, and Clovis Oncology; honoraria from Roche, Novartis, Celgene, Eisai, Pfizer, Samsung Bioepis, Lilly, MSD, and Daiichi Sankyo; research funding to their institution from Roche, Ariad Pharmaceuticals, AstraZeneca, Baxalta GMBH–Servier Affaires, Bayer healthcare, Eisai, F Hoffman-La Roche, Guardant Health, MSD, Pfizer, Piqur Therapeutics, Puma C, and Queen Mary University of London; and intellectual property for MEDSIR. AL-C reports leadership for Eisai, Celgene, Lilly, Pfizer, Roche, Novartis, and MSD; intellectual property for MEDSIR and Initia-Research; a consulting role for Lilly, Roche, Pfizer, Novartis, Pierre-Fabre, GenomicHealth, and GSK; being part of the speaker bureau for Lilly, AstraZeneca, and MSD; research funding from Roche, Foundation Medicine, Pierre-Fabre, and Agendia; and travel expenses from Roche, Lilly, Novartis, Pfizer, and AstraZeneca. LC, NR, NM, CA, FD, and KK declare no competing interests., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Palbociclib plus endocrine therapy (ET) is the standard treatment of hormone receptor-positive and human epidermal growth factor receptor 2-negative, metastatic breast cancer (MBC). However, its efficacy has not been compared with that of chemotherapy in a phase III trial., Patients and Methods: PEARL is a multicentre, phase III randomised study in which patients with aromatase inhibitor (AI)-resistant MBC were included in two consecutive cohorts. In cohort 1, patients were randomised 1 : 1 to palbociclib plus exemestane or capecitabine. On discovering new evidence about estrogen receptor-1 (ESR1) mutations inducing resistance to AIs, the trial was amended to include cohort 2, in which patients were randomised 1 : 1 between palbociclib plus fulvestrant and capecitabine. The stratification criteria were disease site, prior sensitivity to ET, prior chemotherapy for MBC, and country of origin. Co-primary endpoints were progression-free survival (PFS) in cohort 2 and in wild-type ESR1 patients (cohort 1 + cohort 2). ESR1 hotspot mutations were analysed in baseline circulating tumour DNA., Results: From March 2014 to July 2018, 296 and 305 patients were included in cohort 1 and cohort 2, respectively. Palbociclib plus ET was not superior to capecitabine in both cohort 2 [median PFS: 7.5 versus 10.0 months; adjusted hazard ratio (aHR): 1.13; 95% confidence interval (CI): 0.85-1.50] and wild-type ESR1 patients (median PFS: 8.0 versus 10.6 months; aHR: 1.11; 95% CI: 0.87-1.41). The most frequent grade 3-4 toxicities with palbociclib plus exemestane, palbociclib plus fulvestrant and capecitabine, respectively, were neutropenia (57.4%, 55.7% and 5.5%), hand/foot syndrome (0%, 0% and 23.5%), and diarrhoea (1.3%, 1.3% and 7.6%). Palbociclib plus ET offered better quality of life (aHR for time to deterioration of global health status: 0.67; 95% CI: 0.53-0.85)., Conclusions: There was no statistical superiority of palbociclib plus ET over capecitabine with respect to PFS in MBC patients resistant to AIs. Palbociclib plus ET showed a better safety profile and improved quality of life., Competing Interests: Disclosure MM has received consulting fees from AstraZeneca, Amgen, Taiho Oncology, Roche/Genentech, Novartis, PharmaMar, Eli Lilly, PUMA, Taiho Oncology, and Pfizer; speakers' honoraria from AstraZeneca, Amgen, Roche/Genentech, Novartis, Daiichi-Sankyo, and Pfizer; contracted research fees from Roche, Novartis, and PUMA. CZ has received consulting fees and speaker’s honoraria from Roche, Novartis, Bristol-Myers Squibb, Merck Sharp & Dohme, Imugene, Ariad, Pfizer, Merrimack, Merck KGaA, Fibrogen, AstraZeneca, Tesaro, Gilead, Servier, Shire, Eli Lilly, and Athenex. His institution, Central European Cancer Center, Wiener Privatklinik Hospital, has received fees from Bristol-Myers Squibb, Merck Sharp & Dohme, Pfizer, AstraZeneca, and Merck KGaA. MRB has received speaker fees and advisory grants from Pfizer, Novartis, and Lilly. EC, who has a stock and other ownership interests from Lilly, has received travel and accommodation support from Roche, and her husband who has participated in consulting and advisory board activities with Bristol-Myers Squibb, Novartis, Celgene, Roche Pharma, Janssen, Amgen, Incyte, Abbvie, and Pfizer, has received travel and accommodation support from Celgene, Novartis, and Bristol-Myers Squibb. His institution has received research funding from Celgene, Janssen, Bristol-Myers Squibb, Novartis, Celgene, Roche/Genentech, Amgen, Pfizer, and Abbvie. GEICAM has received research funding from Roche/Genentech, Bristol-Myers Squibb, Novartis, Pfizer, Celgene, AstraZeneca, Merck Sharp & Dohme, Pierre Fabre, and Takeda. NT has received advisory board honoraria from AstraZeneca, Bristol-Myers Squibb, Lilly, Merck Sharp & Dohme, Novartis, Pfizer, Roche/Genentech, Bicycle Therapeutics, Taiho, Zeno Pharmaceuticals, and Repare Therapeutics and research funding from AstraZeneca, Bio-Rad, Pfizer, Roche/Genentech, Clovis, Merck Sharp & Dohme, and Guardant Health. MM has received travel and congress assistance support from Roche, Novartis, Pfizer, and Eisai. BB has received advisory board honoraria from Genentech, Novartis, Merck Sharpe and Dohme, speakers’ honoraria from Genentech, Eisai and she has received travel and congress assistance support from Pfizer. MM has received advisory board fees from Roche, Novartis, Pfizer, and Eisai. Her institution, Hospital Universitari Germans Trias i Pujol, Badalona, has received funding research from Roche, Pfizer, Novartis, Lilly, AstraZeneca, Eisai, and Kern. AA has received advisory board fees from Bayer, Spain. EA has received advisory board fees from Roche, Novartis, Pfizer, Lilly, Bristol-Myers Squibb, Genomic Health, and Nanostring. He has received travel support from Celgene. His institution, Hospitales Regional y Virgen de la Victoria, Málaga, has received funding research from Roche, Pfizer, Sysmex, Merck Sharp & Dohme, and Nanostring. EG-Y has received honoraria, travel support, and has participated in advisory boards for Pfizer, Roche, Novartis, and Eli Lilly. ÁG-Z has received investigational fees and travel support from Pfizer. JdelaH has received honoraria from AstrazZeneca, Pfizer, Novartis, Roche, and Agendia. MR has received honoraria from Novartis, Roche, and Pfizer. IÁ has received consulting or advisory board honoraria from AstraZeneca, Pfizer, Novartis, and Roche; speakers’ honoraria from AstraZeneca, Pfizer, Novartis, Roche, and Eisai; travel and congress assistance support from AstraZeneca, Pfizer, Roche, and Eisai. CH has a stock from Pfizer and AstraZeneca, she was an employee of Pfizer during the study, and is an employee of AstraZeneca currently, where she holds a stock. MK has Pfizer stock and was an employee of Pfizer during the study. MC is employed by Pfizer and has the company’s stock options. XH is employed by Pfizer and has the company’s stock options. JAG-S has consultancy/speaker fees from Novartis, Celgene, Eli Lilly, Eisai, and AstraZeneca. He received travel support from Novartis, Roche, and Pfizer. His institution, Hospital Clínico Universitario San Carlos, received research funding from AstraZeneca. MG-G has received honoraria from Pfizer and Eisai and has participated in advisory boards of Genentech and Daiichi-Sankyo. He has received travel support from Pfizer, Novartis, Daiichi-Sankyo, Roche, and Kern. All remaining authors have declared no conflicts of interest. A complete list of the PEARL trial collaborators is provided in the Supplementary Appendix., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Alpelisib, a PI3Kα-selective inhibitor and degrader, plus fulvestrant showed efficacy in hormone receptor-positive, HER2-negative, PIK3CA-mutated advanced breast cancer in SOLAR-1; limited data are available in the post-cyclin-dependent kinase 4/6 inhibitor setting. BYLieve aimed to assess alpelisib plus endocrine therapy in this setting in three cohorts defined by immediate previous treatment; here, we report results from cohort A., Methods: This ongoing, phase 2, multicentre, open-label, non-comparative study enrolled patients with hormone receptor-positive, HER2-negative, advanced breast cancer with tumour PIK3CA mutation, following progression on or after previous therapy, including CDK4/6 inhibitors, from 114 study locations (cancer centres, medical centres, university hospitals, and hospitals) in 18 countries worldwide. Participants aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 2 or less, with no more than two previous anticancer treatments and no more than one previous chemotherapy regimen, were enrolled in three cohorts. In cohort A, patients must have had progression on or after a CDK4/6 inhibitor plus an aromatase inhibitor as the immediate previous treatment. Patients received oral alpelisib 300 mg/day (continuously) plus fulvestrant 500 mg intramuscularly on day 1 of each 28-day cycle and on day 15 of cycle 1. The primary endpoint was the proportion of patients alive without disease progression at 6 months per local assessment using Response Evaluation Criteria in Solid Tumors, version 1.1, in patients with a centrally confirmed PIK3CA mutation. This trial is registered with ClinicalTrials.gov, NCT03056755., Findings: Between Aug 14, 2017, and Dec 17, 2019 (data cutoff), 127 patients with at least 6 months' follow-up were enrolled into cohort A. 121 patients had a centrally confirmed PIK3CA mutation. At data cutoff, median follow-up was 11·7 months (IQR 8·5-15·9). 61 (50·4%; 95% CI 41·2-59·6) of 121 patients were alive without disease progression at 6 months. The most frequent grade 3 or worse adverse events were hyperglycaemia (36 [28%] of 127 patients), rash (12 [9%]), and rash maculopapular (12 [9%]). Serious adverse events occurred in 33 (26%) of 127 patients. No treatment-related deaths were reported., Interpretation: BYLieve showed activity of alpelisib plus fulvestrant with manageable toxicity in patients with PIK3CA-mutated, hormone receptor-positive, HER2-negative advanced breast cancer, after progression on a CDK4/6 inhibitor plus an aromatase inhibitor., Funding: Novartis Pharmaceuticals., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: The ExteNET trial demonstrated improved invasive disease-free survival (iDFS) with neratinib, an irreversible pan-HER tyrosine kinase inhibitor, versus placebo in patients with human epidermal growth factor receptor 2-positive (HER2 + )/hormone receptor-positive (HR + ) early-stage breast cancer (eBC)., Patients and Methods: ExteNET was a multicenter, randomized, double-blind, phase III trial of 2840 patients with HER2 + eBC after neoadjuvant/adjuvant trastuzumab-based therapy. Patients were stratified by HR status and randomly assigned 1-year oral neratinib 240 mg/day or placebo. The primary endpoint was iDFS. Descriptive analyses were performed in patients with HR + eBC who initiated treatment ≤ 1 year (HR + /≤ 1-year) and > 1 year (HR + /> 1-year) post-trastuzumab., Results: HR + /≤ 1-year and HR + /> 1-year populations comprised 1334 (neratinib, n = 670; placebo, n = 664) and 297 (neratinib, n = 146; placebo, n = 151) patients, respectively. Absolute iDFS benefits at 5 years were 5.1% in HR + /≤ 1-year (hazard ratio, 0.58; 95% confidence interval [CI], 0.41-0.82) and 1.3% in HR + />1-year (hazard ratio, 0.74; 95% CI, 0.29-1.84). In HR + /≤ 1-year, neratinib was associated with a numerical improvement in overall survival (OS) at 8 years (absolute benefit, 2.1%; hazard ratio, 0.79; 95% CI, 0.55-1.13). Of 354 patients in the HR + /≤ 1-year group who received neoadjuvant therapy, 295 had residual disease, and results showed absolute benefits of 7.4% at 5-year iDFS (hazard ratio, 0.60; 95% CI, 0.33-1.07) and 9.1% at 8-year OS (hazard ratio, 0.47; 95% CI, 0.23-0.92). There were fewer central nervous system events with neratinib. Adverse events were similar to those previously reported., Conclusion: Neratinib significantly improved iDFS in the HER2 + /HR + /≤ 1-year population, and a similar trend was observed in patients with residual disease following neoadjuvant treatment. Numerical improvements in central nervous system events and OS were consistent with iDFS benefits and suggest long-term benefit for neratinib in this population., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Palbociclib added to endocrine therapy improves progression-free survival in hormone-receptor-positive, HER2-negative, metastatic breast cancer. The PALLAS trial aimed to investigate whether the addition of 2 years of palbociclib to adjuvant endocrine therapy improves invasive disease-free survival over endocrine therapy alone in patients with hormone-receptor-positive, HER2-negative, early-stage breast cancer., Methods: PALLAS is an ongoing multicentre, open-label, randomised, phase 3 study that enrolled patients at 406 cancer centres in 21 countries worldwide with stage II-III histologically confirmed hormone-receptor-positive, HER2-negative breast cancer, within 12 months of initial diagnosis. Eligible patients were aged 18 years or older with an Eastern Cooperative Oncology Group performance score of 0 or 1. Patients were randomly assigned (1:1) in permuted blocks of random size (4 or 6), stratified by anatomic stage, previous chemotherapy, age, and geographical region, by use of central telephone-based and web-based interactive response technology, to receive either 2 years of palbociclib (125 mg orally once daily on days 1-21 of a 28-day cycle) with ongoing standard provider or patient-choice adjuvant endocrine therapy (tamoxifen or aromatase inhibitor, with or without concurrent luteinising hormone-releasing hormone agonist), or endocrine therapy alone, without masking. The primary endpoint of the study was invasive disease-free survival in the intention-to-treat population. Safety was assessed in all randomly assigned patients who started palbociclib or endocrine therapy. This report presents results from the second pre-planned interim analysis triggered on Jan 9, 2020, when 67% of the total number of expected invasive disease-free survival events had been observed. The trial is registered with ClinicalTrials.gov (NCT02513394) and EudraCT (2014-005181-30)., Findings: Between Sept 1, 2015, and Nov 30, 2018, 5760 patients were randomly assigned to receive palbociclib plus endocrine therapy (n=2883) or endocrine therapy alone (n=2877). At the time of the planned second interim analysis, at a median follow-up of 23·7 months (IQR 16·9-29·2), 170 of 2883 patients assigned to palbociclib plus endocrine therapy and 181 of 2877 assigned to endocrine therapy alone had invasive disease-free survival events. 3-year invasive disease-free survival was 88·2% (95% CI 85·2-90·6) for palbociclib plus endocrine therapy and 88·5% (85·8-90·7) for endocrine therapy alone (hazard ratio 0·93 [95% CI 0·76-1·15]; log-rank p=0·51). As the test statistic comparing invasive disease-free survival between groups crossed the prespecified futility boundary, the independent data monitoring committee recommended discontinuation of palbociclib in patients still receiving palbociclib and endocrine therapy. The most common grade 3-4 adverse events were neutropenia (1742 [61·3%] of 2840 patients on palbociclib and endocrine therapy vs 11 [0·3%] of 2903 on endocrine therapy alone), leucopenia (857 [30·2%] vs three [0·1%]), and fatigue (60 [2·1%] vs ten [0·3%]). Serious adverse events occurred in 351 (12·4%) of 2840 patients on palbociclib plus endocrine therapy versus 220 (7·6%) of 2903 patients on endocrine therapy alone. There were no treatment-related deaths., Interpretation: At the planned second interim analysis, addition of 2 years of adjuvant palbociclib to adjuvant endocrine therapy did not improve invasive disease-free survival compared with adjuvant endocrine therapy alone. On the basis of these findings, this regimen cannot be recommended in the adjuvant setting. Long-term follow-up of the PALLAS population and correlative studies are ongoing., Funding: Pfizer., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: This study evaluated efficacy and safety of palbociclib, a CDK4/6 inhibitor, in heavily-pretreated hormone receptor-positive and human epidermal growth factor receptor 2-negative (HR + /HER2 - ) metastatic breast cancer (mBC) patients during the compassionate use program in Spain from February 2015 to November 2017., Patients and Methods: Patient data were collected retrospectively from 35 hospitals in Spain. Patients with HR + /HER2 - mBC who had progressed on ≥4 treatments for advanced disease were eligible., Results: A total of 219 patients received palbociclib in combination with aromatase inhibitors (110; 50.2%), fulvestrant (87; 39.7%), tamoxifen (8; 3.6%) or as single agent (10; 4.6%). Mean age of the patients was 58 years; 31 patients (16.1%) were premenopausal and 162 (83.9%) were postmenopausal at the beginning of treatment with palbociclib. Patients had received a median of 3 previous lines of endocrine therapy (ET) for advanced disease. Real-world tumor response (rwTR) and clinical benefit rate were 5.9% (n = 13) and 46.2% (n = 101), respectively. The median real world progression-free survival (rwPFS) was 6.0 months (95% CI 5.7-7.0) and the median overall survival was 19.0 months (95% CI 16.4-21.7). Subgroup analysis revealed a significant difference in median rwPFS in patients treated with palbociclib plus fulvestrant depending on the duration of prior treatment with fulvestrant monotherapy (>6 versus ≤6 months; HR 1.93, 95% CI 1.37-2.73, p < 0.001). The most frequently reported toxicities were neutropenia, asthenia, thrombopenia and anemia., Conclusions: Palbociclib can be an effective and safe treatment option in patients with heavily pretreated endocrine-sensitive mBC, especially in those with longer PFS to previous ET., Competing Interests: Declaration of competing interest L. Manso reports consulting or advisory roles from Roche, AstraZeneca, Novartis, Tesaro, and Pfizer; speaker’s bureau participation from Roche, AstraZeneca, Novartis, Tesaro, and Pfizer; research funding from Tesaro; travel expenses from Roche, Novartis, and Tesaro. M. Oliveira reports receiving speaking and advisory honoraria as from Roche and Seattle Genetics; speaking fees from Novartis; and advisory honoraria from GSK, PUMA Biotechnology and AstraZeneca; and financial support from AstraZeneca, Philips, Genentech, Roche, Seattle Genetics, Zenith Epigenetics, GSK, Immunomedics, Novartis, Boehringer-Ingelheim, and PUMA Biotechnology. M. Ruiz-Borrego reports speaker grants and advisory fees from Pfizer, Eli Lilly and Co., and Novartis. Iñaki Álvarez-Busto reports consultant or advisory roles from Kyowa Kirin and Pharma Mar; speaker honoraria from Angelini, Astra-Zeneca, Bayer, Boehringer Ingelheim, EISAI, Grunenthal pharma, Novartis, Pierre Fabre, Pfizer, and Roche; financial support for attending symposia from Roche; and financial support for educational programs from Bristol-Myers Squibb and Roche. E. Aguirre reports financial support for attending symposiafrom Roche and MSD; financial support for educational programs from Astra Zeneca and MSD; and participation in advisory board from Roche, Pfizer and AstraZeneca. J. E. Alés-Martínez reports speaking honoraria from Roche, MSD and BMS; consulting honoraria from Tesaro and Pfizer; and travel grants from MSD, BMS, and Roche. D. Malón reports participation in advisories, formative activities, and financial support for attending symposia from Pfizer, Roche, Novartis, BMS, MSD, Eisai, and Ipsen. I. Echevarría reports receiving travel grants from Pfizer, Novartis, and Lilly; and speaking honoraria from Novartis. S. Servitja reports receiving speaking honoraria from Roche and Pfizer; advisory board participation with Genomichealth, AstraZeneca, and MSD; and financial support for attending symposia from Roche, Pfizer, and MSD. F. Moreno reports receiving financial support for attending symposia from Pfizer, Roche, Novartis; support from Pfizer as project sponsor; and positions on advisory board or board of directors or other type of management relationships from Roche, Novartis, Pfizer, and MSD. Other authors declare no conflicts of interest., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Purpose: Neoadjuvant clinical trials with dual HER2 blockade with pertuzumab and trastuzumab plus chemotherapy demonstrated high rates of pathological complete response (pCR) in HER2-positive early breast cancer (BC). We investigated whether the benefit on pCR seen in clinical trials is confirmed in a real-world setting., Methods: Multicenter, retrospective study in patients with HER2-positive early BC receiving neoadjuvant treatment with pertuzumab and trastuzumab in routine clinical practice (n = 243). The primary endpoint was total pCR (tpCR) (ypT0/is ypN0)., Results: A total of 243 evaluable patients were included. Pertuzumab and trastuzumab were combined with anthracyclines and taxanes in 74.1% of patients, with single-agent taxane in 11.1% of patients and with platinum-based chemotherapy (CT) in 14.4% of patients. The tpCR rate was 66.4%:71% with anthracyclines and taxanes, 59.3% with single-agent taxane, and 48.6% with platinum-based combinations. The tpCR rate was higher among patients with hormone receptor (HR)-negative tumors (80.9%) vs HR-positive tumors (55.4%) (p < 0.001). A pCR in the breast (ypT0/is) was achieved in 67.6% of patients. Of 143 patients who showed radiological complete response (rCR) (62%), 112 (78.3%) patients also achieved tpCR. Assessment of rCR by magnetic resonance imaging (MRI) showed the highest negative predictive value (NPV) for predicting tpCR (83.5%). Breast-conserving surgery was performed in 58.7% of patients. Grade 3 and grade 4 toxicities were reported in 33 (18.2%) and 12 (6.6%) patients, respectively. No toxicity leading to death was reported., Conclusions: This real-world analysis shows that neoadjuvant pertuzumab, trastuzumab, and chemotherapy achieve comparable or even higher rates of tpCR than those seen in clinical trials. The pCR benefit is higher in HR-negative tumors. The assessment of rCR by MRI showed the highest ability for predicting pCR. In addition, this neoadjuvant strategy confers an acceptable safety profile.

Background: Neratinib is an irreversible pan-HER tyrosine kinase inhibitor approved for extended adjuvant treatment in early-stage HER2-positive breast cancer based on the phase III ExteNET study. In that trial, in which no antidiarrheal prophylaxis was mandated, grade 3 diarrhea was observed in 40% of patients and 17% discontinued due to diarrhea. The international, open-label, sequential-cohort, phase II CONTROL study is investigating several strategies to improve tolerability., Patients and Methods: Patients who completed trastuzumab-based adjuvant therapy received neratinib 240 mg/day for 1 year plus loperamide prophylaxis (days 1-28 or 1-56). Sequential cohorts evaluated additional budesonide or colestipol prophylaxis (days 1-28) and neratinib dose escalation (DE; ongoing). The primary end point was the incidence of grade ≥3 diarrhea., Results: Final data for loperamide (L; n = 137), budesonide + loperamide (BL; n = 64), colestipol + loperamide (CL; n = 136), and colestipol + as-needed loperamide (CL-PRN; n = 104) cohorts, and interim data for DE (n = 60; completed ≥six cycles or discontinued; median duration 11 months) are available. No grade 4 diarrhea was observed. Grade 3 diarrhea rates were lower than ExteNET in all cohorts and lowest in DE (L 31%, BL 28%, CL 21%, CL-PRN 32%, DE 15%). Median number of grade 3 diarrhea episodes was one; median duration per grade 3 episode was 1.0-2.0 days across cohorts. Most grade 3 diarrhea and diarrhea-related discontinuations occurred in month 1. Diarrhea-related discontinuations were lowest in DE (L 20%, BL 8%, CL 4%, CL-PRN 8%, DE 3%). Decreases in health-related quality of life did not cross the clinically important threshold., Conclusions: Neratinib tolerability was improved with preemptive prophylaxis or DE, which reduced the rate, severity, and duration of neratinib-associated grade ≥3 diarrhea compared with ExteNET. Lower diarrhea-related treatment discontinuations in multiple cohorts indicate that proactive management can allow patients to stay on neratinib for the recommended time period. CLINICALTRIALS.GOV: NCT02400476., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Purpose: To evaluate the efficacy and safety of lapatinib (L) and trastuzumab (T) combination in HER2-positive metastatic breast cancer (MBC) patients previously treated with T and/or L., Materials and Methods: We conducted a retrospective, post-authorized, multicenter study including patients with HER2-positive MBC or locally advanced breast cancer (ABC) treated with the combination of L-T. Concomitant endocrine therapy, as well as brain metastasis and/or prior exposure to L, were allowed., Results: One hundred and fifteen patients from 14 institutions were included. The median age was 59.8 years. The median number of prior T regimens in the advanced setting was 3 and 73 patients had received a prior L regimen. The clinical benefit rate (CBR) was 34.8% (95% CI 26.1-43.5). Among other efficacy endpoints, the overall response rate was 21.7%, and median progression-free survival (PFS) and overall survival were 3.9 and 21.6 months, respectively. Heavily pretreated and ≥ 3 metastatic organ patients showed lower CBR and PFS than patients with a low number of previous regimens and < 3 metastatic organs. Moreover, CBR did not significantly change in L-pretreated compared with L-naïve patients (31.5% versus 40.5% for L-pretreated versus L-naïve). Grade 3/4 adverse events were reported in 19 patients (16.5%)., Conclusion: The combination of L-T is an effective and well-tolerated regimen in heavily pretreated patients and remains active among patients progressing on prior L-based therapy. Our study suggests that the L-T regimen is a safe and active chemotherapy-free option for MBC patients previously treated with T and/or L.

The use of adjuvant pertuzumab in HER2-positive early-stage breast cancer has recently been approved by the EMA on the basis of data from the APHINITY trial. Accordingly, we have produced this opinion article with the aim of putting the study data in perspective against other add-on therapeutic strategies, to clarify methodological or statistical doubts about the study, and to define the population of high-risk patients with hormone receptor-negative breast cancer that we agree, in general, should be treated. With this approval, physicians must be well prepared to place the APHINITY study data in context. It is now up to each country to ratify the EMA-approved indications and to agree on reimbursement, and doctors must optimize their use based on knowledge and discussion with patients., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Purpose: Operable triple-negative breast cancers (TNBCs) have a higher risk of relapse than non-TNBCs with standard therapy. The GEICAM/2003-11&#95;CIBOMA/2004-01 trial explored extended adjuvant capecitabine after completion of standard chemotherapy in patients with early TNBC., Patients and Methods: Eligible patients were those with operable, node-positive-or node negative with tumor 1 cm or greater-TNBC, with prior anthracycline- and/or taxane-containing chemotherapy. After central confirmation of TNBC status by immunohistochemistry, patients were randomly assigned to either capecitabine or observation. Stratification factors included institution, prior taxane-based therapy, involved axillary lymph nodes, and centrally determined phenotype (basal v nonbasal, according to cytokeratins 5/6 and/or epidermal growth factor receptor positivity by immunohistochemistry). The primary objective was to compare disease-free survival (DFS) between both arms., Results: Eight hundred seventy-six patients were randomly assigned to capecitabine (n = 448) or observation (n = 428). Median age was 49 years, 55.9% were lymph node negative, 73.9% had a basal phenotype, and 67.5% received previous anthracyclines plus taxanes. Median length of follow-up was 7.3 years. DFS was not significantly prolonged with capecitabine versus observation [hazard ratio (HR), 0.82; 95% CI, 0.63 to 1.06; P = .136]. In a preplanned subgroup analysis, nonbasal patients seemed to derive benefit from the addition of capecitabine with a DFS HR of 0.53 versus 0.94 in those with basal phenotype (interaction test P = .0694) and an HR for overall survival of 0.42 versus 1.23 in basal phenotype (interaction test P = .0052). Tolerance of capecitabine was as expected, with 75.2% of patients completing the planned 8 cycles., Conclusion: This study failed to show a statistically significant increase in DFS by adding extended capecitabine to standard chemotherapy in patients with early TNBC. In a preplanned subset analysis, patients with nonbasal phenotype seemed to obtain benefit with capecitabine, although this will require additional validation.

Objectives: The study aimed to estimate the burden of metastatic breast cancer (mBC) in Spain over 5 years., Methods: An incidence-based cost-of-illness model was developed in which a cohort of patients with mBC was followed from the diagnosis of metastatic disease over 5 years or death. Resource use data were collected through a physician survey conducted with 10 clinical experts in Spain. The model distinguished patients according to HER2 and hormonal receptor (HR) status, and followed the patient cohort in monthly cycles., Results: The incident cohort was estimated to be 2,923 patients with mBC, consisting of 1,575 HER2-/HR+, 520 HER2+/HR+, 324 HER2+/HR-, and 503 triple negative patients. The estimated mean survival over the 5-year time period was 2.51 years, on average, with longer survival of 3.36 years for HER2+/HR+, 2.41 years for HER2-/HR+, 2.82 years for HER2+/HR- and shortest mean survival of 1.74 years for triple negative patients. The total costs were €469,92,731 for the overall population, €190,079,787 for the HER2-/HR+, €151,045,260 for the HER2+/HR+, €80,827,171 for the HER2+/HR- and €47,540,512 for the triple negative subgroups over 5 years. Per patient total costs were €160,642 on average, €120,664 for HER2-/HR+, €290,346 for HER2+/HR+, €249,152 for HER2+/HR-and €94,572 for triple negative patients over 5 years., Conclusions: The economic burden of mBC in Spain is significant, but differs by HER2 and HR status. HER2-/HR +patients account for the highest burden due to the prevalence of this category, but HER2+/HR +patients have the highest per patient costs., Competing Interests: Competing interests: None declared., (© European Association of Hospital Pharmacists 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Single-agent paclitaxel and vinorelbine are recommended treatments for advanced breast cancer (ABC) non-responsive to hormone therapy and without visceral crisis. This phase II trial compared first-line oral vinorelbine versus weekly paclitaxel for ABC., Methods: Eligible female patients had measurable locally recurrent/metastatic estrogen receptor-positive HER2-negative breast cancer and had received prior endocrine therapy (any setting) but no chemotherapy for ABC. Patients were stratified by prior taxane and visceral metastases and randomized to either oral vinorelbine 80 mg/m 2 (first cycle at 60 mg/m 2 , escalated to 80 mg/m 2 in the absence of grade 3/4 toxicity) or intravenous paclitaxel 80 mg/m 2 on days 1, 8, and 15 every 3 weeks until disease progression or unacceptable toxicity. The primary endpoint was disease control rate (DCR; confirmed complete or partial response, or stable disease for ≥6 weeks)., Results: The 131 randomized patients had received a median of 2 prior endocrine therapies; >70% had prior (neo)adjuvant chemotherapy and 79% visceral metastases. DCR was 75.8% (95% confidence interval: 63.6-85.5%) with vinorelbine and 75.4% (63.1-85.2%) with paclitaxel. The most common grade 3/4 adverse events were neutropenia (52%), fatigue (11%), and vomiting (5%) with vinorelbine, and neutropenia (17%), dyspnea (6%), hypertension (6%), and peripheral sensory neuropathy (5%) with paclitaxel. Grade 2 alopecia occurred in 2% of vinorelbine-treated and 34% of paclitaxel-treated patients. Neither arm showed relevant global health status changes., Conclusion: Oral vinorelbine and paclitaxel demonstrated similar DCRs (∼75%). Safety profiles differed and, together with administration route and convenience, may influence treatment choice (EudraCT number, 2012-003530-16)., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: An important proportion of HER2-positive metastatic breast cancer patients do not respond to trastuzumab. The combination of dasatinib and trastuzumab has shown to be synergistic in preclinical models., Methods: We conducted a phase II trial combining dasatinib 100 mg once daily with trastuzumab 2 mg/kg and paclitaxel 80 mg/m 2 weekly. Primary objective was objective response rate (ORR) and secondary included safety, other efficacy parameters and pharmacodynamics in tumour tissue, blood samples and skin biopsies., Results: From June 2013 to December 2015, 29 patients were included. Median number of cycles was 12 (1-49). Only 6 patients discontinued due to adverse events. ORR was 79.3% (95% CI 60.3-92), clinical benefit rate 82.8% (95% CI 64.2-94.2). Median time to progression 23.9 months (95% CI 14.9-not reached [NR]), median progression-free survival 23.9 months (95% CI 10.3-NR). No grade 4 toxicity was seen. Grade 3 toxicities included: ejection fraction decrease, neutropenia, hyponatremia, fatigue and sensory neuropathy and one left ventricular systolic dysfunction. Phosphorylated (p)-SRC was reduced in peripheral blood mononuclear cells. Phosphorylated SRC, ERK and AKT were also reduced in epidermal keratinocytes., Conclusions: Dasatinib can be safely combined with trastuzumab and paclitaxel. The combination is active with an ORR of almost 80%., Trial Registration: NCT01306942, EudraCT 2010-023304-27.

Up-regulation of the Hedgehog (Hh) pathway is implicated in the genesis of a wide range of tumors including triple negative breast cancer (TNBC). Sonidegib is a potent and selective oral inhibitor of Smo, a key component of the Hh signaling pathway. We designed a phase I clinical study to explore the combination of sonidegib plus docetaxel (fixed dose at 75 mg/m 2 ) in advanced TNBC patients. The primary objective was to ascertain the combination's maximum tolerated dose and the recommended phase II dose (RP2D), based on dose limiting toxicities (DLTs) in the first 2 cycles. A standard "3 + 3" design was followed including three dose levels (DL) of sonidegib: 400 mg (DL1), 600 mg (DL2), and 800 mg (DL3). Twelve patients were included. Sonidegib 800 mg orally q.d. plus docetaxel 75 mg/m 2 given intravenously on day 1 of 21-day cycles was established as the RP2D. No DLTs were observed at any DL. The median number of administered cycles at DL3 was 8 (range: 6 to 9). Grade 3 adverse events (AEs) at DL3 were neutropenia (66.7%), CPK increase (33.3%), leukopenia (33.3%), and paresthesia (33.3%), grade 4 AEs were not reported at this DL. At the RP2D, the combination showed antitumor activity in three out of 10 patients with measurable disease. Median time to progression for the overall study was 42.5 days (95% Confidence Interval: 29-155), and 188 days at DL3. No drug-to-drug interactions between sonidegib and docetaxel were found in the PK assessment. Trial Registration: EudraCT study number: 2013-001750-96. Study GEICAM/2012-12. TRIAL REGISTRATION: EudraCT study number: 2013-001750-96. Study GEICAM/2012-12. ClinicalTrials.gov: NCT02027376.

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