Search

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported. PALOMA-2 demonstrated statistically and clinically significant improvement in progression-free survival with palbociclib plus letrozole versus placebo plus letrozole in estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) advanced breast cancer (ABC). Here, we report results for the secondary end point overall survival (OS). Postmenopausal women (N = 666) with ER+/HER2- ABC without previous systemic therapy for ABC were randomly assigned 2:1 to palbociclib plus letrozole or placebo plus letrozole. After a median follow-up of 90.1 months, 405 deaths were observed and 155 patients were known to be alive. The median OS was 53.9 months (95% CI, 49.8 to 60.8) with palbociclib plus letrozole versus 51.2 months (95% CI, 43.7 to 58.9) with placebo plus letrozole (hazard ratio [HR], 0.96 [95% CI, 0.78 to 1.18]; stratified one-sided P = .34). An imbalance in the number of patients with unknown survival outcome between the treatment arms (13.3% v 21.2%, respectively) limited interpretation of OS results. With recovered survival data, the median OS was 53.8 (95% CI, 49.8 to 59.2) versus 49.8 months (95% CI, 42.3 to 56.4), respectively (HR, 0.92 [95% CI, 0.76 to 1.12]; one-sided P = .21). OS was not significantly improved with palbociclib plus letrozole compared with placebo plus letrozole.

Purpose: The PALLAS study investigated whether the addition of palbociclib, an oral CDK4/6 inhibitor, to adjuvant endocrine therapy (ET) improves invasive disease-free survival (iDFS) in early hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) breast cancer. In this analysis, we evaluated palbociclib exposure and discontinuation in PALLAS., Methods: Patients with stage II-III HR+, HER2- disease were randomly assigned to 2 years of palbociclib with adjuvant ET versus ET alone. The primary objective was to compare iDFS between arms. Continuous monitoring of toxicity, dose modifications, and early discontinuation was performed. Association of baseline covariates with time to palbociclib reduction and discontinuation was analyzed with multivariable competing risk models. Landmark and inverse probability weighted per-protocol analyses were performed to assess the impact of drug persistence and exposure on iDFS., Results: Of the 5,743 patient analysis population (2,840 initiating palbociclib), 1,199 (42.2%) stopped palbociclib before 2 years, the majority (772, 27.2%) for adverse effects, most commonly neutropenia and fatigue. Discontinuation of ET did not differ between arms. Discontinuations for non-protocol-defined reasons were greater in the first 3 months of palbociclib, and in the first calendar year of accrual, and declined over time. No significant relationship was seen between longer palbociclib duration or ≥ 70% exposure intensity and improved iDFS. In the weighted per-protocol analysis, no improvement in iDFS was observed in patients receiving palbociclib versus not (hazard ratio 0.89; 95% CI, 0.72 to 1.11)., Conclusion: Despite observed rates of discontinuation in PALLAS, analyses suggest that the lack of significant iDFS difference between arms was not directly related to inadequate palbociclib exposure. However, the discontinuation rate illustrates the challenge of introducing novel adjuvant treatments, and the need for interventions to improve persistence with oral cancer therapies., Competing Interests: Erica L. MayerConsulting or Advisory Role: Lilly, Novartis, AstraZeneca, Gilead SciencesResearch Funding: Pfizer (Inst) Christian FeslResearch Funding: Pfizer (Inst) Dominik HlauschekResearch Funding: Pfizer (Inst) Laura Garcia-EstevezConsulting or Advisory Role: Daiichi Sankyo/Astra Zeneca, Palex, Seattle GeneticsResearch Funding: Roche/Genentech (Inst) Nicholas ZdenkowskiHonoraria: Roche, Pfizer, EisaiConsulting or Advisory Role: Lilly, AstraZeneca, EisaiResearch Funding: Roche (Inst), Pfizer (Inst)Travel, Accommodations, Expenses: Roche, Amgen, Novartis Kathy D. MillerThis author is the Senior Deputy Editor of Journal of Clinical Oncology. Journal policy recused the author from having any role in the peer review of this manuscript.Consulting or Advisory Role: Merck, Genentech/Roche, Athenex, AstraZeneca, Bristol Myers Squibb/CelgeneResearch Funding: Taiho Pharmaceutical (Inst), Novartis (Inst), Seattle Genetics (Inst), Pfizer (Inst), Astex Pharmaceuticals (Inst), British Biotech (Inst), CytomX Therapeutics (Inst), Alphamab (Inst) Marija BalicConsulting or Advisory Role: Amgen, AstraZeneca, Daiichi Sankyo/Astra Zeneca, Lilly, MSD, Novartis, Pierre Fabre, Pfizer, Roche, SamsungSpeakers' Bureau: Amgen, AstraZeneca, Daiichi Sankyo/Astra Zeneca, Lilly, Novartis, Pierre Fabre, Pfizer, Roche, Seattle GeneticsResearch Funding: Lilly (Inst), Novartis (Inst), Pfizer (Inst)Travel, Accommodations, Expenses: MSD Ingrid A. MayerConsulting or Advisory Role: Novartis, AstraZeneca, Lilly, Genentech, GlaxoSmithKline, Immunomedics, Macrogenics, Pfizer, AbbVie, Seattle Genetics, Puma Biotechnology, Cyclacel, Blueprint Medicines, SanofiResearch Funding: Novartis (Inst), Pfizer (Inst), Genentech (Inst) David CameronConsulting or Advisory Role: Lilly (Inst), Novartis (Inst), Novartis (Inst), Research Triangle Institute RTI Health Solutions (Inst), Daiichi Sankyo (Inst), Prima BioMed (Inst), Merck Sharp & Dohme (Inst), Zymeworks (Inst), Eisai (Inst), Puma Biotechnology (Inst), Pfizer (Inst), Oncolytics (Inst), Roche (Inst), Roche (Inst), Samsung Bioepis (Inst), Seattle Genetics (Inst), Synthon (Inst), Clarity Pharmaceuticals (Inst), Bexon/Zymeworks (Inst), Sanofi (Inst)Research Funding: Roche (Inst), Novartis (Inst), AstraZeneca (Inst) Eric P. WinerHonoraria: Genentech/Roche, Genomic HealthConsulting or Advisory Role: Leap Therapeutics, Seattle Genetics, Jounce Therapeutics, GlaxoSmithKline, Carrick Therapeutics, Lilly, G1 Therapeutics, Syros Pharmaceuticals, Genentech/Roche, Gilead Sciences, Zymeworks, AthenexResearch Funding: Genentech (Inst)Other Relationship: InfiniteMD José Juan Ponce LorenzoHonoraria: Seattle Genetics, Novartis, Pfizer, AstraZeneca/Daiichi Sankyo, Lilly, RocheConsulting or Advisory Role: Seattle Genetics, Novartis, AstraZeneca/Daiichi Sankyo, Roche Tufia C. HaddadResearch Funding: Takeda (Inst) Hiroji IwataHonoraria: Chugai Pharma, AstraZeneca, Eisai, Pfizer, Daiichi Sankyo, Lilly Japan, Kyowa Hakko Kirin, Taiho PharmaceuticalConsulting or Advisory Role: Chugai Pharma, Daiichi Sankyo, Pfizer, AstraZeneca, Lilly Japan, Kyowa Hakko Kirin, NovartisResearch Funding: MSD (Inst), AstraZeneca (Inst), Kyowa Hakko Kirin (Inst), Daiichi Sankyo (Inst), Chugai Pharma (Inst), Nihonkayaku (Inst), Lilly Japan (Inst), Novartis (Inst), Bayer (Inst), Pfizer (Inst), Boehringer Ingelheim (Inst), Sanofi (Inst) Matthew GoetzConsulting or Advisory Role: Lilly, bioTheranostics, Genomic Health, Novartis, Eisai, Sermonix Pharmaceuticals, Context Therapeutics, Pfizer, BiovicaResearch Funding: Lilly (Inst), Pfizer (Inst), Sermonix Pharmaceuticals (Inst)Patents, Royalties, Other Intellectual Property: Methods and Materials for Assessing Chemotherapy Responsiveness and Treating Cancer, Methods and Materials for Using Butyrylcholinesterases to Treat Cancer, Development of Human Tumor Xenografts from Women with Breast Cancer Treated with Neoadjuvant Chemotherapy (Inst)Travel, Accommodations, Expenses: Lilly Fatima CardosoConsulting or Advisory Role: Roche, Novartis, Pfizer, AstraZeneca, Teva, Astellas Pharma, Merus, Celgene, Eisai, Daiichi Sankyo, Genentech, Merck Sharp & Dohme, Sanofi, Pierre Fabre, Macrogenics, Amgen, GE Healthcare, GlaxoSmithKline, Mylan, Mundipharma, Seattle Genetics, Samsung Bioepis, Medscape, Prime OncologyTravel, Accommodations, Expenses: Pfizer, Roche, AstraZeneca Tiffany A. TrainaConsulting or Advisory Role: Genentech/Roche, Pfizer, AstraZeneca, Merck, Puma Biotechnology, Athenex, Daiichi Sankyo, Ionis Pharmaceuticals, Seattle Genetics, Eisai, Exact Sciences, Foundation Medicine, Ayala Pharmaceuticals, Gilead Sciences, Blueprint Medicines, Ellipses Pharma, Fuji Pharma, ITeos Therapeutics, AgendiaResearch Funding: Eisai (Inst), Pfizer (Inst), Novartis (Inst), Innocrin Pharma (Inst), AstraZeneca (Inst), Astellas Pharma (Inst), Immunomedics (Inst), Genentech/Roche (Inst), Daiichi Sankyo (Inst), Carrick Pharm (Inst), Ayala Pharmaceuticals (Inst) Urs BreitensteinConsulting or Advisory Role: AstraZeneca (Inst), Elie Lilly (Inst), Novartis (Inst), Pierre Fabre (Inst), Roche (Inst) Kerstin AckerlResearch Funding: Pfizer (Inst) Otto Metzger FilhoHonoraria: Grupo Oncoclinicas, RocheResearch Funding: Susan G. Komen for the Cure (Inst), Pfizer (Inst), Roche/Genentech (Inst), Eisai (Inst), Cascadian Therapeutics (Inst), AbbVie (Inst)Travel, Accommodations, Expenses: Grupo Oncoclinicas Karin ZehetnerResearch Funding: Pfizer (Inst) Kadine SolomonEmployment: Alliance Foundation TrialsStock and Other Ownership Interests: Pfizer, Merck, Moderna Therapeutics Sarra El-AbedEmployment: Astellas Pharma (I), argenx (I)Research Funding: Novartis (Inst), Roche/Genentech (Inst), Pfizer (Inst) Kathy Puyana TheallEmployment: Pfizer (I)Stock and Other Ownership Interests: Pfizer (I)Honoraria: PfizerTravel, Accommodations, Expenses: Pfizer Dongrui Ray LuEmployment: PfizerStock and Other Ownership Interests: Pfizer Amylou DueckPatents, Royalties, Other Intellectual Property: Royalties from licensing fees for a patient symptom questionnaire (MPN-SAF) Michael GnantEmployment: Sandoz (I)Honoraria: Amgen, Novartis, AstraZeneca, LillyConsulting or Advisory Role: Daiichi-Sankyo, Veracyte, Tolmar, LifeBrain, Lilly Angela DeMicheleResearch Funding: Pfizer (Inst), Genentech (Inst), Calithera Biosciences (Inst), Novartis (Inst)No other potential conflicts of interest were reported.

Purpose: Palbociclib is a cyclin-dependent kinase 4 and 6 inhibitor approved for advanced breast cancer. In the adjuvant setting, the potential value of adding palbociclib to endocrine therapy for hormone receptor-positive breast cancer has not been confirmed., Patients and Methods: In the prospective, randomized, phase III PALLAS trial, patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative early breast cancer were randomly assigned to receive 2 years of palbociclib (125 mg orally once daily, days 1-21 of a 28-day cycle) with adjuvant endocrine therapy or adjuvant endocrine therapy alone (for at least 5 years). The primary end point of the study was invasive disease-free survival (iDFS); secondary end points were invasive breast cancer-free survival, distant recurrence-free survival, locoregional cancer-free survival, and overall survival., Results: Among 5,796 patients enrolled at 406 centers in 21 countries worldwide over 3 years, 5,761 were included in the intention-to-treat population. At the final protocol-defined analysis, at a median follow-up of 31 months, iDFS events occurred in 253 of 2,884 (8.8%) patients who received palbociclib plus endocrine therapy and in 263 of 2,877 (9.1%) patients who received endocrine therapy alone, with similar results between the two treatment groups (iDFS at 4 years: 84.2% v 84.5%; hazard ratio, 0.96; CI, 0.81 to 1.14; P = .65). No significant differences were observed for secondary time-to-event end points, and subgroup analyses did not show any differences by subgroup. There were no new safety signals for palbociclib in this trial., Conclusion: At this final analysis of the PALLAS trial, the addition of adjuvant palbociclib to standard endocrine therapy did not improve outcomes over endocrine therapy alone in patients with early hormone receptor-positive breast cancer., Competing Interests: Michael GnantEmployment: Sandoz (I)Honoraria: Amgen, Novartis, AstraZeneca, LillyConsulting or Advisory Role: Daiichi Sankyo, Veracyte, Tolmar¸ LifeBrain, Lilly Amylou C. DueckPatents, Royalties, Other Intellectual Property: Royalties from licensing fees for a patient symptom questionnaire (MPN-SAF) Miguel MartinHonoraria: Roche/Genentech, Lilly, Pfizer, Novartis, Pierre FabreConsulting or Advisory Role: Roche/Genentech, Novartis, Pfizer, Lilly, AstraZeneca, Taiho Pharmaceutical, PharmaMarSpeakers' Bureau: Lilly/ImClone, Roche/Genentech, Pierre FabreResearch Funding: Novartis (Inst), Roche (Inst)¸ Puma Biotechnology (Inst)Other Relationship: Roche, Novartis Hal J. BursteinThis author is an Associate Editor for Journal of Clinical Oncology. Journal policy recused the author from having any role in the peer review of this manuscript. Richard GreilHonoraria: Celgene, Roche, Merck, Takeda, AstraZeneca, Novartis, Amgen, Bristol Myers Squibb, MSD¸ Sandoz, AbbVie, Gilead Sciences, Daiichi SankyoConsulting or Advisory Role: Celgene, Novartis, Roche, Bristol Myers Squibb, Takeda, AbbVie, AstraZeneca, Janssen, MSD, Merck, Gilead Sciences, Daiichi SankyoResearch Funding: Celgene (Inst), Merck (Inst), Takeda (Inst), AstraZeneca (Inst), Novartis (Inst), Amgen (Inst), Bristol Myers Squibb (Inst), MSD (Inst), Sandoz (Inst), Gilead Sciences (Inst), Roche (Inst)Travel, Accommodations, Expenses: Roche, Amgen, Janssen-Cilag, AstraZeneca, Novartis, MSD, Celgene, Gilead Sciences, Bristol Myers Squibb, AbbVie, Daiichi Sankyo Antonio C. WolffThis author is an Associate Editor for Journal of Clinical Oncology. Journal policy recused the author from having any role in the peer review of this manuscript.Consulting or Advisory Role: Ionis PharmaceuticalsPatents, Royalties, Other Intellectual Property: A.C.W. has been named as an inventor on one or more issued patents or pending patent applications related to methylation in breast cancer, has assigned his rights to JHU, and participates in a royalty sharing agreement with JHUOpen Payments Link: https://openpaymentsdata.cms.gov/physician/357301/summary Arlene ChanHonoraria: Novartis, LillyConsulting or Advisory Role: LillyResearch Funding: Eisai Eric P. WinerHonoraria: Genomic Health, Genentech/RocheConsulting or Advisory Role: Leap Therapeutics, Seattle Genetics, Jounce Therapeutics, GlaxoSmithKline, Carrick Therapeutics, Lilly, G1 Therapeutics, Syros Pharmaceuticals, Genentech/Roche, Gilead Sciences, Zymeworks, AthenexResearch Funding: Genentech (Inst)Other Relationship: InfiniteMD Georg PfeilerHonoraria: Amgen, Roche/Genentech, Pfizer¸ Lilly, AstraZeneca/Merck, AstraZeneca/Daiichi Sankyo, Novartis, UCB, Accord HealthcareConsulting or Advisory Role: Pfizer¸ Amgen¸ Lilly, Novartis, AstraZeneca/Merck, AstraZeneca/Daiichi Sankyo, UCB, Roche/GenentechSpeakers' Bureau: Roche/Genentech, Pfizer, Lilly, Novartis, UCB, AstraZeneca/Merck, AstraZeneca/Daiichi Sankyo, Accord Healthcare, Amgen, Accord HealthcareResearch Funding: Pfizer, Roche/GenentechTravel, Accommodations, Expenses: Novartis, Lilly, Roche/Genentech, Lilly, AstraZeneca/Daiichi Sankyo Kathy MillerThis author is an Associate Editor for Journal of Clinical Oncology. Journal policy recused the author from having any role in the peer review of this manuscript.Consulting or Advisory Role: Merck, Genentech/Roche, Athenex, AstraZeneca, Bristol Myers Squibb/CelgeneResearch Funding: Taiho Pharmaceutical (Inst), Novartis (Inst), Seattle Genetics (Inst), Pfizer (Inst), Astex Pharmaceuticals (Inst), British Biotech (Inst), CytomX Therapeutics (Inst), Alphamab (Inst) Marco ColleoniResearch Funding: Roche (Inst) Gabor RubovskyConsulting or Advisory Role: Pfizer, Novartis, Roche, Gilead SciencesTravel, Accommodations, Expenses: Amgen Judith M. BlissResearch Funding: AstraZeneca (Inst), Merck Sharp & Dohme (Inst), Puma Biotechnology (Inst), Pfizer (Inst), Roche (Inst), GlaxoSmithKline/Novartis (Inst), Lilly (Inst), Janssen-Cilag (Inst), Clovis Oncology (Inst)Travel, Accommodations, Expenses: Pfizer Ingrid A. MayerConsulting or Advisory Role: Novartis, AstraZeneca, Lilly, Genentech, GlaxoSmithKline, Immunomedics, MacroGenics, Pfizer, AbbVie, Seattle Genetics, Puma Biotechnology, Cyclacel, Blueprint Medicines, SanofiResearch Funding: Novartis (Inst), Pfizer (Inst), Genentech (Inst) Christian SingerHonoraria: Novartis, AstraZeneca/MedImmune, Daiichi Sankyo Europe GmbHConsulting or Advisory Role: AstraZeneca/MedImmune, Daiichi-Sankyo, Gilead Sciences, Sanofi/Aventis, NovartisSpeakers' Bureau: Novartis, AstraZeneca/MedImmuneResearch Funding: Novartis, Sanofi, Myriad Genetics, Roche, AstraZeneca/MedImmuneTravel, Accommodations, Expenses: Roche, Novartis Zbigniew NoweckiTravel, Accommodations, Expenses: Roche/Genentech Olwen HahnLeadership: Via OncologyStock and Other Ownership Interests: Teleflex MedicalHonoraria: Cardinal Health (I)Consulting or Advisory Role: Pfizer, hmpglobal.comTravel, Accommodations, Expenses: Cardinal Health (I) Jacqui ThomsonHonoraria: MSD Oncology, Roche/Genentech Norman WolmarkOpen Payments Link: https://openpaymentsdata.cms.gov/physician/159597 Hope S. RugoHonoraria: Puma Biotechnology, MylanConsulting or Advisory Role: SamsungResearch Funding: MacroGenics (Inst), OBI Pharma (Inst), Eisai (Inst), Pfizer (Inst), Novartis (Inst), Lilly (Inst), Genentech (Inst), Merck (Inst), Immunomedics (Inst), Odonate Therapeutics (Inst), Daiichi Sankyo (Inst), Seattle Genetics (Inst), Sermonix Pharmaceuticals (Inst), AstraZeneca (Inst)Travel, Accommodations, Expenses: Pfizer, Novartis, Mylan, AstraZeneca Spain, MerckOpen Payments Link: https://openpaymentsdata.cms.gov/summary Guenther G. StegerHonoraria: Pfizer, Lilly, Novartis, Roche, AstraZeneca/Daiichi Sankyo, Teva, Pfizer, Lilly, NovartisTravel, Accommodations, Expenses: Roche, Teva Blanca Hernando Fernández de AránguizHonoraria: GlaxoSmithKline, PharmaMar, Clovis OncologyTravel, Accommodations, Expenses: Pfizer, MSD Oncology, Roche Tufia C. HaddadResearch Funding: Takeda (Inst) Meritxell Bellet EzquerraConsulting or Advisory Role: Pfizer, Lilly, NovartisSpeakers' Bureau: Lilly, Pfizer, Novartis Hannes FohlerEmployment: Takeda (I)Research Funding: Pfizer (Inst) Otto MetzgerHonoraria: Grupo Oncoclinicas, RocheResearch Funding: Susan G. Komen for the Cure (Inst), Pfizer (Inst), Roche/Genentech (Inst), Eisai (Inst), Cascadian Therapeutics (Inst), AbbVie (Inst)Travel, Accommodations, Expenses: Grupo Oncoclinicas Anita Jallitsch-HalperResearch Funding: Pfizer (Inst) Kadine SolomonEmployment: Alliance Foundation TrialsStock and Other Ownership Interests: Pfizer, Merck, Moderna Therapeutics Céline SchurmansResearch Funding: Pfizer (Inst), Roche/Genentech (Inst), AstraZeneca (Inst), Novartis (Inst), Servier (Inst), Pfizer (Inst), Sanofi (Inst)Patents, Royalties, Other Intellectual Property: My organization receives royalties from Agendia Kathy P. TheallEmployment: PfizerStock and Other Ownership Interests: PfizerHonoraria: PfizerTravel, Accommodations, Expenses: Pfizer Dongrui R. LuEmployment: PfizerStock and Other Ownership Interests: Pfizer Kathleen TennerStock and Other Ownership Interests: Merck Christian FeslResearch Funding: Pfizer (Inst) Angela DeMicheleResearch Funding: Pfizer (Inst), Genentech (Inst), Calithera Biosciences (Inst), Novartis (Inst) Erica L. MayerConsulting or Advisory Role: Lilly, Novartis, AstraZeneca, Gilead SciencesResearch Funding: Pfizer (Inst)No other potential conflicts of interest were reported.

This report examined the benefits and risks of palbociclib plus endocrine therapy (ET) in men with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC). Palbociclib was evaluated using three independent data sources: real-world data from pharmacy and medical claims, a de-identified real-world data source derived from electronic health records (EHRs), and a global safety database. From medical and pharmacy records, 1,139 men with MBC were identified; in the first-line setting, median duration of treatment was longer with palbociclib plus ET (n = 37, 8.5 months, 95% confidence interval (CI), 4.4-13.0) than ET alone (n = 214, 4.3 months, 95% CI, 3.0-5.7) and specifically, was longer with palbociclib plus letrozole (n = 26, 9.4 months, 95% CI, 4.4-14.0) than letrozole alone (n = 63, 3.0 months, 95% CI, 1.8-4.8). In the EHR-derived database, 59 men received treatment for MBC; real-world response across all lines of therapy in the metastatic setting was reported in 4 of 12 patients (33.3%) in the palbociclib plus ET group vs. 1 of 8 (12.5%) patients in the ET group. Review of the global safety database did not identify any new safety signals in palbociclib-treated men. Real-world data indicated that men with MBC benefit from palbociclib plus ET, with a safety profile consistent with previous observations in women with MBC. Collective data on palbociclib in women and men in this report, including clinical trial data, real-world data, and a well-established risk/benefit profile, led to US approval of an expansion of the palbociclib indication to include men with MBC., (© 2021 Pfizer Inc. Clinical Pharmacology & Therapeutics © 2021 American Society for Clinical Pharmacology and Therapeutics.)

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: In PALOMA-2, palbociclib + letrozole significantly prolonged progression-free survival (PFS) versus placebo + letrozole in patients with estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER + /HER2 - ) advanced breast cancer (ABC). We investigated clinical outcomes of patients who achieved or did not achieve a confirmed objective response (OR) according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 (data cutoff: May 31, 2017)., Patients and Methods: Postmenopausal patients untreated for ER + /HER2 - ABC were randomized 2:1 to palbociclib + letrozole or placebo + letrozole. Median PFS, median duration of OR, baseline characteristics, and palbociclib exposure were compared in patients with or without OR by treatment arm., Results: In the intent-to-treat population, OR was achieved by 194 (44%) of 444 and 77 (35%) of 222 patients in the palbociclib and placebo arms, respectively (odds ratio, 1.5; 95% confidence interval [CI], 1.0-2.1; P = .0156). Regardless of treatment, more OR than non-OR patients had de novo metastatic disease (47%-50% and 28%-31%, respectively) and no prior endocrine therapy (55% and 35%-37%, respectively). Rates of palbociclib dose reduction owing to adverse events were similar regardless of OR (41% and 38%, respectively). Among the patients with OR during the study, approximately 50% achieved OR within the first 3 months regardless of treatment. The median PFS was significantly prolonged with palbociclib + letrozole versus placebo + letrozole in patients with measurable disease in both OR (37.2 months; 95% CI, 28.1 months to not estimable vs. 27.4 months; 95% CI, 22.2-31.1 months; hazard ratio, 0.66; 95% CI, 0.47-0.94; P = .009) and non-OR groups (10.9 months; 95% CI, 8.2-11.2 months vs. 5.6 months; 95% CI, 5.3-8.3 months; hazard ratio, 0.72; 95% CI, 0.54-0.97; P = .016)., Conclusions: Palbociclib + letrozole provided significant clinical benefit versus placebo + letrozole to patients with ER + /HER2 - ABC regardless of achieving RECIST-defined OR. Pfizer; ClinicalTrials.gov: NCT01740427., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Palbociclib improves outcomes for women with hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer (HR+/HER2- ABC). Dose reductions are recommended for the management of hematologic toxicities. A previous pooled analysis from the PALOMA clinical trials showed that 36.9% of patients required dose reduction, predominantly during the first 6 months of treatment and with decreasing frequency during subsequent 28-day treatment cycles (C). Previous data have shown that palbociclib dose reductions do not affect efficacy. This pooled, post hoc analysis evaluated the frequency of hematologic adverse events (AEs) before and after palbociclib dose reduction in PALOMA-1, PALOMA-2, and PALOMA-3., Methods: This analysis evaluated the frequency of hematologic AEs 30 days before dose reduction and during each subsequent treatment from C1 to C6 among patients who required palbociclib dose reduction. Data were pooled from 3 randomized studies. PALOMA-1 was a phase 2, open-label study of postmenopausal patients untreated for ABC receiving palbociclib plus letrozole or letrozole alone. PALOMA-2 was a phase 3, double-blind study of postmenopausal patients untreated for ABC receiving palbociclib plus letrozole or placebo plus letrozole. PALOMA-3 was a phase 3, double-blind study of pre/perimenopausal or postmenopausal patients, whose disease progressed on prior endocrine therapy, receiving palbociclib plus fulvestrant or placebo plus fulvestrant., Results: A total of 311 (35.5%) patients with HR+/HER2- ABC required a palbociclib dose reduction (93.6% due to AEs) from 125 to 100 mg. Mean patient age was 59.9 years, and 46.9% of patients had visceral disease. Median time to dose reduction was 70 days. The majority of dose reductions occurred within 3 months of starting palbociclib treatment. Incidences of all-grade and grades 3/4 hematologic AEs were lower following dose reduction., Conclusions: A decrease in frequency and severity of hematologic AEs, including febrile neutropenia, following palbociclib dose reduction was observed, supporting the recommended use of dose reduction in AE management., Trial Registration: These studies were sponsored by Pfizer. ClinicalTrials.gov: NCT00721409; registration date July 24, 2008. ClinicalTrials.gov: NCT01740427; registration date December 4, 2012. ClinicalTrials.gov: NCT01942135; registration date September 13, 2013.

Background: PALOMA-2 confirmed that first-line palbociclib + letrozole improved progression-free survival (hazard ratio, 0.58; 95% confidence interval, 0.46-0.72) in postmenopausal women with estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC). This analysis evaluated palbociclib-associated hematologic adverse events (AEs) and provides insight on managing these AEs., Materials and Methods: Postmenopausal women with ER+/HER2- ABC were randomly assigned 2:1 to letrozole (2.5 mg daily continuously) plus oral palbociclib (125 mg daily; 3 weeks on/1 week off) or placebo. Safety assessments were performed at baseline, days 1 and 15 (first two cycles) and day 1 of subsequent cycles, and included white blood cell, platelet, and absolute neutrophil count (ANC)., Results: PALOMA-2 randomized 666 women to palbociclib + letrozole ( n = 444) or placebo + letrozole (n = 222). Neutropenia was the most common AE (95.3%) with palbociclib (grade 3, 55.6%; grade 4, 11.5%) and was managed by dose modifications; progression-free survival was similar between patients who experienced grade ≥ 3 neutropenia versus those who did not. Median (range) time to onset of neutropenia with palbociclib + letrozole was 15 (12-700) days (grade ≥ 3, 28.0 [12-854] days); median duration of each neutropenia episode grade ≥ 3 was 7.0 days. Asian ethnicity and low baseline ANC were associated with increased risk of grade 3/4 neutropenia with palbociclib ( p < .001)., Conclusion: Palbociclib + letrozole was generally well tolerated. Neutropenia, the most frequently reported AE in women with ER+/HER2- ABC, was mostly transient and manageable by dose modifications in patients who experienced grade ≥ 3 neutropenia, without appearing to compromise efficacy. (Pfizer; NCT01740427) IMPLICATIONS FOR PRACTICE: Palbociclib demonstrated an acceptable safety profile in PALOMA-2 in women with estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) receiving first-line palbociclib + letrozole. Although hematologic adverse events (AEs) are typically expected with anticancer therapies and are often clinically significant, palbociclib-related hematologic AEs, particularly neutropenia (most frequent AE), were transient/manageable by dose reduction, interruption, or cycle delay, which is in contrast to the more profound neutropenia associated with chemotherapy. Palbociclib dose adjustments decreased hematologic AE severity without appearing to compromise efficacy, supporting palbociclib + letrozole as a first-line treatment for ER+/HER2- ABC., Competing Interests: Disclosures of potential conflicts of interest may be found at the end of this article., (© 2019 The Authors. The Oncologist published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.)

Background: A phase 2 study showed that progression-free survival was longer with palbociclib plus letrozole than with letrozole alone in the initial treatment of postmenopausal women with estrogen-receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer. We performed a phase 3 study that was designed to confirm and expand the efficacy and safety data for palbociclib plus letrozole for this indication., Methods: In this double-blind study, we randomly assigned, in a 2:1 ratio, 666 postmenopausal women with ER-positive, HER2-negative breast cancer, who had not had prior treatment for advanced disease, to receive palbociclib plus letrozole or placebo plus letrozole. The primary end point was progression-free survival, as assessed by the investigators; secondary end points were overall survival, objective response, clinical benefit response, patient-reported outcomes, pharmacokinetic effects, and safety., Results: The median progression-free survival was 24.8 months (95% confidence interval [CI], 22.1 to not estimable) in the palbociclib-letrozole group, as compared with 14.5 months (95% CI, 12.9 to 17.1) in the placebo-letrozole group (hazard ratio for disease progression or death, 0.58; 95% CI, 0.46 to 0.72; P<0.001). The most common grade 3 or 4 adverse events were neutropenia (occurring in 66.4% of the patients in the palbociclib-letrozole group vs. 1.4% in the placebo-letrozole group), leukopenia (24.8% vs. 0%), anemia (5.4% vs. 1.8%), and fatigue (1.8% vs. 0.5%). Febrile neutropenia was reported in 1.8% of patients in the palbociclib-letrozole group and in none of the patients in the placebo-letrozole group. Permanent discontinuation of any study treatment as a result of adverse events occurred in 43 patients (9.7%) in the palbociclib-letrozole group and in 13 patients (5.9%) in the placebo-letrozole group., Conclusions: Among patients with previously untreated ER-positive, HER2-negative advanced breast cancer, palbociclib combined with letrozole resulted in significantly longer progression-free survival than that with letrozole alone, although the rates of myelotoxic effects were higher with palbociclib-letrozole. (Funded by Pfizer; PALOMA-2 ClinicalTrials.gov number, NCT01740427 .).

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.PALOMA-2 demonstrated statistically and clinically significant improvement in progression-free survival with palbociclib plus letrozole versus placebo plus letrozole in estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) advanced breast cancer (ABC). Here, we report results for the secondary end point overall survival (OS). Postmenopausal women (N = 666) with ER+/HER2- ABC without previous systemic therapy for ABC were randomly assigned 2:1 to palbociclib plus letrozole or placebo plus letrozole. After a median follow-up of 90.1 months, 405 deaths were observed and 155 patients were known to be alive. The median OS was 53.9 months (95% CI, 49.8 to 60.8) with palbociclib plus letrozole versus 51.2 months (95% CI, 43.7 to 58.9) with placebo plus letrozole (hazard ratio [HR], 0.96 [95% CI, 0.78 to 1.18]; stratified one-sided P = .34). An imbalance in the number of patients with unknown survival outcome between the treatment arms (13.3% v 21.2%, respectively) limited interpretation of OS results. With recovered survival data, the median OS was 53.8 (95% CI, 49.8 to 59.2) versus 49.8 months (95% CI, 42.3 to 56.4), respectively (HR, 0.92 [95% CI, 0.76 to 1.12]; one-sided P = .21). OS was not significantly improved with palbociclib plus letrozole compared with placebo plus letrozole.

PURPOSE: Palbociclib is a cyclin-dependent kinase 4 and 6 inhibitor approved for advanced breast cancer. In the adjuvant setting, the potential value of adding palbociclib to endocrine therapy for hormone receptor-positive breast cancer has not been confirmed. PATIENTS AND METHODS: In the prospective, randomized, phase III PALLAS trial, patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative early breast cancer were randomly assigned to receive 2 years of palbociclib (125 mg orally once daily, days 1-21 of a 28-day cycle) with adjuvant endocrine therapy or adjuvant endocrine therapy alone (for at least 5 years). The primary end point of the study was invasive disease-free survival (iDFS); secondary end points were invasive breast cancer-free survival, distant recurrence-free survival, locoregional cancer-free survival, and overall survival. RESULTS: Among 5,796 patients enrolled at 406 centers in 21 countries worldwide over 3 years, 5,761 were included in the intention-to-treat population. At the final protocol-defined analysis, at a median follow-up of 31 months, iDFS events occurred in 253 of 2,884 (8.8%) patients who received palbociclib plus endocrine therapy and in 263 of 2,877 (9.1%) patients who received endocrine therapy alone, with similar results between the two treatment groups (iDFS at 4 years: 84.2% v 84.5%; hazard ratio, 0.96; CI, 0.81 to 1.14; P = .65). No significant differences were observed for secondary time-to-event end points, and subgroup analyses did not show any differences by subgroup. There were no new safety signals for palbociclib in this trial. CONCLUSION: At this final analysis of the PALLAS trial, the addition of adjuvant palbociclib to standard endocrine therapy did not improve outcomes over endocrine therapy alone in patients with early hormone receptor-positive breast cancer.

BackgroundPalbociclib administered with endocrine therapy was tolerable when the overall incidence of toxicities was assessed separately for three PALOMA studies. This study analyzed pooled, longer-term PALOMA safety data longitudinally.MethodsData were pooled from three randomized phase II and III studies (ClinicalTrials.gov: NCT00721409, NCT01740427, NCT01942135) of hormone receptor-positive/human epidermal growth factor receptor 2‒negative advanced breast cancer patients. Front-line patients were randomly assigned to receive letrozole with/without palbociclib (PALOMA-1) or letrozole plus palbociclib/placebo (PALOMA-2). In PALOMA-3, patients with prior endocrine resistance received fulvestrant plus palbociclib/placebo. The cumulative event rates of adverse events (AEs), reporting up to 50 months of treatment, were assessed over time.ResultsPatients who received endocrine therapy (n = 1343) were included in this pooled analysis (872 were also treated with palbociclib, and 471 were not). The most common AEs with palbociclib plus endocrine therapy were neutropenia and infections (any grade, 80.6% and 54.7%, respectively), which were higher than in the endocrine monotherapy arm (any grade, 5.3% and 36.9%). The most common hematologic AEs (≥15.0% in the palbociclib arm) were more likely to be reported in the initial months of the study, after which time the cumulative event rate did not substantially increase. With palbociclib plus endocrine therapy, any grade AEs leading to permanent discontinuation over three years occurred in only 8.3% of patients.ConclusionsBased on these long-term safety analyses, there is no evidence of specific cumulative or delayed toxicities with palbociclib plus endocrine therapy, supporting the ongoing investigation of palbociclib plus endocrine therapy in early breast cancer (NCT02513394).

The aim of this study was to assess the potential effects of palbociclib in combination with letrozole on QTc. PALOMA-2, a phase 3, randomized, double-blind, placebo-controlled trial, compared palbociclib plus letrozole with placebo plus letrozole in postmenopausal women with estrogen receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer. The study included a QTc evaluation substudy carried out as a definitive QT interval prolongation assessment for palbociclib. Time-matched triplicate ECGs were performed at 0, 2, 4, 6, and 8 h at baseline (Day 0) and on Cycle 1 Day 14. Additional ECGs were collected from all patients for safety monitoring. The QT interval was corrected for heart rate using Fridericia's correction (QTcF), Bazett's correction (QTcB), and a study-specific correction factor (QTcS). In total, 666 patients were randomized 2 : 1 to palbociclib plus letrozole or placebo plus letrozole. Of these, 125 patients were enrolled in the QTc evaluation substudy. No patients in the palbociclib plus letrozole arm of the substudy (N=77) had a maximum postbaseline QTcS or QTcF value of ≥ 480 ms, or a maximum increase from clock time-matched baseline for QTcS or QTcF values of ≥ 60 ms. The upper bounds of the one-sided 95% confidence interval for the mean change from time-matched baseline for QTcS, QTcF, and QTcB at all time points and at steady-state Cmax following repeated administration of 125 mg palbociclib were less than 10 ms. Palbociclib, when administered with letrozole at the recommended therapeutic dosing regimen, did not prolong the QT interval to a clinically relevant extent.