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AdAPT-001 is an investigational therapy consisting of a replicative type 5 adenovirus armed with a TGF-β receptor-immunoglobulin Fc fusion trap, designed to neutralize isoforms 1 and 3 of the profibrotic and immunosuppressive cytokine, TGF-β. In preclinical studies with an immunocompetent mouse model, AdAPT-001 eradicated directly treated 'cold' tumors as well as distant untreated tumors, and, from its induction of systemic CD8The purpose of this study is to find out more about the experimental oncolytic virus called AdAPT-001 that has been designed to selectively eliminate cancer cells. The virus is also designed to make a particular protein called a TGF-β trap, which neutralizes TGF-β, an overproduced chemical in cancer cells that puts the immune system into a comatose state. This article discusses a clinical trial called BETA PRIME for patients with no other standard treatment options. The trial will explore different doses of AdAPT-001 both alone and in combination with an approved checkpoint inhibitor or another immunotherapy, which blocks the ‘off' signal on immune cells, to determine the safest and best dose.

PURPOSE Adagrasib (MRTX849) is an oral, highly selective, small-molecule, covalent inhibitor of KRASG12C. We report results from a phase I/IB study of adagrasib in non–small-cell lung cancer, colorectal cancer, and other solid tumors harboring the KRAS G12C mutation. MATERIALS AND METHODS Patients with advanced KRAS G12C-mutant solid tumors were treated with adagrasib 150 mg orally once daily, 300 mg once daily, 600 mg once daily, 1,200 mg once daily, or 600 mg orally twice a day using an accelerated titration design, which transitioned to a modified toxicity probability interval design when a predefined degree of toxicity was observed or target adagrasib exposure was achieved. Safety, pharmacokinetics, and clinical activity were evaluated. RESULTS Twenty-five patients were enrolled and received at least one dose of adagrasib. The recommended phase II dose (RP2D) was 600 mg twice a day on the basis of safety, tolerability, and observed pharmacokinetics properties. No maximum tolerated dose was formally defined. After a median follow-up of 19.6 months, eight of 15 patients (53.3%; 95% CI, 26.6 to 78.7) with RECIST-evaluable KRAS G12C-mutant non–small-cell lung cancer treated at 600 mg twice a day achieved a confirmed partial response. The median duration of response was 16.4 months (95% CI, 3.1 to not estimable). The median progression-free survival was 11.1 months (95% CI, 2.6 to not estimable). One of two patients with KRAS G12C-mutant colorectal cancer treated at 600 mg twice a day achieved a partial response (duration of response, 4.2 months). At the RP2D, the most common treatment-related adverse events (any grade) were nausea (80.0%), diarrhea (70.0%), vomiting (50.0%), and fatigue (45.0%). The most common grade 3-4 treatment-related adverse event was fatigue (15.0%). CONCLUSION Adagrasib 600 mg twice a day was well tolerated and exhibited antitumor activity in patients with advanced solid tumors harboring the KRAS G12C mutation.

Background: Engineered toxin bodies (ETBs) are composed of a de-immunized Shiga-like Toxin A subunit genetically fused to an antibody-like binding domain. ETBs can force receptor internalization, induce potent cell-kill via enzymatic and permanent inactivation of ribosomes, and may not be subject to resistance mechanisms of other therapeutics. MT-5111 is a 55 kD ETB targeting HER2 in solid tumors that binds to an epitope distinct from trastuzumab and pertuzumab, offering potential combination strategies with other HER2-targeting agents. MT-5111 may demonstrate efficacy in patients (pts) resistant to other HER2-targeting agents, as its mechanism of action does not rely on inhibition of kinase signaling or cytoskeletal or DNA damage. Methods: The primary objective is to determine the maximum tolerated dose (MTD) of MT-5111 monotherapy in adult pts with advanced HER2+ solid tumors. Secondary objectives are pharmacokinetics (PK), efficacy, and immunogenicity. Using a modified 3+3 design, the dose-escalation part of the study enrolls pts with HER2+ tumors into 7 cohorts: 0.5, 1, 2, 3, 4.5, 6.75, and 10 µg/kg/dose. Three dose-expansion cohorts will follow for HER2+ breast cancer, gastro-esophageal cancer, and other HER2+ tumors. All pts receive MT-5111 weekly as 30-min IV infusions in each 21-day treatment (tx) cycle (C) until disease progression (PD), unacceptable toxicity, death, or withdrawn consent (NCT04029922). Results: Per data cut in June 2021, 21 pts (mean age 64 years, range 34-78; 38% male) in cohorts 1-6 with breast (n=7), biliary (n=6), gastric (n=3), pancreatic (n=2), lung (n=2), and colon (n=1) cancer were treated (Table 1). Pts had a median of 4 prior lines of systemic therapies (range, 1-8) and 2 prior lines of HER2-targeting treatments (range, 0-6). No Grade (G)4 or 5 tx-emergent (TE) adverse events (AEs) occurred. Tx-related AEs occurred in 11 (52%) pts; the most common was fatigue (n=7, 33%). One pt (4.5 µg/kg) had a possibly (per PI) related G3 serious AE (SAE) of dyspnea and hypoxia, but also lymphangitic carcinomatosis and H. influenzae infection. The other related SAE occurred in a pt (6.75 µg/kg) who had a G1 transient troponin increase without concomitant cardiac symptoms or ECG/ECHO changes. All other related AEs were ≤G2. There were no clinically significant changes in cardiac biomarkers (troponin, ECG, left ventricular ejection fraction) nor were there cases of capillary leak syndrome. Two pts (3 µg/kg and 4.5 µg/kg) had reversible G2 infusion-related reactions. Best response to date has been stable disease. AUClast data matched PK simulations based on non-human primate studies, and Cmax data at 6.75 µg/kg indicated that current in-human exposure was between the IC50 values of high and medium HER2-expressing cell lines (approximately 10-89 ng/mL). Thus, a dose of at least 10 µg/kg may be required to achieve effective exposure. To date, no dose-limiting toxicities have been observed and the 10 µg/kg/dose cohort is now accruing. Conclusions: MT-5111 was well tolerated with no clinically significant immuno- or cardiotoxicity. Dose escalation is ongoing and nearing levels expected to be required for efficacious exposure. Table 1.Metastatic HER2 status and MT-5111 treatment by cohortDose0.5 µg/kg1.0 µg/kg2.0 µg/kg3.0 µg/kg4.5 µg/kg6.75 µg/kgCohort123456Number of patients treated with MT-5111433335Metastatic HER2 2+ by IHC: ALL/BC1/11/11/01/10/04/0Metastatic HER2 3+ by IHC: ALL/BC3/12/02/12/13/01/1BC, breast cancer. Citation Format: Brian A. Van Tine, Monica Mita, Minal A. Barve, Erika P. Hamilton, Andrew J. Brenner, Frances Valdes, Daniel Ahn, Joleen Hubbard, Jason Starr, Angela Georgy, Joshua Pelham, Banmeet S. Anand, Thomas Strack, Andrés Machado Sandri, Zev A. Wainberg. Interim results of a phase 1 study of the novel immunotoxin MT-5111 in patients with HER2+tumors [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-13-45.

Dilpacimab (formerly ABT-165), a novel dual-variable domain immunoglobulin, targets both delta-like ligand 4 (DLL4) and VEGF pathways. Here, we present safety, pharmacokinetic (PK), pharmacodynamic (PD), and preliminary efficacy data from a phase I study (trial registration ID: NCT01946074) of dilpacimab in patients with advanced solid tumors. Eligible patients (≥18 years) received dilpacimab intravenously on days 1 and 15 in 28-day cycles at escalating dose levels (range, 1.25–7.5 mg/kg) until progressive disease or unacceptable toxicity. As of August 2018, 55 patients with solid tumors were enrolled in the dilpacimab monotherapy dose-escalation and dose-expansion cohorts. The most common treatment-related adverse events (TRAE) included hypertension (60.0%), headache (30.9%), and fatigue (21.8%). A TRAE of special interest was gastrointestinal perforation, occurring in 2 patients (3.6%; 1 with ovarian and 1 with prostate cancer) and resulting in 1 death. The PK of dilpacimab showed a half-life ranging from 4.9 to 9.5 days, and biomarker analysis demonstrated that the drug bound to both VEGF and DLL4 targets. The recommended phase II dose for dilpacimab monotherapy was established as 3.75 mg/kg, primarily on the basis of tolerability through multiple cycles. A partial response was achieved in 10.9% of patients (including 4 of 16 patients with ovarian cancer). The remaining patients had either stable disease (52.7%), progressive disease (23.6%), or were deemed unevaluable (12.7%). These results demonstrate that dilpacimab monotherapy has an acceptable safety profile, with clinical activity observed in patients with advanced solid tumors.

425082 Background: KRAS, a mediator of signalling pathways essential for cellular growth, proliferation, and survival, is the most frequently mutated oncogene in cancer. Notably, KRAS mutations occur in ~90% of pancreatic cancers, of which ~2% are KRASG12C mutations. Other gastrointestinal (GI) tumors also harbor KRASG12C mutations, such as biliary tract cancer (BTC; 1%) and appendiceal cancer (3–4%), and they are also seen in non-GI tumors, such as endometrial and ovarian cancer (1–2%). Adagrasib, a covalent KRASG12C inhibitor that irreversibly and selectively binds KRASG12C in its inactive state, was selected for favorable properties, including long half-life (23 h), dose-dependent pharmacokinetics, and central nervous system penetration. Methods: KRYSTAL-1 is a multicohort phase 1/2 study (NCT03785249) evaluating adagrasib in patients (pts) with advanced solid tumors harboring a KRASG12C mutation. Here we report data from a phase 2 cohort evaluating adagrasib monotherapy administered orally at 600 mg BID in pts with unresectable or metastatic KRASG12C-mutated solid tumors (excluding non-small cell lung cancer and colorectal cancer), including pancreatic ductal adenocarcinoma (PDAC), BTC, other GI, and non-GI tumors. Study objectives include evaluation of clinical activity (ORR, DCR, DOR, PFS, OS) and safety. Results: As of October 1, 2022, 64 pts with KRASG12C-mutated solid tumors were enrolled and 63 were treated with adagrasib (median follow-up, 16.8 months); of these, 21 pts had PDAC, 12 BTC, 16 other GI tumors (9 appendiceal, 4 gastro-esophageal junction/esophageal, 3 small bowel), and 14 non-GI tumors (5 ovarian, 4 unknown primary, 3 endometrial, 1 breast, 1 glioblastoma). Overall, median age was 65 years, 61% had ECOG PS 1, and median prior lines of systemic therapy was 2. Among 57 pts with measurable disease (blinded independent central review), ORR was 35.1% (20/57; all partial responses); DCR was 86.0% (49/57); median DOR was 5.3 months (n=20; 95% CI 2.8–7.3); median PFS was 7.4 months (95% CI 5.3–8.6); and median OS was 14.0 months (n=64; 95% CI 8.5–18.6). Among 21 pts with PDAC, ORR was 33.3% (7/21); DCR was 81.0% (17/21); median PFS was 5.4 months (95% CI 3.9–8.2); and median OS was 8.0 months (95% CI 5.2–11.8). Among 12 pts with BTC, ORR was 41.7% (5/12); DCR was 91.7% (11/12); median PFS was 8.6 months (95% CI 2.7–11.3); and median OS was 15.1 months (95% CI 8.6–not estimable). Overall (n=63), treatment-related adverse events (TRAEs) of any grade were observed in 96.8% of pts (most commonly [≥20%] nausea [49.2%], diarrhea [47.6%], fatigue [41.3%], vomiting [39.7%]), grade 3 TRAEs in 25.4%, and grade 4 TRAEs in 1.6%. No grade 5 TRAE occurred. Conclusions: Adagrasib is well tolerated and demonstrates promising clinical activity in pretreated pts with PDAC, BTC, and other solid tumors harboring a KRASG12C mutation. Clinical trial information: NCT03785249 .

Small cell lung cancer (SCLC) is a leading cause of cancer death worldwide, with few treatment options. Rovalpituzumab tesirine (Rova-T) is an antibody-drug conjugate that targets delta-like 3 on SCLC cells to deliver a cytotoxic payload directly to tumor cells. In this study, the cardiac safety profile of Rova-T was assessed by evaluating changes in QT interval, electrocardiogram (ECG) waveform, heart rate, and proarrhythmic adverse events (AEs) after treatment with Rova-T in patients with previously treated extensive-stage SCLC. Patients underwent ECG monitoring for 2 weeks after each of 2 i.v. infusions of 0.3 mg/kg Rova-T over 30 minutes, administered 6 weeks apart. Forty-six patients received at least one dose of Rova-T. At the geometric mean Rova-T maximum serum concentration of 7,940 ng/mL, ECG monitoring showed no significant changes in the Fridericia-corrected QT (QTcF) interval; the upper limit of the 2-sided 90% confidence interval did not exceed 10 msec for any time point. There were no clinically significant changes in QRS or PR intervals, ECG waveforms, or heart rate after Rova-T administration. All patients experienced a treatment-emergent AE (TEAE); 78% had a grade ≥ 3 TEAE, 59% had a serious TEAE, and 41% had a cardiac-related TEAE. The TEAEs that might signal proarrhythmia tendencies were uncommon. Confirmed partial responses were observed in 24% of patients. Based on the evaluation of ECG data collected in this study from patients treated with Rova-T at 0.3 mg/kg i.v. administered every 6 weeks, a QTcF effect of clinical concern can be excluded.

Neurotrophic tyrosine receptor kinase genes (NTRK1/2/3) act as oncogenic drivers across a range of tumors. NTRK fusions occur at low frequency (90% of secretory breast carcinomas. Furthermore, up to 30% of patients (pts) with breast cancer will develop central nervous system (CNS) metastases (mets). Entrectinib is a potent, oral TRKA/B/C, ROS1 and ALK inhibitor, specifically selected for its CNS penetration properties. Entrectinib was evaluated in 3 global phase 1/2 clinical trials (ALKA-372-001 [EudraCT 2012-000148-88], STARTRK-1 [NCT02097810], and STARTRK-2 [NCT02568267]), where it demonstrated strong and durable systemic and intracranial efficacy in pts with NTRK-fp solid tumors, including those with breast cancer. We present updated data from this integrated analysis (data cut-off: 31 October 2018) focusing on pts with breast cancer. The entrectinib trials were conducted at >150 sites in 15 countries, and enrolled pts with locally advanced/metastatic NTRK-fp tumors (with or without baseline CNS mets) confirmed by nucleic acid-based methods. Tumor assessments were performed at the end of cycle 1 (4 weeks) and every 8 weeks thereafter, and evaluated by blinded independent central review (BICR) using RECIST v1.1. Primary endpoints were objective response rate (ORR) and duration of response (DoR) by BICR. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety. At clinical cut-off, the overall efficacy-evaluable population included 74 adults from the 3 trials, with 12 different NTRK-fp tumor types and >25 histopathologies. In these pts, ORR by BICR was 63.5% (95% CI 51.5-74.4), including five complete responses (CR) and 42 partial responses (PR). Median (95% CI) DoR, PFS and OS were 12.9 (9.3-not estimable [NE]), 11.2 (8.0-15.7) and 23.9 (16.0-NE) months, respectively. The efficacy-evaluable NTRK-fp breast cancer cohort included 6 pts with a median age of 63 (range 36-67) years; most had an Eastern Cooperative Oncology Group performance status of 0 (3/6; 50%) or 1 (1/6; 17%). Breast cancer tumors were classified as secretory (4/6; 67%; all NTRK3-fp) or non-secretory (2/6; 33%; all NTRK1-fp). Pts had received 0 (3/6; 50%), 1 (1/6; 17%) or ≥4 (2/6; 33%) lines of prior therapy for metastatic disease. At data cut off, the median survival follow-up was 17.4 (range 1.7-23.9) months. ORR was 100% (2 CR, 2 PR; 95% CI 39.8-100.0) in pts with secretory and 50% (1 PR, 1 missing/unevaluable; 95% CI 1.3-98.7) in pts with non-secretory histology. Median (95% CI) DoR, PFS, and OS were 12.9 (4.2-NE), 10.1 (5.1-NE), and 23.9 (5.1-23.9) months, respectively. At baseline, 2 pts had CNS mets per investigator assessment; 1 of these pts had missing response data. CNS mets were confirmed by BICR in the other pt (non-secretory); this pt had received whole brain radiotherapy 2-6 months before starting entrectinib treatment, and had systemic PR and intracranial non-CR/non-progressive disease (non-measurable CNS lesion). The overall integrated safety-evaluable population comprised 504 pts with any gene fusion who received ≥1 dose of entrectinib. Most treatment-related adverse events (TRAEs) were Grade ≤3 (96.1%); the most frequently reported TRAEs were dysgeusia (39.7%) and fatigue (31.5%). Seven breast cancer pts were evaluated for safety, of whom six (85.7%) reported TRAEs; all were Grade ≤3. The most frequently reported TRAEs (each occurring in 3/7 pts; 42.9%) were nausea, anemia, and increased alanine or aspartate aminotransferase. Dose reductions and interruptions due to TRAEs were each reported in 3/7 pts (42.9%); no discontinuations or deaths due to TRAEs were recorded. In this updated integrated analysis, entrectinib induced objective responses in all pts with NTRK-fp breast cancer who had data available, and was generally well tolerated with no discontinuations due to TRAEs. Citation Format: Janice Lu, Collin M. Blakely, Christophe Le Tourneau, Saiama N. Waqar, Todd M. Bauer, Filippo de Braud, David S. Hong, Alexander Spira, Tira Tan, Samuel McCallum, Stuart Osborne, Brian Simmons, Minal Barve. Efficacy and safety of entrectinib in NTRK fusion-positive (NTRK-fp) breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS11-28.

Covalent BTK inhibitors (BTKi) have transformed the management of mantle cell lymphoma (MCL), but most patients will require additional treatment. Pirtobrutinib is a highly selective, non-covalent (reversible) BTKi that inhibits both wild-type and C481-mutated BTK with equal low nM potency.To evaluate pirtobrutinib safety and efficacy in patients with MCL.BRUIN is an ongoing multicenter phase 1/2 study (NCT03740529) of pirtobrutinib monotherapy.Global; community hospitals, academic medical centers.Patients with advanced B-cell malignancies.Oral pirtobrutinib, phase 1 dose-escalated in a standard 3+3 design, phase 2 continuous therapy, 28-day cycles.The primary phase 1 objective was to determine the recommended phase 2 dose (RP2D) and the primary phase 2 objective was overall response rate (ORR); secondary objectives included duration of response, progression-free survival, overall survival, safety/tolerability, and pharmacokinetics.As of 27 September 2020, 323 patients (170 CLL/SLL, 61 MCL, 26 WM, 26 DLBCL, 13 MZL, 12 FL, 9 RT, and 6 other NHL) were treated on 7 dose levels (25-300mg QD). No DLTs were reported and MTD was not reached (n=323). 200mg QD was selected as the RP2D. Fatigue (20%), diarrhea (17%) and contusion (13%) were the most frequent treatment-emergent adverse events regardless of attribution or grade seen in10% of patients. The most common adverse event of grade ≥3 was neutropenia (10%). Five (1%) patients discontinued due to treatment-related adverse events. 52 prior BTKi treated MCL patients were efficacy evaluable with an ORR of 52% (95% CI 38-66; 13 CR [25%], 14 PR [27%], 9 SD [17%]), 11 PD [21%] and 5 [10%] discontinued prior to first response assessment). Median follow-up was 6 months (0.7-18.3+). Responses were observed in 9/14 patients (64%) with prior autologous or allogeneic stem cell transplant, and 2/2 with prior CAR-T cell therapy.Pirtobrutinib demonstrated promising efficacy in heavily pretreated, poor-prognosis MCL following multiple prior lines of therapy, including a covalent BTKi. Pirtobrutinib was well tolerated and exhibited a wide therapeutic index. Updated data, including approximately 60 new patients with MCL and an additional 10 months since the prior data-cut will be presented.

Summary Background Gemogenovatucel-T is an autologous tumour cell vaccine manufactured from harvested tumour tissue, which specifically reduces expression of furin and downstream TGF-β1 and TGF-β2. The aim of this study was to determine the safety and efficacy of gemogenovatucel-T in front-line ovarian cancer maintenance. Methods This randomised, double-blind, placebo-controlled, phase 2b trial involved 25 hospitals in the USA. Women aged 18 years and older with stage III/IV high-grade serous, endometrioid, or clear cell ovarian cancer in clinical complete response after a combination of surgery and five to eight cycles of chemotherapy involving carboplatin and paclitaxel, and an Eastern Cooperative Oncology Group status of 0 or 1 were eligible for inclusion in the study. Patients were randomly assigned (1:1) to gemogenovatucel-T or placebo by an independent third party interactive response system after successful screening using randomly permuted block sizes of two and four and stratified by extent of surgical cytoreduction and neoadjuvant versus adjuvant chemotherapy. Gemogenovatucel-T (1 × 107 cells per injection) or placebo was administered intradermally (one per month) for a minimum of four and up to 12 doses. Patients, investigators, and clinical staff were masked to patient allocation until after statistical analysis. The primary endpoint was recurrence-free survival, analysed in the per-protocol population. All patients who received at least one dose of gemogenovatucel-T were included in the safety analysis. The study is registered with ClinicalTrials.gov , NCT02346747 . Findings Between Feb 11, 2015, and March 2, 2017, 310 patients consented to the study at 22 sites. 217 were excluded. 91 patients received gemogenovatucel-T (n=47) or placebo (n=44) and were analysed for safety and efficacy. The median follow-up from first dose of gemogenovatucel-T was 40·0 months (IQR 35·0–44·8) and from first dose of placebo was 39·8 months (35·5–44·6). Recurrence-free survival was 11·5 months (95% CI 7·5–not reached) for patients assigned to gemogenovatucel-T versus 8·4 months (7·9–15·5) for patients assigned to placebo (HR 0·69, 90% CI 0·44–1·07; one-sided p=0·078). Gemogenovatucel-T resulted in no grade 3 or 4 toxic effects. Two patients in the placebo group had five grade 3 toxic events, including arthralgia, bone pain, generalised muscle weakness, syncope, and dyspnea. Seven patients (four in the placebo group and three in the gemogenovatucel-T group) had 11 serious adverse events. No treatment-related deaths were reported in either of the groups. Interpretation Front-line use of gemogenovatucel-T immunotherapy as maintenance was well tolerated but the primary endpoint was not met. Further investigation of gemogenovatucel-T in patients stratified by BRCA mutation status is warranted. Funding Gradalis.

Background Fusions involving the neurotrophic tropomyosin receptor kinase (NTRK) gene family NTRK1, NTRK2, and NTRK3 lead to the expression of chimeric rearrangements in the TRK tyrosine kinase proteins (TRKA, TRKB, and TRKC, respectively) with constitutively active kinase function. NTRK fusions act as oncogenic drivers, and are potential therapeutic targets across a broad range of tumor types including breast cancer. Entrectinib is a CNS-active, oral, potent inhibitor of TRKA/B/C, ALK and ROS1 designed to cross the blood-brain-barrier. Here we present integrated efficacy data from three trials of entrectinib in NTRK fusion-positive solid tumors focusing on a small cohort of patients with breast cancer, and safety data from the integrated safety population. Methods Patients with locally advanced/metastatic NTRK fusion-positive tumors (with or without baseline CNS disease) confirmed by nucleic acid-based methods were enrolled in three global phase 1/2 entrectinib trials at >150 sites in 15 countries (ALKA-372-001 [EudraCT 2012-000148-88], STARTRK-1 [NCT02097810], STARTRK-2 [NCT02568267]). Disease burden was assessed per blinded independent central review (BICR) using RECIST v1.1 after cycle 1 (4 weeks) then every 8 weeks thereafter. The primary endpoints were objective response rate (ORR) and duration of response (DOR) by BICR. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety. Results The total efficacy-evaluable population comprised 54 adult patients with advanced/metastatic NTRK fusion-positive tumors; within this population 10 different tumor types and >19 histopathologies were identified. In the overall integrated analysis population, responses to treatment with entrectinib occurred in all tumor types and included 4 complete responses (7.4%). The ORR by BICR was 57.4% (95% CI 43.2-70.8), and median (95% CI) DOR, PFS, and OS were 10.4 (7.1-not estimable [NE]), 11.2 (8.0-14.9), and 20.9 (14.9-NE) months, respectively. In the cohort of 6 patients with NTRK fusion-positive breast cancer, the median age was 63 years (range 36-67 years). Three patients reported prior systemic therapies (6, 4 and 1 prior therapies). The majority of patients had an Eastern Cooperative Oncology Group performance status (ECOG PS) of 0 or 1 (66.7%). Two patients had investigator-assessed CNS metastases at baseline; 1 patient (16.7%) had previously received radiotherapy in the brain 2-6 months prior to treatment with entrectinib. ORR by BICR was 83.3% (95% CI 35.9-99.6); 2 were complete responses, 3 were partial responses, and 1 patient had missing/unevaluable data. Median (95% CI) DOR, PFS, and OS were: 12.9 (4.2- NE), 10.1 (5.1-NE), and NE (5.1-NE) months, respectively. The integrated safety population comprised 355 patients who received ≥1 dose of entrectinib, of which 60.5% of patients had grade 1 or 2 treatment-related adverse events (TRAEs), 27.6% had grade 3, 3.4% had grade 4, and there were no grade 5 TRAEs. The most frequently reported TRAEs were dysgeusia (41.4%), fatigue (27.9%), dizziness (25.4%) and constipation (23.7%). TRAEs led to dose reductions in 27.3%, interruptions in 25.4% and discontinuations in 3.9% of patients. Conclusion In this integrated analysis of global multicenter clinical trials, entrectinib was well tolerated and induced clinically meaningful, durable responses in patients with NTRK fusion-positive breast cancer. Study Sponsor: Ignyta, Inc., a wholly owned subsidiary of F. Hoffmann-La Roche Ltd. Citation Format: Collin Blakely, Christophe Le Tourneau, Janice Lu, Saiama N. Waqar, Xinhui Huang, Bann-mo Day, Brian Simmons, Minal Barve. Entrectinib in NTRK fusion-positive breast cancer: Integrated analysis of patients enrolled in STARTRK-2, STARTRK-1 and ALKA-372-001 [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-10-11.

BackgroundNKTR-255 is an investigational IL-15Rα-dependent, polymer-conjugated, recombinant human IL-15 agonist designed to provide sustained pharmacodynamic (PD) responses without the need for daily dosing. NKTR-255 engages all IL-15 receptor binding complexes to expand, proliferate and activate natural killer (NK) and CD8+ T-cells. This Phase 1b/2 trial (NCT04616196) evaluates NKTR-255+cetuximab in highly refractory patients with head-and-neck squamous cell carcinoma (HNSCC) or colorectal cancer (CRC).MethodsSuccessive cohorts received escalating doses of NKTR-255 (q3w) +cetuximab (250mg/m< sup >2 weekly), 1 week after a loading dose of cetuximab alone. Safety (CTCAEv5.0; MTD/recommended Phase 2 dose [RP2D]) and efficacy (RECISTv1.1) were measured. PK/PD analyses were conducted, including assessment by flow cytometry/plasma cytokine analysis. Fold-change was calculated as treatment over baseline for NKTR-255 (baseline=1).ResultsAs of August 15, 2021, 12 patients had received ≥1 dose of NKTR-255+cetuximab; (37–70 years; 92% male; HNSCC n=4, CRC n=8; NKTR-255 1.5µg/kg n=7, NKTR-255 3.0µg/kg n=5). Patients had received a median 3.5 lines of prior therapy for metastatic disease. 11 patients had no response to the most recent prior therapy. Of the 12 patients, seven remain on treatment, with five not yet reaching first scan. RP2D has not yet been reached; dose escalation is ongoing.10 patients experienced an AE; one G5 AE occurred (due to progression). Seven patients reported NKTR-255-related AEs (all G1-2, except one G3 [which resolved in 24 hours]). Any-cause AEs in ≥20% were acneiform dermatitis, fatigue, and infusion-related reaction.Treatment-induced transient changes in inflammatory cytokines, including IFNy, MCP-1 and IL-6, at 1.5µg/kg (n=3) peaked 4 hours post-infusion and resolved by 24-48 hours. Mean T1/2 of NKTR-255 (1.5µg/kg dose, first cycle) was 27.8 hours.Dose-dependent expansion of NK and CD8+ T-cells was observed in peripheral blood. For NK cells, mean peak fold-change was ~4-fold and ~6-fold, and for CD8+ T-cells was ~2-fold and ~3-fold (1.5µg/kg and 3µg/kg dose levels, respectively). NK and CD8+ T-cells demonstrated increased Ki67+ proliferative ability.As of August 15, four patients in the 1.5µg/kg NKTR-255 dose cohort were response-evaluable: one CRC patient (4 prior metastatic treatment lines) reported a confirmed PR (–52%) after 3 cycles; two HNSCC patients reported SD.ConclusionsNKTR-255 was biologically active and led to expansion and proliferation of NK and CD8+ T-cells. Early dose-escalation data suggest that NKTR-255+cetuximab is safe and tolerable with preliminary anti-tumor activity. Updated data will be presented. NKTR-255, alone and in combination with daratumumab and rituximab, is also being evaluated in liquid tumors.AcknowledgementsThe authors thank the patients and their families involved in the trial.Trial RegistrationNCT04616196Ethics ApprovalThe study was approved by site IRBs.ConsentN/A

Colorectal cancer is the third most diagnosed cancer in the United States. Five-year survival rates remain low and many patients will develop liver metastasis. Vigil is an immunotherapy manufactured from autologous tumor cells and transfected ex vivo with a plasmid that encodes the GM-CSF gene and bifunctional shRNA construct to knockdown furin. Here, we report two patients with colorectal cancer and resectable liver metastasis entered into a clinical trial involving Vigil in combination with standard of care modified FOLFOX-6 chemotherapy. The first dose of Vigil was given two weeks before the modified FOLFOX-6 regimen. Vigil treatment continued until Vigil supply was exhausted. Both patients exhibited remarkable response to combination therapy, demonstrating no evidence of disease recurrence for over eight years. Additionally, both patients demonstrated systemic immune response to Vigil therapy as tested by ELISPOT.

Background: Covalent BTK inhibitors (BTKi) have transformed the management of MCL, WM, and MZL. Despite the marked efficacy of covalent BTKi, treatment failure can occur through the development of resistance and discontinuation for adverse events. Covalent BTKi also share pharmacologic liabilities (e.g. low oral bioavailability, short half-life) that may lead to suboptimal BTK target coverage, for example in rapidly proliferating tumors with high BTK protein turnover, ultimately manifesting as acquired resistance in some patients (pts). To address these limitations, LOXO-305, a highly selective, non-covalent BTKi that inhibits both wild type (WT) and C481-mutated BTK with equal low nM potency was developed. The aim of the BRUIN trial was to define the safety and early efficacy of LOXO-305 in pts with B-cell malignancies. Here we report these data in pts with previously treated MCL, WM, and other NHLs. Methods: BRUIN is a multicenter phase 1/2 trial (NCT 03740529) enrolling pts with advanced B-cell malignancies who have received >2 prior therapies. Dose was escalated according to a standard 3+3 design with LOXO-305 dosed orally in 28-day cycles. The primary endpoint was MTD/RP2D identification. Intra-patient dose-escalation to previously cleared dose levels was permitted. Efficacy evaluable pts included all dosed pts who underwent their first response evaluation or discontinued therapy. Response was assessed every 8 weeks from cycle 3, and every 12 weeks from cycle 13 and was measured according to Lugano Classification or iWWM. Safety was assessed in all pts (CLL/SLL and NHL, n=186). Results: As of 30 April 2020, 186 pts with B-cell malignancies (94 CLL/SLL, 38 MCL, 19 DLBCL, 17 WM, 6 FL, 5 MZL, and 7 Other [B-PLL and Richter's transformation]) were treated on 7 dose levels (25mg to 300mg QD). Among the 92 pts with NHL, the median age was 68 (range 27-87) years. Median number of prior lines of therapy was 2 for MCL (range 2-8), and 3 for other NHLs (range 2-11). 92% of MCL pts had received a prior BTKi; 87% received at least an anti-CD20 antibody, chemotherapy, and BTKi; 10 pts had received SCT/CAR-T; 71% of WM pts had received a prior BTKi. LOXO-305 demonstrated high oral exposures, with doses ≥100mg QD exceeding the BTK IC90 for the entirety of the dosing interval. There were no DLTs or dose reductions. Consistent with LOXO-305's selectivity, the only treatment emergent adverse events regardless of attribution or grade seen in >10% of pts (n=186) were fatigue (n=29, 16%) and diarrhea (n=28, 15%). Responses were observed at the first dose level of 25mg QD. A RP2D of 200mg QD was selected for future studies. At the efficacy cutoff date, 24 MCL pts (63%) and 35 other NHL pts (65%) remained on therapy. Among the 35 efficacy-evaluable MCL pts treated across all dose levels, the ORR was 51% including 9 CRs, 9 PRs, 7 SDs, 8 PDs, and 2 NEs. An additional 3 MCL pts were awaiting initial radiologic assessment. Among the subset of 20 efficacy evaluable MCL pts who started at the RP2D (200mg QD), the ORR was 65% including 7 CRs, 6 PR, 4 SDs, 1 PD and 2 NEs. Of the 18 responding pts treated at any dose, all except 2 remain on therapy, with the longest followed responding pt on treatment for 14 months and ongoing. Of the 2 responding pts who have discontinued treatment, 1 progressed and 1 achieved a CR and electively discontinued treatment to undergo allogeneic stem cell transplant. Responses in MCL have been observed in pts who received prior cell therapy, including 3 of 7 patents with prior SCT, and 1 of 2 with prior CAR-T. Among the 15 efficacy-evaluable pts with WM, the ORR was 60% (1 VGPR, 4 PRs, 4 MRs, 5 SDs, 1 NE), and also 60% in the subset with prior BTKi treatment. 8 of 9 WM responders were ongoing (follow-up time from initial response: 0.1-4.8 months). For the remaining 29 efficacy-evaluable other NHL pts, best response was as follows: DLBCL (3 CRs, 1 SD, 6 PDs, 5 NEs), FL (3 PRs, 1 SD, 1 PD), MZL (2 PRs, 1 SD) and Other [5 Richter's transformation, 1 B-PLL] (2 PRs, 2 SDs, 2 NEs). Conclusion: LOXO-305 demonstrated promising efficacy in heavily pretreated, poor-prognosis MCL pts following multiple prior lines of therapy, including covalent BTKi. Early efficacy was also observed in BTK-treated WM, as well as heavily pretreated other NHLs. LOXO-305 was well tolerated and exhibited a wide therapeutic index. Disclosures Wang: Kite Pharma: Consultancy, Other: Travel, accommodation, expenses, Research Funding; Loxo Oncology: Consultancy, Research Funding; Verastem: Research Funding; Molecular Templates: Research Funding; Dava Oncology: Honoraria; InnoCare: Consultancy; Oncternal: Consultancy, Research Funding; Nobel Insights: Consultancy; VelosBio: Research Funding; OMI: Honoraria, Other: Travel, accommodation, expenses; Celgene: Consultancy, Other: Travel, accommodation, expenses, Research Funding; AstraZeneca: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Janssen: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Pharmacyclics: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Targeted Oncology: Honoraria; Juno: Consultancy, Research Funding; BioInvent: Research Funding; Lu Daopei Medical Group: Honoraria; OncLive: Honoraria; Beijing Medical Award Foundation: Honoraria; MoreHealth: Consultancy; Guidepoint Global: Consultancy; Acerta Pharma: Research Funding; Pulse Biosciences: Consultancy. Shah:Cell Vault: Research Funding; Miltenyi Biotec: Honoraria, Research Funding; Celgene: Consultancy, Honoraria; Incyte: Consultancy; Lily: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria; Verastim: Consultancy; TG Therapeutics: Consultancy. Alencar:Genentech, Celgene, KITE, Loxo Oncology at Lilly: Consultancy. Gerson:Loxo: Research Funding; Pharmacyclics: Consultancy; Abbvie: Consultancy; Genentech: Consultancy. Fakhri:University of California San Francisco: Current Employment. Jurczak:MeiPharma: Research Funding; Roche: Research Funding; Takeda: Research Funding; Jagiellonian University, Krakow, Poland: Ended employment in the past 24 months; Pharmacyclics: Research Funding; Bayer: Research Funding; Janssen: Research Funding; Acerta: Research Funding; TG Therapeutics: Research Funding; Maria Sklodowska-Curie National Research Institute of Oncology, Krakow, Poland: Current Employment. Tan:Sir Charles Gairdner Hospital and Linear Clinical Research: Current Employment. Lewis:Sir Charles Gairdner Hospital and Linear Clinical Research: Current Employment. Fenske:Medical College of Wisconsin: Current Employment. Coombs:Novartis: Honoraria; Octapharma: Honoraria; LOXO Oncology: Honoraria; MEI Pharma: Honoraria; AstraZeneca: Honoraria; Genentech: Honoraria; Abbvie: Consultancy, Honoraria. Flinn:Calithera Biosciences: Research Funding; Loxo: Research Funding; IGM Biosciences: Research Funding; Takeda: Consultancy, Research Funding; Genentech, Inc.: Research Funding; F. Hoffmann-La Roche: Research Funding; Gilead Sciences: Consultancy, Research Funding; Agios: Research Funding; Karyopharm Therapeutics: Research Funding; Incyte: Research Funding; BeiGene: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; TG Therapeutics: Consultancy, Research Funding; Curio Science: Consultancy; MorphoSys: Consultancy, Research Funding; Curis: Research Funding; Nurix Therapeutics: Consultancy; Novartis: Research Funding; Pfizer: Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; Portola Pharmaceuticals: Research Funding; Seattle Genetics: Consultancy, Research Funding; Teva: Research Funding; Constellation Pharmaceuticals: Research Funding; Great Point Partners: Consultancy; Forma Therapeutics: Research Funding; Iksuda Therapeutics: Consultancy; Unum Therapeutics: Consultancy, Research Funding; Juno Therapeutics: Consultancy, Research Funding; Infinity Pharmaceuticals: Research Funding; Acerta Pharma: Research Funding; AbbVie: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Trillium Therapeutics: Research Funding; Triphase Research & Development Corp.: Research Funding; Verastem: Consultancy, Research Funding; Yingli Pharmaceuticals ≠: Consultancy, Research Funding; Rhizen Pharmaceuticals: Research Funding; Johnson & Johnson: Other; Roche: Consultancy, Research Funding; Vincera Pharma: Consultancy; Merck: Research Funding; Celgene: Research Funding; ArQule: Research Funding; Kite Pharma: Consultancy, Research Funding; Forty Seven: Research Funding. Le Gouill:Loxo Oncology at Lilly: Consultancy; Roche Genentech, Janssen-Cilag and Abbvie, Celgene, Jazz pharmaceutical, Gilead-kite, Loxo, Daiichi-Sankyo and Servier: Honoraria. Palomba:Celgene: Honoraria; Pharmacyclics: Honoraria; Genentech: Research Funding; Novartis: Honoraria; Merck: Honoraria; Juno Therapeutics, a Bristol-Meyers Squibb Company: Honoraria, Research Funding; Regeneron: Research Funding. Woyach:Janssen, Pharmacyclics, AstraZeneca, Abbvie, Arqule: Consultancy; Pharmacyclics, Janssen, Morphosys, Karyopharm, Verastem, Abbvie, Lox: Research Funding; Pharmacyclics LLC, an AbbVie Company, AbbVie, Janssen, AstraZeneca, ArQule: Honoraria. Lamanna:Columbia University Medical Center: Current Employment; MingSight: Other: Institutional research grants, Research Funding; Octapharma: Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bei-Gene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Juno: Other: Institutional research grants, Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Loxo: Research Funding; Oncternal, Verastem, TG Therapeutics: Other: Institutional research grants, Research Funding. Cohen:Genentech, BMS, Novartis, LAM, BioInvent, LRF, ASH, Astra Zeneca, Seattle Genetics: Research Funding; Janssen, Adicet, Astra Zeneca, Genentech, Aptitude Health, Cellectar, Kite/Gilead, Loxo: Consultancy. Ghia:Gilead: Consultancy, Honoraria, Research Funding; ArQule: Consultancy, Honoraria; Acerta/AstraZeneca: Consultancy, Honoraria; BeiGene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Celgene/Juno: Consultancy, Honoraria; Lilly: Consultancy, Honoraria; MEI: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding; Adaptive, Dynamo: Consultancy, Honoraria; Novartis: Research Funding; AbbVie: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding. Eyre:KITE, AZ, Loxo Oncology at Lilly: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Other: travel support; AbbVie: Consultancy, Honoraria, Other: travel support; Gilead: Consultancy, Honoraria, Other: travel support. Yin:Loxo Oncology at Lilly: Current Employment. Nair:Loxo Oncology at Lilly: Current Employment. Tsai:Loxo Oncology at Lilly: Current Employment. Ku:Loxo Oncology at Lilly: Current Employment. Mato:Pharmacyclics: Consultancy, Research Funding; TG Therapeutics: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; Adaptive: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Loxo: Consultancy, Research Funding; Genentech: Consultancy, Research Funding. Cheah:Celgene, F. Hoffmann-La Roche, MSD, Janssen, Gilead, Ascentage Pharma, Acerta, Loxo Oncology, TG therapeutics: Honoraria; Celgene, F. Hoffmann-La Roche, Abbvie, MSD: Research Funding.

Background: Covalent BTK inhibitors (BTKi) have transformed the management of CLL/SLL. Despite the marked efficacy of covalent BTKi, treatment failure can occur through the development of resistance and discontinuation for adverse events. The activity of covalent BTK inhibitors is markedly reduced or absent in the presence of BTK cysteine binding site (C481) mutations. Moreover, these agents share pharmacologic liabilities (e.g. low oral bioavailability, short half-life) that may lead to suboptimal BTK target coverage, for example in rapidly proliferating tumors with high BTK protein turnover, ultimately manifesting as acquired resistance in some patients (pts). To address these limitations, LOXO-305, a highly selective, non-covalent BTKi that inhibits both wild type (WT) and C481-mutated BTK with equal low nM potency was developed. The aim of the BRUIN trial was to define the safety and early efficacy of LOXO-305 in pts with B-cell malignancies. Here we report these data in pts with previously treated CLL/SLL. Methods: BRUIN is a multicenter phase 1/2 trial (NCT 03740529) enrolling pts with advanced B-cell malignancies who have received >2 prior therapies. Dose was escalated according to a standard 3+3 design with LOXO-305 dosed orally in 28-day cycles. The primary endpoint was MTD/RP2D identification. Intra-patient dose-escalation to previously cleared dose levels was permitted. Efficacy evaluable pts included all dosed pts who underwent their first response evaluation or discontinued therapy. Response was assessed every 8 weeks from cycle 3, and every 12 weeks from cycle 13 and was measured according to the iwCLL 2018 criteria, including PR with lymphocytosis (PR-L). Safety was assessed in all pts (CLL/SLL and NHL, n=186). Results: As of 30 April 2020, 186 pts with B-cell malignancies (94 CLL/SLL, 38 MCL, 19 DLBCL, 17 WM, 6 FL, 5 MZL, and 7 Other [B-PLL and Richter's transformation]) were treated on 7 dose levels (25mg to 300mg QD). Among the 94 pts with CLL/SLL, the median age was 69 (range 36-84) years and median number of prior therapies was 4 (range 1-10). 84% of CLL/SLL pts had received a prior BTKi, and 69% had received an anti-CD20 antibody, chemotherapy, and BTKi. In addition, 21% had received a PI3K inhibitor and 31% venetoclax. At enrollment, central molecular characterization for high-risk features in available samples revealed 17p deletion in 21% (13/63), TP53 mutation in 30% (27/91), and unmutated IGHV in 84% (51/61). LOXO-305 demonstrated high oral exposures, with doses ≥100mg QD exceeding the BTK IC90 for the entirety of the dosing interval. There were no DLTs or dose reductions. Consistent with LOXO-305's selectivity, the only treatment-emergent adverse events regardless of attribution or grade seen in >10% of pts (n=186) were fatigue (n=29, 16%) and diarrhea (n=28, 15%). Responses were observed at the first dose level of 25mg QD. A RP2D of 200mg QD was selected for future studies. At the efficacy cutoff date, 88 CLL/SLL pts (94%) remained on therapy and 65 CLL/SLL pts were efficacy-evaluable (58 BTKi-treated, 7 BTKi-naïve). Median follow up time was 3 months (range 0.1-13) for all pts and 6.7 months for responders. The ORR was 57%, with 23 PRs, 14 PR-Ls, 26 SDs, 1 PD, and 1 NE (Figure). An additional 29 pts were ongoing and awaiting initial radiologic assessment. As has been observed with covalent BTK inhibitors, responses deepened over time; among pts with at least 6 months of follow-up (n=26), the ORR was 77%. Response rate was not influenced by the presence or absence of a pretreatment BTK C481 mutation, the reason for prior BTKi discontinuation (i.e. progression vs intolerance), or other classes of prior therapy received (including a covalent BTK and BCL2 inhibitor). Of the 37 responding pts, all except 2 remain on therapy (1 progressed and 1 achieved a PR and electively discontinued treatment to undergo an allogeneic stem cell transplant). The longest-followed responding patient has been on treatment for 13.5 months and is ongoing. Responding pts with BTK C481 mutations demonstrated corresponding decreases in mutant disease burden by ddPCR. Conclusion: LOXO-305 demonstrated promising efficacy in heavily pretreated, poor-prognosis CLL/SLL pts following multiple prior lines of therapy including covalent BTKi and a BCL2 inhibitor. Importantly, the activity of LOXO-305 was not restricted to pts with BTK C481 mutations. LOXO-305 was well tolerated and exhibited a wide therapeutic index. Figure Disclosures Mato: Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; TG Therapeutics: Consultancy, Other: DSMB, Research Funding; Genentech: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; LOXO: Consultancy, Research Funding; BeiGene: Consultancy; AstraZeneca: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Adaptive: Consultancy, Research Funding. Coombs:Abbvie: Consultancy, Honoraria; Genentech: Honoraria; AstraZeneca: Honoraria; MEI Pharma: Honoraria; LOXO Oncology: Honoraria; Octapharma: Honoraria; Novartis: Honoraria. Shah:TG Therapeutics: Consultancy; Celgene: Consultancy, Honoraria; Incyte: Consultancy; Cell Vault: Research Funding; Kite Pharma: Consultancy, Honoraria; Miltenyi Biotec: Honoraria, Research Funding; Verastim: Consultancy; Lily: Consultancy, Honoraria. Lamanna:Oncternal, Verastem, TG Therapeutics: Other: Institutional research grants, Research Funding; MingSight: Other: Institutional research grants, Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Columbia University Medical Center: Current Employment; Bei-Gene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Loxo: Research Funding; Octapharma: Research Funding; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Juno: Other: Institutional research grants, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees. Lech-Marańda:Roche, Novartis, Takeda, Janssen-Cilag, Amgen, Gilead, AbbVie, Sanofi: Consultancy; Roche, Amgen, Gilead: Speakers Bureau. Eyre:Gilead: Consultancy, Honoraria, Other: travel support; Janssen: Consultancy, Honoraria, Other: travel support; KITE, AZ, Loxo Oncology at Lilly: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Consultancy, Honoraria, Other: travel support. Woyach:Janssen, Pharmacyclics, AstraZeneca, Abbvie, Arqule: Consultancy; Pharmacyclics, Janssen, Morphosys, Karyopharm, Verastem, Abbvie, Lox: Research Funding; Pharmacyclics LLC, an AbbVie Company, AbbVie, Janssen, AstraZeneca, ArQule: Honoraria. Cheah:Celgene, F. Hoffmann-La Roche, Abbvie, MSD: Research Funding; Celgene, F. Hoffmann-La Roche, MSD, Janssen, Gilead, Ascentage Pharma, Acerta, Loxo Oncology, TG therapeutics: Honoraria. Roeker:AbbVie: Other: spouse with minority ownership interest ; Abbott Laboratories: Other: spouse with minority ownership interest ; American Society of Hematology: Research Funding. Fakhri:University of California San Francisco: Current Employment. Tam:Janssen: Honoraria, Research Funding; Pharmacyclics LLC, an AbbVie Company: Honoraria; AbbVie: Honoraria, Research Funding; BeiGene: Honoraria, Research Funding. Gerson:Genentech: Consultancy; Pharmacyclics: Consultancy; Abbvie: Consultancy; Loxo: Research Funding. Alencar:Genentech, Celgene, KITE, Loxo Oncology at Lilly: Consultancy. Abdel-Wahab:Merck: Consultancy; Janssen: Consultancy; Envisagenics Inc.: Current equity holder in private company; H3 Biomedicine Inc.: Consultancy, Research Funding. Ghia:MEI: Consultancy, Honoraria; Lilly: Consultancy, Honoraria; Celgene/Juno: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; BeiGene: Consultancy, Honoraria; Acerta/AstraZeneca: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Gilead: Consultancy, Honoraria, Research Funding; ArQule: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding; Novartis: Research Funding; Adaptive, Dynamo: Consultancy, Honoraria. Schuster:Novartis, Genentech, Inc./ F. Hoffmann-La Roche: Research Funding; AlloGene, AstraZeneca, BeiGene, Genentech, Inc./ F. Hoffmann-La Roche, Juno/Celgene, Loxo Oncology, Nordic Nanovector, Novartis, Tessa Therapeutics: Consultancy, Honoraria. Chen:Loxo Oncology at Lilly: Current Employment. Nair:Loxo Oncology at Lilly: Current Employment. Tsai:Loxo Oncology at Lilly: Current Employment. Ku:Loxo Oncology at Lilly: Current Employment. Brown:Abbvie, Acerta, AstraZeneca, Beigene, Invectys, Juno/Celgene, Kite, Morphosys, Novartis, Octapharma, Pharmacyclics, Sunesis, TG Therapeutics, Verastem: Consultancy; Janssen, Teva: Speakers Bureau; Gilead, Loxo, Sun, Verastem: Research Funding. Jurczak:Bayer: Research Funding; Janssen: Research Funding; MeiPharma: Research Funding; Pharmacyclics: Research Funding; Roche: Research Funding; Takeda: Research Funding; TG Therapeutics: Research Funding; Acerta: Research Funding; Maria Sklodowska-Curie National Research Institute of Oncology, Krakow, Poland: Current Employment; Jagiellonian University, Krakow, Poland: Ended employment in the past 24 months.

This abstract was withdrawn by the authors. Citation Format: Hamilton EP, Barve M, Bardia A, Beeram M, Edenfield WJ, Noonan A, Tolcher A, Bendell J, Mosher R, Xu J, Hailman E, Burris III H, Soliman HH. Withdrawn [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-17-35.

Survival outcomes in ovarian cancer are poor. The aims of this Phase I progressive design study (NCT02903771) were to evaluate the maximum tolerated dose (MTD), tolerability, and antitumor activity of Cantrixil—a novel third-generation benzopyran molecule—in patients (n = 25) with advanced, recurrent/persistent epithelial ovarian, primary peritoneal, or fallopian tube cancer. All had completed ≥ 2 prior regimens, 3 (12%) had platinum-refractory disease, and 17 (68%) had platinum-resistant disease. Following intraperitoneal (IP) port placement, patients received weekly IP Cantrixil in 3-week cycles as monotherapy (Cycles 1–2), and then in combination with intravenous (IV) chemotherapy (Cycles 3–8). Part A (dose escalation) enrolled 11 patients in 6 dose-level cohorts. An MTD of 5 mg/kg was established with dose-limiting toxicity of ileus. Most treatment-related adverse events were gastrointestinal. Across Parts A and B (dose expansion), 16 (64%) patients received ≥ 1 3-week Cantrixil cycle, and had ≥ 1 post-baseline efficacy measurement available. The results show promising anti-tumor activity in monotherapy (stable disease rate of 56%) and in combination with IV chemotherapy (objective response rate of 19%, disease control rate of 56%, and median progression-free survival of 13.1 weeks). The molecular target and mechanism of action of Cantrixil are yet to be confirmed. Preliminary analysis of stem cell markers suggests that IP Cantrixil might induce ovarian cancer stem cell death and sensitize cells to standard chemotherapy, warranting further evaluation.

Purpose: Telisotuzumab vedotin (Teliso-V) is an anti–c-Met–directed antibody–drug conjugate. Here, we present safety and efficacy data from a phase I/Ib study of Teliso-V monotherapy evaluated in once every 2 weeks/once every 3 weeks schedules in patients with non–small cell lung cancer (NSCLC). Patients and Methods: During dose escalation, patients received Teliso-V monotherapy intravenously once every 3 weeks (0.15–3.3 mg/kg) or once every 2 weeks (1.6–2.2 mg/kg). The dose-expansion phase enrolled patients with NSCLC and c-Met H-score ≥150 (c-Met+) or MET amplification/exon 14 skipping mutations. Safety, pharmacokinetics, and efficacy were assessed. Herein, the analysis of patients receiving ≥1.6 mg/kg once every 2 weeks or ≥2.4 mg/kg once every 3 weeks Teliso-V is reported. Results: Fifty-two patients with NSCLC were enrolled and received ≥1.6 mg/kg Teliso-V once every 2 weeks (n = 28) or ≥2.4 mg/kg Teliso-V once every 3 weeks (n = 24). The most common adverse events were fatigue (54%), peripheral neuropathy (42%), and nausea (38%). No dose-limiting toxicities were observed for Teliso-V once every 2 weeks and once every 3 weeks up to 2.2 and 2.7 mg/kg, respectively. The recommended phase II dose was established at 1.9 mg/kg once every 2 weeks and 2.7 mg/kg once every 3 weeks on the basis of overall safety and pharmacokinetics. Forty of 52 patients were c-Met+ (33 nonsquamous, 6 squamous, 1 mixed histology) and were included in the efficacy-evaluable population. Of those, 9 (23%) had objective responses with median duration of response of 8.7 months; median progression-free survival was 5.2 months. Conclusions: Teliso-V monotherapy was tolerated and showed antitumor activity in c-Met+ NSCLC. On the basis of overall safety, pharmacokinetics, and efficacy outcomes, 1.9 mg/kg Teliso-V once every 2 weeks and 2.7 mg/kg once every 3 weeks schedules were selected for further clinical development.

International audience; Background: Covalent Bruton's tyrosine kinase (BTK) inhibitors are efficacious in multiple B-cell malignancies, but patients discontinue these agents due to resistance and intolerance. We evaluated the safety and efficacy of pirtobrutinib (working name; formerly known as LOXO-305), a highly selective, reversible BTK inhibitor, in these patients.Methods: Patients with previously treated B-cell malignancies were enrolled in a first-in-human, multicentre, open-label, phase 1/2 trial of the BTK inhibitor pirtobrutinib. The primary endpoint was the maximum tolerated dose (phase 1) and overall response rate (ORR; phase 2). This trial is registered with ClinicalTrials.gov, NCT03740529.Findings: 323 patients were treated with pirtobrutinib across seven dose levels (25 mg, 50 mg, 100 mg, 150 mg, 200 mg, 250 mg, and 300 mg once per day) with linear dose-proportional exposures. No dose-limiting toxicities were observed and the maximum tolerated dose was not reached. The recommended phase 2 dose was 200 mg daily. Adverse events in at least 10% of 323 patients were fatigue (65 [20%]), diarrhoea (55 [17%]), and contusion (42 [13%]). The most common adverse event of grade 3 or higher was neutropenia (32 [10%]). There was no correlation between pirtobrutinib exposure and the frequency of grade 3 treatment-related adverse events. Grade 3 atrial fibrillation or flutter was not observed, and grade 3 haemorrhage was observed in one patient in the setting of mechanical trauma. Five (1%) patients discontinued treatment due to a treatment-related adverse event. In 121 efficacy evaluable patients with chronic lymphocytic leukaemia (CLL) or small lymphocytic lymphoma (SLL) treated with a previous covalent BTK inhibitor (median previous lines of treatment 4), the ORR with pirtobrutinib was 62% (95% CI 53-71). The ORR was similar in CLL patients with previous covalent BTK inhibitor resistance (53 [67%] of 79), covalent BTK inhibitor intolerance (22 [52%] of 42), BTK C481-mutant (17 [71%] of 24) and BTK wild-type (43 [66%] of 65) disease. In 52 efficacy evaluable patients with mantle cell lymphoma (MCL) previously treated with covalent BTK inhibitors, the ORR was 52% (95% CI 38-66). Of 117 patients with CLL, SLL, or MCL who responded, all but eight remain progression-free to date.Interpretation: Pirtobrutinib was safe and active in multiple B-cell malignancies, including patients previously treated with covalent BTK inhibitors. Pirtobrutinib might address a growing unmet need for alternative therapies for these patients.Funding: Loxo Oncology.

TPS3176 Background: XL102 is an orally bioavailable, selective, and covalent small-molecule inhibitor of cyclin-dependent kinase 7 (CDK7). CDK7 is a serine/threonine kinase that is overexpressed in multiple tumor types. CDK7 controls cell cycle progression via the phosphorylation of CDKs (1, 2, 4, and 6) and regulates transcription through phosphorylation of RNA polymerase II. XL102 induced cell death in various cancer cell lines and caused tumor regression in multiple human tumor cell line to mouse xenograft tumor models. Here, we present the study design of an ongoing phase 1 trial in pts with advanced solid tumors, including hormone receptor-positive breast cancer (HR+BC), triple-negative breast cancer (TNBC), epithelial ovarian cancer (EOC), and metastatic castration-resistant prostate cancer (mCRPC). Methods: This first-in-human, open-label, phase 1 trial (NCT04726332) consists of a dose-escalation stage and a disease-specific cohort expansion stage. In the dose-escalation stage (modified interval 3+3 design), a maximum tolerated dose and/or recommended dose (MTD/RD) of XL102 will be established (primary endpoint) for use alone (solid tumors) and then for use in combination with standard dose fulvestrant (HR+BC) or abiraterone/prednisone (mCRPC); dose escalation will require ̃36 pts for the single-agent cohort and ̃15 pts for each combination cohort. Pts enrolled in the dose-escalation stage must have an unresectable or metastatic tumor for which available therapies are intolerable, ineffective, or do not exist. Upon determining the MTD/RD for each regimen, the cohort-expansion stage will enroll according to Simon’s Two-Stage Minimax design, assuming a power of 80% and one-sided α of 15%, for single-agent XL102 (HR+BC, TNBC, EOC, and mCRPC) and XL102 in combination therapy (HR+BC and mCRPC); the expansions will enroll ̃36 pts for each single-agent cohort and ̃44 pts for each combination cohort. Pts enrolled in the expansion stage must have measurable disease per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1), adequate organ function, and exposure to prior therapy, with specific therapy requirements based on the disease cohort. The primary endpoint of the expansion stage is objective response rate (ORR) of XL102 alone and in combination therapy as assessed by investigator per RECIST v1.1. Secondary endpoints are safety, tolerability, and pharmacokinetics. Exploratory endpoints include duration of response (DOR) and progression-free survival (PFS) as assessed by the investigator per RECIST v1.1, overall survival, and correlation of tumor and blood biomarkers with response. ORR, DOR, and PFS may also be assessed by blinded independent radiology committee in selected expansion cohorts. The study began enrolling pts in February 2021 and is ongoing. Total enrollment is estimated to be up to 298 pts. Clinical trial information: NCT04726332.

2514 Background: Checkpoint inhibitors (CPIs) are usually ineffective in patients (pts) with immune-cold microsatellite stable colorectal cancer (MSS-CRC) or pancreatic cancer (PDAC) and in those who progressed on previously treated with antibodies against PD1 or PD-L1. Here, we report the combination of NT-I7 plus pembrolizumab (pembro) on CPI-naïve MSS-CRC and PDAC cohorts, and patients (pts) with CPI-treated triple-negative breast cancer (TNBC), non-small cell lung cancer (NSCLC), and small cell lung cancer (SCLC) cohorts of this ongoing phase 2a trial. Methods: Pts with CPI-naïve relapsed/refractory (R/R) MSS-CRC and PDAC, and CPI-treated R/R TNBC, NSCLC, and SCLC, were enrolled. NT-I7 (efineptakin alfa) 1200 µg/kg intramuscularly every 6 weeks and 200 mg pembro intravenously every 3 weeks were administered until disease progression/unacceptable toxicity. The primary endpoint of the Phase 2a is the objective response rate (ORR), assessed by RECIST v1.1 and iRECIST. The secondary endpoints are duration of response (DoR), disease control rate, progression-free survival, and overall survival. Results: As of 14 Jan 2022, 92 pts with metastatic or locally advanced cancer who had received a median of 3 prior treatments were enrolled in the study; 32 in PDAC, 28 in MSS-CRC, 22 in NSCLC, 6 in TNBC, and 4 in SCLC. The median age was 62 years [29-81], ECOG PS 0 in 23 (25%), 1 in 68 (74%) and 2 in 1 (1%). Among 71 evaluable pts, the median follow up (months) was 7.7, 5.3, 5.0, 3.7, and 2.4 in TNBC, MSS-CRC, NSCLC, PDAC and SCLC, respectively. The ORR was 50% (1/2) in SCLC, 12% (3/25) in MSS CRC, 8% (2/26) in PDAC 6% (1/16) in NSCLC and 0% (0/2) in TNBC per iRECIST; and 50% (1/2) in SCLC, 4% (1/25) in MSS CRC, and 4% (1/26) in PDAC per RECIST 1.1. All 7 responders are ongoing. The two PDAC pts had DoR over 1.35 months (mos) and 6.64 mos with the best tumor reduction 100% and 72% respectively. The one SCLC pt had DoR over 1.5 mos with the tumor reduction 67%. The one NSCLC pt had DoR over 2.73 mos with the tumor reduction 60%, and the three MSS-CRC pts had DoR 6.34, 2.96, and 0.03 mos with the tumor reduction 60%, 56%, and 43% respectively. A sustained and significant (approximate 3X from baseline) increase of peripheral lymphocytes in all arms was observed as shown in our previous report. Among 92 treated pts, NT-I7-related adverse events (AEs) occurred in 67 (72.8%) pts, including 52 (56.5%) Grade (G)1-2, 13 (14.1%) G3, and 2 (2.2%) G4. There were no NT-I7 related G5 AEs. Additional updated efficacy, safety and biomarker data will be presented. Conclusions: The combination of NT-I7 and pembro demonstrated antitumor activity and manageable toxicity profile in heavily pretreated pts with CPI-naïve MSS-CRC and PDAC and CPI-treated TNBC, NSCLC, and SCLC, suggesting that the addition of NT-I7 to CPI can overcome the primary resistance to CPI in the former group and acquired resistance in the latter. Clinical trial information: NCT04332653.

1504 Background: Trial recruitment that requires specific actionable mutations based on next-generation sequencing (NGS) is challenging. Barriers can include competing studies, physician study awareness, site proximity, mutation incidence, among other concerns. Methods: This study (NCT04432454) opened clinical sites using two methods during the COVID-19 pandemic. The “Traditional” approach included site selection, IRB and contract approval, and trial activation prior to a patient being identified for enrollment. The second approach used the Tempus “TIME” Trials network that would only open a site after identifying a patient with a mutation of interest and eligible for the trial. Results: The first patient enrolled was on 10/12/20 and the last patient was on 6/24/21. A total of 16 sites (6 Traditional and 10 TIME) participated. All Traditional sites, and none of the TIME sites, were affiliated with major academic institutions. Duration for full CTA execution for Traditional sites averaged 200.5 days (range 142 to 257) and for TIME sites averaged 7.6 days (range 2 to 14). IRB approval time average for Traditional sites was 27.5 days (range 12 to 71) and TIME sites was 3.0 days (range 1 to 12 days). Days from site selection to activation letter for Traditional sites was on average 250.0 days (range 187 to 281) and for TIME sites was 131.6 days (range 22 to 248). Time from study activation to first consent was 33.3 days (range 18 to 58) for Traditional sites and 8.8 days (range 1 to 35) for TIME sites. The first patient on-study was at a TIME site 115 days prior to a Traditional site and the first 7 patients enrolled were at TIME sites. Traditional sites consented 23 and enrolled 16 patients while the TIME sites consented 16 and enrolled 13. The trial enrolled all 29 patients in 8 months with the anticipated enrollment duration being 12 to 18 months. Conclusions: Although the Traditional and TIME programs had different operational models, they both contributed a significant number of patients and reduced the projected enrollment timeline. TIME sites enrolled the initial patients. These results demonstrate that the “Just-in-Time model,” in conjunction with a Traditional model, can reduce projected overall time to enrollment in biomarker-driven studies. [Table: see text]

TPS9143 Background: HER2 mutations are present in 2–4% of NSCLC tumors; of these ̃50% are exon 20 insertion (ex20ins) mutations. There is an unmet need for effective targeted therapy against HER2 mutations in solid tumors, particularly in NSCLC. Historically, ex20ins mutations have responded poorly to TKIs. Moreover, TKIs that inhibit both mutant EGFR and HER2 are typically limited by toxicities associated with inhibition of wild-type EGFR. Despite the promise of trastuzumab deruxtecan and other agents in this setting, the development of orally available selective TKIs is important given the heterogeneity of HER2 aberrations, potential for combination regimens, and the risk of ILD with ADCs. BI 1810631 is a HER2 selective TKI that covalently binds to both wild-type and mutated HER2 receptors, including ex20ins, whilst sparing EGFR signaling; preclinical data suggest good tolerability and efficacy. This Phase Ia/Ib, open-label, non-randomized study aims to determine the safety, MTD, PK, pharmacodynamics, and preliminary efficacy of BI 1810631 in pts with HER2+ solid tumors (NCT04886804). Methods: ̃96 pts from 5–7 sites in the US, Netherlands, Japan, and China will be recruited. Phase Ia: consecutive cohorts of pts will receive BI 1810631 QD or BID at escalating doses. Starting dose level: 15 mg BID (̃36 pts); QD schedule will begin after one dose level above estimated therapeutic dose of BI 1810631 is determined safe by the Dose Escalation Committee (expected starting dose: 60 mg [̃30 pts]). BI 1810631 dose escalation will continue until MTD/RP2D for each schedule is determined, as well as a preferred Phase Ib schedule. Phase Ib: an initial 30 pts with HER2 ex20ins mutation-positive, pre-treated NSCLC will be enrolled, with possible inclusion of additional cohorts in the future. Overall pt inclusion criteria (Phase Ia): ≥18 years of age; histologically/cytologically confirmed HER2+ (defined as overexpression, gene amplification, non-synonymous somatic mutation, or gene rearrangement involving HER2 or NRG1) advanced/unresectable/metastatic solid tumor refractory/not suitable for standard therapy; exhausted treatment options; measurable/evaluable lesions (per RECIST v1.1); ECOG PS ≤1. Phase Ib criteria: HER2 ex20ins mutation-positive NSCLC; received ≥1 line of platinum-based combination chemotherapy in the advanced/metastatic setting. Primary endpoints: MTD based on number of DLTs/number of pts with DLTs (Phase Ia); objective response (Phase Ib). Secondary endpoints: number of pts with DLTs throughout entire treatment period and PK parameters (Phase Ia/Ib); duration of response, disease control, duration of disease control, and PFS (Phase Ib). The trial is actively recruiting with 6 pts enrolled to date. More patients may be recruited depending on whether 2 dose levels have been completed and the MTD/RP2D determined. Clinical trial information: NCT04886804.

2583 Background: MT-5111 is a 55kD engineered toxin body (ETB) targeting HER2 in solid tumors that binds to an epitope distinct from trastuzumab and pertuzumab, offering potential combination strategies with other HER2-targeting agents. MT-5111 may demonstrate efficacy in patients (pts) resistant to other HER2-targeting agents, as its mechanism of action induces direct cell kill via enzymatic and permanent ribosome destruction. Methods: This is a phase 1 study in adults with advanced HER2+ solid tumors. The dose-escalation portion (Part A) enrolls pts into sequential dose cohorts, followed by Part B expansion cohorts for HER2+ breast cancer (BC), gastroesophageal adenocarcinoma (GEA), and any other HER2+ cancer (CA). MT-5111 is dosed weekly IV over 30 min in each 21-day treatment (tx) cycle until disease progression, unacceptable toxicity, death or withdrawn consent. Results: As of Jan 2022, 27 pts had enrolled in Part A cohorts (0.5 to 10 µg/kg/dose) with completed DLT assessments: 9 (33%) pts were male and 18 (67%) female, median age 67 and a median of 4 prior systemic and 2 prior HER2-targeting tx. Common tissue types were BC (9/30%), biliary CA (6/22%), GEA (4/15%). The following safety data reflect 33 treated pts to date including ongoing 13 µg/kg/dose Part A and 10 µg/kg/dose BC expansion cohorts. No Grade (G) 4/5 tx-emergent adverse events (AEs) or DLTs occurred. Tx-related AEs occurred in 17 (52%) pts, most commonly G1/2 fatigue (8/24%). 3 pts had G1 troponin elevations without clinical signs or symptoms of cardiac distress: 1 at 6.75 µg/kg/dose, 2 at 10 µg/kg/dose. 2 pts (3 and 4.5 µg/kg/dose) had reversible G2 and G1, respectively, infusion-related reactions (IRR)s. A comparison of cytokines from baseline to on-treatment timepoints reveals no evidence of significant changes, even in pts with IRR. Best response per RECIST thus far was stable disease (SD) in 7 pts or non-CR/non-PD in 2 pts: 1 pt had SD for 12 weeks (wks) (4.5 μg/kg, pancreatic CA); 1 pt (1 μg/kg/dose, BC) had non-CR/non-PD for 30 wks; 1 pt (10 μg/kg/dose, GEA) has ongoing SD for 18 wks. AUClast data match PK simulations in non-human primate studies. Cmax at 10 µg/kg/dose is ≥5 times the IC50 values of high HER2 expressing gastric CA and BC cell lines while approaching the IC50 of a moderately HER2 expressing liver CA cell line. Conclusions: MT-5111 is well tolerated to-date with no clinically significant immuno/cardiotoxicity. Dose escalation is ongoing at a dose of 13µg/kg, expected to be required for efficacious exposure. Clinical trial information: NCT04029922.

Context: Despite the marked efficacy of covalent BTK inhibitors (BTKi) in CLL/SLL, the development of resistance and discontinuation for adverse events can lead to treatment failure. Low oral bioavailability or short half-life of these agents can lead to suboptimal BTK target coverage and ultimately result in acquired resistance in some patients (pts). Pirtobrutinib (LOXO-305) is a highly selective, non-covalent BTKi that inhibits both WT and C481-mutated BTK with equal, low nM potency. Objective: To evaluate pirtobrutinib safety and efficacy in pts with CLL/SLL. Design: BRUIN is an ongoing multi-center phase 1/2 trial (NCT03740529). Enrollment was initiated 21 March 2019. Setting: Global: community hospitals, and academic medical centers. Patients: As of 27 September 2020, 323 previously treated pts with B-cell malignancies (170 CLL/SLL, 61 MCL, 26 WM, and 66 other B-cell lymphomas) were enrolled. Interventions: Oral pirtobrutinib (7 dose escalation levels: 25–300mg once daily) in 28-day cycles. Main Outcomes Measures: Determining the maximum tolerated dose/recommended phase 2 dose (RP2D), safety profile, and efficacy based on response assessment using disease-specific criteria (iwCLL2018 for CLL/SLL) per protocol. Results: Pirtobrutinib demonstrated high oral exposures, with doses ≥100mg QD exceeding BTK IC90 for the entirety of the dosing interval. No DLTs occurred. The only treatment-emergent adverse events, regardless of attribution or grade seen in ≥10% of pts (n=323), were fatigue (20%), diarrhea (17%), and contusion (13%). An RP2D of 200 mg QD was selected for future studies. The ORR (per iwCLL 2018) was 63%, with 69 PRs, 19 PR-Ls, 45 SDs, 1 PD, and 5 discontinued prior to first response assessment. Responses deepened over time among pts with ≥10 months of follow-up (n=29; 86% ORR). ORR was not influenced by the reason for prior BTKi discontinuation (i.e., progression vs intolerance) or other classes of prior therapy received (including a covalent BTK and a BCL2 inhibitor). The longest followed responding pt continues on treatment for 17.8+ months. Conclusions: Pirtobrutinib showed promising efficacy in pre-treated CLL/SLL pts, was well-tolerated, and exhibited a wide therapeutic index.

Context Despite the marked efficacy of covalent BTK inhibitors (BTKi) in MCL, WM, and MZL, the development of resistance and discontinuation for adverse events can lead to treatment failure. Low oral bioavailability or short half-life of these agents can lead to suboptimal BTK target coverage and ultimately result in acquired resistance in some patients (pts). Pirtobrutinib (LOXO-305) is a highly selective, non-covalent BTKi that inhibits both WT and C481-mutated BTK with equal, low nM potency. Objective To evaluate safety and efficacy of pirtobrutinib in pts with MCL/NHLs. Design BRUIN is an ongoing multi-center phase 1/2 trial (NCT03740529). Enrollment was initiated 21 March 2019. Setting Global: community hospitals, academic medical centers. Patients Previously treated pts with advanced B-cell malignancies. Interventions Oral pirtobrutinib (7 dose escalation levels: 25–300mg once daily) in 28-day cycles. Main Outcomes Measures Determining the maximum tolerated dose/recommended phase 2 dose (RP2D), safety profile, and efficacy based on response assessment using disease-specific criteria per protocol. Results As of 27 September 2020, 323 pts with B-cell malignancies (170 CLL/SLL, 61 MCL, 26 WM, and 66 other B-cell lymphomas) were treated on 7 dose levels (25–300mg QD). Pirtobrutinib demonstrated high oral exposures, with doses ≥100 mg QD exceeding the BTK IC90 for the entirety of the dosing interval. No DLTs occurred. The only TEAEs, regardless of attribution or grade in ≥10% of pts (n=323), were fatigue (20%), diarrhea (17%) and contusion (13%). A RP2D of 200mg QD was selected. At the efficacy cutoff date, 35 (57%) MCL pts, 18 (69%) WM pts, and 34 (52%) other NHL pts remained on therapy. Among the 52 efficacy evaluable prior BTKi treated MCL pts, the ORR was 52%. Among the 19 efficacy evaluable pts with WM, the ORR was 68%. For the other 55 efficacy evaluable NHL pts, ORR was 24% (DLBCL), 50% (FL), 22% (MZL), and 75% (Richter's transformation). Conclusion Pirtobrutinib demonstrated promising efficacy in MCL and other NHL pts, was well-tolerated and exhibited a wide therapeutic index.

95 Background: mCRPC remains an incurable disease with unmet need for improved therapies. PARP inhibition has demonstrated antitumor activity, and preclinical studies suggest synergy between PARP and AKT inhibition. This phase Ib trial (NCT03840200) sought to determine the maximum tolerated dose of PARP inhibitor rucaparib (ruca) with AKT inhibitor ipatasertib (ipat) and explore early safety and efficacy in patients (pts) with mCRPC. Methods: The study had 2 parts: a part 1 dose-escalation phase (cohort [C]1: ipat 300 mg QD + ruca 400 mg BID; C2a: ipat 300 mg QD + ruca 600 mg BID; C2b ipat 400 mg QD + ruca 400 mg BID; C3: ipat 400 mg QD + ruca 600 mg BID) in unselected pts with mCRPC or advanced breast or ovarian cancer, and a Part 2 dose-expansion phase in pts with mCRPC whose previous androgen deprivation therapy failed. The primary safety endpoints were AEs and dose-limiting toxicities, with the goal of identifying a recommended phase II dose (RP2D). The primary efficacy endpoint was prostate-specific antigen (PSA) response (PSA reduction of ≥ 50%) in pts with mCRPC. Secondary efficacy endpoints included ORR per RECIST 1.1, radiographic PFS (rPFS) per Prostate Cancer Working Group 3 and OS in pts with mCRPC. We assessed homologous recombination deficiency (HRD), PIK3CA/ AKT1/ PTEN status and other alterations by next-generation sequencing. Results: Part 1 enrolled 21 pts: 17 with mCRPC, 3 with ovarian cancer and 1 with breast cancer (C1 [n=8], C2a [n=6] and C2b [n=7], C3 [not opened]). Ipat 400 mg QD + ruca 400 mg BID was the selected RP2D. 30 pts enrolled in Part 2, so 37 pts with mCRPC (C2b + Part 2) received the RP2D (median follow-up 93 days). All grade AEs occurred in 37 pts (100%), serious AEs in 8 pts (22%) and AEs leading to treatment modification in 26 pts (70%). The most frequent AEs (all grade and grade 3, respectively) were diarrhea (35 [95%] and 2 [5%]); asthenia (24 [65%] and 4 [11%]); and nausea (24 [65%] and 2 [5%]). There was 1 grade 4 AE (anemia) and no grade 5 AEs. See the table for efficacy data. In biomarker subgroups, the PSA response rate was 50% (3/6) in pts with HRD tumors vs 25% (4/16) in pts with HR-proficient tumors, and 14% (1/7) vs 40% (6/15) in pts with PIK3CA/ AKT1/ PTEN–altered or intact tumors, respectively. Conclusions: The combination of ipat and ruca was well tolerated but did not show clinically relevant antitumor activity in pts with mCRPC, including in predefined biomarker subpopulations. Clinical trial information: NCT03840200. [Table: see text]

TPS214 Background: Approximately 3% of patients (pts) with CRC have the oncogenic Kirsten rat sarcoma viral oncogene homolog (KRAS) p.G12C mutation. Sotorasib, a small molecule that specifically and irreversibly inhibits the KRAS G12C mutant protein, has demonstrated modest clinical activity and no dose-limiting toxicities as a single agent in heavily pretreated pts with KRAS p.G12C-mutated CRC. The combination of sotorasib with other anticancer therapies, such as EGFR or MEK inhibitors, may enhance antitumor efficacy and counteract potential escape mechanisms. Other attractive partners for sotorasib in CRC include biologics and chemotherapy combinations. The CodeBreaK 101 master protocol is designed to evaluate safety, tolerability, pharmacokinetics (PK), and efficacy of multiple sotorasib-based combinations in pts with KRAS p.G12C mutated solid tumors. Key subprotocols with CRC combination treatment arms are highlighted here. Methods: This is a phase 1b, open-label study evaluating sotorasib alone and in combination regimens in pts with advanced KRAS p.G12C mutated CRC, NSCLC, and other solid tumors. Key regimens being explored in CRC include (1) Subprotocol A: Sotorasib + trametinib (MEK inhibitor) +/- panitumumab (EGFR inhibitor), (2) Subprotocol H: Sotorasib + panitumumab and sotorasib + panitumumab + FOLFIRI, and (3) Subprotocol M: Sotorasib + bevacizumab-awwb + FOLFIRI or FOLFOX. Key eligibility criteria include advanced or metastatic solid tumor with KRAS p.G12C mutation identified through molecular testing in treatment-naïve and pretreated patients depending on cohort. Primary endpoints include dose-limiting toxicities and treatment-emergent or treatment-related adverse events. Secondary endpoints include PK profile of combination regimens and efficacy (objective response, disease control, duration of response, time to response, and progression-free survival assessed per RECIST 1.1, and overall survival). Enrollment is ongoing. Contact Amgen Medical Information for more information: medinfo@amgen.com (NCT04185883). Abbreviations: EGFR = epidermal growth factor receptor; FOLFIRI = 5-fluorouracil + leucovorin + irinotecan; FOLFOX = 5-fluorouracil + leucovorin + oxaliplatin; MEK = mitogen-activated protein kinase. Clinical trial information: NCT04185883.

297 Background: MT-5111 is a 55 kD engineered toxin body (ETB) targeting HER2 in solid tumors that binds to an epitope distinct from trastuzumab and pertuzumab, offering potential combination strategies with other HER2-targeting agents. MT-5111 may demonstrate efficacy in patients (pts) resistant to other HER2-targeting agents, as its mechanism of action induces direct cell kill via enzymatic and permanent ribosome destruction and does not rely on inhibition of kinase signaling or cytoskeletal or DNA damage. Methods: This is a phase 1 study in adult pts with advanced HER2+ solid tumors. The dose-escalation portion (modified 3+3 design) enrolls pts into sequential cohorts followed by expansion cohorts for HER2+ breast cancer (BC), gastric or gastroesophageal junction adenocarcinoma (GEA), and other HER2+ tumors. MT-5111 is dosed weekly IV over 30 min in each 21-day treatment (tx) cycle until disease progression, unacceptable toxicity, death, or withdrawn consent. Results: As of Sep 2021 (contains preliminary data), 24 pts (mean age 64 yrs) were treated, 13 (54%) of whom had gastrointestinal (GI) tumors (6 biliary, 3 GEA, 2 pancreatic, 2 colo/rectal) (Table). Pts with GI tumors had a median of 3 prior systemic tx and 1 prior HER2-targeting tx. No Grade (G) 4/5 tx-emergent adverse events (AEs) occurred. Tx-related AEs occurred in 13 (54%) pts, most commonly fatigue (n=7, 29%). One pt with biliary cancer and concurrent lymphangitic carcinomatosis and H. influenzae infection (4.5 µg/kg) had a possibly related G3 serious AE (SAE) of dyspnea, which resolved 9 days later. Another related SAE occurred in a pt with GEA (6.75 µg/kg) who had a G1 transient troponin increase that resolved during hospitalization, with no clinical symptoms or ECG/ECHO changes; the pt withdrew from study before further dosing. All other related AEs were ≤G2. No other clinically significant changes in cardiac biomarkers (troponin, ECG, LVEF) or cases of capillary leak syndrome occurred. Two pts (3 and 4.5 µg/kg) had reversible G2 infusion-related reactions. Best response to date has been stable disease. AUClast data matched PK simulations based on non-human primate studies. Cmax data at 10 µg/kg indicate that current in-pt exposure was between IC50 values of high and medium HER2-expressing cell lines (approx 10-89 ng/mL). Thus, at least 10 µg/kg may be required to achieve effective exposure. No dose-limiting toxicities have been observed. The 10 µg/kg cohort is now accruing. Following this cohort, an expansion cohort for pts with BC will open. Conclusions: MT-5111 was well tolerated with no clinically significant immuno/cardiotoxicity. Dose escalation is ongoing and is nearing levels expected to be required for efficacious exposure. Clinical trial information: NCT04029922. [Table: see text]

519 Background: KRAS, the most frequently mutated oncogene in cancer, is a key mediator of the RAS/MAPK signaling cascade that promotes cellular growth and proliferation. KRAS mutations occur in approximately 90% of pancreatic cancer, and approximately 2% of these are KRASG12C mutations. Adagrasib, an investigational agent, is a KRASG12C inhibitor that irreversibly and selectively binds KRASG12C, locking it in its inactive state; adagrasib has been optimized for favorable pharmacokinetic (PK) properties, including long half-life (̃24 h), extensive tissue distribution, dose-dependent PK, as well as CNS penetration. Methods: KRYSTAL-1 (NCT03785249) is a multicohort Phase 1/2 study evaluating adagrasib as monotherapy or in combinations in pts with advanced solid tumors harboring a KRASG12C mutation. Here we report preliminary data from pts enrolled in a Phase 2 cohort evaluating single-agent adagrasib administered orally at 600 mg BID in previously treated pts with unresectable or metastatic solid tumors (excluding NSCLC and CRC), including pancreatic and other GI cancers. Study endpoints include clinical activity, safety, and PK. Results: The data cutoff was 10 September 2021. A total of 42 pts were enrolled in this cohort (median age 63.5 years, range 21–89; 52% female; 71% white; 29%/71% ECOG PS 0/1; median 2 prior lines of therapy, range 1–7; median follow-up 6.3 months), of whom 30 pts had KRASG12C-mutant GI tumors (12 PDAC, 8 biliary tract, 5 appendiceal, 2 gastro-esophageal junction, 2 small bowel, and 1 esophageal). In a preliminary analysis, 27 pts with GI tumors were evaluable for clinical activity; partial responses (PRs) were seen in 41% (11/27, including 3 unconfirmed PRs); the disease control rate (DCR) was 100% (27/27). Of the 12 pts with PDAC (median 3 prior lines of therapy; median follow-up 8.1 months), 10 were evaluable for clinical activity; PRs were seen in 50% (5/10, including 1 unconfirmed PR); the DCR was 100% (10/10). Median progression-free survival (PFS) was 6.6 months (95% CI 1.0–9.7), and treatment was ongoing in 50% of pts with PDAC. Among the 17 evaluable pts with other GI tumors, 6 achieved PR (35%; 2 unconfirmed) with a DCR of 100% (17/17); 11 pts were still receiving treatment. In the overall cohort, treatment-related adverse events of any grade occurred in 91% (38/42), the most frequent being nausea (48%), diarrhea (43%), vomiting (43%), and fatigue (29%); grade 3/4 events occurred in 21% of pts, with no grade 5 events. Conclusions: Adagrasib monotherapy is well tolerated and demonstrates encouraging clinical activity in pretreated pts with PDAC and other GI tumors harboring a KRASG12C mutation. Further exploration of adagrasib is ongoing in this pt population (NCT03785249). Clinical trial information: NCT03785249.

We aimed to increase pathologic complete response (pCR) in patients with invasive breast cancer by adding preoperative capecitabine to docetaxel following 5‐fluorouracil, epirubicin, cyclophosphamide (FEC) (with trastuzumab for patients with HER2‐positive disease) and to evaluate 5‐year disease‐free survival (DFS) associated with this preoperative regimen. Chemotherapy included four cycles of FEC100 (5‐fluorouracil 500 mg/m2, epirubicin 100 mg/m2, cyclophosphamide 500 mg/m2 IV on Day 1 every 21 days) followed by 4 21‐day cycles of docetaxel (35 mg/m2 days 1 and 8) concurrently with capecitabine (825 mg/m2 orally twice daily for 14 days followed by 7 days off) (wTX). For HER2‐positive patients, treatment was modified by decreasing epirubicin to 75 mg/m2 and adding trastuzumab (H) in standard doses (FEC75‐H →wTX‐H). The study objective was to achieve a pCR rate in the breast and axillary lymph nodes of 37% in patients with HER2‐negative breast cancer and of 67% in patients with HER2‐positive breast cancer treated with preoperative trastuzumab. A total of 186 patients were enrolled on study. In an intent‐to‐treat analysis, the pCR rate was 31% (37/118, 95% CI: 24–40%) in the HER2‐negative patients, 24% (15/62, 95% CI: 14–37%) in ER‐positive/HER2‐negative patients, 39% (22/56, 95% CI: 27–53%) in the ER‐negative/HER2‐negative patients, and 46% (29/63, 95% CI: 34–48%) in the HER2‐positive patients. The pCR rate in the 40 trastuzumab‐treated patients was 53% (21/40, 95% CI: 38–67%). Grade 3 and 4 adverse events included neutropenia, leukopenia, diarrhea, and hand‐foot skin reactions. One trastuzumab‐treated patient developed grade 3 cardiotoxicity, and 4 others experienced grade 1–2 decrements in left ventricular function; all five patients’ cardiac function returned to their baseline upon completion of trastuzumab. At 5 years, disease‐free survival was 70% in the HER2‐negative population (78% in ER‐positive/HER2‐negative and 62% in the ER‐negative/HER2‐negative patients) and 80% in the HER2‐positive patients (87% in the trastuzumab‐treated HER2‐positive patients). At 5 years, overall survival was 80% in the HER2‐negative population (88% in ER‐positive/HER2‐negative and 71% in the ER‐negative/HER2‐negative patients) and 86% in the HER2‐positive patients (94.5% in the trastuzumab‐treated HER2‐positive patients). FEC100 (FEC75 with trastuzumab) followed by weekly docetaxel plus capecitabine, with or without trastuzumab is a safe, effective preoperative cytotoxic regimen. However, the addition of capecitabine to docetaxel following FEC, with or without trastuzumab, did not increase pCR rates nor 5‐year DFS over the rates that have been reported with standard preoperative doxorubicin/cyclophosphamide (AC) followed by paclitaxel, with or without trastuzumab. Therefore, the use of capecitabine as part of preoperative chemotherapy is not recommended.

Background: Covalent BTK inhibitors (BTKi) have transformed the management of mantle cell lymphoma (MCL), but these treatments are not curative and the majority of patients (pts) will require additional treatment. Covalent BTKi share pharmacologic liabilities (e.g. low oral bioavailability, short half-life) that collectively may lead to suboptimal BTK target coverage, for example in rapidly proliferating tumors with high BTK protein turnover such as MCL. To address these limitations, pirtobrutinib, a highly selective, non-covalent BTKi that inhibits both wild type (WT) and C481-mutated BTK with equal low nM potency was developed. In the phase 1/2 BRUIN study, pirtobrutinib achieved pharmacokinetic exposures that exceeded its BTK IC96 at trough, was well tolerated and demonstrated promising efficacy in heavily pretreated, poor-prognosis MCL pts, most of whom had prior treatment with a covalent BTKi (Mato et al. Lancet 2021;397, 10277:892-901). Methods: BRUIN is a multicenter phase 1/2 study (NCT03740529) of oral pirtobrutinib monotherapy in pts with advanced B-cell malignancies who have received >2 prior therapies. Pirtobrutinib was dose escalated in a standard 3+3 design in 28-day cycles. The primary objective for phase 1 was to determine the recommended phase 2 dose (RP2D) and the primary objective of phase 2 was overall response rate (ORR); secondary objectives included duration of response (DoR), progression-free survival (PFS), overall survival (OS), safety and tolerability, and pharmacokinetics. Efficacy evaluable pts included all dosed pts who underwent their first response evaluation or discontinued therapy. Response was assessed every 8 weeks from cycle 3, and every 12 weeks from cycle 13 and was measured according to Lugano Classification. Safety was assessed in all pts (CLL/SLL and NHL). Results: As of 27 September 2020, 323 pts (170 CLL/SLL, 61 MCL, 26 WM, 26 DLBCL, 13 MZL, 12 FL, 9 RT, and 6 other NHL [other transformation, B-PLL and hairy cell leukemia]) were treated on 7 dose levels (25-300mg QD). Median age was 69 (range 50-87) years for MCL pts. Among the 61 MCL pts, median number of prior lines of therapy was 3 (range, 1-8) and a majority of them had received a prior BTKi (93%), an anti-CD20 antibody (98%) or chemotherapy (92%). No DLTs were reported and MTD was not reached (n=323). 200mg QD was selected as the RP2D. Fatigue (20%), diarrhea (17%), and contusion (13%) were the most frequent treatment-emergent adverse events regardless of attribution or grade seen in >10% of pts (n=323). The most common adverse event of grade ≥3 was neutropenia (10%). Treatment-related hemorrhage and hypertension occurred in 5 (2%) and 4 (1%) pts, respectively. Five (1%) pts discontinued due to treatment-related adverse events. At the efficacy cutoff date, 52 prior BTKi treated MCL pts were efficacy evaluable with an ORR of 52% (95% CI 38-66; 13 CR [25%], 14 PR [27%], 9 SD [17%], 11 PD [21%] and 5 [10%] pts discontinued prior to first response assessment). Median follow up was 6 months (range 0.7-18.3+). Responses were observed in 9/14 pts (64%) with prior autologous or allogeneic stem cell transplant, and 2 of 2 with prior CAR-T cell therapy. Conclusion: Pirtobrutinib demonstrated promising efficacy in heavily pretreated, poor-prognosis MCL following multiple prior lines of therapy, including a covalent BTKi. Pirtobrutinib was well tolerated and exhibited a wide therapeutic index. Updated data, including approximately 60 new pts with MCL and an additional 10 months since the prior data cut will be presented. Disclosures Wang: Juno: Consultancy, Research Funding; Miltenyi Biomedicine GmbH: Consultancy, Honoraria; Lilly: Research Funding; Moffit Cancer Center: Honoraria; Newbridge Pharmaceuticals: Honoraria; VelosBio: Consultancy, Research Funding; OMI: Honoraria; BGICS: Honoraria; Mumbai Hematology Group: Honoraria; BioInvent: Research Funding; CStone: Consultancy; Hebei Cancer Prevention Federation: Honoraria; Celgene: Research Funding; Oncternal: Consultancy, Research Funding; Molecular Templates: Research Funding; Epizyme: Consultancy, Honoraria; InnoCare: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Clinical Care Options: Honoraria; AstraZeneca: Consultancy, Honoraria, Research Funding; Chinese Medical Association: Honoraria; Scripps: Honoraria; Imedex: Honoraria; Physicians Education Resources (PER): Honoraria; The First Afflicted Hospital of Zhejiang University: Honoraria; DTRM Biopharma (Cayman) Limited: Consultancy; Dava Oncology: Honoraria; Genentech: Consultancy; Janssen: Consultancy, Honoraria, Research Funding; Anticancer Association: Honoraria; BeiGene: Consultancy, Honoraria, Research Funding; CAHON: Honoraria; Kite Pharma: Consultancy, Honoraria, Research Funding; Bayer Healthcare: Consultancy; Loxo Oncology: Consultancy, Research Funding; Acerta Pharma: Consultancy, Honoraria, Research Funding. Shah: Epizyme: Consultancy; Miltenyi Biotec: Consultancy, Honoraria, Research Funding; Lily: Consultancy, Honoraria, Research Funding; Incyte: Consultancy; Umoja: Consultancy; Kite: Consultancy; Legend: Consultancy. Alencar: Amgen: Consultancy; BeiGene: Consultancy; Celgene: Consultancy; Epizyme: Consultancy; Incyte: Consultancy; Janssen: Consultancy; Karyopharm: Consultancy; Kite Pharma: Consultancy; Seattle Genetics: Consultancy. Gerson: Abbvie, Genentech: Membership on an entity's Board of Directors or advisory committees; Loxo Oncology at Lilly: Research Funding. Patel: Hutchinson MediPharma: Research Funding; Florida Cancer Specialists: Research Funding; Mirati Therapeutics: Research Funding; Lycera: Research Funding; Millennium Pharmaceuticals: Research Funding; Mabspace: Research Funding; Macrogenics: Research Funding; Merck: Research Funding; Daiichi Sankyo: Research Funding; Effector Therapeutics: Research Funding; Cyteir Therapeutics: Research Funding; ADC Therapeutics: Research Funding; Vedanta: Research Funding; Loxo Oncology: Research Funding; Forma Therapeutics: Research Funding; Genentech/Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Research Funding; GlaxoSmithKline: Research Funding; LSK Biopartners: Research Funding; ModernaTX: Research Funding; ORIC Pharmaceuticals: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; Phoenix Molecular Designs: Research Funding; Placon Therapeutics: Research Funding; Portola Pharmaceuticals: Research Funding; Prelude Therapeutics: Research Funding; Qilu Puget Sound Biotherapeutics: Research Funding; Revolution Medicines: Research Funding; Ribon Therapeutics: Research Funding; Exelixis: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Alexion, AstraZeneca Rare Disease: Other: Study investigator; Evelo Biosciences: Research Funding; EMD Serono: Membership on an entity's Board of Directors or advisory committees, Research Funding; Boehringer Ingelheim: Research Funding; Eli Lilly: Research Funding; Curis: Research Funding; Jacobio: Research Funding; Acerta Pharma: Research Funding; AstraZeneca: Research Funding; Ciclomed: Research Funding; BioNTech: Research Funding; Clovis: Research Funding; Checkpoint Therapeutics: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Calithera: Research Funding; Bicycle Therapeutics: Research Funding; Artios Pharma: Research Funding; TopAlliance: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Stemline Therapeutics: Research Funding; Seven and Eight Biopharmaceuticals: Research Funding; Taiho: Research Funding; H3 Biomedicine: Research Funding; Vigeo: Research Funding; Tesaro: Research Funding; Aileron Therapeutics: Research Funding; Agenus: Research Funding; Ignyta: Research Funding; Xencor: Research Funding; Syndax: Research Funding; Synthorx: Research Funding; Incyte: Research Funding; Kymab: Research Funding; Hengrui: Research Funding; Verastem: Research Funding; Takeda: Research Funding; Klus Pharma: Research Funding; Jounce Therapeutics: Research Funding. Fakhri: Loxo/Lilly: Research Funding. Jurczak: European Medicines Agency, Sandoz-Novartis, Janssen China R&D, BeiGene, Epizyme, Acerta, AstraZeneca: Consultancy; Jagiellonian University: Ended employment in the past 24 months; AbbVie, AstraZeneca, Bayer, BeiGene, Celtrion, Celgene, Debbiopharm, Epizyme, Incyte, Janssen, Loxo Oncology, Merck, Mei Pharma, Morphosys, Novo Nordisk, Roche, Sandoz, Takeda, TG Therapeutics, Pharmacyclics, Affirmed, Gilead Sciences, Nordic Nanovecto: Research Funding; AstraZeneca, BeiGene, Janssen, Loxo Oncology, Sandoz, Roche: Membership on an entity's Board of Directors or advisory committees; Maria Sklodowska-Curie National Research Institute of Oncology: Current Employment. Lewis: AstraZeneca: Consultancy, Honoraria; Janssen: Honoraria, Patents & Royalties; Novartis: Patents & Royalties; Roche: Consultancy, Honoraria. Fenske: Sanofi: Speakers Bureau; Pharmacyclics: Consultancy; Servier Pharmaceuticals: Consultancy; Kite (Gilead): Speakers Bureau; MorphoSys: Consultancy; TG Therapeutics: Consultancy, Speakers Bureau; Seattle Genetics: Speakers Bureau; KaryoPharm: Consultancy; CSL Therapeutics: Consultancy; Bristol-Myers Squibb: Speakers Bureau; Biogen: Consultancy; Beigene: Consultancy; AstraZeneca: Speakers Bureau; ADC Therapeutics: Consultancy; Adaptive Biotechnologies: Consultancy; AbbVie: Consultancy. Coombs: LOXO: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria; AstraZeneca: Honoraria; AbbVie: Honoraria; Genentech: Honoraria; MEI Pharma: Honoraria. Flinn: Celgene: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Acerta Pharma: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Takeda: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Forty Seven: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Kite, a Gilead Company: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; ArQule: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Agios: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; IGM Biosciences: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; TG Therapeutics: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Triphase Research & Development Corp.: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Forma Therapeutics: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Merck: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Nurix Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Juno Therapeutics: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Roche: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Calithera Biosciences: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Unum Therapeutics: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Seagen: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; AstraZeneca: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Verastem: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Yingli Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; MorphoSys: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Constellation Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Loxo: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Incyte: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Karyopharm Therapeutics: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Infinity Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Curis: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Novartis: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Pfizer: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Trillium Therapeutics: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Portola Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Rhizen Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Teva: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; AbbVie: Consultancy, Other: All Consultancy and Research Funding payments made to Sarah Cannon Research Institute, Research Funding; BeiGene: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Genentech: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Gilead Sciences: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Great Point Partners: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Iksuda Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Janssen: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Century Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Hutchison MediPharma: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Vincerx Pharma: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Sarah Cannon Research Institute: Current Employment; Servier Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Yingli Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Seagen: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Servier Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Unum Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute, Research Funding; Johnson & Johnson: Current holder of individual stocks in a privately-held company; Seattle Genetics: Research Funding. Lewis: Loxo Oncology at Lilly: Membership on an entity's Board of Directors or advisory committees. Palomba: Pluto: Honoraria; Priothera: Honoraria; Wolters Kluwer: Patents & Royalties; WindMIL: Honoraria; Notch: Honoraria, Other: Stock; Ceramedix: Honoraria; Novartis: Consultancy; Kite: Consultancy; PCYC: Consultancy; Lygenesis: Honoraria; Seres: Honoraria, Other: Stock, Patents & Royalties, Research Funding; Juno: Patents & Royalties; Nektar: Honoraria; Rheos: Honoraria; BeiGene: Consultancy; Magenta: Honoraria. Woyach: AbbVie Inc, ArQule Inc, Janssen Biotech Inc, AstraZeneca, Beigene: Other: Advisory Committee; AbbVie Inc, ArQule Inc, AstraZeneca Pharmaceuticals LP, Janssen Biotech Inc, Pharmacyclics LLC, an AbbVie Company,: Consultancy; AbbVie Inc, Loxo Oncology Inc, a wholly owned subsidiary of Eli Lilly & Company: Research Funding; Gilead Sciences Inc: Other: Data & Safety. Pagel: Pharmacyclics/AbbVie: Consultancy; Epizyme: Consultancy; MEI Pharma: Consultancy; Actinium Pharmaceuticals: Consultancy; Incyte/MorphoSys: Consultancy; AstraZeneca: Consultancy; Kite, a Gilead Company: Consultancy; BeiGene: Consultancy; Gilead: Consultancy. Lamanna: Juno Therapeutics, Inc.: Research Funding; Pharmacyclics: Consultancy; MingSight Pharmaceuticals, Inc.: Research Funding; Janssen Pharmaceuticals, Inc.: Consultancy; TG Therapeutics, Inc: Research Funding; Oncternal Therapeutics: Research Funding; AbbVie: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; BeiGene: Consultancy; Celgene Corporation: Consultancy; Genentech, Inc.: Consultancy, Research Funding; Gilead Sciences, Inc.: Consultancy; Verastem Oncology: Research Funding. Cohen: Genentech, BMS/Celgene, LAM, BioINvent, LOXO, Astra Zeneca, Novartis, M2Gen, Takeda: Research Funding; Janssen, Adicet, Astra Zeneca, Genentech, Aptitude Health, Cellectar, Kite/Gilead, Loxo, BeiGene, Adaptive: Consultancy. Ghia: AbbVie: Consultancy, Honoraria, Research Funding; Sunesis: Research Funding; Roche: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Acerta/AstraZeneca: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding; BeiGene: Consultancy, Honoraria; ArQule/MSD: Consultancy, Honoraria; Celgene/Juno/BMS: Consultancy, Honoraria; Gilead: Consultancy, Research Funding. Eyre: Abbvie: Consultancy, Honoraria, Other: Travel to conferences; Loxo Oncology: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Consultancy; Gilead/KITE: Honoraria, Other: Travel support for conferences, Research Funding, Speakers Bureau; Secura Bio: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Beigene: Honoraria, Research Funding; Janssen: Honoraria; AstraZeneca: Honoraria, Research Funding. Zinzani: Janssen-Cilag: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Servier: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bristol Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Therapeutics Inc: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BeiGene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kyowa Kirin: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ImmuneDesign: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Portola: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; EUSA Pharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ADC Therapeutics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck Sharp & Dohme: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Ujjani: Gilead: Honoraria; TG Therapeutics: Honoraria; Janssen: Consultancy; Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Atara Bio: Consultancy; Loxo: Research Funding; Adaptive Biotechnologies: Research Funding; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; ACDT: Honoraria; Kite, a Gilead Company: Honoraria; AbbVie: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding. Koh: Pfizer: Consultancy; Jassen: Honoraria; AstraZeneca: Honoraria; Novartis: Honoraria; GSK: Honoraria; Roche: Honoraria; Takeda: Honoraria. Izutsu: Yakult: Research Funding; Symbio: Honoraria; Takeda: Honoraria, Research Funding; Solasia: Research Funding; Pfizer: Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; MSD: Research Funding; Kyowa Kirin: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Incyte: Research Funding; Huya Biosciences: Research Funding; Genmab: Honoraria, Research Funding; Fuji Film Toyama Chemical: Honoraria; Eisai: Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Chugai: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Beigene: Research Funding; Bayer: Research Funding; AstraZeneca: Honoraria, Research Funding; Allergan Japan: Honoraria; AbbVie: Honoraria. Lech-Marańda: Sanofi: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Janssen-Cilag: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees. Tam: Loxo: Consultancy; Janssen: Consultancy, Honoraria, Research Funding; BeiGene: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria, Research Funding; Novartis: Honoraria; Roche: Consultancy, Honoraria; Pharmacyclics: Honoraria. Yin: Loxo Oncology at Lilly: Current Employment; AstraZeneca: Ended employment in the past 24 months. Nair: Loxo Oncology at Lilly: Current Employment, Current equity holder in publicly-traded company. Balbas: Nektar Therapeutics: Current equity holder in publicly-traded company, Ended employment in the past 24 months; Loxo Oncology at Lilly: Current Employment, Current equity holder in publicly-traded company. Tsai: Loxo Oncology at Lilly: Current Employment, Current equity holder in publicly-traded company. Mato: LOXO: Consultancy, Research Funding; Genmab: Research Funding; Sunesis: Consultancy, Research Funding; AstraZeneca: Consultancy; MSKCC: Current Employment; Johnson and Johnson: Consultancy, Research Funding; TG Therapeutics: Consultancy, Other: DSMB, Research Funding; Nurix: Research Funding; DTRM BioPharma: Consultancy, Research Funding; Acerta/AstraZeneca: Consultancy, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; Adaptive Biotechnologies: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; BeiGene: Consultancy, Research Funding; Janssen: Consultancy, Research Funding. Cheah: Novartis: Consultancy, Honoraria; Beigene: Consultancy, Honoraria; TG therapeutics: Consultancy, Honoraria; Lilly: Consultancy, Honoraria; AstraZeneca: Consultancy, Honoraria; Ascentage Pharma: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; MSD: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Abbvie: Research Funding; BMS: Consultancy, Research Funding; Roche: Consultancy, Honoraria, Other: travel, Research Funding.

Background: Covalent BTK inhibitors (BTKi) have transformed the management of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), but these treatments are not curative and many patients (pts) will require additional treatment. Covalent BTKi share pharmacologic liabilities (e.g. low oral bioavailability, short half-life) that collectively may lead to suboptimal BTK target coverage, for example in rapidly proliferating tumors with high BTK protein turnover such as accelerating CLL/SLL, ultimately manifesting as acquired resistance in some pts. To address these limitations, pirtobrutinib, a highly selective, non-covalent BTKi that inhibits both wild type (WT) and C481-mutated BTK with equal low nM potency was developed. In the phase 1/2 BRUIN study, pirtobrutinib achieved pharmacokinetic exposures that exceeded its BTK IC96 at trough, was well tolerated and demonstrated promising efficacy in CLL/SLL pts regardless of prior therapy, number of prior lines of therapy, or BTK C481 mutation status(Mato et al. Lancet 2021;397,10277:892-901). Methods: BRUIN is a phase 1/2 multicenter study (NCT03740529) of oral pirtobrutinib monotherapy in pts with advanced B-cell malignancies who have received >2 prior therapies. Pirtobrutinib was dose escalated in a standard 3+3 design in 28-day cycles. The primary objective for phase 1 was to determine the recommended phase 2 dose (RP2D) and the primary objective of phase 2 was overall response rate (ORR); secondary objectives included duration of response (DoR), progression-free survival (PFS), overall survival (OS), safety and tolerability, and pharmacokinetics. Efficacy evaluable pts included all dosed pts who underwent their first response evaluation or discontinued therapy. Response was assessed every 8 weeks from cycle 3, and every 12 weeks from cycle 13 and was measured according to the iwCLL 2018 criteria, including PR with lymphocytosis (PR-L). Safety was assessed in all pts (CLL/SLL and NHL). Results: As of 27 September 2020, 323 pts with B-cell malignancies (170 CLL/SLL, 61 MCL, 26 WM, 26 DLBCL, 13 MZL, 12 FL, 9 RT, and 6 other [other transformation, B-PLL and hairy cell leukemia]) were treated on 7 dose levels (25-300mg QD). Among the 170 pts with CLL/SLL, the median age was 69 (range 36-88) years. Median number of prior lines of therapies was 3 (range 1-11). Majority of the CLL/SLL pts had received a prior BTKi (86%), an anti-CD20 antibody (90%), or a chemotherapy (82%); 21% had received a PI3K inhibitor and 34% a BCL2 inhibitor. High risk molecular features such as 17p deletion, TP53 mutation, and unmutated IGHV were present in 25% (20/81), 30% (27/91), and 88% (71/81) of pts, respectively. No DLTs were reported and MTD was not reached (n=323). 200mg QD was selected as the RP2D. Fatigue (20%), diarrhea (17%), and contusion (13%) were the most frequent treatment-emergent adverse events regardless of attribution or grade seen in >10% of pts (n=323). The most common adverse event of grade ≥3 was neutropenia (10%). Treatment-related hemorrhage and hypertension occurred in 5 (2%) and 4 (1%) pts, respectively. Five (1%) pts discontinued due to treatment-related adverse events. At the efficacy cutoff date, 139 CLL/SLL pts were efficacy-evaluable with a median follow up time of 6 months (range 0.16-17.8+). The ORR was 63% (95% CI 55-71) among the 139 efficacy evaluable pts with 69 PRs (50%), 19 PR-Ls (14%), 45 SDs (32%), and 1 PD (1%), and 5 (4%) pts discontinued prior to first response assessment. Among the 121 BTKi pretreated pts, the ORR was 62% (95% CI 53-71). Responses deepened over time with an ORR of 86% among the pts with at least 10 months follow-up. ORR was similar in pts who discontinued prior BTKi due to progression (67%), or adverse events or other reasons (52%). Of the 88 responding pts, all except 5 remained on therapy (4 progressed and 1 achieved a PR and electively discontinued treatment to undergo transplant). The longest-followed responding patient as of the data cutoff date had been on treatment for 17.8+ months. Conclusion: Pirtobrutinib demonstrated promising efficacy in heavily pretreated CLL/SLL pts following multiple prior lines of therapy, including a covalent BTKi and a BCL2 inhibitor, and in pts with BTK C481 mutations. Pirtobrutinib was well tolerated and exhibited a wide therapeutic index. Updated data, including approximately 100 new pts with CLL and an additional 10 months since the prior data cut will be presented. Disclosures Mato: MSKCC: Current Employment; Acerta/AstraZeneca: Consultancy, Research Funding; AstraZeneca: Consultancy; Johnson and Johnson: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Genmab: Research Funding; TG Therapeutics: Consultancy, Other: DSMB, Research Funding; Janssen: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Adaptive Biotechnologies: Consultancy, Research Funding; DTRM BioPharma: Consultancy, Research Funding; LOXO: Consultancy, Research Funding; Nurix: Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; BeiGene: Consultancy, Research Funding; Sunesis: Consultancy, Research Funding. Pagel: AstraZeneca: Consultancy; Gilead: Consultancy; Pharmacyclics/AbbVie: Consultancy; BeiGene: Consultancy; Epizyme: Consultancy; MEI Pharma: Consultancy; Kite, a Gilead Company: Consultancy; Actinium Pharmaceuticals: Consultancy; Incyte/MorphoSys: Consultancy. Coombs: LOXO: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria; AstraZeneca: Honoraria; AbbVie: Honoraria; Genentech: Honoraria; MEI Pharma: Honoraria. Shah: Incyte: Consultancy; Miltenyi Biotec: Consultancy, Honoraria, Research Funding; Umoja: Consultancy; Lily: Consultancy, Honoraria, Research Funding; Legend: Consultancy; Epizyme: Consultancy; Kite: Consultancy. Lamanna: AstraZeneca: Consultancy, Research Funding; TG Therapeutics, Inc: Research Funding; Juno Therapeutics, Inc.: Research Funding; Genentech, Inc.: Consultancy, Research Funding; Oncternal Therapeutics: Research Funding; AbbVie: Consultancy, Research Funding; BeiGene: Consultancy; Celgene Corporation: Consultancy; Verastem Oncology: Research Funding; Janssen Pharmaceuticals, Inc.: Consultancy; MingSight Pharmaceuticals, Inc.: Research Funding; Pharmacyclics: Consultancy; Gilead Sciences, Inc.: Consultancy. Munir: Janssen, Abbvie, AstraZeneca, Alexion, Apellis, Gilead, Novartis: Honoraria; Janssen, Abbvie, AstraZeneca, Morphosys, Alexion, Gilead, Novartis: Membership on an entity's Board of Directors or advisory committees. Lech-Marańda: Takeda: Membership on an entity's Board of Directors or advisory committees; Janssen-Cilag: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees. Eyre: Janssen: Honoraria; Roche: Consultancy, Honoraria; AstraZeneca: Honoraria, Research Funding; Abbvie: Consultancy, Honoraria, Other: Travel to conferences; Gilead/KITE: Honoraria, Other: Travel support for conferences, Research Funding, Speakers Bureau; Incyte: Consultancy; Secura Bio: Consultancy, Honoraria; Beigene: Honoraria, Research Funding; Loxo Oncology: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Woyach: AbbVie Inc, Loxo Oncology Inc, a wholly owned subsidiary of Eli Lilly & Company: Research Funding; Gilead Sciences Inc: Other: Data & Safety; AbbVie Inc, ArQule Inc, Janssen Biotech Inc, AstraZeneca, Beigene: Other: Advisory Committee; AbbVie Inc, ArQule Inc, AstraZeneca Pharmaceuticals LP, Janssen Biotech Inc, Pharmacyclics LLC, an AbbVie Company,: Consultancy. Wierda: Xencor: Research Funding; Gilead Sciences: Research Funding; Karyopharm: Research Funding; Acerta Pharma Inc.: Research Funding; KITE Pharma: Research Funding; Pharmacyclics LLC, an AbbVie Company: Research Funding; Sunesis: Research Funding; Miragen: Research Funding; Oncternal Therapeutics, Inc.: Research Funding; AbbVie: Research Funding; Loxo Oncology, Inc.: Research Funding; Genzyme Corporation: Consultancy; Juno Therapeutics: Research Funding; GSK/Novartis: Research Funding; Cyclacel: Research Funding; Janssen: Research Funding; Genentech: Research Funding; AstraZeneca: Research Funding. Cheah: TG Therapeutics: Consultancy, Honoraria, Other: advisory; AbbVie: Research Funding; Celgene: Research Funding; AstraZeneca: Consultancy, Honoraria, Other: advisory; MSD: Consultancy, Honoraria, Other: advisory, Research Funding; Janssen: Consultancy, Honoraria, Other: advisory; Roche: Consultancy, Honoraria, Other: advisory and travel expenses, Research Funding; Gilead: Consultancy, Honoraria, Other: advisory; Loxo/Lilly: Consultancy, Honoraria, Other: advisory; Beigene: Consultancy, Honoraria, Other: advisory; Ascentage pharma: Consultancy, Honoraria, Other: advisory. Cohen: Genentech, BMS/Celgene, LAM, BioINvent, LOXO, Astra Zeneca, Novartis, M2Gen, Takeda: Research Funding; Janssen, Adicet, Astra Zeneca, Genentech, Aptitude Health, Cellectar, Kite/Gilead, Loxo, BeiGene, Adaptive: Consultancy. Roeker: Pfizer: Consultancy, Research Funding; TG Therapeutics: Consultancy; Pharmacyclics: Consultancy; Loxo Oncology: Consultancy; Abbot Laboratories: Current equity holder in publicly-traded company; AbbVie, AstraZeneca, Janssen, LOXO, Pharmacyclics, TG Therapeutics, Vaniam Group, Verastem: Consultancy. Patel: H3 Biomedicine: Research Funding; Ribon Therapeutics: Research Funding; Evelo Biosciences: Research Funding; Aileron Therapeutics: Research Funding; Portola Pharmaceuticals: Research Funding; Phoenix Molecular Designs: Research Funding; Jacobio: Research Funding; Placon Therapeutics: Research Funding; Forma Therapeutics: Research Funding; Ciclomed: Research Funding; Clovis: Research Funding; Curis: Research Funding; Cyteir Therapeutics: Research Funding; Daiichi Sankyo: Research Funding; Effector Therapeutics: Research Funding; Eli Lilly: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Jounce Therapeutics: Research Funding; Klus Pharma: Research Funding; Kymab: Research Funding; Loxo Oncology: Research Funding; LSK Biopartners: Research Funding; Lycera: Research Funding; Mabspace: Research Funding; AstraZeneca: Research Funding; Bicycle Therapeutics: Research Funding; BioNTech: Research Funding; Boehringer Ingelheim: Research Funding; Takeda: Research Funding; Tesaro: Research Funding; TopAlliance: Research Funding; Vedanta: Research Funding; Verastem: Research Funding; Vigeo: Research Funding; Xencor: Research Funding; Exelixis: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Alexion, AstraZeneca Rare Disease: Other: Study investigator; Taiho: Research Funding; Stemline Therapeutics: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; ORIC Pharmaceuticals: Research Funding; ModernaTX: Research Funding; Mirati Therapeutics: Research Funding; Millennium Pharmaceuticals: Research Funding; Ignyta: Research Funding; Checkpoint Therapeutics: Research Funding; Synthorx: Research Funding; Prelude Therapeutics: Research Funding; Merck: Research Funding; Agenus: Research Funding; ADC Therapeutics: Research Funding; Acerta Pharma: Research Funding; Florida Cancer Specialists: Research Funding; GlaxoSmithKline: Research Funding; Revolution Medicines: Research Funding; Gilead: Research Funding; EMD Serono: Membership on an entity's Board of Directors or advisory committees, Research Funding; Calithera: Research Funding; Artios Pharma: Research Funding; Hutchinson MediPharma: Research Funding; Syndax: Research Funding; Qilu Puget Sound Biotherapeutics: Research Funding; Macrogenics: Research Funding; Incyte: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Seven and Eight Biopharmaceuticals: Research Funding; Hengrui: Research Funding; Genentech/Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding. Fakhri: Loxo/Lilly: Research Funding. Tam: Loxo: Consultancy; Janssen: Consultancy, Honoraria, Research Funding; BeiGene: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria; Novartis: Honoraria; Pharmacyclics: Honoraria. Lewis: Loxo Oncology at Lilly: Membership on an entity's Board of Directors or advisory committees. Gerson: Abbvie, Genentech: Membership on an entity's Board of Directors or advisory committees; Loxo Oncology at Lilly: Research Funding. Alencar: Amgen: Consultancy; BeiGene: Consultancy; Celgene: Consultancy; Epizyme: Consultancy; Incyte: Consultancy; Janssen: Consultancy; Karyopharm: Consultancy; Kite Pharma: Consultancy; Seattle Genetics: Consultancy. Ujjani: Kite, a Gilead Company: Honoraria; ACDT: Honoraria; Gilead: Honoraria; Janssen: Consultancy; TG Therapeutics: Honoraria; Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Atara Bio: Consultancy; Loxo: Research Funding; Adaptive Biotechnologies: Research Funding; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding. Flinn: Celgene: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Trillium Therapeutics: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Gilead Sciences: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; BeiGene: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Genentech: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; AbbVie: Consultancy, Other: All Consultancy and Research Funding payments made to Sarah Cannon Research Institute, Research Funding; AstraZeneca: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Merck: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Iksuda Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Portola Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Pfizer: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Loxo: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Incyte: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Kite, a Gilead Company: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Karyopharm Therapeutics: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Rhizen Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; MorphoSys: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Janssen: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Constellation Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Great Point Partners: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Teva: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Curis: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Forma Therapeutics: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Infinity Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Takeda: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Roche: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Juno Therapeutics: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; IGM Biosciences: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Forty Seven: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Novartis: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Calithera Biosciences: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Nurix Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; ArQule: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; TG Therapeutics: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Agios: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Verastem: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Unum Therapeutics: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Yingli Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Acerta Pharma: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Seagen: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Triphase Research & Development Corp.: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Century Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Hutchison MediPharma: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Vincerx Pharma: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Sarah Cannon Research Institute: Current Employment; Servier Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Yingli Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Seagen: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Servier Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Unum Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute, Research Funding; Johnson & Johnson: Current holder of individual stocks in a privately-held company; Seattle Genetics: Research Funding. Ma: Loxo: Research Funding; AstraZeneca: Honoraria, Research Funding, Speakers Bureau; Juno: Research Funding; Beigene: Research Funding, Speakers Bureau; Abbvie: Honoraria, Research Funding; Janssen: Research Funding, Speakers Bureau; TG Therapeutics: Research Funding; Pharmacyclics: Research Funding, Speakers Bureau. Rhodes: Conquer Cancer Foundation Young Investigator Award: Other: Grant/Research Support; AbbVie, Genentech, Pharmacyclics, TG Therapeutics: Other: Consultant. Abdel-Wahab: H3B Biomedicine: Consultancy, Research Funding; Foundation Medicine Inc: Consultancy; Merck: Consultancy; Prelude Therapeutics: Consultancy; LOXO Oncology: Consultancy, Research Funding; Lilly: Consultancy; AIChemy: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Envisagenics Inc.: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees. Ghia: Gilead: Consultancy, Research Funding; Roche: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Acerta/AstraZeneca: Consultancy, Honoraria, Research Funding; ArQule/MSD: Consultancy, Honoraria; AstraZeneca: Consultancy, Honoraria, Research Funding; BeiGene: Consultancy, Honoraria; Celgene/Juno/BMS: Consultancy, Honoraria; Sunesis: Research Funding. Schuster: Abbvie: Consultancy, Research Funding; Incyte: Research Funding; TG Theraputics: Research Funding; Tessa Theraputics: Consultancy; Acerta Pharma/AstraZeneca: Consultancy; Nordic Nanovector: Consultancy; Novartis: Consultancy, Honoraria, Patents & Royalties, Research Funding; Alimera Sciences: Consultancy; BeiGene: Consultancy; Juno Theraputics: Consultancy, Research Funding; Loxo Oncology: Consultancy; Genentech/Roche: Consultancy, Research Funding; Merck: Research Funding; Pharmacyclics: Research Funding; Adaptive Biotechnologies: Research Funding; Celgene: Consultancy, Honoraria, Research Funding. Wang: Loxo Oncology at Lilly: Current Employment. Nair: Loxo Oncology at Lilly: Current Employment, Current equity holder in publicly-traded company. Zhu: Loxo Oncology at Lilly: Current Employment, Current equity holder in publicly-traded company. Tsai: Loxo Oncology at Lilly: Current Employment, Current equity holder in publicly-traded company. Davids: AbbVie: Consultancy; Verastem: Consultancy, Research Funding; MEI Pharma: Consultancy; Surface Oncology: Research Funding; Eli Lilly and Company: Consultancy; Adaptive Biotechnologies: Consultancy; BeiGene: Consultancy; Astra-Zeneca: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; MEI Pharma: Consultancy, Research Funding; Janssen: Consultancy; Celgene: Consultancy; TG Therapeutics: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Merck: Consultancy; Research to Practice: Consultancy; Takeda: Consultancy; Ascentage Pharma: Consultancy, Research Funding. Brown: Genentech/Roche: Consultancy; Invectys: Other: Data Safety Monitoring Committee Service; SecuraBio: Research Funding; Sun: Research Funding; TG Therapeutics: Research Funding; Loxo/Lilly: Research Funding; Eli Lilly and Company: Consultancy; MEI Pharma: Consultancy; Morphosys AG: Consultancy; Nextcea: Consultancy; Janssen: Consultancy; Novartis: Consultancy; Pfizer: Consultancy; Rigel: Consultancy; Acerta/Astra-Zeneca: Consultancy; Beigene: Consultancy; Gilead: Research Funding; Abbvie: Consultancy; Bristol-Myers Squib/Juno/Celegene: Consultancy; Catapult: Consultancy. Jurczak: European Medicines Agency, Sandoz-Novartis, Janssen China R&D, BeiGene, Epizyme, Acerta, AstraZeneca: Consultancy; AstraZeneca, BeiGene, Janssen, Loxo Oncology, Sandoz, Roche: Membership on an entity's Board of Directors or advisory committees; AbbVie, AstraZeneca, Bayer, BeiGene, Celtrion, Celgene, Debbiopharm, Epizyme, Incyte, Janssen, Loxo Oncology, Merck, Mei Pharma, Morphosys, Novo Nordisk, Roche, Sandoz, Takeda, TG Therapeutics, Pharmacyclics, Affirmed, Gilead Sciences, Nordic Nanovecto: Research Funding; Maria Sklodowska-Curie National Research Institute of Oncology: Current Employment; Jagiellonian University: Ended employment in the past 24 months.

BackgroundTHOR-707 (SAR444245) is a recombinant human IL-2 molecule irreversibly bound to a PEG chain to block alpha-binding while retaining near-native affinity for beta/gamma IL-2 receptor subunits. We report updated results from the ongoing HAMMER phase 1/2 trial.MethodsSAR444245 was given via IV infusion as monotherapy Q2W [A] or Q3W [B], with pembrolizumab 200mg IV Q3W [C], or Q3W with cetuximab 400mg/m2 IV on D1 then 250mg/m2 IV QW [D] after pre-medication and peri-infusion hydration. A 3+3 design was used to identify the MTD/RP2D in pts with advanced solid tumors. Key objectives included assessments of safety, efficacy, pharmacokinetics (PK) and pharmacodynamics (PD).Results68 pts, median age 61.5 (37–78) yrs with median 3 (1–10) prior therapies enrolled. Most common tumors: melanoma (n=10), colorectal (n=11). Doses tested by cohort: [A]: 8–16 µg/kg (n=9); [B]: 8–40 µg/kg (n=29); [C]: 8–32 µg/kg (n=20); [D]: 16–24 µg/kg (n=10). The most common (>30%) AEs included pyrexia (52.5%), nausea (50.0%), flu-like symptoms (44.1%), vomiting (36.8%), chills (32.4%), fatigue (32.4%), AST elevation (30.9%). AEs generally resolved promptly with supportive care. Grade(G) 3/4 (>5%) related AEs included ALT/AST elevation (5.9%), and decreased lymphocyte count (26.5% within first 24 hrs, recovering by 48–72 hrs, this lymphocyte migration is mechanistically consistent with immune cell margination). G3/4 CRS was observed in 2 pts. Two DLTs occurred: G3 infusion reaction (32 µg/kg [B]) and G3 AST/ALT/G2 bilirubin elevation with G2 CRS (24 µg/kg [C]). No vascular leak syndrome, QTc prolongation, cardiac, or end organ toxicity was observed. Half-life was ~10 h. Sustained increases in CD8 T and NK cells were observed (fold relative to baseline): monotherapy (1–9.4x and 2–43.3x); with pembrolizumab (0.5–5.78x and 1.5–26.9x); with cetuximab (1.3–7.57x and 3.6–45.4x). Max CD4 and eosinophils increased to 136 cell/µL and 1078 cell/µL. No IL-5 elevation or ADAs were observed. Transient IL-6 increases in 4 pts (500, 627, 1000, 1100 pg/mL) were not associated with AEs. Four pts had confirmed PRs (1 PD1-treated SCC, unknown primary [B]; 2 PD1-naïve BCC and 1 PD1-treated HNSCC [C]); 3 pts had minor responses -- prostate (-24%) and PD1-treated melanoma (-17%) [B]; PD1-treated NSCLC (¬-29%) [C] -- after ≥2 scans. 23 pts completed ≥5 cycles.ConclusionsSAR444245 was well tolerated and demonstrated antitumor activity in heavily pretreated patients, including prior checkpoint inhibitor therapy. Clinical safety, efficacy and PD suggest a wide therapeutic window. Combination with pembrolizumab and cetuximab leveraged SAR44245’s effects on CD8 T and NK cells.Trial RegistrationNCT04009681Ethics ApprovalThe clinical trial was approved by each institutions ethics’ and review board prior to beginning study enrollment.

BackgroundPancreatic cancer (PaC) is immune-quiescent and resistant to single-agent checkpoint inhibitor (CPI). NT-I7 (efineptakin alfa) is the first-in-class long-acting IL-7 that can increase T-cell infiltration in the tumor microenvironment (TME) and may enhance tumor responsiveness to CPI therapy. We hypothesize that the combination of NT-I7 and pembrolizumab may result in enhanced efficacy in CPI-naïve advanced PaC.MethodsThis is an open-label, phase 2a, study in subjects with relapsed/refractory (R/R) tumors, including CPI-naïve R/R PaC. Subjects received NT-I7 intramuscularly at 1200 µg/kg every 6 weeks (Q6W) plus pembro 200 mg intravenously Q3W. Antitumor activity based on Overall Response Rate (ORR) was assessed by Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. Biomarker analyses of peripheral blood and tumor biopsies were performed.ResultsAs of 15-July-2021, 26 subjects were enrolled in the CPI naïve R/R PaC cohort. Median age 69 years [31–81], ECOG PS 0 (35%), 1 (65%). Twenty-one (81%) subjects had ≥ 2 prior therapies All subjects had metastatic or locally advanced disease at enrollment. The median duration of follow-up was 3.3 months. Among 10 subjects with at least 1 post-treatment tumor assessment, the RECIST1.1-based ORR and disease-control rate (DCR) were 10% and 50%, respectively. One subject with MSS and TMB of 1, achieved a confirmed partial response (cPR) with 65% tumor reduction and drastically improving CA19-9. Treatment-related adverse events (AEs) occurred in 14 (53.8%) subjects, 9 (34.6%) G1–2, 3 (11.5%) G3; 2 (7.7%) G4; no G5 AEs were reported. No subjects discontinued from treatment due to AE. NT-I7 + pembro elicited a significant increase in the peripheral absolute lymphocyte count that peaked at week 3 (>3X from baseline, p15X, pConclusionsThe chemo-free combination of NT-I7 + pembro was well tolerated and showed promising anti-tumor activity in subjects with CPI-naïve R/R PaC. Increased TSCM and CD8+ T-cell infiltration within TME may be the underlying mechanisms of action for the observed efficacy. These results support continued evaluation of NT-I7 + pembro in subjects with CPI-naïve R/R PaC.AcknowledgementsThe authors thank ICON for their partnership in conducting this trial.Trial RegistrationNCT04332653Ethics ApprovalThe trial was approved by MD Anderson IRB (#2020–0008_MOD001), Mary Crowley IRB (#20–13) and Advarra IRB (#Pro00042639)All participant gave informed consent prior to study enrollment.

BackgroundCheckpoint inhibitor (CPI) monotherapy is ineffective for microsatellite stable colorectal cancer (MSS-CRC). NT-I7 (efineptakin alfa) is the first-in-class long-acting IL-7 that can increase T-cell infiltration in the tumor microenvironment (TME). We hypothesize that NT-I7 may create a favorable immune-reactive TME to enhance the efficacy of CPI when combined with pembrolizumab (pembro).MethodsThis is an open-label, phase 2a study in subjects with relapsed/refractory (R/R) tumors, including CPI-naïve R/R MSS-CRC. Subjects received the recommended-phase-2-dose of NT-I7 intramuscularly at 1200 µg/kg every 6 weeks (Q6W) plus pembro 200 mg intravenously Q3W. Preliminary anti-tumor activity based on Overall Response Rate (ORR) was assessed by Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 as a primary objective and by iRECIST as an exploratory objective. Biomarker analyses in peripheral blood and tumor biopsies were performed.ResultsAs of 15-July-2021, 19 subjects were enrolled in the CPI-naïve R/R MSS-CRC cohort. Six subjects are ongoing. Median age 58 years [37–81], ECOG PS 0 (26%), 1 (74%). Sixteen (84%) subjects received ≥ 2 prior therapies. All subjects had metastatic or locally advanced disease at enrollment. The median duration of follow-up was 4.64 months. Among 15 evaluable subjects, disease-control rate (DCR) based on RECIST1.1 was 47% and 1 subject achieved partial response per iRECIST (iPR) with 33% tumor reduction. Treatment-related adverse events (AEs) occurred in 14 (73.7%) subjects, 9 (47.4%) G1–2 events and 5 (26.3%) G3 events; no G4 or G5 AEs were reported. No subjects discontinued from the study due to AE. NT-I7 + pembro elicited a significant increase in the absolute lymphocyte count that peaked at week 3 (>3X from baseline, p25X from baseline, pConclusionsThe chemo-free combination of NT-I7 + pembro was well tolerated and showed encouraging anti-tumor activity in subjects with CPI-naïve R/R MSS-CRC. Increased TSCM and CD8+ T-cell infiltration in TME may be the underlying mechanisms of action for the observed efficacy. These results support continued evaluation of NT-I7 + pembro in CPI-naïve subjects with R/R MSS-CRC.AcknowledgementsThe authors thank ICON for their partnership in conducting this trial.Trial RegistrationNCT04332653Ethics ApprovalThe trial was approved by MD Anderson IRB (#2020–0008_MOD001), Mary Crowley IRB (#20–13) and Advarra IRB (#Pro00042639)All participant gave informed consent prior to study enrollment.

BackgroundTransforming growth factor-beta 1 (TGFβ1) plays an important role in mediating the primary resistance to PD-1/PD-L1 [PD-(L)1] blockade. SRK-181 is a fully human monoclonal antibody that selectively inhibits latent TGFβ1 activation. Mouse tumor models (bladder, melanoma, and breast cancer) demonstrated that treatment with SRK-181+anti-PD-1 overcame primary anti-PD-1 resistance. Four-week GLP nonclinical toxicology studies showed that SRK-181 has improved safety profile (no cardiotoxicities) compared to broad TGFβ pathway inhibition.MethodsThe DRAGON trial (NCT04291079) is an ongoing open-label, phase 1 study. Part A of the study follows a standard 3+3 dose escalation design to determine the dose for Part B. Part B (expansion phase) evaluates combination treatment in patients with non-small cell lung cancer (NSCLC), urothelial carcinoma, melanoma, or other advanced solid tumors. SRK-181 is administered IV every 3 or 2 weeks (Q3W/Q2W) alone in patients with advanced solid tumors (Part A1), or in combination with anti-PD-(L)1 in patients who did not respond to prior anti-PD-(L)1 therapy (Part A2/B).ResultsAs of 7 June 2021, 25 patients have enrolled to Part A; median 4 prior lines of therapies (range 1–9). Cancer types: colorectal, ovarian, prostate, and unknown primary (Part A1); liver, melanoma, NSCLC, oropharynx, renal cell carcinoma (RCC) and uterine (Part A2). In Part A1, 15 patients were treated with SRK-181 monotherapy at doses of 80, 240, 800, 1600, 2400, 3000mg Q3W, with no dose limiting toxicity (DLT) observed. The last cohort (2000mg Q2W) remains under evaluation. The most common treatment-related AEs (TRAE, >10%) of any grade were decreased appetite and fatigue (each: 13.3%, n=2). Six patients had stable disease (SD) as best response (2/colorectal cancer, 1/prostate cancer, and 3/ovarian cancer). Three ovarian cancer patients were stable ≥153 days with tumor regressions. In Part A2, 10 patients were treated with SRK-181 at doses of 240, 800 and 1600mg Q3W+pembrolizumab. No DLT was observed up to 800mg. 1600mg Q3W is under evaluation. No TRAE (>10%) of any grade were observed. One confirmed RECIST1.1 partial response (PR) was observed (800mg) in a patient with anti-PD-1 resistant RCC and 2 patients had best response of SD (1/oropharynx cancer, 1/liver cancer). The half-life of SRK-181 ranged from 3.9 to 19.3 days across the doses tested.ConclusionsAs of 7 June 2021, SRK-181 has been well tolerated as monotherapy and in combination with anti-PD-(L)1. One RECIST1.1 PR (800mg) was observed in a patient with anti-PD-1 resistant RCC. Next planned dose in Part A2 will be 2400mg Q3W.Trial RegistrationDRAGON trial (NCT04291079)Ethics ApprovalThe human study was approved by the Massachusetts General Hospital and Beth Israel Deaconess Medical Center (20–286), Sarah Cannon Research Institute (1276118), Mary Crowley Cancer Research (20–06), MD Anderson Cancer Center (2020–0110) Institutional Review Boards with written informed consent obtained from each participant and/or their legal representative, as appropriate.