Gouill, Steven Le

TPS7587 Background: Covalent (c) Bruton tyrosine kinase inhibitors (BTKi) have transformed the management of MCL, but these agents are not curative. cBTKi share pharmacologic liabilities (e.g., low oral bioavailability, short half-life), which collectively may lead to suboptimal BTK target coverage especially in rapidly proliferating tumors with high BTK protein turnover such as MCL, which can manifest as acquired resistance to BTKi. Pirtobrutinib, a highly selective, non-covalent (reversible) BTKi, has favorable oral pharmacology that enables continuous BTK inhibition throughout the dosing interval regardless of intrinsic rate of BTK turnover. In the phase 1/2 BRUIN study, pirtobrutinib demonstrated promising durable overall response rates and was well tolerated in patients (pts) with MCL regardless of prior therapy (including cBTKi), number of prior lines of therapy, or reason for prior cBTKi discontinuation. Pirtobrutinib was approved by the FDA in January 2023 for R/R MCL after 2 prior lines of therapy including a BTKi. The objective of this study is to establish whether pirtobrutinib is superior to investigator’s choice of cBTKi in pts with previously treated, BTKi naïve MCL. Methods: BRUIN MCL-321 (NCT04662255) is a randomized, open-label, global phase 3 study comparing pirtobrutinib monotherapy versus investigator’s choice of cBTKi monotherapy (ibrutinib, acalabrutinib, or zanubrutinib) in pts with previously treated, BTKi naïve MCL. Approximately 500 pts will be randomized 1:1 and stratified by sMIPI risk (low/intermediate vs high), comparator BTKi (ibrutinib vs acalabrutinib/zanubrutinib), and number of prior lines of therapy (1 vs ≥ 2). Enrollment for this study is ongoing. Adults with a diagnosis of MCL who have received ≥ 1 prior line of systemic therapy for MCL and are BTKi naïve are eligible. Pts must have measurable disease by imaging per Lugano criteria and have progressed on or relapsed following the most recent line of therapy. A history of current or prior CNS involvement, significant cardiovascular disease, stroke or intracranial hemorrhage within 6 months of randomization, and autologous stem cell transplant (SCT), allogeneic SCT or chimeric antigen receptor (CAR) T-cell therapy within 60 days of randomization are key exclusion criteria. Progression-free survival (PFS) per Lugano criteria assessed by an independent review committee is the primary endpoint. Overall response rate, duration of response, investigator-assessed PFS per Lugano criteria, overall survival, event-free survival, time to treatment failure, time to next treatment, PFS2 (time from randomization to disease progression on next line of treatment or death from any cause), safety and tolerability, and pt reported outcomes are secondary endpoints. Clinical trial information: NCT04662255 .

AbstractBackgroundStudies suggest that immune checkpoint inhibitors may represent a promising strategy for boosting immune responses and improving the antitumor activity of standard therapies in patients with relapsed/refractory hematologic malignancies.AimsPhase 1/2 FUSION NHL 001 was designed to determine the safety and efficacy of durvalumab, an anti‐programmed death ligand 1 (PD‐L1) antibody, combined with standard‐of‐care therapies for lymphoma or chronic lymphocytic leukemia (CLL).Methods and ResultsThe primary endpoints were to determine the recommended phase 2 dose of the drugs used in combination with durvalumab (durvalumab was administered at the previously recommended dose of 1500 mg every 4 weeks) and to assess safety and tolerability. Patients were enrolled into one of four arms: durvalumab monotherapy (Arm D) or durvalumab in combination with lenalidomide ± rituximab (Arm A), ibrutinib (Arm B), or rituximab ± bendamustine (Arm C). A total of 106 patients with relapsed/refractory lymphoma were enrolled. All but two patients experienced at least one treatment‐emergent adverse event (TEAE); those not experiencing a TEAE were in Arm C (diffuse large B‐cell lymphoma [DLBCL]) and Arm D (DLBCL during the durvalumab monotherapy treatment period). No new safety signals were identified, and TEAEs were consistent with the respective safety profiles for each study treatment. Across the study, patients with follicular lymphoma (FL; n = 23) had an overall response rate (ORR) of 59%; ORR among DLBCL patients (n = 37) was 18%. Exploratory biomarker analysis showed that response to durvalumab monotherapy or combination therapy was associated with higher interferon‐γ signature scores in patients with FL (p = .02).ConclusionDurvalumab as monotherapy or in combination is tolerable but requires close monitoring. The high rate of TEAEs during this study may reflect on the difficulty in combining durvalumab with full doses of other agents. Durvalumab alone or in combination appeared to add limited benefit to therapy.

Abstract Background: Standard of care (SOC) for second-line (2L) therapy (tx) of relapsed/refractory aggressive B-cell non-Hodgkin lymphomas (R/R aNHL) includes platinum-based chemotherapy (PCT) followed by autologous hematopoietic cell transplantation (aHCT) in responders. Outcomes are poor for patients (pts) with R/R aNHL who experience progression during or within 12 months (mo) of 1L tx. Tisagenlecleucel (tisa-cel) is an autologous chimeric antigen receptor (CAR) T-cell tx targeting CD19 approved for pts with large B-cell lymphoma (LBCL; US) and diffuse LBCL (non-US) after ≥2 lines of tx. BELINDA (NCT03570892) is a Phase III, randomized, global (18 countries) study of tisa-cel vs SOC as 2L tx for R/R aNHL. Methods: Adults with confirmed R/R aNHL within 12 mo after 1L chemo-immunotherapy were eligible. All pts underwent leukapheresis for tisa-cel production and were randomized 1:1 to receive tisa-cel (Arm A) or SOC (Arm B) and stratified by 1L duration of response, International Prognostic Index (IPI), and geographic region. Arm A received optional bridging tx (investigator choice of protocol-defined PCT regimens) followed by lymphodepletion (LD; generally, fludarabine 25 mg/m 2/day [d] + cyclophosphamide 250 mg/m 2/d for 3 d) and followed by a single tisa-cel infusion (0.6-6×10 8 CAR-T cells). Arm B received investigator choice of PCT regimen followed by aHCT in responders or a second PCT in nonresponders. Disease assessments were performed at 6 and 12 weeks (wk), then planned every 3 mo for year (y) 1 and every 6 mo for y 2. The primary endpoint was event-free survival (EFS), defined as time from randomization to stable disease (SD) or progressive disease (PD) at or after wk 12 assessment or death at any time. SD/PD at wk 6 was not considered an event on either Arm. Arm A's wk 6 assessment evaluated disease burden before tisa-cel infusion and after bridging if administered. Arm B's wk 6 assessment determined if response was sufficient for aHCT or if a second PCT regimen was needed prior to aHCT. Results: As of May 6, 2021, 322 pts were randomized: 162 to Arm A and 160 to Arm B. In Arms A and B, 33% and 29% were ≥65 y, and 66% and 67% had primary refractory disease, respectively. Baseline characteristics indicated imbalances with more high-grade B-cell lymphomas (24% vs 17%) and IPI ≥2 (65% vs 58%) in Arm A vs B. In Arm A, 47% received ≥2 cycles of bridging PCT, 36% received 1 cycle, and 17% received 0. In Arm A, 96% received tisa-cel; the median dose was 2.9×10 8 cells. In Arm B, 96% received ≥2 PCT cycles and 54% received ≥2 different PCT regimens; 33% received aHCT, including 10% requiring ≥2 different PCT regimens before aHCT. Median time from randomization to aHCT was 92 d (range, 61-158 d). Median follow-up was 10 mo (range, 2.9-23.2 mo). At wk 6 assessment, 26% had PD in Arm A vs 14% in Arm B. Median EFS in Arms A and B was 3 mo (HR 1.07; 95% CI, 0.82-1.40; P=0.69); Arm A pts with PD at wk 6 had shorter EFS. Overall response rate (ORR) at wk 12 in Arm A was 46% vs 43% in Arm B; complete response rate in both arms was 28%. Some pts responded to tisa-cel after SD/PD at wk 12 without additional tx but were counted as an event in EFS analysis. In Arm B, 81 pts (51%) crossed over to receive tisa-cel, 71 without receiving aHCT. Of 72 crossover pts with response assessment, ORR to tisa-cel was 40%. Overall survival was immature at data cutoff. In Arm A, 84% had a grade ≥3 adverse event (AE; vs 90% in Arm B), including grade ≥3 cytokine release syndrome in 5% (CRS; Lee 2014) and grade ≥3 neurologic events (NE) in 3% (CTCAE v5.0), with no grade 5 CRS/NE. Median times to CRS and NE onset were 4 and 5 d, respectively; median time to resolution was 5 and 9 d. Fifty-two (32%) and 45 (28%) pts in Arms A and B died on study, including 42 (26%) and 32 (20%) deaths due to PD, respectively. Ten pts in Arm A and 13 in Arm B died of AEs. Conclusions: Tisa-cel as 2L tx in R/R aNHL pts did not have a higher EFS vs SOC. Possible contributing factors include study design elements, such as optional PCT bridging tx in Arm A with potential delay of tisa-cel infusion until after wk 6 assessment, allowance of a different PCT regimen to reach aHCT in Arm B after inadequate response to first PCT, and imbalances in relevant pt characteristics. Insights from this randomized Phase III study will inform use of cellular tx in the 2L R/R aNHL setting and the design of future CAR-T trials. Figure 1 Figure 1. Disclosures Bishop: Arcellx, Autolus, Bristol-Myers Squibb, CRISPR, Kite/Gilead, and Novartis: Consultancy, Research Funding; Bristol-Myers Squibb and Kite/Gilead: Other: fees for non-CME/CE services . Dickinson: Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Roche: Consultancy, Honoraria, Other: travel, accommodation, expenses, Research Funding, Speakers Bureau; Gilead Sciences: Consultancy, Honoraria, Speakers Bureau; MSD: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Takeda: Research Funding; Celgene: Research Funding; Amgen: Honoraria. Purtill: Novartis: Honoraria; Gilead: Honoraria; BMS Celgene: Honoraria. Barba: Amgen, Celgene, Gilead, Incyte, Jazz Pharmaceuticals, MSD, Novartis, Pfizer and Roche, Jazz Phar,aceuticals: Honoraria; Cqrlos III heqlth Institute, aSOCIACION espanola contra el cancer, PERIS: Research Funding. Santoro: Arqule: Consultancy, Speakers Bureau; Sanofi: Consultancy; Takeda: Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Speakers Bureau; AbbVie: Speakers Bureau; Amgen: Speakers Bureau; Celgene: Speakers Bureau; Servier: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AstraZeneca: Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Eli-Lilly: Speakers Bureau; Sandoz: Speakers Bureau; Eisai: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Speakers Bureau; Bayer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Hamad: Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Kato: Abbvie: Consultancy, Research Funding; AstraZeneca: Consultancy; Bristol-Myers Squibb: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Chugai: Consultancy, Honoraria, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Dainippon-Sumitomo: Honoraria; Eisai: Consultancy, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; MSD: Honoraria; Mundi: Honoraria; Novartis: Consultancy, Research Funding; Ono: Honoraria, Research Funding. Sureda: Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Support for attending meetings and/or travel, Research Funding, Speakers Bureau; BMS/Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Support for attending meetings and/or travel, Speakers Bureau; MSD: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kite, a Gilead Company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; GSK: Consultancy, Honoraria, Speakers Bureau; Roche: Other: Support for attending meetings and/or travel; Bluebird: Membership on an entity's Board of Directors or advisory committees; Mundipharma: Consultancy. Greil: Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; AstraZeneca: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; Merck Sharp & Dohme: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Daiichi Sankyo: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Sankyo: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Sandoz: Honoraria, Research Funding. Thieblemont: Gilead Sciences: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Bristol Myers Squibb/Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses , Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Kyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Cellectis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Hospira: Research Funding; Bayer: Honoraria; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses . Morschhauser: F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees; Epizyme: 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; Chugai: Honoraria; Janssen: Honoraria; Genmab: Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech, Inc.: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; AstraZenenca: Membership on an entity's Board of Directors or advisory committees; Servier: Consultancy; Incyte: Membership on an entity's Board of Directors or advisory committees. Janz: Janssen: Honoraria, Other: Meeting Fees; Novartis: Honoraria; Takeda: Honoraria, Other: Travel Accommodations, Expenses, Meeting fees; Roche: Honoraria; Gilead: Other: Travel Accommodations, Expenses, Meeting fees. Flinn: 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 equity holder in publicly-traded company; Seattle Genetics: Research Funding; Sarah Cannon Research Institute: Current Employment; Vincerx Pharma: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Hutchison MediPharma: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Century Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Triphase Research & Development Corp.: 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; Teva: 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; 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; Novartis: 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; Loxo: 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; Incyte: 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; Forty Seven: 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; Curis: Other: All 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; Celgene: Other: All 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; 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; Acerta Pharma: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding; Yingli Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; 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; TG Therapeutics: Consultancy, Other: All consultancy and 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; Seagen: 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; Pharmacyclics LLC, an AbbVie Company: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Nurix Therapeutics: 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; Kite, a Gilead Company: 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; Janssen: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding; Iksuda Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Great Point Partners: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; Gilead Sciences: 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; BeiGene: 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; AbbVie: Consultancy, Other: All Consultancy and Research Funding payments made to Sarah Cannon Research Institute, Research Funding. Kwong: Novartis: Consultancy, Honoraria, Research Funding. Kersten: Novartis: Consultancy, Honoraria, Other: Travel support; Takeda: Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel support, Research Funding; Celgene: Research Funding; Roche: Consultancy, Honoraria, Other: Travel support, Research Funding; Miltenyi Biotec: Consultancy, Honoraria, Other: Travel support; BMS/Celgene: Consultancy, Honoraria. Minnema: Janssen: Consultancy, Honoraria; Celgene: Other: Travel expenses; BMS: Consultancy; Kite/Gilead: Consultancy; Alnylam: Consultancy. Holte: Roche: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Nanovector: Membership on an entity's Board of Directors or advisory committees, Other: lectures honorarias; Novartis: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Nordic: Membership on an entity's Board of Directors or advisory committees. Martinez-Lopez: Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees. Maziarz: Novartis: Consultancy, Other: Data and Safety Monitoring board, Research Funding; Incyte Corporation: Consultancy, Honoraria; Bristol-Myers, Squibb/Celgene,, Intellia, Kite: Honoraria; Allovir: Consultancy, Research Funding; Artiva Therapeutics: Consultancy; CRISPR Therapeutics: Consultancy; Intellia: Honoraria; Omeros: Research Funding; Athersys: Other: Data and Safety Monitoring Board, Patents & Royalties; Vor Pharma: Other: Data and Safety Monitoring Board. McGuirk: Kite/ Gilead: Consultancy, Honoraria, Other: travel accommodations, expense, Kite a Gilead company, Research Funding, Speakers Bureau; Juno Therapeutics: Consultancy, Honoraria, Research Funding; Allovir: Consultancy, Honoraria, Research Funding; Magenta Therapeutics: Consultancy, Honoraria, Research Funding; EcoR1 Capital: Consultancy; Novartis: Research Funding; Fresenius Biotech: Research Funding; Astelllas Pharma: Research Funding; Bellicum Pharmaceuticals: Research Funding; Novartis: Research Funding; Gamida Cell: Research Funding; Pluristem Therapeutics: Research Funding. Bachy: Kite, a Gilead Company: Honoraria; Novartis: Honoraria; Daiishi: Research Funding; Roche: Consultancy; Takeda: Consultancy; Incyte: Consultancy. Dreyling: Amgen: Speakers Bureau; Astra Zeneca: Consultancy, Speakers Bureau; Bayer: Consultancy, Research Funding, Speakers Bureau; Celgene: Consultancy, Research Funding, Speakers Bureau; Gilead Kite: Consultancy, Research Funding, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Janssen: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Roche: Consultancy, Research Funding, Speakers Bureau; AbbVie: Research Funding; BeiGene: Consultancy, Speakers Bureau; Genmab: Consultancy; MorphoSys: Consultancy. Harigae: Bristol Myers Squibb: Honoraria; Novartis Pharma: Honoraria, Research Funding; Chugai Pharma: Honoraria; Janssen Pharma: Honoraria; Ono pharma: Honoraria, Other: Subsidies or Donations; Astellas Pharma: Other: Subsidies or Donations; Kyowakirin: Other: Subsidies or Donations. Bond: Kite/Gilead: Honoraria. Andreadis: Merck: Research Funding; BMS: Research Funding; CRISPR Therapeutics: Research Funding; GenMAB: Research Funding; Novartis: Research Funding; Roche: Current equity holder in publicly-traded company, Ended employment in the past 24 months; Epizyme: Honoraria; Incyte: Honoraria; TG Therapeutics: Honoraria; Kite: Honoraria; Karyopharm: Honoraria; Atara: Consultancy, Honoraria. McSweeney: Kite-Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau; Gamida: Consultancy, Honoraria; TG Theraputics: Consultancy, Honoraria; Autolous Limited: Research Funding; Novartis: Research Funding; NKARTA: Research Funding; Allovir: Research Funding. Newsome: Novartis: Current Employment. Degtyarev: Novartis: Current Employment, Current equity holder in publicly-traded company. Del Corral: Novartis: Current Employment. Andreola: Novartis: Current Employment, Current holder of stock options in a privately-held company. Masood: Novartis: Current Employment, Current holder of stock options in a privately-held company. Schuster: AbbVie, Acerta, Celgene/Juno, DTRM Bio, Genentech, Incyte, Merck, Novartis, Portola, and TG Therapeutics: Research Funding; Acerta, AlloGene, AstraZeneca, BeiGene, Celgene/Juno, Genentech/Roche, LoxoOncology, Novartis, and Tessa Therapeutics: Consultancy; Acerta, AlloGene, AstraZeneca, BeiGene, Celgene, Genentech/Roche, LoxoOncology, Novartis, Nordic Nanovector, Pfizer, and Tessa Therapeutics;: Honoraria; Novartis: Other: Personal fees, Patents & Royalties; AbbVie, Celgene, Novartis, Juno, Nordic Nanovector, and Pfizer: Other: Steering Committee Participation. Jaeger: BMS/Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Norvartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees. Westin: Kite, a Gilead Company: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; MorphoSys: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; ADC Therapeutics: Consultancy, Research Funding; Umoja: Consultancy; Iksuda Therapeutics: Consultancy; Curis: Research Funding; Morphosys: Research Funding; 47 Inc: Research Funding.

Abstract Background: Covalent Bruton's Tyrosine Kinase (BTK) inhibitors (BTKi) have transformed the management of relapsed mantle cell lymphoma (MCL), but these treatments are not curative and the majority of patients 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 especially 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 patients, most of whom had prior treatment with a covalent BTKi (Mato et al. Lancet 2021;397,10277:892-901). The purpose of this randomized study is to demonstrate the superiority of pirtobrutinib compared to investigator's choice of covalent BTKi in patients with previously treated MCL. Study Design and Methods: BRUIN MCL-321 is a randomized, open-label, global phase 3 study comparing pirtobrutinib monotherapy versus investigator's choice of covalent BTKi monotherapy (ibrutinib, acalabrutinib, or zanubrutinib) in patients with previously treated, BTKi naïve MCL. Approximately 500 patients will be randomized 1:1. Randomization will be stratified by sMIPI risk (low/intermediate vs high), comparator BTKi (ibrutinib vs acalabrutinib/ zanubrutinib), and number of prior lines of therapy (1 vs ≥ 2). Eligible patients are adults aged ≥18 years with a confirmed diagnosis of MCL (cyclin D1 overexpression, and ≥ 1 B-cell marker) who have received ≥ 1 prior line of systemic therapy for MCL that did not include a prior BTKi. Patients must have measurable disease per Lugano criteria and must have progressed on or relapsed following the most recent line of therapy prior to study enrollment. Key exclusion criteria include a history of current or prior CNS involvement, significant cardiovascular disease, stroke, or intracranial hemorrhage within 6 months of randomization, and allogeneic stem cell transplant (SCT), autologous SCT or chimeric antigen receptor (CAR) T-cell therapy within 60 days of randomization. The primary endpoint is progression-free survival (PFS) per Lugano criteria assessed by an independent review committee (IRC), with the goal of demonstrating superiority of pirtobrutinib over investigator's choice of covalent BTKi. Secondary endpoints include overall response rate (ORR), duration of response (DoR), investigator-assessed PFS per Lugano criteria, overall survival (OS), event-free survival (EFS), time to treatment failure (TTF), time to next treatment (TTNT), time from randomization to disease progression on next line of treatment or death from any cause (PFS2), safety and tolerability, and patient reported outcomes. This global study is currently enrolling patients (NCT04662255). Disclosures Eyre: Gilead/KITE: Honoraria, Other: Travel support for conferences, Research Funding, Speakers Bureau; Janssen: Honoraria; Loxo Oncology: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Consultancy; Abbvie: Consultancy, Honoraria, Other: Travel to conferences; Roche: Consultancy, Honoraria; AstraZeneca: Honoraria, Research Funding; Beigene: Honoraria, Research Funding; Secura Bio: Consultancy, Honoraria. Shah: Miltenyi Biotec: Consultancy, Honoraria, Research Funding; Kite: Consultancy; Epizyme: Consultancy; Umoja: Consultancy; Legend: Consultancy; Incyte: Consultancy; Lily: Consultancy, Honoraria, Research Funding. Dreyling: Novartis: Consultancy, Speakers Bureau; Janssen: Consultancy, Research Funding, Speakers Bureau; Roche: Consultancy, Research Funding, Speakers Bureau; Astra Zeneca: Consultancy, Speakers Bureau; BeiGene: Consultancy; Celgene: Consultancy, Research Funding, Speakers Bureau; Amgen: Speakers Bureau; Genmab: Consultancy; Bayer HealthCare Pharmaceuticals: Consultancy, Research Funding, Speakers Bureau; Gilead/Kite: Consultancy, Research Funding, Speakers Bureau; Abbvie: Research Funding; Incyte: Consultancy, Speakers Bureau. Vandenberghe: Jansnens: Honoraria; Abbvie: Honoraria. Jurczak: Abbvie, AstraZeneca, BeiGene, Celtrion, Celgene, Debbiopharm, Epizyme, Incyte, Janssen, Loxo Oncology, Merck, Mei Pharma, Morphosys, Novo Nordisk, Roche, Sandoz, Takeda, TG Therapeutics: Research Funding; Astra Zeneca, BeiGene, Janssen, Loxo Oncology, Sandoz, Roche,: Membership on an entity's Board of Directors or advisory committees. Wang: Genentech: Research Funding; Eli Lilly: Membership on an entity's Board of Directors or advisory committees; MorphoSys: Research Funding; LOXO Oncology: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; InnoCare: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees. Cheah: Loxo/Lilly: Consultancy, Honoraria, Other: advisory; Janssen: Consultancy, Honoraria, Other: advisory; Roche: Consultancy, Honoraria, Other: advisory and travel expenses, Research Funding; TG Therapeutics: Consultancy, Honoraria, Other: advisory; AstraZeneca: Consultancy, Honoraria, Other: advisory; Celgene: Research Funding; AbbVie: Research Funding; Beigene: Consultancy, Honoraria, Other: advisory; Ascentage pharma: Consultancy, Honoraria, Other: advisory; Gilead: Consultancy, Honoraria, Other: advisory; MSD: Consultancy, Honoraria, Other: advisory, Research Funding. Gandhi: Karyopharm Therapeutics: Honoraria; TG Therapeutics: Honoraria; GlaxoSmithKline: Honoraria. Sharman: AstraZeneca: Consultancy; Lilly: Consultancy; Pharmacyclics LLC, an AbbVie Company: Consultancy; Centessa: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees; BeiGene: Consultancy; BMS: Consultancy; TG Therapeutics: Consultancy; AbbVie: Consultancy. Andorsky: Abbvie: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding; Epizyme: Research Funding. Yin: Loxo Oncology at Lilly: Current Employment; AstraZeneca: Ended employment in the past 24 months. 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. Kherani: Loxo Oncology at Lilly: Current Employment, Current equity holder in publicly-traded company. Wang: AstraZeneca, Bayer Healthcare, BeiGene, CSTone, DTRM Biopharma (Cayman) Limited, Epizyme, Genentech, InnoCare, Janssen, Juno, Kite Pharma, Loxo Oncology, Miltenyi Biomedicine GmbH, Oncternal, Pharmacyclics, VelosBio: Consultancy; Acerta Pharma, AstraZeneca, BeiGene, BioInvent, Celgene, Innocare, Janssen, Juno, Kite, Pharma, Lilly, Loxo Oncology, Molecular Templates, Oncternal, Pharmacyclics, VelosBio: Research Funding; Acerta Pharma, Anticancer Association, AstraZeneca, BeiGene, CAHON, Chinese Medical Association, Clinical Care Options, Dava Oncology, Epizyme, Hebei Cancer Prevention Federation, Imbruvica, Imedex, Janssen, Kite Pharma, Miltenyi Biomedicine GmbH, Moffit : Honoraria.

Abstract Interleukin-6 (IL-6) and insulin-like growth factor-1 (IGF-1) mediate growth of MM cells via activation of the mitogen-activated protein kinase (MAPK), JAK2/STAT3, and phosphatidylinositol 3′-kinase/Akt kinase (PI3-K/Akt) signaling cascades. We have previously demonstrated the in vitro and in vivo activity of Revlimid™ (CC-5013), an immunomodulatory analog (IMiD) of thalidomide, in MM. In the present study, we have examined the anti-MM activity of rapamycin, a specific mTOR inhibitor, combined with Revlimid™. This combination was highly synergistic at 0.1nmol/L of rapamycin with 0.1mmol/L of Revlimid™, and remained synergistic at higher concentrations. Based on the Chou-Talalay method, combination indices of < 1 were noted for all dose ranges of Revlimid™ and rapamycin, suggesting strong synergism. Importantly, this combination was able to overcome drug resistance when tested against MM cell lines resistant to conventional (doxorubicin, melphalan, dexamethasone) chemotherapy. Moreover, the combination, but not rapamycin alone, was able to overcome the growth advantage conferred on MM cells by IL-6, IGF-1, or adherence to bone marrow stromal cells (BMSCs). Cytotoxicity triggered by a combination of rapamycin with Revlimid™ resulted in apoptosis of MM cells. Furthermore, differential signaling cascades, including the MAPK and PI3-K/Akt pathways, were targeted by these drugs individually and in combination, suggesting the molecular mechanism by which they interfere with MM growth and survival. These studies therefore provide the framework for the clinical evaluation of targeted agents like mTOR inhibitors combined with immunomodulatory agents like Revlimid™ to improve patient outcome in MM.