Background: Zanubrutinib is a selective next-generation Bruton tyrosine kinase (BTK) inhibitor designed to have high specificity for BTK and minimize off-target effects (J Med Chem 2019;62:7923-40). Data from several phase 2 CLL trials assessing BCL-2 and BTK inhibitor combination treatment suggested that undetectable minimal residual disease (uMRD)-driven fixed-duration combination treatment was tolerable and enabled durable responses after treatment discontinuation (JAMA Oncol 2021;1649.; EHA 2021 S147). However, a limited number of patients with the high-risk feature, deletion of chromosome 17p13.1 [del(17p)], have been included in these studies. Preliminary data from Arm C of the SEQUOIA trial suggested that zanubrutinib monotherapy was active (18-mo progression-free survival: 90.6%) and well-tolerated in CLL/SLL patients with del(17p) (ASH 2020 1306). Here, we present early results for patients with TN del(17p) CLL/SLL receiving zanubrutinib + venetoclax in Arm D of the SEQUOIA trial (NCT03336333).

Methods: SEQUOIA is an open-label, global, multicenter, phase 3 study that includes a nonrandomized cohort (Arm D) of patients with TN del(17p) CLL/SLL (Blood 2020;136 [supplement 1]:24-5). Patients in Arm D were treated with zanubrutinib (160 mg twice daily) for 3 mos followed by zanubrutinib (same dosing) + venetoclax (ramp-up cycle followed by 400 mg once daily) combination treatment for 12-24 cycles until progressive disease (PD), unacceptable toxicity, or achievement of uMRD at <10 -4 sensitivity by flow cytometry (whichever occurred first). Adult patients with CLL/SLL who met International Workshop on CLL (iwCLL) criteria for treatment (Blood 2008;111:5446-56) were eligible if they had central verification of del(17p) by fluorescence in situ hybridization with >7% aberrant nuclei present. Initial safety and tolerability of zanubrutinib + venetoclax was assessed, including the risk of tumor lysis syndrome (TLS) both at baseline and prior to initiation of venetoclax. Responses for CLL and SLL were investigator-assessed per modified iwCLL criteria (Blood 2008;111:5446-56; J Clin Oncol 2012;30:2820-2) and Lugano criteria (J Clin Oncol 2014;32:3059-68), respectively. Bone marrow exams to confirm a suspected complete response (CR) or CR with incomplete hematological recovery were required starting at the end of Cycle 9.

Results: As of 1 JUN 2021 (data cutoff), 35 of approximately 80 planned patients with centrally confirmed del(17p) were enrolled. Median follow-up was 9.7 mos. In the safety analysis population (n=35), 94.3% had CLL and high-risk characteristics including Binet stage C (51.5%), bulky disease ≥5 cm (42.9%), unmutated immunoglobulin heavy chain variable locus (85.3%, n=34), median del(17p) frequency of 81.5%, and elevated β 2-microglobulin (71.4%). At data cutoff, 29 patients had started combination therapy and 27 patients completed ramp-up venetoclax dosing. Thirty-two patients remained on study treatment and 3 patients ended treatment due to withdrawal of consent, PD, or adverse event (AE of lung cancer), all n=1. The patient with lung cancer had lung nodules present at screening and died due to lung adenocarcinoma. AEs and serious AEs were reported in 29 patients (82.9%) and 4 patients (11.4%), respectively. AEs reported in ≥10% of patients included diarrhea (n=5), neutropenia (n=5), fatigue (n=4), nausea (n=4), and petechiae (n=4). Thirteen patients (37.1%) had grade ≥3 AEs; most frequently neutropenia (n=4) and diarrhea (n=2). One patient with ongoing grade 2 atrial fibrillation at baseline reported grade 3 atrial fibrillation on study. To date, no AEs of TLS have been reported. At baseline, the TLS risk categories were high, medium, and low in 12 (34.3%), 22 (62.9%), and 1 (2.9%) patients, compared with 0 (0%), 21 (67.7%), and 10 (32.3%) patients, respectively, prior to initiation of venetoclax. For the 31 patients who reached the initial efficacy assessment at 3 mos after starting zanubrutinib, the overall response rate was 96.8% (30/31); one patient reported PD after having an initial partial response while on combination therapy.

Conclusion: Preliminary safety data with the 9.7-mo median follow-up suggest that zanubrutinib + venetoclax was generally well tolerated in this high-risk population, with no new safety signals identified and no TLS reported. Enrollment is ongoing; updated safety, efficacy, and biomarker data will be presented.

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Disclosures

Tedeschi: AbbVie: Honoraria, Other: Advisory Board and Travel, Accommodations, Expenses, Speakers Bureau; Janssen: Honoraria, Other: Advisory Board and Travel, Accommodations, Expenses, Speakers Bureau; BeiGene: Honoraria, Other: Advisory Board, Speakers Bureau; AstraZeneca: Honoraria, Other: Advisory Board, Speakers Bureau. Ferrant: Janssen: Other: Travel, Accommodations, Expenses; AbbVie: Honoraria, Other: Travel, Accommodations, Expenses; AstraZeneca: Honoraria. Flinn: Calithera Biosciences: 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; Triphase Research & Development Corp.: 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; Portola Pharmaceuticals: 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; Genentech: 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; Kite, a Gilead Company: Consultancy, Other: All consultancy and 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; Incyte: Other: All 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; Forty Seven: 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; Janssen: 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; Loxo: 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; Rhizen 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; Trillium Therapeutics: Other: All 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; Verastem: 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; TG Therapeutics: 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; Gilead Sciences: 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; Forma Therapeutics: 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; IGM Biosciences: Other: All 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; Unum Therapeutics: Consultancy, Other: All consultancy and 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; 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; Merck: 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; Curis: 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; Iksuda Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute; 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. Tam: Roche: Consultancy, Honoraria; Novartis: Honoraria; Pharmacyclics: Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Loxo: Consultancy; AbbVie: Consultancy, Honoraria, Research Funding; BeiGene: Consultancy, Honoraria. Ghia: Acerta/AstraZeneca: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; ArQule/MSD: Consultancy, Honoraria; Celgene/Juno/BMS: Consultancy, Honoraria; BeiGene: Consultancy, Honoraria; Gilead: Consultancy, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria; Sunesis: Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding. Robak: Biogen, Abbvie, Octapharma, Janssen: Honoraria, Other: Advisory board; AstraZeneca, Abbvie, Janssen, Octapharma, Gilead,Oncopeptides AB, Pharmacyclics, Pfizer, GlaxoSmithKline, Biogen: Research Funding; Medical University of Lodz: Current Employment. Brown: MEI Pharma: Consultancy; Bristol-Myers Squib/Juno/Celegene: Consultancy; Pfizer: Consultancy; Abbvie: Consultancy; Sun: Research Funding; Gilead: Research Funding; Rigel: Consultancy; Catapult: Consultancy; Eli Lilly and Company: Consultancy; Genentech/Roche: Consultancy; Novartis: Consultancy; Invectys: Other: Data Safety Monitoring Committee Service; Beigene: Consultancy; Nextcea: Consultancy; Morphosys AG: Consultancy; TG Therapeutics: Research Funding; Acerta/Astra-Zeneca: Consultancy; Janssen: Consultancy; SecuraBio: Research Funding; Loxo/Lilly: Research Funding. Ramakrishnan: BeiGene: Current Employment, Current equity holder in publicly-traded company, Divested equity in a private or publicly-traded company in the past 24 months, Other: Travel, Accommodations, Expenses. Tian: AbbVie: Ended employment in the past 24 months; BeiGene: Current Employment. Kuwahara: BeiGene: Current Employment, Current equity holder in publicly-traded company, Divested equity in a private or publicly-traded company in the past 24 months. Paik: BeiGene USA, Inc.: Current Employment, Current equity holder in publicly-traded company. Cohen: BeiGene: Current Employment, Current equity holder in publicly-traded company, Other: Travel, Accommodations, Expenses. Huang: BeiGene: Current Employment, Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company, Divested equity in a private or publicly-traded company in the past 24 months, Other: Travel, Accommodations, Expenses; Protara Therapeutics: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company). Hillmen: BeiGene: Honoraria; Janssen: Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; AbbVie: Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Pharmacyclics: Honoraria, Research Funding; Roche: Research Funding; Gilead: Research Funding; AstraZeneca: Honoraria; SOBI: Honoraria.

OffLabel Disclosure:

Zanubrutinib is an investigational agent and has not been approved for TN del(17p) CLL/SLL in the US

© 2021 by The American Society of Hematology
2021
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