Furman, Richard R.

Abstract High-count monoclonal B-cell lymphocytosis (HCMBL) is a precursor condition to chronic lymphocytic leukemia (CLL). We have shown that among individuals with HCMBL, the CLL-International Prognostic Index (CLL-IPI) is prognostic for time-to-first therapy (TTFT). Little is known about the prognostic impact of somatically mutated genes among individuals with HCMBL. We sequenced DNA from 371 individuals with HCMBL using a targeted sequencing panel of 59 recurrently mutated genes in CLL to identify high-impact mutations. We compared the sequencing results with that of our treatment-naïve CLL cohort (N = 855) and used Cox regression to estimate hazard ratios and 95% confidence intervals (CIs) for associations with TTFT. The frequencies of any mutated genes were lower in HCMBL (52%) than CLL (70%). At 10 years, 37% of individuals with HCMBL with any mutated gene had progressed requiring treatment compared with 10% among individuals with HCMBL with no mutations; this led to 5.4-fold shorter TTFT (95% CI, 2.6-11.0) among HCMBL with any mutated gene vs none, independent of CLL-IPI. When considering individuals with low risk of progression according to CLL-IPI, those with HCMBL with any mutations had 4.3-fold shorter TTFT (95% CI, 1.6-11.8) vs those with none. Finally, when considering both CLL-IPI and any mutated gene status, we observed individuals with HCMBL who were high risk for both prognostic factors had worse prognosis than patients with low-risk CLL (ie, 5-year progression rate of 32% vs 21%, respectively). Among HCMBL, the frequency of somatically mutated genes at diagnosis is lower than that of CLL. Accounting for both the number of mutated genes and CLL-IPI can identify individuals with HCMBL with more aggressive clinical course.

Abstract ELEVATE-RR demonstrated noninferior progression-free survival and lower incidence of key adverse events (AEs) with acalabrutinib vs ibrutinib in previously treated chronic lymphocytic leukemia. We further characterize AEs of acalabrutinib and ibrutinib via post hoc analysis. Overall and exposure-adjusted incidence rate was assessed for common Bruton tyrosine kinase inhibitor–associated AEs and for selected events of clinical interest (ECIs). AE burden scores based on previously published methodology were calculated for AEs overall and selected ECIs. Safety analyses included 529 patients (acalabrutinib, n = 266; ibrutinib, n = 263). Among common AEs, incidences of any-grade diarrhea, arthralgia, urinary tract infection, back pain, muscle spasms, and dyspepsia were higher with ibrutinib, with 1.5- to 4.1-fold higher exposure-adjusted incidence rates. Incidences of headache and cough were higher with acalabrutinib, with 1.6- and 1.2-fold higher exposure-adjusted incidence rate, respectively. Among ECIs, incidences of any-grade atrial fibrillation/flutter, hypertension, and bleeding were higher with ibrutinib, as were exposure-adjusted incidence rates (2.0-, 2.8-, and 1.6-fold, respectively); incidences of cardiac events overall (the Medical Dictionary for Regulatory Activities system organ class) and infections were similar between arms. Rate of discontinuation because of AEs was lower for acalabrutinib (hazard ratio, 0.62; 95% confidence interval, 0.41-0.93). AE burden score was higher for ibrutinib vs acalabrutinib overall and for the ECIs atrial fibrillation/flutter, hypertension, and bleeding. A limitation of this analysis is its open-label study design, which may influence the reporting of more subjective AEs. Overall, event-based analyses and AE burden scores demonstrated higher AE burden overall and specifically for atrial fibrillation, hypertension, and hemorrhage with ibrutinib vs acalabrutinib. This trial was registered at www.clinicaltrials.gov as #NCT02477696.

Abstract Background: The phase 3 head-to-head trial of acalabrutinib (acala) vs ibrutinib (ibr) (NCT02477696) demonstrated noninferior efficacy and improved tolerability with acala in previously treated CLL (Byrd J Clin Oncol 2021). We now report additional data to further characterize BTKi-related adverse events (AEs) and the safety profile of acala and ibr, including measures of AE burden that account for frequency, duration, and drug exposure, which are not captured by incidence alone. Methods: Patients (pts) received oral acala 100 mg BID or ibr 420 mg QD until disease progression or unacceptable toxicity. Overall incidence, exposure-adjusted (exp-adj) incidence, and exp-adj time with event (sum of event durations [all grades]*100/sum of treatment-emergent period [for all pts in each arm]) were assessed for the most common BTKi-related AEs. Atrial fibrillation (afib)/flutter, hypertension (htn), and bleeding events were further characterized by time to onset, cumulative incidence by Kaplan-Meier method, pt subgroup, and AE management. Results: A total of 533 pts (acala, n=268; ibr, n=265) were randomized; median treatment exposures were 38.3 and 35.5 mo, respectively. Incidence and exp-adj incidence and time with event are reported for the most common AEs and events of clinical interest (ECIs) (Table). Among cardiovascular (CV) ECIs, incidences of any-grade afib/flutter, htn, and bleeding were statistically higher with ibr, with higher exp-adj incidence (2.0-, 2.8-, and 1.6-fold, respectively) and exp-adj time with event (2.8-, 3.7-, and 1.8-fold). Ventricular arrhythmias were reported in 3 ibr-treated pts vs 0 pts in the acala arm. Among other BTKi-related AEs, incidences of any-grade diarrhea, arthralgia, contusion, urinary tract infection (UTI), back pain, muscle spasms and dyspepsia were statistically higher with ibr, with a 1.5- to 4.1-fold higher exp-adj incidence, and a 1.4- to 13.1-fold higher exp-adj time with event (except for UTI, which had a 1.4-fold lower exp-adj time with event for ibr). Incidences of headache and cough were statistically higher with acala, with a 1.6- and 1.2-fold higher exp-adj incidence, respectively, and a 1.4- and 1.1-fold higher exp-adj time with event. The total exp-adj time with event for all any-grade AEs was 37% higher with ibr (234 [acala] vs 320 [ibr] mo/100 person-mo). For any-grade afib/flutter, median time to onset was longer for acala vs ibr (28.8 vs 16.0 mo), and cumulative incidence was lower for acala at 6 mo (2% vs 6%), 12 mo (3% vs 8%), 18 mo (4% vs 10%), and 24 mo (5% vs 12%). Afib/flutter also occurred less frequently with acala vs ibr in subgroups of age (<65 y: 3% vs 7%; ≥65 y: 15% vs 23%), prior line of therapy (1-3: 10% vs 16%; ≥4: 7% vs 19%), and among pts without prior history (6% vs 15%). Cox proportional-hazards (PH) analysis of new-onset afib/flutter showed a 63% rate reduction favoring acala (Figure 1). Among all pts, concomitant medication use for afib/flutter was less common for acala (8%) vs ibr (14%), with antithrombotic use reported in 5% vs 9% of pts, respectively. For any-grade htn, median time to onset was similar for acala and ibr (8.1 vs 7.0 mo), but cumulative incidence was lower for acala at 6 mo (5% vs 12%), 12 mo (6% vs 16%), 18 mo (8% vs 20%), and 24 mo (8% vs 23%). Htn also occurred less frequently with acala vs ibr in subgroups of age (<65 y: 9% vs 23%; ≥65 y: 10% vs 23%), prior line of therapy (1-3: 10% vs 25%; ≥4: 4% vs 11%), and among pts without prior history (7% vs 23%). Cox PH analysis of new-onset htn showed a 77% rate reduction favoring acala (Figure 2). No dose reductions or treatment discontinuations due to htn occurred in either arm. Concomitant medication use for htn was less common for acala (5%) vs ibr (19%). For any-grade bleeding events, the median time to onset was similar for acala vs ibr (1.2 vs 1.2 mo), and cumulative incidence was lower for acala at 6 mo (29% vs 42%), 12 mo (32% vs 45%), 18 mo (34% vs 49%), and 24 mo (38% vs 51%). Bleeding events also occurred less frequently with acala vs ibr in most subgroups of age (<65 y: 26% vs 47%; ≥65 y: 49% vs 55%) and prior line of therapy (1-3: 39% vs 54%; ≥4: 32% vs 30%). Bleeding events were associated with dose reduction in 3 vs 2 pts in the acala vs ibr arms, respectively, and led to treatment discontinuation in 2 vs 4 pts. Conclusions: In this head-to-head trial of BTKis in CLL, event-based analyses demonstrated a higher BTKi-related toxicity burden with ibr, with a lower impact of CV-related toxicity with acala across subgroups. Figure 1 Figure 1. Disclosures Seymour: AstraZeneca: 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, Research Funding; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Mei Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees; Morphosys: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sunesis: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: 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; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Research Funding, Speakers Bureau. Byrd: Novartis, Trillium, Astellas, AstraZeneca, Pharmacyclics, Syndax: Consultancy, Honoraria; Newave: Membership on an entity's Board of Directors or advisory committees; Vincerx Pharmaceuticals: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees. Hillmen: 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; BeiGene: Honoraria. Ghia: Acerta/AstraZeneca: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding; Sunesis: Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Research Funding; Celgene/Juno/BMS: Consultancy, Honoraria; ArQule/MSD: Consultancy, Honoraria; BeiGene: Consultancy, Honoraria; Roche: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria, Research Funding. Kater: Genmab, LAVA: Other: Ad Board, Steering Committee; Janssen, AstraZeneca: Other: Ad Board, steering committee, Research Funding; Abbvie: Honoraria, Other: Ad Board, Research Funding; BMS, Roche/Genentech: Other: Ad Board, , Research Funding. Chanan-Khan: Ascentage: Research Funding; Alpha2 Pharmaceuticals, NonoDev, Starton: Current holder of stock options in a privately-held company; Cellectar: Current equity holder in publicly-traded company; Alpha2 Pharmaceuticals: Patents & Royalties: Tabi; BeiGene, Jansen, Ascentage: Honoraria; Ascentage, Starton, Cellectar, NonoDev, Alpha2 Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; BieGene, Jansen, Ascentage: Consultancy. Furman: Genentech: Consultancy; Sanofi: Consultancy; Morphosys: Consultancy; Incyte: Consultancy; Beigene: Consultancy; Loxo Oncology: Consultancy; TG Therapeutics: Consultancy; X4 Pharmaceuticals: Consultancy; Sunesis: Consultancy; Acerta/AstraZeneca: Consultancy; Abbvie: Consultancy, Honoraria, Other: Expert testimony; Pharmacyclics: Consultancy; Oncotracker: Consultancy; Janssen: Consultancy, Honoraria; Verastem: Consultancy; AstraZeneca: Honoraria. O'Brien: Amgen, Astellas, Celgene, GlaxoSmithKline, Janssen Oncology, Aptose Biosciences Inc., Vaniam Group LLC, AbbVie, Alexion, Verastem, Juno Therapeutics, Vida Ventures, Autolus, Johnson and Johnson, Merck, Bristol Myers Squibb, NOVA Research Company, Eli Lill: Consultancy; Kite, Regeneron, Acerta, Caribou, Gilead, Pharmacyclics, TG Therapeutics, Pfizer, Sunesis: Research Funding. Brown: Gilead, Loxo/Lilly, SecuraBio, Sun, TG Therapeutics: Research Funding; Invectys: Other: Data Safety Monitoring Committee Service; Abbvie, Acerta/Astra-Zeneca, Beigene, Bristol-Myers Squibb/Juno/Celgene, Catapult, Eli Lilly, Genentech/Roche, Janssen, MEI Pharma, Morphosys AG, Nextcea, Novartis, Pfizer, Rigel: Consultancy. Mato: Genmab: Research Funding; Janssen: Consultancy, Research Funding; LOXO: Consultancy, Research Funding; Nurix: Research Funding; TG Therapeutics: Consultancy, Other: DSMB, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; Adaptive Biotechnologies: Consultancy, Research Funding; Sunesis: Consultancy, Research Funding; AstraZeneca: Consultancy; BeiGene: Consultancy, Research Funding; MSKCC: Current Employment; Acerta/AstraZeneca: Consultancy, Research Funding; Johnson and Johnson: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; DTRM BioPharma: Consultancy, Research Funding; Genentech: Consultancy, Research Funding. Stilgenbauer: AbbVie, Amgen, AstraZeneca, Celgene, Gilead, GSK, Hoffmann-La Roche, Janssen, Novartis, Sunesis: Honoraria; AbbVie, Amgen, AstraZeneca, Celgene, Gilead, GSK, Hoffmann-La Roche, Janssen, Novartis, Sunesis: Other: Research Support; AbbVie, Amgen, AstraZeneca, Celgene, Gilead, GSK, Hoffmann-La Roche, Janssen, Novartis, Sunesis: Consultancy; AbbVie, Amgen, AstraZeneca, Celgene, Gilead, GSK, Hoffmann-La Roche, Janssen, Novartis, Sunesis: Research Funding. Kuptsova-Clarkson: AstraZeneca: Current Employment, Current equity holder in publicly-traded company; AbbVie: Current holder of individual stocks in a privately-held company. Miranda: ASTRAZENECA: Current Employment; ASTRAZENECA: Current equity holder in publicly-traded company. Wagner: AstraZeneca: Current Employment. Higgins: AstraZeneca: Current Employment; PROMETRIKA, LLC: Ended employment in the past 24 months. Sohoni: AstraZeneca: Current equity holder in publicly-traded company, Ended employment in the past 24 months; Revolution Medicines: Current Employment, Current equity holder in publicly-traded company; Theravance: Current equity holder in publicly-traded company. Jurczak: 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; Jagiellonian University: Ended employment in the past 24 months; European Medicines Agency, Sandoz-Novartis, Janssen China R&D, BeiGene, Epizyme, Acerta, AstraZeneca: Consultancy.

Abstract Introduction: The management of CLL patients historically utilized FD chemoimmunotherapy (CIT), including fludarabine, cyclophosphamide and rituximab (FCR), or bendamustine and rituximab (BR). That changed with the introduction of Bruton Tyrosine Kinase inhibitors (BTKi) as an option for oral targeted monotherapy delivered continuously until disease progression or intolerance. Recently, novel combinations that include a B-cell lymphoma 2 inhibitor (BCL2i), such as venetoclax, have been developed as FD therapy. In addition, though not FDA approved, MRD assessment is emerging as a potential tool to guide FD therapy. Understanding the patient and their caregiver perspectives on FD and MRD is critical to providing the best care. Methods: CLL Society developed a web-based survey instrument of multiple-choice questions to assess patient and caregiver awareness, understanding, and preferences with MRD and FD therapies, where FD referred to both time and MRD guided limited duration therapies. Patients and caregivers were invited to participate via message boards, CLL Society's website, email, and online communities. Results: A total of 607 (96%) self-identified US patients and 36 (5%) caregivers, who answered on behalf of patients in their care, completed the survey between 31/AUG/2020 and 31/JAN/2021. The mean patient age was 64 (range, 30-90) years, 54% were female, 169 patients (27%) treatment-naïve, 239 (38%) with one line of prior therapy, and 214 (34%) with two or more. Targeted agents (e.g., venetoclax, ibrutinib, acalabrutinib, idelalisib, and duvelisib) had been used by 401 (64%). FD use with some novel therapies was known of by 565 (90%) patients, while 588 (93%) knew some were used as continuous daily treatment until disease progression or intolerance. If effectiveness and side effects were assumed similar, 485 (77%) preferred FD, and 398 (63%) wanted that finite treatment to be guided by MRD status. Only 42 (7%) preferred continuous therapy until disease progression or intolerance. The chance for continued remission while off treatment was ranked as a very important potential benefit after stopping a FD therapy by 581 (92%) patients. When considering therapy, 589 (93%), 575 (91%), 447 (71%), 415 (66%), 302 (48%), and 288 (46%) rated having overall survival, having future therapeutic options, avoiding chemotherapy, the ability to reach undetectable (u)MRD, minimal lab and office visits, and FD therapy as very important, respectively (Fig. 1). Being tested for MRD at least once was reported by 215 (34%), while 327 (52%) had not been tested, and 88 (14%) were unsure. There were 562 (89%) who were somewhat or very familiar with the term MRD, while 450 (71%) were confident of understanding what MRD testing measures, and 446 (70%) understood its role in CLL. Only 225 (36%) stated they understood different testing methods. While self-rated understanding of the indications for MRD testing was relatively high, some wanted testing done when not clinically indicated, such as when there was persistent CLL by routine laboratory findings, or at the time of diagnosis (Fig. 2). Respondents were mixed in their stated understanding as to which therapies could result in uMRD, with 241 (38%), 197 (32%), and 195 (32%) not knowing if CIT, BCL2i, and BTKi, could lead to uMRD, respectively. Two hundred and sixty-five (42%), 84 (13%), and 57 (9%) believed it was possible for most on a BCL2i, BTKi, or CIT to achieve uMRD, respectively (Fig. 3). If patients had evidence of MRD at the end of treatment, 365 (58%) would request frequent monitoring but would make no immediate treatment decisions based on MRD status, 279 (44%) were unsure, and only 88 (14%) would want further treatment immediately. Conclusions: The results from this patient-based study reveal a high awareness of FD therapies and MRD testing, as well as a clear preference for FD among internet-active patients and caregivers. However, there are gaps in the knowledge base, thus significant educational opportunities. Limitations included the opt-in sample where the survey results may not be projectable to the total CLL population. Moreover, the survey was not designed to assess preferences if either FD or continuous therapy offered improved outcomes. Nonetheless, as the potential role of MRD and FD therapy grows in CLL it will be incumbent on clinicians to ensure patients are well informed and engaged to help them better share therapeutic decisions. Figure 1 Figure 1. Disclosures Koffman: AbbVie: Current equity holder in publicly-traded company; AstraZeneca: Current equity holder in publicly-traded company, Honoraria; Beigene: Current equity holder in publicly-traded company; Bristol Myer Squibb: Current equity holder in publicly-traded company, Honoraria; Gilead: Current equity holder in publicly-traded company; Johnson & Johnson: Current equity holder in publicly-traded company, Honoraria; Sunesis Pharmaceuticals: Current equity holder in publicly-traded company; TG Therapeutics: Current equity holder in publicly-traded company; Regeneron: Current equity holder in publicly-traded company; Miragen Therapeutics: Current equity holder in publicly-traded company; Novartis: Membership on an entity's Board of Directors or advisory committees; Portola Pharma: Current equity holder in publicly-traded company; MEI Pharma: Current equity holder in publicly-traded company; Merck: Current equity holder in publicly-traded company. Stewart: Johnson & Johnson: Current equity holder in publicly-traded company; Novartis: Current equity holder in publicly-traded company; Dr. Reddy's Laboratories Limited: Current equity holder in publicly-traded company; Adaptive Biotechnologies: Current equity holder in publicly-traded company; Pacific Biosciences: Current equity holder in publicly-traded company. Byrd: Novartis, Trillium, Astellas, AstraZeneca, Pharmacyclics, Syndax: Consultancy, Honoraria; Vincerx Pharmaceuticals: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Newave: Membership on an entity's Board of Directors or advisory committees. Danilov: Bayer Oncology: Consultancy, Honoraria, Research Funding; Genentech: Consultancy, Honoraria, Research Funding; Takeda Oncology: Research Funding; Rigel Pharm: Honoraria; TG Therapeutics: Consultancy, Research Funding; Abbvie: Consultancy, Honoraria; Beigene: Consultancy, Honoraria; Pharmacyclics: Consultancy, Honoraria; Gilead Sciences: Research Funding; Bristol-Meyers-Squibb: Honoraria, Research Funding; SecuraBio: Research Funding; Astra Zeneca: Consultancy, Honoraria, Research Funding. Davids: BeiGene: Consultancy; Janssen: Consultancy; Ascentage Pharma: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Astra-Zeneca: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; BMS: Consultancy, Research Funding; MEI Pharma: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Adaptive Biotechnologies: Consultancy; AbbVie: Consultancy; Surface Oncology: Research Funding; TG Therapeutics: Consultancy, Research Funding; Celgene: Consultancy; Verastem: Consultancy, Research Funding; Eli Lilly and Company: Consultancy; MEI Pharma: Consultancy; Merck: Consultancy; Research to Practice: Consultancy; Takeda: Consultancy. Furman: Beigene: Consultancy; Acerta/AstraZeneca: Consultancy; Janssen: Consultancy, Honoraria; Sunesis: Consultancy; Genentech: Consultancy; Incyte: Consultancy; Pharmacyclics: Consultancy; TG Therapeutics: Consultancy; Loxo Oncology: Consultancy; Sanofi: Consultancy; Morphosys: Consultancy; Verastem: Consultancy; X4 Pharmaceuticals: Consultancy; Oncotracker: Consultancy; Abbvie: Consultancy, Honoraria, Other: Expert testimony; AstraZeneca: Honoraria. Jain: Bristol Myers Squibb: Honoraria, Research Funding; Genentech: Honoraria, Research Funding; AstraZeneca: Honoraria, Research Funding; Fate Therapeutics: Research Funding; Beigene: Honoraria; AbbVie: Honoraria, Research Funding; Pfizer: Research Funding; TG Therapeutics: Honoraria; Cellectis: Honoraria, Research Funding; Precision Biosciences: Honoraria, Research Funding; ADC Therapeutics: Honoraria, Research Funding; Aprea Therapeutics: Research Funding; Adaptive Biotechnologies: Honoraria, Research Funding; Servier: Honoraria, Research Funding; Janssen: Honoraria; Incyte: Research Funding; Pharmacyclics: Research Funding. Kay: Oncotracker: Membership on an entity's Board of Directors or advisory committees; Genentech: Research Funding; Targeted Oncology: Membership on an entity's Board of Directors or advisory committees; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Acerta Pharma: Research Funding; MEI Pharma: Research Funding; Behring: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Rigel: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Dava Oncology: Membership on an entity's Board of Directors or advisory committees; Tolero Pharmaceuticals: Research Funding; CytomX Therapeutics: Membership on an entity's Board of Directors or advisory committees; Bristol Meyer Squib: Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios Pharm: Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Research Funding; Sunesis: Research Funding; Juno Therapeutics: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding. Lamanna: Juno Therapeutics, Inc.: Research Funding; BeiGene: Consultancy; AstraZeneca: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; MingSight Pharmaceuticals, Inc.: Research Funding; Genentech, Inc.: Consultancy, Research Funding; Gilead Sciences, Inc.: Consultancy; TG Therapeutics, Inc: Research Funding; Verastem Oncology: Research Funding; Celgene Corporation: Consultancy; Oncternal Therapeutics: Research Funding; Pharmacyclics: Consultancy; Janssen Pharmaceuticals, Inc.: Consultancy. Mato: MSKCC: Current Employment; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; TG Therapeutics: Consultancy, Other: DSMB, Research Funding; Nurix: Research Funding; BeiGene: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; LOXO: Consultancy, Research Funding; Genmab: Research Funding; AstraZeneca: Consultancy; Sunesis: Consultancy, Research Funding; DTRM BioPharma: Consultancy, Research Funding; Acerta/AstraZeneca: Consultancy, Research Funding; Johnson and Johnson: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Adaptive Biotechnologies: Consultancy, Research Funding; Genentech: Consultancy, Research Funding. Ujjani: Adaptive Biotechnologies: Research Funding; Atara Bio: Consultancy; Janssen: Consultancy; Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Honoraria; Gilead: Honoraria; ACDT: Honoraria; Kite, a Gilead Company: Honoraria; Loxo: 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. Pagel: Kite, a Gilead Company: Consultancy; Incyte/MorphoSys: Consultancy; AstraZeneca: Consultancy; Actinium Pharmaceuticals: Consultancy; Gilead: Consultancy; Pharmacyclics/AbbVie: Consultancy; MEI Pharma: Consultancy; Epizyme: Consultancy; BeiGene: Consultancy.

PURPOSE Among Bruton's tyrosine kinase inhibitors, acalabrutinib has greater selectivity than ibrutinib, which we hypothesized would improve continuous therapy tolerability. We conducted an open-label, randomized, noninferiority, phase III trial comparing acalabrutinib and ibrutinib in patients with chronic lymphocytic leukemia (CLL). METHODS Patients with previously treated CLL with centrally confirmed del(17)(p13.1) or del(11)(q22.3) were randomly assigned to oral acalabrutinib 100 mg twice daily or ibrutinib 420 mg once daily until progression or unacceptable toxicity. The primary end point was independent review committee–assessed noninferiority of progression-free survival (PFS). RESULTS Overall, 533 patients (acalabrutinib, n = 268; ibrutinib, n = 265) were randomly assigned. At the data cutoff, 124 (46.3%) acalabrutinib patients and 109 (41.1%) ibrutinib patients remained on treatment. After a median follow-up of 40.9 months, acalabrutinib was determined to be noninferior to ibrutinib with a median PFS of 38.4 months in both arms (95% CI acalabrutinib, 33.0 to 38.6 and ibrutinib, 33.0 to 41.6; hazard ratio: 1.00; 95% CI, 0.79 to 1.27). All-grade atrial fibrillation/atrial flutter incidence was significantly lower with acalabrutinib versus ibrutinib (9.4% v 16.0%; P = .02); among other selected secondary end points, grade 3 or higher infections (30.8% v 30.0%) and Richter transformations (3.8% v 4.9%) were comparable between groups and median overall survival was not reached in either arm (hazard ratio, 0.82; 95% CI, 0.59 to 1.15), with 63 (23.5%) deaths with acalabrutinib and 73 (27.5%) with ibrutinib. Treatment discontinuations because of adverse events occurred in 14.7% of acalabrutinib-treated patients and 21.3% of ibrutinib-treated patients. CONCLUSION In this first direct comparison of less versus more selective Bruton's tyrosine kinase inhibitors in CLL, acalabrutinib demonstrated noninferior PFS with fewer cardiovascular adverse events.

Abstract Chronic lymphocytic leukemia (CLL) is a neoplastic disease of mature B-cells with a highly heterogeneous clinical course. While European ancestry (EA) populations present an increased incidence of CLL, African ancestry (AA) populations have a younger median age of onset, higher frequency of adverse prognostic factors, and inferior clinical outcomes. Despite the considerable effort to characterize the genetic landscape of CLL, AA are overwhelmingly underrepresented. Our hypothesis is that the clinical differences observed between AA and EA populations are, in part, explained by underlying genetic features. To address this imbalance, we identified 90 AA patients diagnosed with CLL, 64% of which were untreated at sample collection. RNA and DNA were extracted from CD5+/CD19+ clonal B-cells. We performed mRNA-seq and targeted sequencing in 59 recurrently mutated somatic CLL driver genes. Differentially expressed genes were identified using edgeR. Data was compared to our previously analyzed EA CLL cohort (N=445). The median age at diagnosis was 59 years for AA and 66 for EA and 74% of AA and 50% of EA had unmutated IGHV (u-IGHV) status. When evaluating the entire AA and EA cohorts, there was a significant increased frequency of mutations in TP53, SF3B1, and NFKBIE, identified in 29%, 24%, and 20% of AA CLLs, compared to 5%, 9%, and 9%, respectively, in EA CLLs (p<0.01). When exclusively evaluating the untreated and u-IGHV cases, AA CLLs showed greater proportion of TP53 (30% vs 12%; p=0.0145), NFKBIE (30% vs 15%; p=0.0492), BIRC3 (21% vs 10%; p=0.0697), and KRAS (15% vs 7%; p=0.1683). Furthermore, there was an increase in mutations targeting relevant molecular pathways, such as NF-κB (42% vs 15%) and MAPK (18% vs 8%). Upregulation MAPK pathway was also confirmed by mRNA-seq analysis in the AA u-IGHV CLLs. Because of the high prevalence of TP53 mutations in the AA cohort, we further evaluated differential gene expression in the DNA Damage/Telomere Stress-Induced Senescence pathway. AA CLLs presented a significant downregulation of multiple genes associated with genome stability and cellular DNA damage response - DDR (including TP53 and ATM), double strand break repair (H2AFX and RAD50), telomere maintenance (POT1 and ACD), and cell cycle regulation (RB1, CCNA1, and CCNE2) (FDR<0.05). DDR is responsible for DNA repair or induction of apoptosis, with its deficiency resulting in the accumulation of chromosomal aberrations, negatively impacting clinical outcome in CLL. Disparities in cancer are influenced by numerous factors that affect disease risk, screening and diagnosis, access to treatment, and survival. We identified an increased number of genomic alterations in the AA CLL cohort, primarily inducing activation of NF-κB and MAPK pathways and DDR impairment, with the increased frequency of mutations, notably in TP53 and BIRC3, expected to negatively impact prognosis. Citation Format: Cecilia Bonolo de Campos, Daniel R. O'Brien, Chantal E. McCabe, Huihuang Yan, Geffen Kleinstern, Zhiquan Wang, Laura A. Bruins, Cristine Allmer, Nicholas J. Boddicker, Charla R. Secreto, Aaron D. Norman, Shulan Tian, Kari G. Rabe, Timothy G. Call, Sameer A. Parikh, Jose F. Leis, Wei Ding, Richard Furman, J Brice Weinberg, James R. Cerhan, Celine M. Vachon, Neil E. Kay, Susan L. Slager, Esteban Braggio. Characterization of underlying genomic features among African ancestry populations diagnosed with chronic lymphocytic leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2209.