Kater, Arnon P.

CD19-directed CAR T-cells (CTL019) can produce durable remissions in chronic lymphocytic leukemia (CLL), but therapeutic success depends on whether autologous T-cells expand, persist, and retain cytotoxic function after manufacturing. Failure of CLL T-cells is often attributed to exhaustion, although many dysfunctional CLL T-cells retain inflammatory cytokine production. We tested whether this paradox reflects immunosenescence, an aging-like program defined by costimulatory loss, DNA damage, inflammatory secretion, repertoire restriction, and proliferative arrest. In response-linked preinfusion CTL019 products, nonresponders and short partial responders had higher senescence and senescence-associated secretory phenotype (SASP) programs than the functional-responder group, comprising complete responders and partial responders with transformed disease. These programs were detectable before infusion and became more prominent during manufacture in susceptible products. They tracked with weak in vivo CAR T-cell expansion and were associated with inferior survival. Serum proteomics revealed a circulating, CLL-associated SASP-like inflammatory milieu in nonresponders. Flow cytometry and T-cell receptor (TCR) profiling showed that poor responders carried CD27⁻CD28⁻ and KLRG1⁺ CD8 T-cells at apheresis, lower product CD27, and reduced product TCR diversity. Research-manufactured CAR T-cells from treatment-naïve CLL samples displayed the same state, most prominently in CD4 CAR T-cells, with SA-β-gal, p16, p53, DNA damage, depletion of less-differentiated states, and senescence-enriched transcriptomes. Under repeated CD19 stimulation, CLL-derived products reached a proliferative ceiling, and p53-high products lost cytotoxic reserve. Ibrutinib improved proliferative fitness, attenuated senescence-associated features and SASP output in paired patient and direct-exposure assays, and enhanced CAR T-cell expansion in an ibrutinib-resistant CLL model. Together, these data identify immunosenescence as a measurable and functionally consequential barrier to CAR T-cell efficacy in CLL and a candidate for therapeutic modulation.

Abstract Richter transformation (RT) is defined as an aggressive lymphoma emerging in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL). Despite novel therapeutics developed in CLL, RT is associated with poor outcomes. In light of recent progress regarding the diagnostic procedures and therapeutic concepts of RT, an international group of experts, under the coordination of the European Research Initiative on CLL, has developed consensus recommendations for clinical procedures and future research on this disease. Patients with RT typically present with a rapid clinical decline, worsening B-symptoms, elevated lactate dehydrogenase, and/or rapidly enlarging lymphadenopathy. Workup should include a positron emission tomography–computed tomography scan for patients with suspected RT. An excisional biopsy should be taken from an accessible lesion, preferably with the highest fluorodeoxyglucose avidity, and analyzed for the presence of aggressive lymphoma. The molecular relationship to the original CLL clone(s) should be defined. Because no effective standard treatment for RT exists, patients should be treated in a clinical trial. Response of both RT and CLL should be assessed at an early time point, and survival end points should be prioritized in trial design. We hope that these recommendations can help to harmonize clinical and translational research and improve outcomes for patients with RT.

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 The management of chronic lymphocytic leukemia (CLL) has undergone unprecedented changes over the last decade. Modern targeted therapies are incorporated into clinical practice. Unfortunately, patients have begun to develop resistance or intolerance to multiple classes. Symptomatic patients previously treated with a BTK inhibitor (BTKi) and venetoclax represent a new and rapidly growing unmet need in CLL. Here, we define unmet needs in a modern treatment context. We also critically review the literature for PI3K inhibitors and chemoimmunotherapy and lack of data to support their utility following BTKis and venetoclax. Finally, we suggest opportunities to ensure the continued innovation for patients with CLL.

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.

7500 Background: Increased selectivity of the Bruton tyrosine kinase inhibitor (BTKi) acalabrutinib (Aca) vs ibrutinib (Ib) may improve tolerability. We conducted an open-label, randomized, noninferiority, phase 3 trial to compare Aca vs Ib in patients (pts) with chronic lymphocytic leukemia (CLL). Methods: Previously treated CLL pts with del(17p) or del(11q) by central lab were randomized to receive oral Aca 100 mg BID or Ib 420 mg QD (stratified by del(17p) status, ECOG PS [2 vs ≤1], and number of prior therapies [1–3 vs ≥4]) until progression or unacceptable toxicity. Primary endpoint was progression-free survival (PFS) as assessed by IRC; secondary endpoints of all grade atrial fibrillation (AF), grade ≥3 infection, Richter transformation, and overall survival (OS) were assessed in hierarchical order. Results: 533 pts (Aca, n=268; Ib, n=265) were randomized (median age 66 y; median 2 prior therapies; del(17p) 45.2%; del(11q) 64.2%). At a median follow-up of 40.9 mo (range 0.0–59.1), Aca was noninferior to Ib with a median PFS of 38.4 mo in both arms (HR 1.00; 95% CI 0.79–1.27). Aca was statistically superior to Ib in all-grade AF incidence (9.4% vs 16.0%; P=0.023). Among the other secondary endpoints, incidences of grade ≥3 infection (Aca: 30.8%, Ib: 30.0%) and Richter transformation (Aca: 3.8%, Ib: 4.9%) were comparable between arms. Median OS was not reached in either arm (HR 0.82 [95% CI 0.59–1.15]), with 63 (23.5%) deaths in the Aca arm and 73 (27.5%) in the Ib arm. Among any-grade AEs in ≥20% of pts in either arm, Aca was associated with a lower incidence of hypertension (9.4%, 23.2%), arthralgia (15.8%, 22.8%), and diarrhea (34.6%, 46.0%) but a higher incidence of headache (34.6%, 20.2%) and cough (28.9%, 21.3%). AEs led to treatment discontinuation in 14.7% of Aca- vs 21.3% of Ib-treated pts. Among any-grade events of clinical interest, cardiac, hypertension, and bleeding events were less frequent with Aca (Table). Conclusions: In this first head-to-head trial of BTKis in CLL, Aca demonstrated non-inferior PFS with less cardiotoxicity and fewer discontinuations due to AEs vs Ib. Clinical trial information: NCT02477696. [Table: see text]

Abstract Chronic lymphocytic leukemia (CLL) is characterized by the existence of subsets of patients with (quasi)identical, stereotyped B-cell receptor (BcR) immunoglobulins. Patients in certain major stereotyped subsets often display remarkably consistent clinicobiological profiles, suggesting that the study of BcR immunoglobulin stereotypy in CLL has important implications for understanding disease pathophysiology and refining clinical decision-making. Nevertheless, several issues remain open, especially pertaining to the actual frequency of BcR immunoglobulin stereotypy and major subsets, as well as the existence of higher-order connections between individual subsets. To address these issues, we investigated clonotypic IGHV-IGHD-IGHJ gene rearrangements in a series of 29 856 patients with CLL, by far the largest series worldwide. We report that the stereotyped fraction of CLL peaks at 41% of the entire cohort and that all 19 previously identified major subsets retained their relative size and ranking, while 10 new ones emerged; overall, major stereotyped subsets had a cumulative frequency of 13.5%. Higher-level relationships were evident between subsets, particularly for major stereotyped subsets with unmutated IGHV genes (U-CLL), for which close relations with other subsets, termed “satellites,” were identified. Satellite subsets accounted for 3% of the entire cohort. These results confirm our previous notion that major subsets can be robustly identified and are consistent in relative size, hence representing distinct disease variants amenable to compartmentalized research with the potential of overcoming the pronounced heterogeneity of CLL. Furthermore, the existence of satellite subsets reveals a novel aspect of repertoire restriction with implications for refined molecular classification of CLL.