Allan, John N.

Abstract The Bridging the Gaps (BTG) in Leukemia, Lymphoma and Multiple Myeloma Consensus Conference 2025 brought together a multidisciplinary group of oncology experts to address the complexities of lymphoma management, focusing on mantle cell lymphoma (MCL), chronic lymphocytic leukemia (CLL), and diffuse large B‐cell lymphoma (DLBCL). This article presents consensus recommendations developed through a modified Delphi process, which emphasize the need for tailored therapeutic strategies in light of recent advancements in treatment options. Key recommendations include the screening for high‐risk features in MCL, use of the BOVen regimen (zanubrutinib, obinutuzumab, and venetoclax) for TP53 ‐aberrant cases, and integration of chimeric antigen receptor T‐cell therapy for patients with mantle cell lymphoma that is refractory to covalent Bruton tyrosine kinase inhibitors. For CLL, recommendations include consideration of time‐limited therapies for younger patients and a “watch and wait” strategy for asymptomatic patients despite the improved activity and safety of current treatment regimens. For DLBCL, this article highlights the challenges in treatment sequencing and the role of circulating tumor DNA and minimal residual disease testing in monitoring disease progression. Overall, the conference describes the importance of ongoing research to refine management strategies and improve patient outcomes in lymphoma care, addressing the gaps in clinical practice where high‐level evidence is lacking.

Abstract Patients with relapsed/refractory diffuse large B-cell lymphoma progressing after chimeric antigen receptor T-cell (CAR-T) therapy have dismal outcomes. The prespecified post–CAR-T expansion cohort of the ELM-1 study investigated the efficacy and safety of odronextamab, a CD20×CD3 bispecific antibody, in patients with disease progression after CAR-Ts. Sixty patients received IV odronextamab weekly for 4 cycles followed by maintenance until progression. The primary end point was objective response rate (ORR) by independent central review. The median number of prior lines of therapy was 3 (range, 2-9), 71.7% were refractory to CAR-Ts, and 48.3% relapsed within 90 days of CAR-T therapy. After a median follow-up of 16.2 months, ORR and complete response (CR) rate were 48.3% and 31.7%, respectively. Responses were similar across prior CAR-T products and time to relapse on CAR-T therapy. Median duration of response was 14.8 months and median duration of CR was not reached. Median progression-free survival and overall survival were 4.8 and 10.2 months, respectively. The most common treatment-emergent adverse event was cytokine release syndrome (48.3%; no grade ≥3 events). No cases of immune effector cell–associated neurotoxicity syndrome were reported. Grade ≥3 infections occurred in 12 patients (20.0%), 2 of which were COVID-19. Odronextamab monotherapy demonstrated encouraging efficacy and generally manageable safety, supporting its potential as an off-the-shelf option for patients after CAR-T therapy. This trial was registered at www.clinicaltrials.gov as #NCT02290951.

Introduction: Complex karyotype (CK, ≥3 chromosome (chr) abnormalities (abn)) is an important adverse prognostic indicator in chronic lymphocytic leukemia (CLL). CK at diagnosis (dx) of CLL, particularly with major structural chr abn (i.e. unbalanced translocation, add, marker, ring chr), called type-2 CK (CK2), has been associated with an increased risk of Richter transformation (RT) (Visentin Haematologica 2022). RT is defined as development of aggressive lymphoma, most often large B-cell lymphoma, in the setting of CLL. In patients (pts) with relapsed/refractory CLL treated with ibrutinib, CK as a continuous variable and the presence of polyploidy were independent predictors for RT. CK is a common finding at the time of RT, and high-CK (≥5) has been associated with short survival in RT, although previous studies predominantly included pts with prior chemoimmunotherapy (CIT) administration for their CLL. The prognostic significance of CK in pts with RT whose prior CLL-directed therapies include only non-CIT, as is the current standard of care for CLL, has not been evaluated. Methods: We conducted a multicenter, retrospective analysis of pts from 14 academic centers. Pts with RT diagnosed between 6/2011 to 6/2023, who had CLL-directed treatment that did not include prior CIT, with stimulated karyotype data available, were included. Pts who did not receive treatment for their CLL prior to developing RT were not included. Baseline pt, disease, and cytogenetics data were collected via chart review at time of CLL diagnosis and at the development of RT. Karyotype abn up to 20 were counted on both CLL tissue (peripheral blood or bone marrow) and RT tissue using IWGMC guidelines (Chun Leuk Res 2010). CK was categorized as CK1 (balanced abn, deletion, aneusomies) or CK2. Polyploidy was defined as ≥58 chrs. Karyotype was considered evolved if one or more chr abn were seen in a follow-up sample of CLL tissue that were not seen at CLL dx.TP53 disruption was defined as presence of del(17p) or TP53 mutation. Overall survival (OS) was measured from RT dx and estimated using the Kaplan-Meier method. Cox regression model was used to identify prognostic factors associated with OS. Results: A total of 64 eligible pts were identified. Median age at RT dx was 65 years (range 40-89) and 71.9% of pts were male. Of those evaluated (n=49), 79.6% had unmutated IGVH. Median number of therapies for CLL prior to RT was 1 (range 1-5) and included BTK inhibitor (n=37), BCL2 inhibitor (n=3), both (n=18), or other non-CIT treatment (n=6). At CLL diagnosis, 54.7% of pts had a CK, and the median number of chr abn was 3 (range 0-20). Of those with CK, 96.9% had a CK2, and 6.3% had a polyploid subclone. TP53 disruption was found in 46% of pts. At time of RT, chr analysis of CLL tissue was available for 38 pts and showed 78.9% had a CK, and the median number of chr abn was 8 (range 0-20). Polyploidy was found in 29.6%. TP53 disruption (46 pts evaluated) was found in 52.2%. Karyotype evolution from dx (35 pts evaluated) occurred in 74.3% of pts. In RT tissue, of those evaluated (n=29), 96.6% were clonally related to the preceding CLL. MYC translocation (45 pts evaluated) occurred in 17.8%. CK (20 pts evaluated) was found in 70%, with a median number of chr abn of 8 (range 0-20). Of those with CK, 33.3% had a polyploid subclone. With a median follow-up of 17.8 months (range 2.1-83.0) there were 42 deaths, with a median OS of 14.3 months (range 6.9-29.1). For this subset of patients with karyotype data available who would go on to develop RT, an exploratory univariable analysis for OS from RT found that increasing number of chr abn as a continuous variable at CLL dx was associated with worse OS (HR 1.10, 95% CI 1.02-1.19, p=0.01). Similarly, at RT, increasing number of chr abn in CLL tissue (HR 1.09, 95% CI 1.02-1.16, p=0.01) and in RT tissue (HR 1.09, 95% CI 1.01-1.18, p=0.03) was also prognostic of survival. Karyotype evolution in CLL tissue at RT (HR 3.02, 95% CI 1.02-8.94, p=0.05) was borderline significant for worse OS. Conclusions: Our multi-center study identified increasing number of chr abn at CLL diagnosis and at time of RT, and clonal evolution in the CLL tissue, are associated with worse OS in pts with RT whose CLL was treated without CIT. Limitations include incomplete cytogenetics data across the cohort and potential variability across institutions in cytogenetics laboratory practices. This provides further evidence for the clinical utility of chr analysis in the modern era of CLL therapy.

Introduction: Richter transformation is the development of an aggressive lymphoma, most commonly diffuse large B-cell lymphoma, in patients (pts) with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Transformation into Hodgkin lymphoma (HT) is a rare event and outcomes in pts with this complication in the current CLL/SLL therapeutic era of small molecule inhibitors (SMI; e.g., Bruton tyrosine kinase inhibitors [BTKi] and BCL2 inhibitors [BCL2i]) are unknown. Methods: We conducted a retrospective study of pts from 12 academic centers. Pts with HT who had not previously received chemotherapy for CLL/SLL-directed treatment (tx) were included. Pt, disease, and tx characteristics were collected. HT was categorized into 3 groups: “Concurrent HT,” defined as HT and CLL/SLL diagnosed simultaneously (within 3 months); “HT without prior CLL/SLL tx,” defined as HT and CLL/SLL diagnosed >3 months apart with the CLL/SLL never treated; and “HT with prior non-chemotherapy tx for CLL/SLL” defined as having received non-chemotherapy CLL/SLL-directed tx prior to the diagnosis (dx) of HT. Overall survival (OS) was measured from HT dx and estimated using the Kaplan-Meier method. Cox regression model was used to identify prognostic factors associated with OS. Results: Within a total cohort of 402 pts with Richter transformation (all histologies) without prior chemotherapy, 41 pts with HT (10%) were identified: 12 with concurrent HT, 10 with HT without prior CLL/SLL tx, and 19 with HT with prior non-chemotherapy tx for CLL/SLL. The median age at CLL/SLL dx was 62 years (range 31-96 years) and 73% were male. At CLL/SLL dx, 67% (14/21 evaluated) had unmutated IGHV, and 24% (8/34 evaluated) had TP53 disruption (del(17p) and/or TP53 mutation). The median age at HT dx was 65 years (range 31-96 years) among all pts. At HT dx, there was no significant difference in highest SUV on PET (median 12.3, range 3-31.1), lactate dehydrogenase (LDH) level (median 242 U/L, range 112-859 U/L), or lymph node longest diameter (median 4.6 cm, range 1.6-25 cm) among the 3 subgroups. The median time from CLL/SLL dx to HT dx was 5.4 years (range 0.3-16.5 years) in pts with HT without prior CLL/SLL tx and 4.2 years (range 0.5-17.3 years) in pts with HT with prior non-chemotherapy tx for CLL/SLL. The median number of prior non-chemotherapy CLL/SLL-directed tx was 1 (range 1-6) and included BTKi only (n=17) and BTKi and BCL2i sequentially (n=2); no patient had received only prior BCL2i. Among the 19 pts with HT with prior non-chemotherapy tx for CLL/SLL, 18 pts were on active tx at time of dx (17 BTKi, 1 BCL2i). Initial HT management included: doxorubicin, bleomycin, vinblastine, dacarbazine (ABVD; n=16), brentuximab vedotin (BV)-AVD (n=10), radiation only (n=2), other systemic tx (n=11), and supportive cares / hospice (n=2). All but 1 of the 11 other systemic tx were various HL tx regimens. Across all pts with available data (n=32), the overall response rate to 1st line HT tx was 78% (69% complete response rate); 13% had progressive disease and 9% (n=3; all with concurrent HT) died within 6 months without formal response assessment. A total of 11 pts received at least 1 additional line of therapy for HT, which included BV (n=4), an immune checkpoint inhibitor (n=1), or both (n=6) at any point beyond 1st line HT tx. Median follow-up from HT dx was 32.8 months (range 2.4-253.8 months). The 36-month OS for the entire cohort was 75% (95% CI: 55-87%). The 36-month OS estimates by subgroups were: 62% (95% CI: 26-84%) in pts with concurrent HT, 100% in pts with HT without prior CLL/SLL tx (no events by 36 months), and 67% (95% CI: 33-87%) in pts with HT with prior non-chemotherapy tx for CLL/SLL. Exploratory univariable analysis identified TP53 disruption at CLL dx (HR 12.36; 95% CI: 2.55-59.84) and lymph node longest diameter (HR 1.32 per 1 cm increase; 95% CI: 1.12-1.55) and LDH 2-fold increase (HR 3.97; 95% CI 1.24-12.68) at HT dx as prognostic for worse OS. HT subgroup was not prognostic. Conclusions: This is the largest report of outcomes in pts with CLL/SLL who develop HT following SMI tx without any prior chemotherapy, representing a contemporary cohort. Prior CLL/SLL tx status was not associated with OS; however, cautious interpretation is required given the sample size. Our findings support the use of appropriate HL-directed treatment in the setting of HT; however, OS estimates remain worse than would be expected in an older adult de novo HL cohort (Cheng Blood Adv 2022).

Background: Epcoritamab (epcor) is a first-in-class CD3xCD20 bispecific antibody (bsAb) approved for the treatment of 3L+ LBCL and follicular lymphoma. In the single-arm, phase 1/2, EPCORE NHL-1 trial (NCT03625037), epcor given until disease progression or unacceptable toxicity, demonstrated deep and durable responses, a median overall survival (OS) of 18.5 months, and a manageable safety profile in R/R LBCL. A second CD3xCD20 bsAb given as fixed-treatment duration, glofitamab (glofit), also demonstrated durable responses, conferring a median OS of 11.5 months in the pivotal study. Understanding how long-term outcomes compare among bsAb agents remains an important knowledge gap. With over 2 years of follow-up, in the absence of a head-to-head study, it is now relevant to compare the efficacy of these agents via indirect comparison. This study evaluated OS, progression-free survival (PFS), and duration of complete response (DoCR) of epcor vs glofit in R/R LBCL using data from the respective pivotal trials. Methods: Two analyses were conducted to compare the efficacy of epcor and glofit. First, a matching-adjusted indirect treatment comparison (MAIC) was conducted using published OS and PFS data from the full cohort of the glofit pivotal trial (12.6 months of follow-up, Dickinson et al, 2022) and the epcor pivotal trial (EPCORE NHL-1). Piece-wise hazard ratios (HRs) were calculated when proportional hazards assumptions were not met. Baseline characteristic prognostic variables were selected based on literature, clinical judgement, and empirical statistical testing and were adjusted between epcor and glofit cohorts. Second, in sensitivity analyses, indirect comparisons were conducted using an updated analysis of glofit with longer follow-up that included DoCR, together with OS and PFS data starting at cycle (C) 3 with 32 months of follow-up (Hutchings et al, ASH 2023). Sensitivity analyses with longer follow-up could not be adjusted because glofit pt baseline characteristics were not presented. Aggregate OS and PFS curves for glofit were derived from subgroups of pts with complete response/partial response/no response (CR/PR/NR) at C3 (Hutchings et al, ASH 2023). Aggregate epcor OS and PFS curves were similarly derived for pts with CR/PR/NR at C3 without prior disease progression. Weighted Cox proportional-hazards models were used to estimate the OS and PFS HRs between the 2 comparators. The DoCR comparison included all glofit and epcor pts achieving CR. All comparisons used EPCORE NHL-1 data with a median of 37.1 months of follow-up. Results: Pts enrolled into the pivotal trials of epcor and glofit were comparable by several key baseline characteristics before adjustment: age ≥65 y; male gender; Ann Arbor disease stage III-IV; primary refractory disease; refractory to most recent anti-CD20 therapy; previous chimeric antigen receptor T-cell therapy (CAR T); refractory to CAR T; and previous autologous stem cell transplant (ASCT). MAIC analysis revealed no significant difference in OS benefit from C1 until month 6 (HR 1.08, 95% CI 0.71, 1.64; P=0.72), but a demonstrable OS advantage from 6 months onward (HR 0.60, 95% CI 0.37, 0.98; P=0.04) in favor of epcor. An OS comparison starting at C3 with longer glofit follow-up demonstrated a consistent survival advantage in favor of epcor (HR 0.68, 95% CI 0.46, 1.01; P=0.05). The proportion of pts who received CAR T or ASCT subsequent therapy were similar for epcor and glofit (CAR T: 7.0% vs 8.9%; ASCT: 6.4% vs 6.3%) (National Institute for Health and Care Excellence Glofit Single Technology Appraisal, 2023). The MAIC analysis showed comparable PFS between epcor and glofit (HR 1.06, 95% CI 0.79, 1.41; P=0.71), although there was substantial censoring in the glofit PFS curve due to immature follow-up. With longer follow-up in the analysis starting at C3, with less censoring, the glofit PFS curve remained similar to the epcor PFS curve from C3 until month 6 (HR 0.67, 95% CI 0.42, 1.07; P=0.10), where separation of the PFS curves were observed favoring epcor (HR 0.56, 95% CI 0.33, 0.97; P=0.04). Median DoCR was longer for epcor (36.1 months) vs glofit (26.9 months). Conclusion: These indirect treatment comparisons suggest that epcor may provide an overall survival benefit over glofit through longer PFS with more mature follow-up, potentially driven by longer DoCR. Survival data with longer follow-up in the full glofit cohort are needed to confirm these findings.

Introduction: Bruton tyrosine kinase (BTK) inhibitors are highly effective against Waldenström macroglobulinemia (WM). Their effectiveness can be limited by resistance caused by BTK mutations and intolerance. BGB-16673 is a bivalent small molecule that induces BTK degradation by binding specifically to BTK and the E3 ligase. The E3 ligase catalyzes the transfer of ubiquitin molecules to BTK, which marks BTK for destruction by the proteasome. Preclinically, BGB-16673 degraded wild-type and mutant BTK associated with covalentand noncovalent BTK inhibitors (ncBTKis), leading to tumor suppression. CaDAnCe-101 (BGB-16673-101; NCT05006716) is an ongoing, open-label, first-in-human, phase 1/2 study evaluating BGB-16673 monotherapy in patients with a range of B-cell malignancies. Here, early results in patients with WM enrolled in the phase 1 portion are presented. Methods: Eligiblepatients must have confirmed R/R WM (≥2 prior therapies), an ECOG performance status of 0-2, and adequate organ function. Patients must have previously received an anti-CD20 antibody and, in the US and EU, a covalent BTK inhibitor (cBTKi). BGB-16673 was orally dosed once daily in 28-day cycles. Dose escalation used a Bayesian optimal interval design (6 planned dose levels, 50-600 mg once daily). Primary objectives were to evaluate safety/tolerability (CTCAE v5.0) and to establish the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D). Dose-limiting toxicities (DLTs) were assessed in the first 4 weeks (cycle 1). A secondary objective was to evaluate the overall response rate (ORR, IWWM-6 consensus criteria), with the first assessment occurring after 4 weeks of treatment. Results: As of May 24, 2024, 22 patients with WM were enrolled and treated (100 mg, n=4; 200 mg, n=10; 350 mg, n=8). The median age was 73.0 (range, 56-81) years, and the median number of prior therapies was 3.5 (range, 2-11), including prior cBTKis (n=22 [100%]), BCL2 inhibitors (n=4 [18%]), and ncBTKis (n=3 [14%]). Twenty patients (91%) had previously received chemotherapy. According to the International Prognostic Scoring System for WM, 6 patients (27%) had low-risk disease, 7 (32%) had intermediate-risk disease, and 8 (36%) had high-risk disease (missing/unknown data, n=1). Five patients (23%) had BTK mutations, 20 (91%) had MYD88 mutations, and 8 (36%) had CXCR4 mutations. The median follow-up was 4.3 (range, 0.3-21.3) months. Ninety-five percent of patients reported any-grade treatment-emergent adverse events (TEAEs; grade ≥3, 45%; serious, 23%), the most common (≥20%) of which were neutropenia/neutrophil count decreased (32%; grade ≥3, 23%), contusion (23%; no grade ≥3), and diarrhea (23%; no grade ≥3). The most common grade ≥3 TEAE (≥20%) was neutropenia/neutrophil count decreased. No atrial fibrillation, hypertension, febrile neutropenia, or major hemorrhage occurred. Three patients (14%) had a grade ≥3 infection (bronchopulmonary/cerebral aspergillosis, septic shock, and pseudomonal bacteremia/sinusitis). No patients had a TEAE that led to treatment discontinuation or dose reduction. No DLTs occurred, and the MTD was not reached. One patient (5%) died due to a TEAE (septic shock, considered related to disease progression). One patient died due to disease progression. In 21 response-evaluable patients (1 too early), the ORR (minor response or better) was 90%, the major response rate (partial response [PR] or better) was 81%, and the very good PR or better rate was 14%. Median time to first response was 0.95 (range, 0.9-3.7) months, with responses deepening over time. Seventeen patients remain on treatment and have ongoing responses. Responses were seen at the lowest dose (100 mg, 4/4), in patients previously treated with a cBTKi (19/21) and an ncBTKi (3/3), and in patients discontinued from prior BTKi due to disease progression (15/17). In addition, responses were observed in patients with and without mutations in BTK (with, 5/5; without, 6/8; unknown, 8/8), MYD88 (with, 18/20; without, 1/1), and CXCR4 (with, 8/8; without, 11/13). One patient had IgM flare at initial response assessment and went on to develop PR. Conclusions: Early data from this ongoing, first-in-human study demonstrate that the novel BTK degrader BGB-16673 has a tolerable safety profile and shows promising antitumor activity in heavily pretreated patients with BTK inhibitor-exposed R/R WM, including those with BTK and CXCR4 mutations.

Introduction CD19-directed CAR T-cell therapies are an important option for the management of relapsed/refractory (R/R) DLBCL. Studies suggest that ~50% of pts receiving CAR T-cell therapies will relapse within 6 months, with an estimated overall survival (OS) of only 5 months. Additionally, 25-35% of pts do not receive subsequent treatment, indicating a high unmet need. CD19 loss is a potential mechanism of resistance to CAR T-cell therapies; thus, treatments that target alternate B-cell antigens are an attractive option. Here, we report for the first time the primary analysis of the ELM-1 expansion cohort investigating the efficacy and safety of odronextamab, a CD20×CD3 bispecific antibody, in pts with R/R DLBCL progressing after CAR T-cell therapy (NCT02290951). Methods Pts aged ≥18 with DLBCL and disease progression after CAR T-cell therapy received intravenous odronextamab weekly in 21-day (D) cycles during Cycles (C) 1-4, with steroid prophylaxis and step-up dosing in C1 (described previously), followed by 160 mg on D 1, 8, and 15 of C2-4. After C4, odronextamab maintenance treatment continued at 320 mg Q2W until disease progression or unacceptable toxicity. Pts with complete response (CR) for ≥9 months transitioned to Q4W dosing. All pts received infection prophylaxis. The primary analysis was conducted when all pts had completed ≥9 months of follow-up. Primary endpoint was objective response rate (ORR), as assessed by independent central review (ICR) according to the Lugano classification. Key secondary endpoints included duration of response (DOR), progression-free survival (PFS), and OS. Exploratory endpoints included immune biomarker assessment. Results As of January 22, 2024, 60 pts were treated and evaluable for efficacy and safety, with median follow-up of 16.2 months. Prior CAR T-cell therapies were axi-cel (50%), tisa-cel (12%), liso-cel (10%), and not specified (28%). Median time since prior CAR T-cell therapy was 6.5 months (range 1.2-46.2). Median age was 63 years (range 27-82; aged ≥75 years: 10%), and 65% were male. Pts had received a median of 3 prior lines of therapies (range 2-9); 77% of pts were refractory to their last therapy, 77% were double refractory, and 72% were refractory to prior CAR T-cell therapy. 48% of pts relapsed within 90 D of CAR T-cell therapy, and 67% relapsed within 180 D. Of the 20 pts with available tumor biopsies at baseline, 10 were CD19(-) and only 2 were CD20(-). 92% of pts completed C1 and 52% completed ≥4 C of treatment. The median duration of treatment was 12 weeks (range 0.7-154.1). The ORR and CR rate by ICR were 48% and 32%, respectively, and were consistent across pts with high-risk features and across prior CAR T products. ORR in pts relapsing in ≤90 D was 21% (6/29) and in pts relapsing in ≤180 D was 33% (13/40). ORR was observed even in pts with low CD20. Median DOR was 14.8 months (95% CI 2.8-not estimable [NE]) and median duration of CR was not reached (NR) (95% CI 3.3-NE); the probability of maintaining CR for 24 months was 68%. Median PFS was 4.8 months (95% CI 2.6-5.4) and median OS was 10.2 months (95% CI 4.6-15.8). Median PFS and OS in complete responders was NR. T-cell counts increased at Week 14 and demonstrated a functional phenotype (CD69 expression and TEMRA count), which was confirmed by ex vivo stimulation. T-cell expansion was observed regardless of CAR T product or time from CAR T administration. The most common TEAE was CRS (any grade [G]: 48%; G1: 25%; G2: 23%; G≥3: 0%). G≥3 TEAEs occurred in 77% of pts (most common: neutropenia 17%, anemia 13%, and neutrophil and white blood cell count decrease 10% each). Five pts (8%) permanently discontinued odronextamab due to AEs (COVID-19, pneumonia, encephalopathy, epilepsy, and gait disturbance [n=1 each]). There was one treatment-related death (COVID-19 pneumonia). No cases of ICANS were reported. G≥3 infections occurred in 12 pts (20%); 2 were due to COVID-19. No cases of tumor flare or TLS were reported. Conclusions ELM-1 is the only study to prospectively evaluate efficacy and safety of a CD20×CD3 bispecific antibody in pts with R/R DLBCL progressing after CAR T-cell therapy. Odronextamab monotherapy was associated with encouraging efficacy and generally manageable safety in a setting with limited treatment options and historically dismal outcomes. Efficacy was observed even in pts relapsing in ≤90 D, supporting the potential of odronextamab as an accessible, off-the-shelf option in the post-CAR T setting.

Introduction: Ibrutinib, a Bruton tyrosine kinase inhibitor (BTKi), changed the treatment landscape by demonstrating improved overall survival (OS) compared with chemotherapy/chemoimmunotherapy across multiple phase 3 trials in patients (pts) with CLL, including those with high-risk genomic features. Recently, data were reported for pts treated with ibrutinib in the phase 3 RESONATE-2 trial with up to 10 years of follow-up, representing the longest follow-up of any BTKi used in first-line treatment of CLL. With the most robust long-term follow-up data among BTKis, ibrutinib therapy trials are uniquely positioned to assess the long-term OS benefit of first-line BTKi treatment in pts with CLL across pt subgroups. We previously demonstrated that first-line ibrutinib is associated with OS rates that are similar to those in the age-matched general population, with a median follow-up of 5.9 years since initial diagnosis (Ghia P et al. HemaSphere 2024), but it remains unclear whether this holds true for pts with high-risk genomic features. This updated analysis evaluated long-term OS outcomes with a median follow-up of 8 years since randomization and 10 years since initial diagnosis in a pooled population of pts with previously untreated CLL, including those with high-risk features, who received first-line ibrutinib treatment in 2 phase 3 trials with comparison of survival estimates to the US age-matched general population. Methods: Data were pooled for pts who received first-line treatment with single-agent ibrutinib or ibrutinib + rituximab in the RESONATE-2 (NCT01722487) and ECOG-ACRIN E1912 (NCT02048813) trials, respectively. OS probabilities from the time of randomization and from the time of initial diagnosis for ibrutinib-treated pts were compared with an age-matched general population using 2021 life tables for the total US population published by the Centers for Disease Control and Prevention using the Kaplan-Meier method. Subgroup analyses were performed for high-risk pts, defined as those with del(11q), del(17p), mutated TP53, and/or unmutated IGHV (uIGHV). Results: A total of490 pts were pooled across the 2 studies: 352 pts (71.8%) were treated with ibrutinib + rituximab, and 135 pts (27.6%) were treated with single-agent ibrutinib; 3 pts did not receive study treatment. The median age at time of randomization was 61 years; 36.5% (179/490) were aged ≥65 years, 21.8% had del(11q), 7.8% had del(17p) and/or mutated TP53, and 54.7% had uIGHV. The median time from initial CLL diagnosis to randomization was 20.9 months (range, 0.0-341.8); the median follow-up was 123.5 months (10.3 years) from initial diagnosis and 99.2 months (8.3 years) from the time of randomization. From the time of randomization, estimated 9-year OS rates were 81.2% (95% CI, 76.8-84.9) in all ibrutinib-treated pts versus 82.0% (95% CI, 78.3-85.2) in the age-matched population (hazard ratio [HR] 1.17; 95% CI, 0.86-1.58). In high-risk pts, estimated 9-year OS rates were 79.5% (95% CI, 73.5-84.3) for ibrutinib-treated pts versus 83.2% (95% CI, 78.5-86.9) in the age-matched general population (HR 1.24; 95% CI, 0.84-1.84). In pts aged ≥65 years, estimated 9-year OS rates were 68.7% (95% CI, 60.5-75.6) for ibrutinib-treated pts and 68.7% (95% CI, 61.4-75.0) in the age-matched general population (HR 1.12; 95% CI, 0.77-1.63). In pts aged <65 years, estimated 9-year OS rates were 89.3% (95% CI, 84.6-92.7) for ibrutinib-treated pts and 90.0% (95% CI, 86.1-92.9) in the age-matched general population (HR 1.15; 95% CI, 0.68-1.94). From the time of initial diagnosis, estimated 15-year OS rates were 78.4% (95% CI, 72.8-83.0) in all ibrutinib-treated pts versus 72.0% (95% CI, 67.8-75.7) in the age-matched general population (HR 0.83; 95% CI, 0.62-1.11). Study treatment had been discontinued in 59.8% (293/490) of pooled ibrutinib-treated pts; the most frequent reasons for discontinuation were adverse events (43.0%; 126/293) and progressive disease (20.5%; 60/293). Study treatment was ongoing in 31.8% of pooled pts (156/490). Conclusions: With the longest follow-up time for any commercially available targeted therapy, this pooled analysis demonstrates that, regardless of evaluation from randomization or initial diagnosis, and irrespective of age or high-risk features, first-line treatment with ibrutinib provides long-term OS benefit with survival estimates that appear similar to those of a US age-matched cohort.

Introduction: Bruton tyrosine kinase (BTK) inhibitors are effective therapies for the treatment of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Their use can be limited by intolerance and/or acquired resistance, due to BTK mutations. BGB-16673 is a bivalent small molecule that induces BTK degradation by binding specifically to BTK and the E3 ligase. The E3 ligase catalyzes the transfer of ubiquitin molecules to BTK which marks BTK for destruction by the proteasome. In preclinical models, BGB-16673 degraded wild-type and mutant forms of BTK associated with resistance to covalent and noncovalent BTK inhibitors, leading to tumor suppression. CaDAnCe-101 (BGB-16673-101, NCT05006716) is an ongoing, open-label, first-in-human, phase 1/2 study designed to evaluate BGB-16673 monotherapy in patients with B-cell malignancies. Here, updated results in patients with relapsed or refractory (R/R) CLL/SLL enrolled in the phase 1 portion are presented. Methods: Eligiblepatients must have confirmed R/R CLL/SLL (≥2 prior therapies), an ECOG performance status of 0-2, and adequate organ function. In the US, EU, and Australia, patients must have previously received a covalent BTK inhibitor (cBTKi). BGB-16673 was dosed once daily orally in 28-day cycles. Dose escalation used a Bayesian optimal interval design (6 planned dose levels, 50-600 mg once daily). Primary objectives were to assess safety/tolerability (CTCAE v5.0 and iwCLL hematologic toxicity criteria), and to establish the maximum tolerated dose (MTD) and the recommended phase 2 dose. Dose-limiting toxicities (DLTs) were assessed in the first 4 weeks (cycle 1). A secondary objective was to evaluate the overall response rate (ORR, iwCLL 2018 criteria or 2014 Lugano criteria for SLL), with the first assessment occurring after 12 weeks of treatment. Results: As of May 24, 2024, 49 patients with CLL were enrolled and treated (50 mg, n=1; 100 mg, n=5; 200 mg, n=16; 350 mg, n=15; 500 mg, n=12). The median age was 70 years (range, 50-91 years), and the median number of prior therapies was 4 (range, 2-10), including prior cBTKis (n=45 [92%]), BCL2 inhibitors (n=42 [86%]), and noncovalent BTK inhibitors (ncBTKis; n=12 [24%]). Of tested patients, 63% (31/49) had del(17p) and/or TP53 mutation and 82% (32/39) had unmutated IGHV. The median follow-up was 7.9 months (range, 0.3-23.1 months). Ninety-six percent of patients reported any-grade treatment-emergent adverse events (TEAEs; grade ≥3, 57%), of which the most common (≥25%) were fatigue (35%; grade ≥3, 2%), contusion (29%; no grade ≥3), and diarrhea (27%; grade ≥3, 2%). The most common grade ≥3 TEAEs (≥10%) were neutropenia/neutrophil count decreased (20%) and pneumonia (10%). One patient (2%) each experienced hypertension (grade 1), febrile neutropenia (in the context of COVID-19 pneumonia and norovirus diarrhea), and major hemorrhage. No atrial fibrillation was observed. Three patients (6%) experienced a TEAE that led to dose reduction. One DLT occurred in 1 patient at 200 mg (grade 3 maculopapular rash on day 27; decreased to grade 1 after 5-day hold; patient continues on treatment). The MTD was not reached. Three patients had TEAEs that led to death (septic shock, bronchopulmonary aspergillosis/cerebral aspergillosis, and pneumonia in the context of disease progression; n=1 each); none of the deaths were considered related to treatment. In 49 response-evaluable patients, the ORR (partial response with lymphocytosis or better) was 78% (38/49), and the CR/CR with incomplete hematologic recovery rate was 4% (n=2). At 200 mg, the ORR was 94% (15/16) including the 2 CRs. Median time to first response was 2.8 months (range, 2.6-8.3 months). Seventeen patients remained on treatment for ≥9 months and all 17 have ongoing responses. Responses were seen at the lowest dose, as well as in patients previously treated with a cBTKi, ncBTKi, double- (cBTKi and BCL2i) and triple- (cBTKi, BCL2i, ncBTKi) exposed patients, and in patients with and without BTK mutations. Conclusions: Emerging data from this ongoing, first-in-human study demonstrate that the novel BTK degrader BGB-16673 has a tolerable safety profile and shows promising and deep overall responses in heavily pretreated patients with R/R CLL/SLL, including those with prior BTK inhibitor treatment and BTK resistance mutations.