Citations

Abstract Background: Covalent Bruton tyrosine kinase inhibitors (cBTKi) have dramatically changed the treatment (tx) landscape of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), especially in the first-line setting. However, cBTKi resistance or intolerance eventually occurs. Pirtobrutinib is a highly selective, non-covalent BTKi that inhibits BTK with low nM potency throughout the daily dosing interval. Pirtobrutinib demonstrated safety and efficacy in the phase 1/2 BRUIN study among patients (pts) with R/R CLL/SLL, including pts previously treated with a BTKi. Pirtobrutinib is approved for treating CLL in adults in the EU after prior tx with a BTKi, and in the USA for adults with CLL/SLL who have received at least 2 prior lines of therapy, including a BTKi and a BCL-2i. Here, we report the final results from the phase 1/2 BRUIN study (NCT03740529) with more than 5 years (yrs) follow-up (f/u), focusing on efficacy and safety of pirtobrutinib in pts with CLL/SLL in the post-cBTKi setting. Methods: Pts with prior cBTKi-exposed CLL/SLL were eligible for tx with pirtobrutinib. Endpoints included overall response rate (ORR) per 2018 iwCLL criteria, ORR including partial response with lymphocytosis (PR-L), duration of response (DOR), and progression-free survival (PFS), assessed by independent review committee (IRC; presented herein) and investigator, overall survival (OS), and safety. Data cut was 27 January 2025, providing a median study f/u of 34.1 months (mos; range, 0.5-69.8). Results: Among the 282 pts with CLL/SLL who were cBTKi-exposed and treated with pirtobrutinib, of which 84.4% (238/282) received 200 mg as the starting dose, the median age was 69 yrs (range, 36-88). The median number of prior therapies was 4 (range, 1-11), with 45.4% of pts having received prior BCL2i, and 77.0% having discontinued prior cBTKi due to progressive disease (PD), 19.5% due to toxicity, and 3.5% due to other reasons/missing. High-risk features were frequent: unmutated IGHV in 85.8% (193/225), mutated TP53 in 40.4% (99/245), and del(17p) in 29.2% (59/202). The ORR was 72.3% (95% CI, 66.7-77.5). ORR including PR-L was 81.6% (95% CI, 76.5-85.9), which was consistent across subgroups including BCL2i-exposed (80.5%; 95% CI, 72.5-86.9), BCL2i-naive (82.5%; 95% CI, 75.5-88.1), unmutated IGHV (82.9%; 95% CI, 6.8-87.9), del(17p) (88.1%; 95% CI, 77.1-95.1), and prior cBTKi discontinuation due to PD (79.7%; 95% CI, 73.8, 84.9) or toxicity (87.5%; 95% CI, 76.8-94.4). The median DOR was 18.4 mos (95% CI, 14.82-20.27), with 36-mos DOR rate of 28.0% (21.6-34.7). The median PFS was 18.7 mos (95% CI, 16.6-21.8) among all pts and the 36-mos PFS rate was 25.0% (95% CI, 19.4-31.0) with 44 mos of f/u. Further, the median PFS was 22.3 mos (95% CI, 19.3-27.6) for BCL2i-naive pts, and 15.9 mos (95% CI, 13.6-17.5) for BCL2i-exposed pts; 16.6 mos (95% CI, 13.8-19.4) among those who discontinued prior cBTKi therapy due to PD, and not estimable (NE) (95% CI, 25.2-NE) in those who discontinued due to toxicity. Among all pts with CLL/SLL, with a median f/u of 46.5 mos, the median OS was NE (95% CI, 47.8-NE), with the 36-mos OS rate of 62.0% (95% CI, 55.8-67.7). Median time on pirtobrutinib was 20.0 mos (range, 0.2-69.8), and 43 (15.2%) pts were still on tx at data cutoff. The most frequent TEAEs, regardless of attribution, were fatigue (38.7%), neutropenia/neutrophil count decreased (35.8%), diarrhea (30.5%), cough (29.8%), COVID-19 (28.4%), and contusion (27.7%). The most frequent grade ≥3 TEAEs were infection (36.5%) and neutropenia/neutrophil count decreased (29.8%). Low rates of grade ≥3 TEAE of hypertension (5.3%), hemorrhage/hematoma (2.5%), and atrial fibrillation/flutter (2.1%) were observed. Grade 5 TEAEs, regardless of attribution, occurred in 35 (12.4%) pts. Overall, 11 (3.9%) pts had a TRAE leading to a dose reduction, and 9 (3.2%) pts had a TRAE leading to pirtobrutinib discontinuation. Conclusion: In heavily pretreated R/R post-cBTKi CLL/SLL pts, pirtobrutinib continues to show favorable and durable efficacy. Pirtobrutinib is well-tolerated, with low rates of hypertension, hemorrhage/hematoma, and atrial fibrillation/flutter, which can be frequently observed with cBTKi. Additionally, dose reductions/discontinuations due to pirtobrutinib TRAEs were low. No new pirtobrutinib safety signals were identified with more than 5 yrs of f/u.

Abstract Introduction: Teclistamab is the first FDA approved BCMA-directed bispecific antibody for the treatment of relapsed and refractory multiple myeloma (RRMM). With BCMA-targeting CAR-T therapies, cytokine release syndrome (CRS) is a risk factor for cardiotoxicity. Teclistamab was associated with fatal cardiovascular adverse events (CVAEs) in a recent US pharmacovigilance database analysis, but this analysis was limited by reporting bias. Therefore, the aim of our study is to conduct a multicenter study to define the real-world incidence of CVAEs in RRMM patients treated with teclistamab. Method We performed a retrospective multi-center cohort study of patients receiving teclistamab at 5 medical centers. Baseline oncologic and cardiovascular characteristics (including vital sign and echocardiographic data) were collected. Baseline cardiovascular disease (CVD) was defined as presence of coronary artery disease, congestive heart failure, severe or symptomatic valvular heart disease, or stroke at baseline. CVAE was collected and categorized based on CTCAE v5.0 by each institution. Major adverse cardiovascular event (MACE) was a composite outcome with any of the following: congestive heart failure, asymptomatic cardiomyopathy (interval LVEF drop >10% to resultant LVEF less than 50%), coronary artery disease requiring intervention, stroke or cardiovascular death. Arrhythmia was a composite outcome with any of the following: atrial tachyarrhythmia, ventricular tachyarrhythmia or bradyarrhythmia. Median follow-up was calculated through reverse Kaplan-Meier method. Multivariable Cox regression analysis was used to define the relation between MACE and survival. Cause of death was categorized as myeloma-related death or non-myeloma-related deaths (i.e. CRS, infection or cardiovascular death). Cause-specific Cox regression was performed to define relationship between MACE and cause of death. Results In a cohort of 219 patients treated with teclistamab with median follow-up of 20.1 months, 7.3% (N=16) developed MACE, 7.3% (N=16) developed arrhythmia and 12.8% (N=28) developing any MACE or arrhythmia. MACE occurred at a median of 4.5 days (IQR 2.25-15.75 days) after teclistamab step-up. The incidence of MACE was 16.4% in patients with baseline CVD versus 2.7% in those without baseline CVD (p<0.001). Patients who developed MACE had inferior ECOG performance status (PS) (PS >=2: 62.5% vs. 27.7%; p=0.008). Additionally, baseline hemoglobin level (9 vs 10g/dL; p=0.072) was numerically lower in MACE, compared to no MACE. There was no difference in age, sex, bone marrow (BM) plasma cell burden, ferritin, C-reactive protein or LDH levels between MACE vs. no MACE group. Patients who developed MACE had lower baseline diastolic blood pressure (67.7 vs 73.8mmHg; p=0.041) and numerically lower LVEF (51.4 vs 59.3%; p=0.059; baseline echocardiogram performed in 86% of all cohort). Patients who developed MACE had similar incidences of CRS (Grade >=2: 25.0 vs 16.7%; p=0.620) and immune effector cell-associated neurotoxicity (ICANS) grade 2 or higher (12.5 vs 7.5%; p=0.812). In multivariable Cox regression analysis, MACE was independently associated with inferior overall survival (HR 2.72; 95% CI 1.41-5.25; p=0.003), after adjusting for baseline CVD, age, high BM burden, extramedullary disease, and plasma cell leukemia. In cause-specific multivariable Cox regression analysis, MACE was independently associated with non-myeloma-related death (HR: 10.77 95% CI 4.39- 26.41; p<0.001) but not with myeloma-related death (1.54; 95% CI 0.64- 3.70; p=0.336). Conclusion In conclusion, in this large, real-world multicenter study, we observed that MACE occurred in over 7% of patients following teclistamab for RRMM, typically within 2 weeks of initiation. MACE was significantly associated with increased non-myeloma-related mortality. In contrast to CAR-T therapy, CRS or ICANS were not associated with MACE, whereas majority of patients who developed MACE had ECOG PS >=2 or baseline cardiovascular disease. More studies are necessary to define mechanisms and strategies to reduce these MACE and improve survival. Patients with baseline cardiovascular disease or poor performance status may benefit from cardiovascular optimization before and during teclistamab therapy.

Abstract Introduction: Bispecific T-cell engagers (TCE) targeting BCMA (teclistamab, elranatamab) and GPRC5D (talquetamab) are important therapeutic options in relapsed/refractory MM (RRMM). However, data on the independent prognostic impact of individual cytogenetic abnormalities and functional high-risk MM on outcomes with TCEs remains limited. Methods We included RRMM patients treated with BCMA TCEs (teclistamab, elranatamab) and talquetamab across 15 centers in the US. Patients where TCEs were used only as bridging therapy to CAR-T were excluded. High-risk cytogenetic abnormalities (HRCA) included del(17p), t(4;14), t(14;16), 1q gain/amplification (1q21+), del(1p) before initiation of TCE. Functional high-risk disease (FHRMM) was defined as PFS <18 months with frontline therapy. Extramedullary disease (EMD) included visceral or soft tissue disease and excluded paraskeletal disease. Progression-free survival (PFS) was estimated from TCE initiation using the Kaplan–Meier method and compared using the log-rank test. Univariate and multivariable Cox proportional hazards models were used to identify predictors of PFS in the entire cohort and the subcohorts of BCMA TCEs and talquetamab (Talq). Results We analyzed 943 treatment initiations with TCEs in RRMM, comprising 577 BCMA-directed TCEs [teclistamab (n=436) and elranatamab (n=141)] and 366 talquetamab initiations. The median follow-up from TCE initiation was 13.4 months (95% CI: 12.5–14.2) and median age was 68 years (interquartile range 61-75 years). Two ore more HRCAs were noted in 30% of the cohort (34% in Talq vs. 28% in BCMA TCEs, p=0.04), EMD was present in 21% of patients (26% in Talq vs. 18% in BCMA TCEs, p=0.002), and 45.5% of patients had FHRMM (47% in Talq vs. 45% in BCMA TCE, p=0.54). The median prior lines of therapy was 6 (interquartile range: 5-8), with 92% being triple-class refractory (TCR); 60% received prior BCMA-directed therapy (85% in Talq vs. 45% in BCMA TCE, p<0.0001) and 45% had prior CAR-T in 45% (57% in Talq vs. 37% in BCMA TCE, p<0.001). The best overall response rate (ORR) was 67.1 % for the entire cohort (66.4% for BCMA cohort and 68.2% for Talq), with 32.5% patients achieving a ≥ complete response. The median PFS was 7.7 months (95% CI: 6.7–8.6) for the entire cohort, with a median PFS of 10.1 months (95% CI: 7.5-13.4) for teclistamab and 10.1 months (95% CI: 3.9-NR) for elranatamab. In the more heavily pretreated talq cohort, the median PFS was 6.4 months (95% CI: 5.1-7.5). In a univariate analysis (UVA), several HRCAs were associated with inferior PFS−del(17p) (HR 1.59), t(4;14) (HR 1.43), del(1p) (HR 1.54), and ≥2 HRCAs (HR 1.64), all p<0.01. Apart from HRCAs, adverse disease characteristics included FHRMM (HR 1.20) and EMD (HR 1.46); all p<0.05. Among laboratory markers, hemoglobin <9 g/dL (HR 2.10), platelet count <75 ×10⁹/L (HR 1.96), and elevated ferritin (≥600 ng/mL; HR 2.17) (all p<0.01) were prognostic for PFS. ECOG ≥2 (HR 1.62), prior BCMA-directed therapy (HR 1.56), and prior CAR-T (HR 1.44) (all p<0.001) were also associated with inferior PFS. In a multivariable analysis (MVA), prior BCMA therapy (HR 1.72, p<0.0001), ferritin >600 ng/mL (HR 1.68, p<0.0001), hemoglobin <9 g/dL (HR 1.53, p=0.001), ECOG PS ≥2 (HR 1.52, p=0.0009), del(17p) (HR 1.44, p=0.0034) and FHRMM (HR 1.26, p=0.047), were associated with inferior PFS. Within the talq cohort (n=366), EMD (HR 1.64), del(17p) (HR 1.42), del(1p) (HR 1.54), FHRMM (HR 1.34), ECOG ≥2 (HR 1.56), ferritin >600 (HR 1.88), hemoglobin <9 g/dL (HR 1.6), platelet count <75 ×10⁹/L (HR 1.36) and leukopenia <0.25 x 10⁹/L (HR 1.52) were adverse prognostic markers on UVA. A MVA confirmed the independent impact of ferritin >600 ng/mL (HR: 1.77), ECOG ≥2 (HR 1.61) and functional high-risk status (HR 1.52) on PFS, whereas del(17p) and EMD were trending toward significance. Within the BCMA TCE cohort (n=577), prior BCMA therapy (HR 1.9), ferritin >600 (HR 1.79), ECOG ≥2 (HR 1.55), Hb <9 g/dL (HR 1.54), and del(17p) (HR 1.52) were independently associated with inferior PFS on a MVA.Conclusions: In this large real-world cohort of TCE, outcomes varied by fitness, disease biology, and treatment history. The ECOG PS, elevated ferritin, functional high-risk status and del(17p) were consistently associated with inferior PFS. Prior BCMA exposure was an independent risk factor for inferior PFS in the BCMA TCE cohort, but not with talquetamab.

Abstract Introduction: MyeloMATCH (mM), is an National Cancer Institute (NCI)-sponsored precision medicine initiative for newly diagnosed AML/MDS. It consists of an initial screening study (Master Screening and Reassessment Protocol, or MSRP) that involves centralized testing of bone marrow/whole blood, leading to assignment into several genetically driven treatment subprotocols within the mM portfolio. MSRP employs karyotype, 8-15 probe fluorescence in situ hybridization (FISH) and NCI-myeloid (NMAv2) assays to determine ploidy, translocations and mutational status needed for accurate disease subclassification, risk stratification as well as for theragnostic determination. NMAv2, a rapid next generation sequencing assay (TAT<48 hrs), interrogates 45 DNA and 35 RNA fusion driver genes to report 1661 hotspot DNA mutations and 779 targeted RNA fusions, including all relevant fusions in AML except Inv3/t(3;3)/MECOM rearrangement (Yeung et al, 2025). The initial mM MSRP workflow relied on karyotype and FISH assay results to identify fusion positive AML/MDS as per the current testing guidelines/ recommendations as well as to abide by the FDA's requirements under the investigational device exemption (IDE). Here we present concordance analysis between karyotype, FISH and NMAv2 assay to identify relevant fusions in AML/MDS. Methods: First 400 participants enrolled in the mM MSRP were included in this analysis. We examined the results from karyotype analysis analyzing 20 metaphase cells, 8-15 probe FISH analyzing 500 nuclei per probe, and NMAv2 curating fusion read counts greater than 100, performed at the mM labs to determine the prevalence of fusions in this cohort. Concordance analysis was performed to determine clinical utility of the NMAv2 assay to report relevant fusions at the time of initial diagnosis. The concordance analysis excluded biomarkers including Inv3/t(3;3)/MECOM rearrangement, KMT2A-PTD and other rare fusions that are beyond the scope of detection by NMAv2 and/or FISH assay. Results: Of the 400 patients analyzed in this cohort (median age 64, [range 20-95]; 43% female; 15.5% non-white; 9.5% Hispanic), translocations/fusions were reported in 67, 73 and 95 patients by karyotype, 8-15 probe FISH and NMAv2, respectively. The karyotypic analysis reported inv(16)/t(16;16) [15], t(11q23) [13], t(9;22) [10], inv3/t(3;3) [9], t(8;21) [6], t(15;17) [5], t(6;9) [4], t(21q22) [3], t(9q34) [1] and t(10;11) [1]. The FISH reported inv(16)/t(16;16) CBFB::MYH11 [15], t(11q23) KMT2A rearrangement [14], t(9;22) BCR::ABL1[10], inv3/t(3;3) MECOM rearrangement [10], t(8;21) RUNX1::RUNX1T1 [7], t(15;17) PML::RARA [5], t(6;9) DEK::NUP214 [5], t(21q22) RUNX1 rearrangement [3], t(11p15.4) NUP98 rearrangement [3], and t(9q34) ABL1 rearrangement [1]. The NMAv2 reported KMT2A-PTD [26], CBFB::MYH11 [15], KMT2A fusion [14], BCR::ABL1[12], RUNX1::RUNX1T1 [8], PML::RARA [5], DEK::NUP214 [5], RUNX1 fusion [4], NUP98 fusion[3], t(9q34) ABL1 fusion [1], PICALM::MLLT10 [1] and ETV6::MECOM [1]. The concordance analysis between NMAv2 and karyotype assay demonstrated positive percent agreement(PPA) of 100%, negative percent agreement(NPA) of 96.81% and overall agreement (OA) of 97.25% when using karyotype as reference. The concordance analysis between NMAv2 and FISH assay demonstrated PPA of 100%, NPA of 98.81% and OA of 99% when using FISH as reference. Of the 12 cases with discrepant results, 7 were due to presence of cryptic translocations missed by karyotype assay, 3 had suboptimal specimen submitted for karyotype/FISH analysis, 1 had false positive BCR::ABL1 fusion reported by NMAv2 due to low level contamination and 1 had minor subclonal population of leukemic blast with BCR::ABL1 fusion detected only by NMAv2. Conclusion: NMAv2 shows high concordance with karyotype and FISH assays which are the most commonly utilized assays to identify fusions/translocations in AML/MDS. NMAv2 is a faster, relatively cheaper and sample conserving method to identify fusions and is less prone to false negative results than karyotype/FISH assay from suboptimal specimen acquisition and testing. Based on the results above, mM MSRP workflow has been amended with FDA concurrence such that a combination of NMAv2, karyotype and MECOM breakapart FISH assay will be used to identify relevant fusion variants in all patients enrolled in mM, whereas additional specific FISH assay will be limited to cases where discrepant results between karyotype and NMAv2 are reported.

Abstract Introduction: Waldenström macroglobulinemia (WM) is characterized by the presence of a MYD88 mutation in >90% and a CXCR4 mutation in 30-40% of cases. The impact of these mutations on treatment responses and disease outcomes is well known. TP53 alterations (TP53ALT) have more recently been described in WM and are reported to occur in up to 25% of patients, with a higher frequency in patients with previously treated WM, especially those with prior alkylator or nucleoside analogue exposure (Tam et al Blood Adv 2024; Poulain et al CCR 2017; Tsakmaklis et al, ASH 2025). TP53 ALT WM is associated with a shorter time to disease progression, as well as worse overall survival (Poulain et al CCR 2017; Gustine et al, BJH 2019). Depth of response to BTK inhibitors is affected by TP53 status, with recent data reporting a very good partial response (VGPR) rate of 34% v. 25% and major response rates of 84% v. 73% in patients without or with a TP53 ALT (Tam et al Blood Adv 2024). No complete responses were reported and median PFS was shorter in those with a TP53ALT compared with wild-type (TP53WT). Loncastuximab tesirine is a humanized IgG1 anti-CD19 antibody that is conjugated to a pyrrolobenzodiazepine (PBD) dimer. Following internalization, the PBD dimer is released via proteolytic cleavage and binds to the DNA minor groove forming highly cytotoxic DNA inter-strand crosslinks. Cells deficient in DNA repair including TP53 alterations are vulnerable to the cytotoxic effects of loncastuximab tesirine (Tarantelli et al, Haematologica 2024). Methods: In an ongoing investigator-initiated, prospective phase II study in symptomatic patients with relapsed or refractory WM (NCT05190705), patients are receiving single agent loncastuximab tesirine. Loncastuximab tesirine is administered at 150 ug/kg in cycles 1 and 2 and 75 ug/kg in cycles 3 to 6. Each cycle is 28 days. The primary outcome measure of this study is attainment of VGPR or complete (VGPR/CR) response. The accrual goal of this trial is 20 patients, based on an alternative VGPR/CR rate ≥40% versus a null of ≤10%, with a double-sided alpha of 0.037 and a power of 87%. The study would meet its endpoint if ≥6 patients attained a VGPR/CR. Results: Of the 14 patients who have completed therapy on this trial to date, the median age is 71 years (range 53-81), 9 (64%) are male, and the median prior number of therapies is 4 (range 2-10). Median baseline hemoglobin is 9.5 g/dL (range 8.2-12.6), serum IgM is 2146 mg/dL (range 723-5955), and bone marrow involvement is 53% (range <5-90). Four patients had extramedullary disease. Twelve patients (86%) are MYD88 mutated; 8 patients (57%) are CXCR4 mutated, and 8 (57%) are TP53 altered. Nine patients completed all 6 cycles of therapy. Of the 5 other patients, treatment was stopped early due to GGT elevation (n=2), disease progression (n=1), patient decision (n=1), and skin toxicity (n=1). No IgM flare and no infusion reactions have occurred. For all patients, the median time to minor response, major response, and deepest response was 28, 55, and 172 days, respectively. The response rates include 1 (7%) CR; 9 (64%) VGPRs; 2 (14%) partial responses (PR); 1 (7%) minor response; and 1 (7%) progressive disease, for an overall response rate of 93% and a VGPR/CR rate of 71%. For the 8 patients with TP53ALT, the baseline characteristics were as follows: 50% male; median age of 70 years (range 53-77), median prior therapies is 4 (range 2-10); median IgM is 1877 mg/dL (range 723-5639); and median hemoglobin is 9.2 g/dL (range 8.2-11.6). All TP53ALT patients had an MYD88 mutation, and 6 (75%) carried a CXCR4 mutation. For those with TP53 ALT, the median time to minor response, major response, and deepest response was 28, 49, and 235 days, respectively. All TP53ALT patients attained a major response; 1 patient (13%) with a CR, 6 (75%) with a VGPR, and 1 (13%) with a PR, for an overall response rate of 100% and a VGPR/CR rate of 89%. One patient had splenomegaly and one had adenopathy, both of which resolved after treatment. Conclusion: Our findings from this ongoing, prospective trial demonstrate a high VGPR/CR rate of 71% in heavily pre-treated WM. Notable, is the VGPR/CR rate of 89% in high-risk patients with TP53ALT WM. No unexpected toxicities have been seen in this trial. Our findings identify a potentially novel time-limited therapy in relapsed or refractory WM, including patients with high-risk TP53ALT WM.

Abstract Background Single-agent R is a common 1st-line therapy for patients (pts) with FL, especially those with low-tumor burden advanced stage disease or comorbidities. EO is a therapeutic vaccine generated from non-self-protein sequences from gut bacteria, including 4 HLA-A2 CD8 T cell epitopes that mimic B cell-specific markers: CD20, CD22, CD37 and BAFF-receptor. EO also contains a CD4 helper epitope UCP2. EO expands pre-existing memory CD8 T cells recognizing non-self-protein sequences from gut bacteria which can cross-react with B cell antigens on tumor cells. The aim adding EO to R is to safely increase the depth and duration of responses. Methods Cohort 3 (C3) of trial EONHL1-20/SIDNEY includes pts with HLA-A2 and previously untreated low-tumor burden (GELF) FL grade 1-3A in need of treatment (per pt/treating physician). Pts receive EO (300μg/peptide) SC with adjuvant Montanide, q2 weeks (w) x 4, then q4w for a total of 12 doses, combined with R starting at w7 (375 mg/m2 IV q1w x4, then q8w x4). For immune responses blood mononuclear cells were assayed by flow cytometry and EO-mimic or B cell peptide specific tetramers without in vitro stimulation. The primary objective is to assess safety; secondary objectives include EO immunogenicity and preliminary efficacy. Results As of July 2025, the 6 planned pts had started EO. Median age was 66 years (range 46-73); 5 ECOG 0/1 ECOG 1; 1 Ann Arbor stage III/5 stage IV; FLIPI low risk 2/intermediate 2/high 2; FLIPI-2 low risk 2/intermediate 4. At median follow-up 10.6 months (mo) 4 pts completed and 2 are ongoing on EO. Median treatment duration was 43 w (range 2-43). Best response by Lugano in the 6 pts included 4 complete (CR) and 2 partial responses (PR). Median time to PR/CR was 17.1 w (range 6.0-18.0). Currently there is only 1 (not yet confirmed) progression at 20.5 mo. All 5 immune response evaluable pts had expansion of CD8 T cells specific for EO mimic and B cell target peptides during treatment; 4 of 5 had detectable expansions at w5 (1st testing time). Currently, the longest tested immune response is at w65 and positive for both EO mimic and B cell target peptides. Expanded specific CD8 T cells had a memory phenotype predominantly composed of effector memory (TEM) cells but also including central memory (TCM) and terminally differentiated effector memory CD8 T (TEMRA) cells. Across the 5 pts, the medians of max % (sum of specific CD8 T cells targeting either the 4 EO mimic peptides or the 4 B cell antigen epitopes at a specific timepoint) among all peripheral CD8 T cells were 0.71% (range 0.19-3.97) for EO mimic and 0.33% (0.20-1.30) for B cell target peptides. The most common EO-related adverse events (AEs) were local administration site reactions (erythema, pain, induration). These included Gr (Grade) 1 reactions in 3 pts, Gr 2 in 1 pt, and Gr 3 in 1 pt; latter being ulceration with EO-interruption at w10.1, and in context of a strong immune response against EO mimic [3.97% of all peripheral CD8 T cells at w5] and B cell target [1.30%] peptides, and CR from w16.7. Other EO related AEs were Gr 1 lymph node pain (1 pt), and related to both EO and R were Gr 2 urticaria (1 pt) and Gr 1 fatigue (1 pt). Only R related were Gr 2 infusion related reaction (3 pts), Gr 2 enterocolitis infection (1 pt), and in 1 pt each Gr 1 flushing, anemia, headache and diarrhea. There were no further Gr 3-4 AE and no death on treatment/follow-up. Complete B cell depletion was seen in 5 pts tested at w18 (R added w7); no recovery in the range of w30-65. Only 3 infections were reported, per above enterocolitis, and 2 cases of COVID-19 both resolved without sequalae. ConclusionsThe combination of EO with R has a predictable and manageable safety profile, with EO only adding local administration site reactions to the well-known R safety profile. In this feasibility cohort all evaluable pts developed a specific immune response against EO and B cell targets, and a Lugano objective response. The combination of EO and R is feasible and can be evaluated in further trials. Updated results will be presented at the meeting.

Abstract Introduction: CD20xCD3 bispecific antibodies (BsAb) have been approved for use in relapsed/refractory (RR) large B-Cell lymphomas (LBCLs) with manageable toxicities. The main adverse events of clinical interest are cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). The risk factors for CRS and ICANS are not well understood. Knowledge of variables that contribute to increased risk may help clinicians identify and tailor management for high-risk patients (pts) and increase the comfort level for providers using these therapies in community practices. Methods: We performed a multicenter retrospective study at 21 US centers evaluating pts with RR LBCLs receiving commercially available epcoritamab (epco) or glofitamab (glofit) between 2023 and 2025. We obtained baseline characteristics, safety and efficacy outcomes. Univariate analysis was performed to identify associations between CRS, ICANS, and clinical variables of interest. Results: As of May 31, 2025, a total of 312 pts with RR LBCLs were treated with BsAb, Epco n=193 (62%), Glofit n= 119 (38%); median age 68; 63% male; 70% ECOG PS 0-1. Most common histologic type was diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS) (n=239, 84%) followed by high-grade B-cell lymphoma (HGBL) (n=46, 16%). 179 pts (57%) were previously treated with chimeric antigen receptor T-cell (CAR-T) therapy, with 47% receiving CAR-T <6 months (mo) prior to BsAb. Among pts with prior CAR-T, CRS with CAR-T therapy of any grade occurred in 63%, with 26% ≥ grade 2. ICANS of any grade (G) occurred in 25% of pts (9.4% ≥ G3). Overall and complete response (ORR and CR) rates to BsAb were 51% and 29%, respectively. With a median follow up of 5 mo, median progression-free and overall survival (PFS and OS) were 2.3 and 7.3 mo, respectively. With BsAb treatment, CRS of any grade occurred in 117 (39%) patients: 24% G1, 8.7% G2, 4% G3, 1% G4 and 1% G5. The max grade CRS occurred most frequently after the third dose of epco (35%) and the first dose of glofit (23%). CRS was managed with additional steroids in 24% of pts and tocilizumab in 22%. 13% of pts experienced ICANS: 5.8% G1, 3.4% G2, 2% G3, 1% G4 and 0.3% G5. Factors that increased the risk for any grade CRS included: bulky disease ≥ 7.5 cm at time of BsAb treatment (OR 2.04, 95% CI 1.17 – 3.55, p = 0.012), elevated LDH (OR 2.56, 95% CI 1.45– 4.76, p = 0.002) and treatment with epco compared to glofit (OR 1.69, 95% CI 1.04- 2.77, p = 0.036). As G ≥2 CRS generally requires inpatient monitoring and management, we next compared the risk factors between pts with no CRS or G1 CRS and G ≥2 CRS. Factors associated with increased risk for high grade CRS included: bone marrow involvement by lymphoma (OR 3.47, 95% CI 0.97 – 11.3, p = 0.043), platelet count ≤ 75 (OR 2.46, 95% CI 1.21 – 4.87, p = 0.011), ≥ 2 extra nodal sites (OR 2.04, 95% CI 1.07 – 3.97, p = 0.032) and ≥G2 CRS with prior CAR-T (OR 3.35, 95% CI 1.13 – 9.97, p = 0.027). Factors that increased the risk for ICANS included: bulky disease (OR 2.67, 95% CI 1.28 – 5.49, p = 0.008), elevated Cr ≥ 1.5x ULN (OR 3.79, 95% CI 1.25 – 10.4, p = 0.012), elevated AST/ALT ≥ 3x ULN (OR 4.65, 95% CI 0.92 – 19.9, p = 0.042), low albumin (OR 2.85, 95% CI 1.49 - 5.5, p = 0.002), and co-occurrence of CRS with BsAb (OR 9.1, 95% CI 3.85- 25, p < 0.001). No other clinical variables including older age, histologic subtype, ECOG PS, B symptoms, IPI score, cell of origin or histologic subtype, baseline labs such as ALC, CRP, fibrinogen or D-dimer were significantly associated with CRS or ICANS risk. There was no difference in ORR or CR rates in patients who experienced CRS or ICANS. Conclusions: Our analysis of pts treated with commercial BsAb for LBCL shows an increased risk for CRS and ICANs based on clinical variables that are routinely obtained at baseline including tumor bulk, sites of disease, laboratory parameters, and history of prior CRS with CAR-T therapy. Differences in baseline populations receiving epco and glofit treatments in this real-world analysis have been previously reported (Brooks et al, Blood 2025) and the comparative risk for CRS between these treatments remains unclear. Future plans including multivariable analysis may allow for development of a predictive model to identify pts at high risk of CRS and ICANS with BsAb treatment, potentially leading to prospective clinical trials evaluating prophylactic interventions for high-risk pts.

Abstract Introduction: Epcoritamab (epco) and glofitamab (glofit) are bispecific antibodies (BsAbs) approved for the treatment of patients (pts) with multiply relapsed or refractory (r/r) large B-cell lymphoma (LBCL). Though response rates are relatively high, most patients (pts) eventually experience progression of disease (POD). We sought to investigate the treatment patterns and clinical outcomes following POD post-BsAb for r/r LBCL Pts, as this has not previously been described. Methods: We performed a multicenter retrospective study including 21 US centers evaluating pts with r/r LBCL receiving commercially available epco or glofit between 2023 and 2025. Baseline characteristics and outcomes were extracted from medical records. Efficacy and survival outcomes were assessed by site investigators and included overall response rate (ORR), complete and partial response (CR, PR) rates, progression-free survival (PFS) and overall survival (OS), analyzed using the Kaplan Meier method. Results: As of May 15, 2025, a total of 312 pts with r/r LBCLs were treated with BsAb, of whom a total of 168 (53.8%) pts experienced POD [104 of 193 (53.8%) treated with prior epco and 64 of 119 (53.8%) treated with prior glofit]. Pts with POD had a median age at BsAb start of 67 years (interquartile range [IQR] 58-76), most were male (68.4%), and the most common histology was diffuse large B-cell lymphoma not otherwise specified (n=122 [71.8%]). Sixty-seven of 168 pts (39.9%) with POD after BsAb had experienced primary refractory disease defined as failure to achieve PR or CR to frontline therapy. A total of 102 (60.7%) pts with POD to BsAb had received chimeric antigen receptor (CAR) T-cell therapy prior to BsAbs, with 33.3% of these pts being refractory to CAR T and 30.4% progressing within 6 months of CAR T-cell infusion. The median time to progression following BsAb start was 48 days. Following POD, 70 pts received no further anti-lymphoma therapy. Among 98 pts receiving subsequent therapy, 85 initially received systemic therapy and 13 initially received local therapy with radiation (concurrently with systemic therapy in 8 pts). The most commonly-used next line of systemic therapies included: loncastuximab tesirine in 19 pts (ORR 16.7%, all PR); commercial CAR T in 11 pts (ORR 50% [CR 36.4%, PR 18.2%); tafasitamab with lenalidomide in 7 (no responses); and other chemotherapy in 46 pts (ORR 27.6% [CR 24.1%]). The median follow-up time from POD was 9.2 months among survivors (95% confidence interval [CI] 7.8-13.3). Among those who initiated subsequent-line therapy following BsAbs, the median progression-free survival (PFS2) was 1.9 months (95% CI 1.5-2.4) and median overall survival (OS) from initiation of subsequent-line therapy was 3.9 months (95% CI 2.4-5.5). The estimated 1-year OS following initiation of next therapy was 12%. Conclusions: We report the outcomes of largest cohort of pts with POD post-BsAbs in r/r LBCL. Progression events occurred early after initiation of single agent BsAbs, and almost half of pts who progressed did not receive subsequent therapy. For those who received standard subsequent-line therapy after POD, response rates and survival outcomes were poor. Pts with POD after BsAB should be strongly considered for clinical trials of novel therapeutics or combination therapies.

Abstract Background: Despite the efficacy of covalent Bruton tyrosine kinase inhibitors (cBTKi) in R/R MCL, patients (pts) ultimately discontinue treatment due to intolerance or development of resistance and disease relapse. Pirtobrutinib is a highly selective, non-covalent BTKi that inhibits BTK with low nM potency throughout the daily dosing interval. Pirtobrutinib was safe and effective in the phase 1/2 BRUIN study in pts with R/R B-cell malignancies, including those previously treated with a BTKi. Pirtobrutinib is approved in the EU for adults with R/R MCL after prior treatment with a BTKi (EMA Conditional Approval, Oct 2023), and in the USA for adults with R/R MCL after ≥ 2 lines of systemic therapy, including a BTKi (FDA Accelerated Approval, Jan 2023).Here, we report the final results from the phase 1/2 BRUIN study (NCT03740529), with a follow-up period of up to 5 yrs, focusing on the efficacy and safety of pirtobrutinib in all R/R MCL pts. Methods: Pts with R/R MCL who received ≥1 prior lines of therapy (including BTKi) were eligible for treatment with pirtobrutinib monotherapy. Key endpoints included overall response rate (ORR), duration of response (DOR) and progression-free survival (PFS), all assessed by independent review committee (IRC) per Lugano 2014 criteria (presented here) and investigator, overall survival (OS), and safety. Pts were included across the range of doses evaluated in dose escalation and expansion (25-300 mg/day). A data cutoff on 27 January 2025 was utilized, with a median study follow-up of 17.5 months (range, 0.5-69.6). Results: Among the 166 pts with R/R MCL, 153 (92%) received the pirtobrutinib approved dose of 200 mg/day, 152 (92%) had received prior cBTKi, of which 128 (84.2%) discontinued any prior cBTKi due to progressive disease (PD), and 15 (9.9%) due to toxicity. The cBTKi-pre-treated pts had a median age of 70 yrs (range, 46-88), 52% had intermediate-risk and 28.3% had high-risk sMIPI scores. The median number of prior lines of therapy was 3 (range 1-9), with most pts having received a prior anti-CD20 antibody (96.7%) and chemotherapy (90.1%). Additional prior therapies included hematopoietic stem cell transplantation (21.7%; 19.7% auto and 4.6% allo), BCL-2 inhibitor (15.8%), CAR-T cell therapy (8.6%). As of the data cutoff, 11 (7.2%) pts who received a prior cBTKi and 6 (42.9%) cBTKi naïve pts remained on treatment. The cBTKi pre-treated pts had an ORR of 49.3% (95% CI, 41.1-57.6), including 15.8% complete responses (CR) (n=24) and 33.6% partial responses (PR) (n=51). The 75 responding pretreated pts had a median DOR of 21.6 months (95% CI, 9.2-27.2) at a median follow-up of 24 months. The ORR among 128 pts who had discontinued any prior cBTKi due to PD and 15 pts who discontinued due to toxicity was 43.0% and 93.3%, respectively. The median PFS and OS for cBTKi pre-treated pts were 5.6 months (95% CI, 5.3-9.2) and 23.9 months (95% CI, 17.3-51.5), respectively. Fourteen pts (9.2%) were censored for PFS due to subsequent anticancer therapy without documented PD, including 8 pts who received CAR-T. The cBTKi naïve pts (n=14) had an ORR of 85.7% (95% CI, 57.2-98.2), including 50.0% CR (n=7) and 35.7% PR (n=5). The 12 responding naïve pts had a median DOR of 42.7 months (95% CI, 25.8-NE) at a median follow-up of 43 months. The median PFS and OS in the cBTKi naïve pts were 44.6 months (95% CI, 16.7-NE) and not reached (95% CI, 33.5-NE), respectively. Among all R/R MCL pts (n=166), the most frequent treatment-emergent adverse events (TEAE), regardless of attribution, were fatigue (31.9%), diarrhea (22.9%), anemia (18.1%), and dyspnea (18.1%). The most common Grade ≥3 TEAE was neutropenia/neutrophil count decreased (13.3%), and the rate of Grade ≥3 infections was 21.1%. Grade ≥3 hemorrhage/hematoma (2.4%) and all-grade atrial fibrillation/flutter (3.6%) were infrequent. In total, 13 (7.8%) pts had a fatal TEAE, with 4 (2.4%) classified as infections. Overall, 8 pts (4.8%) had treatment-related AE leading to dose reductions, and 6 (3.6%) had treatment-related AE leading to pirtobrutinib discontinuation. Conclusion: Pirtobrutinib continues to demonstrate efficacy in pts with heavily pre-treated R/R MCL including both those who previously received a cBTKi and those who were BTKi-naïve. The safety profile of pirtobrutinib remained favorable with a low-rate of dose reductions/discontinuations due to drug-related toxicity. No new safety signals were identified after up to 5 yrs of follow-up.

Abstract Introduction: T-PLL is a rare, aggressive leukemia with poor prognosis and limited therapies. Previous studies on T-PLL patients receiving an allogeneic stem cell transplant (alloSCT) are limited by small numbers with limited data on disease and transplant characteristics. Further, recent data from our large national cohort of patients demonstrated significant survival difference between TCL1A+ and TCL1A- T-PLL, and CD8+ T-PLL vs CD8- T-PLL. In this large multi-center series, utilizing comprehensive disease subtype and alloSCT clinical data, we evaluated prognostic and survival therapeutic outcomes in T-PLL patients that had an alloSCT with a particular focus on T-PLL disease subtypes. Methods: We retrospectively evaluated 572 diagnosed with T-PLL at 21 academic cancer centers throughout the USA between 2000-2023, of which we performed a further evaluation on the169 that proceeded with alloSCT. Overall survival (OS) and progression-free survival (PFS) were assessed using Kaplan-Meier methods and Cox proportional hazard models. Results: Among n=169 alloSCT recipients with T-PLL, the median follow-up time was 20.9 months post-alloSCT (range: 0.2-182.9), the median age at transplant was 59 years (range: 35-77) and 52% were male. In evaluated patients (n=109), TCL1A was positive by cytogenetics or FISH in 69%. As our recent analysis demonstrated significant differences in survival among specific subtypes of T-PLL, we evaluated outcomes in patients with CD4+CD8- T-PLL (n=90, 53%), CD4-CD8+ (n=17, 10%) T-PLL, and CD4+CD8+ T-PLL (n=52, 31%). 53% (87/164) had known nodal involvement at diagnosis identified by PET or CT scan and 45% (43/96) of known patients had minimal residual disease (MRD) at the time of transplant [defined as <5% T-PLL in marrow by flow, or +cytogenetics (e.g. TCL1A)] prior to alloSCT. At the time of alloSCT, 136 (80%) patients were in CR and 23 (14%) patients were in PR. Forty-nine (30%) had a myeloablative (MAC)conditioning regimen and 114 (70%) had a reduced intensity chemotherapy (RIC) conditioning regimen. Eighty (49%) patients had TBI as part of their regimen. The most common regimens were fludarabine (flu)/melphalan based regimens (n=44; 26.0%), flu/cyclophosphamide (cy) based regimens (n=33; 19.5%), flu/busulfan based regimens (n=22; 13.0%), flu/total body irradiation (TBI) (n=8; 4.7%), and cy/TBI (n=4; 2.4%). Across the whole cohort, the median OS and PFS post-alloSCT was 32.6 months (95% CI: 21.0-41.9) and 20.8 months (95% CI: 14.4-30.5) months while the 1-year cumulative incidences (CI) of NRM and relapse were 17% and 20%, respectively. The incidences of grade II-IV acute GVHD and cGVHD were 19% and 23%. There was no difference between patients with myeloablative conditioning (MAC) (n=49, 29%) when compared to patients that received reduced intensity conditioning (RIC) (n=114, 67%) in OS (33.1 vs 29.2; p=0.68) and PFS (20.2 vs 20.8; p=0.97). Patients that were MRD+ (n=31) had worse OS (22.2 vs 48.6; p=0.1) and PFS (14.1 vs 32.5; p=0.04) and higher rates of relapse (1-year relapse 20% vs 8%; p=0.08) than patients that were MRD- (n=50). PFS was improved in those who received alloSCT though only trended towards significance due to low numbers (HR 0.76, p=0.09). In subtype analysis, TCL1A+ T-PLL had significantly worse outcomes compared to TCL1A negative T-PLL. TCL1A+ disease had significantly worse OS (21.6 vs 63.1; p=0.01) and PFS (12.4 vs 50.7; p=0.01) compared to TCL1A-. Additionally, in TCL1A+ disease CI of NRM (24% vs 3%; p=0.02) and relapse (25% vs 12%; p=0.86) was higher vs TCL1A- PLL. CD4+CD8-, CD4-CD8+, and CD4+CD8+ disease had no difference in survival via either OS (28.0 vs 34.4 vs 21.0; p=0.17) or PFS (29.4 vs 23.5 vs 13.6; p=0.09) as well as no difference 1-year CI of NRM ( 11.6 vs 23.5 vs 26.2; p=0.35) and relapse (18.5 vs 23.5 vs 20.0; p=0.67).Conclusions: AlloSCT significantly improved outcomes for patients with T-PLL compared to those who did not proceed to alloSCT and remains he only curative therapy for those with T-PLL. OS, PFS, and CI relapse were significantly worse for patients with TCL1A+ subtype of T-PLL, or those with MRD positivity or PR prior to alloSCT. Novel strategies to decrease relapse such as post-alloSCT maintenance therapy to improve outcomes are urgently needed in these patients.