Hilal, Talal

Abstract Introduction: Multiple myeloma (MM) is a B-cell-derived malignancy associated with immune dysregulation. Anti-CD38 monoclonal antibodies (mAbs) therapies have shown improved outcomes in patients with MM. Silbermann et al. showed that anti-CD38 mAb-containing therapies lead to profound hypogammaglobulinemia and reduction in Ig gene repertoire. The effect of modern therapies such as CAR-T and bispecific antibodies (BsAbs) on B-cell repertoire has not been well described. In this study, we sought to investigate the effect of these therapies on B-cell repertoire in patients with MM. Methods: This is a single-institution retrospective observational study evaluating MM patients treated with anti-BCMA CAR-T and BsAbs. Baseline characteristics, laboratory data, treatment history, were extracted from medical records. Total unique sequences (TUS) and total sequences of IgH, IgK, and IgL were identified and quantified using clonoSEQ. Patients were classified in two groups: CAR-T and BsAbs. The primary objectives were (1) characterize changes in TUS and total sequences within IgH, IgK, and IgL before and after treatment, and (2) examine how the sequences evolve over time following CAR-T. Results: 76 MM patients received CAR-T or BsAbs. Among those, 22 CAR-T and 5 BsAbs patients had pre- and post-treatment sequences available. Median age at initiation of treatment was 66 years in the CAR-T group (42-81 y) and 65 years in the BsAbs group (48-71 y). Based on mSMART v3 criteria, 72% of CAR-T and 60% of BsAbs recipients were classified as high-risk. Median number of prior lines of therapy was 5 (2-8) in the CAR-T group and 6 (5-13) in the BsAbs group.CAR-T recipients were classified into early (<40 days) and late (>40 days), based on when the post-CAR-T treatment clonoSEQ assay was performed. Changes in TUS and total sequences of IgH, IgK, and IgL were calculated, and the averages were assessed independently. The mean early and late change in total unique IgH sequences were (-75, 586 and 131, 038, p=0.052), unique IgK (-57, 797 and 52, 586, p=0.020), and unique IgL (-22, 354 and 25, 056, p=0.011). A subgroup of 8 patients with sequential MRD reports post-CAR-T therapy were identified, six patients showed improvement in B-cell sequence dynamics and two patients showed a decrease over time. For patients who received BsAbs, results indicated a similar pattern, with an early decrease in B-cell repertoires, characterized by reductions in sequence diversity and quantity. Conclusions: Our analysis of B-cell repertoires following CAR-T revealed changes before and after treatment. Patients receiving CAR-T therapy showed a decline in the number of TUS and total sequences of IgH, IgK, and IgL, likely due to the lymphodepletion regimen, followed by a gradual restoration reflecting immune recovery. Longer follow-up and a larger cohort will be necessary to assess the implications of these B-cell repertoire changes on patient outcomes. Citation Format: Feba Miriam Jacob, Rodolfo Garza-Morales, Joseph G Hentz, Alex Wonnaparhown, Julia E. Wiedmeier-Nutor, Mariano Arribas, Gabriela Alatorre, Sharene Best, Jayden Poulignot, Udit Yadav, Saurabh Chhabra, P. Leif Bergsagel, Rafael Fonseca, Talal Hilal. Dynamics of B-cell repertoires following CAR-T and bispecific antibody therapy in multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4537.

ABSTRACTBackgroundChimeric Antigen Receptor (CAR) T‐cell therapy has arisen as a revolutionary treatment for hematologic malignancies. Our study aimed to evaluate how sex differences affect outcomes and complications following CAR T‐cell therapy.MethodsUtilizing the Nationwide Readmissions Database (2018–2020), we identified patients and divided them into male and female groups. Hospital outcomes and complications were compared among these two groups after propensity score matching to match groups based on comorbidities, producing two comparable cohorts.ResultsWe analyzed 2928 patients (1832 males, 62.6%, mean age 60.3 ± 13.7 years; 1096 females, 37.4%, mean age 59.1 ± 13.8 years). After propensity score matching (1:1ratio), 1092 males and females were compared. There were no significant sex differences in early mortality (adjusted odd ratios (aOR): 1.04 [95% CI 0.69–1.57]), 30‐day readmissions (aOR: 1.05 [95% CI 0.86–1.30]), or nonhome discharge (aOR: 0.89 [95% CI 0.60–1.31]). Females had higher odds of leukopenia (aOR: 1.26 [95% CI 1.06–1.50]) but lower odds of acute kidney injury (aOR: 0.68 [95% CI 0.52–0.88]).ConclusionsNo sex differences were found in hospital outcomes, including early mortality, 30‐day readmission, and nonhome discharge after CAR T‐cell therapy.

Introduction: Brexucabtagene autoleucel (brexu cel) is a CD19-targeted chimeric antigen receptor (CAR) T cell therapy approved for the treatment of adults with relapsed/refractory (R/R) acute lymphoblastic leukemia (ALL). Some patients (pts) proceed with a consolidative allogeneic hematopoietic cell transplant (HCT) after breux cel. We do not know which pts can safely avoid a consolidative HCT and its associated morbidity. Methods: We conducted a retrospective cohort study utilizing the Real-World Outcomes Collaborative of CAR-T in Adult ALL (ROCCA) dataset. ROCCA is a registry of brexu cel pts in 32 centers in North America. We defined complete remission (CR) as < 5% blasts in the bone marrow and no central nervous system (CNS) or extramedullary (EM) disease on or around D28 after brexu cel. We defined measurable residual disease negative (MRD-) CR as CR and no abnormal blasts in the bone marrow by multiparameter flow cytometry, quantitative polymerase chain reaction, ClonoSeq next generation sequencing (NGS), or other sequencing modalities with lower sensitivity. ClonoSeq NGS has a sensitivity of 10-6, while the other modalities have a sensitivity of at least 10-4. We defined progression free survival (PFS) as the time from CAR-T infusion to relapse or death, censored at the date of last follow-up. Statistical analyses were performed in R. Univariable Cox proportional hazards regression analyses were performed to determine the association of pre-specified variables with PFS. Variables known to be associated with CAR T outcomes in ALL were entered into a multivariable model. HCT was incorporated as a time-varying covariate. Results: During the study period, 281 pts were infused with brexu cel. We focused our analysis on 172 (61%) pts with confirmed MRD- CR on D28, as that is the group with clinical equipoise regarding maintenance strategy. 38 (22%) of those pts received a consolidative HCT, 30 (17%) received another form of maintenance therapy (primarily tyrosine kinase inhibitors for Philadelphia (Ph)-chromosome positive ALL), and 104 (60%) pts received no maintenance therapy. Pts who underwent consolidative HCT were younger (median age 35 years) than those who received no maintenance (42y) (p = 0.023) and were less likely to have a history of prior HCT (13% vs. 47%, p < 0.001). No differences were observed with respect to sex, TP53 mutation status, prior inotuzumab (ino) or blinatumomab (blina) exposure, disease burden prior to CAR, or development of any cytokine release syndrome (CRS) or any neurotoxicity with brexu cel. We performed univariable Cox proportional hazard regression analyses among pts in MRD- CR on D28, excluding those who received other maintenance therapy besides HCT; the median follow up was 8.1 months. In univariable analyses, D28 MRD negativity by ClonoSeq NGS (versus MRD negativity by other, less sensitive methods), development of CRS, and pre-CAR BM blasts < 5% were associated with improved PFS; prior ino exposure was negatively associated with PFS (p < 0.05). Age, sex, Ph status, TP53 status, and neurotoxicity development were not associated with PFS. In a multivariable model incorporating ALL type, prior HCT, prior ino/blina, and pre-CAR blast burden, as well as consolidative HCT as a time-varying covariate, only MRD negativity by ClonoSeq NGS with at least 10-6 sensitivity retained statistical significance (PFS hazard ratio 0.34, 95% confidence interval (CI) 0.15-0.77, p = 0.005). Pts who were MRD- by ClonoSeq NGS on D28 and received no maintenance had favorable 6m PFS of 76% (95% CI: 59-98%) and OS of 100% with a median follow up of 6.3 months in this subgroup. Among those in MRD- CR by NGS, HCT as a time-varying covariate was not associated with improved PFS (HR 0.6, p = 0.6). Conclusions: In a large real-world cohort of adults with R/R B-ALL infused with brexu cel, we identified practice variation regarding the use of consolidative HCT. Among brexu cel recipients who entered an MRD- CR, we identified ClonoSeq NGS MRD negativity as a novel predictive factor of favorable oncologic outcomes, even without a consolidative HCT. Similar results have been obtained in pediatric ALL patietns ftreated with 41BB-based tisagenleucleucel (Pulsipher et al., Blood Cancer Discovery 2022). Longer follow-up is needed to validate the safety of omitting consolidative HCT in such pts, but these results encourage the potential for definitive therapy with brexu cel when D28 ClonoSeq NGS MRD is negative.

INTRODUCTION Atrial fibrillation (AFib) is a recognized complication in patients with chronic lymphocytic leukemia (CLL) treated with Bruton tyrosine kinase inhibitors (BTKis). Early detection and management of AFib are critical due to its association with increased morbidity and mortality. Traditional detection methods, such as intermittent EKGs and wearable devices, often capture only brief snapshots of cardiac activity, potentially missing episodes. Recent advances in artificial intelligence (AI) have enabled the development of algorithms that analyze electrocardiograms (EKGs) to predict AFib risk. These algorithms can potentially identify patients with undetected AFib and assess risk at a single point, reducing the need for continuous monitoring. This study evaluates the utility of an AI-enabled EKG algorithm in predicting AFib in patients with CLL treated with ibrutinib and acalabrutinib. METHODS Patients with CLL treated with ibrutinib and acalabrutinib were identified from a single-center database. Patients with CLL who received BTKi therapy at Mayo Clinic between 2015 and 2024 with available EKGs in the EMR were included. Patients were excluded if they received BTKi for non-CLL indications or if patients with CLL had documented AFib without accompanying EKGs in their medical records. An AI-enabled EKG algorithm developed by Attia et al. (Lancet, 2019) was used to estimate AFib probability (AFibAI). EKGs were categorized into pre-treatment, during treatment, and post-treatment phases. Mean values of all EKGs within each phase were used for analysis to reduce heterogeneity. Paired t-test was used for continuous variables and ROC analysis was used to evaluate diagnostic performance. A p-value of <0.05 was used for statistical analysis. RESULTS The analysis included 383 individual CLL patients (74% male, median age71; ace/ethnicity not available), of which 79 were treated with acalabrutinib and 304 with ibrutinib, with a total of 5844 EKGs analyzed. The AFibAI was significantly higher in EKGs with documented AFib compared to other EKGs, mostly normal sinus rhythm (0.5710 vs. 0.1857, p <0.001). Pre-treatment AFibAI was higher in patients who ultimately developed AFib after starting BTKi treatment compared to those who did not. Mean AFibAI at baseline was 0.2176 for those who developed AFib and 0.0986 for those who did not (p <0.001; difference between means: -0.1191 +/- 0.02005, 95% CI: 0.-0.1585 - 0.0796). Differences of baseline AFibAI were similar when stratified by BTKi. Trends in AFibAI scores indicated a significant increase during and after BTKi treatment in patients who developed AFib, with mean score of 0.2176 at baseline to 0.4064 post-treatment (p<0.001). In patients who did not develop Afib during BTKi therapy, there was minimal increase of AFibAI scores from 0.1041 at baseline to 0.1620 post-treatment (p = 0.0002). The ROC analysis showed an area under the curve of 0.7280 (SE = 0.03911, 95% CI: 0.6514 to 0.8047, p <0.001), indicating fair discriminatory ability. The sensitivity at the optimal threshold (0.1202) was 65.45% and the specificity was 74.59%, with a Youden's Index of 0.4004. To achieve a sensitivity of ≥90% for detecting patients who ultimately develop AFib, a threshold of 0.2368 was established (specificity of 41.82%). DISCUSSION Our study demonstrates the efficacy of an AI-enabled EKG algorithm in estimating atrial fibrillation risk among CLL patients treated with BTKis. We demonstrated that baseline AFibAI was notably higher in patients who ultimately developed AFib, suggesting that it could potentially identify patients at elevated risk before the onset of AFib. Early identification would allow for closer monitoring and timely intervention, potentially mitigating complications. Pending validation with an external cohort, the 90% sensitivity threshold could help identify the patients at highest risk, where other treatment options could be considered. The trend across different treatment phases revealed a significant increase in scores during treatment, indicating that AFibAI is responsive to changes induced by BTKi therapy and suggest its utility for patient monitoring. Practical questions remain about its impact on clinical decision-making and management. Future prospective studies should confirm the validity of identifying high-risk patients and its role in both treatment decisions and patient outcomes.

Background: Indolent non-Hodgkin lymphomas (iNHL) are incurable and disproportionately affect adults age >65 in whom frailty and functional impairment can impact disease management. The Vulnerable Elders Survey (VES-13) is a 13-item screening tool that incorporates age, self-rated health, physical function limitations, and functional disabilities to identify vulnerable older community-dwelling adults. Adults with a VES-13 score of >3 have a fourfold increased risk of death or functional decline over 2 years as compared to adults with a score <3 (Saliba et al, JAGS 2001). Our team previously showed that VES-13 >3 was associated with a higher risk of 1-year mortality in NHL (OR 3.26, 95% CI 2.15-4.96, Fama et al, ASH 2019), including in adults age <65. In this study, we determined whether VES-13 scores >3 were associated with quality of life (QOL) changes in adults with iNHL across the age spectrum. Methods: We used the Lymphoma Epidemiology of Outcomes (LEO) Cohort Study to identify adults enrolled from 2015-2020 with grade 1-3A follicular and marginal zone lymphoma (FL, MZL) who completed the VES-13 at enrollment and QOL surveys at enrollment and follow-up. The LEO Cohort Study enrolls participants within 6 months of diagnosis and collects information on disease status, QOL, health behaviors, and patient-reported functional assessment. For this analysis we included QOL measured using the Functional Assessment of Cancer Therapy-General (FACT-G) at years 1 and 2 post-enrollment. The FACT-G total score was the sum of 4 subscales (range): physical (PWB, 0-28), social/family (SFWB, 0-28), emotional (EWB, 0-24), and functional (FWB, 0-28) well-being. A higher FACT-G total score (range 0-108) indicated better overall QOL. VES-13 scores ranged from 0 (lowest risk for death or decline) to 10+ (highest risk). Generalized linear mixed models evaluated changes in QOL from baseline based on VES-13 score >3 (vulnerable) vs <3 (non-vulnerable), within groups by age at enrollment >65 and <65. Results: Our study included 1,186 participants: 42% age >65, 54% female, 84% non-Hispanic White, 10% Hispanic, 3.3% Black, and 1.4% Asian/Pacific Islander. Most (68%) were diagnosed with FL. FLIPI was high risk for 20%, and MALT-IPI was high risk for 23%. In the VES-13 <3 group, the mean (SD) baseline FACT-G total score was 86.5 (12.0), PWB 21.0 (3.5), SFWB 24.3 (4.3), EWB 18.8 (3.7), and FWB 22.3 (4.9). In the VES-13 >3 group, the mean (SD) baseline FACT-G total score was 70.4 (16.5), PWB 15.4 (5.6), SFWB 22.3 (5.5), EWB 17.5 (4.5), and FWB 15.3 (6.4); all significantly lower than the VES-13 >3 group (all p<0.01). In adults <65, 63 (9%) had a VES-13 >3, which was associated with a significant improvement from baseline in PWB at years 1 and 2 when compared to VES-13 <3 (changes in baseline PWB were 2.1, 2.9 for VES-13 >3 vs 0.2, 0.1 for VES-13 <3, all p<0.05). Similarly, we observed improvement in FWB from baseline at years 1 and 2 in the VES-13 >3 vs <3 group (2.4, 2.9 vs 0.4, -0.1, respectively all p<0.05). The VES-13 >3 group had a decline in their EWB at 1 year vs the VES <3 group (-0.5 vs 1.2, respectively, p=0.003). At year 2, total FACT-G improved from baseline in the VES-13 >3 group (5.6 for VES-13 >3 vs -0.5 for VES-13 <3, p=0.002). SFWB changes from baseline did not differ between groups. In adults >65, 83 (17%) had a VES-13 >3, which was associated with a significant improvement from baseline PWB (1.3, 1.5 for VES-13 >3 vs. 0.1, -0.1 for VES-13 <3), FWB (3.3, 2.2 for VES-13 >3 vs. 0.5, 0.1 for VES-13 <3), and total FACT-G score (5.2, 3.4 for VES-13 >3 vs. 1.0, -0.4 for VES-13 <3) when compared to VES-13 <3 at years 1 and 2 (all p<0.05). SFWB and EWB changes from baseline did not differ between groups. While there was improvement from baseline PWB and FWB in the VES-13 >3 group, QOL scores across all subscales remained below the VES-13 <3 group in the study period for both age groups. Statistical significance was maintained in models adjusted for baseline characteristics, including initial treatment strategy (observation, systemic, vs local) for both age groups. Conclusion: Although the vulnerable group reported worse QOL throughout the study period compared to the non-vulnerable group, survivors in the vulnerable group saw greater improvement in their physical and functional well-being at 1- and 2-years post-diagnosis. Additional analyses are underway to identify drivers of improvement in physical and functional well-being in vulnerable adults diagnosed with iNHL.

Introduction: Brexucabtagene Autoleucel (brexu-cel) is the first CD19-targeting chimeric antigen receptor (CD19.CAR) T-cell therapy approved for the treatment of relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (B-ALL) in adult (≥18 yo) patients (pts) based on results from the ZUMA-3 trial. However, data on the safety and efficacy of CAR-T cells in older pts (≥60 yo) remains limited, with only 8 pts >65 yo enrolled in the ZUMA-3 trial. We evaluated the treatment characteristics and outcomes with use of brexu-cel amongst patients ≥60 yo in the Real-World Outcomes Collaborative for CAR-T in ALL (ROCCA) consortium database. Methodology: ROCCA is a consortium of over 30 U.S.-based institutions with a database of adult pts with B-ALL who received brexu-cel as standard of care therapy. We identified pts ≥60 yo and further stratified them into two cohorts: 60-69 yo and ≥70 yo. Outcomes of interest included OS, PFS, ORR, and toxicities (CRS and ICANS). Both OS and PFS were calculated from the day of brexu-cel infusion. Response assessment occurred on day +28, and MRD evaluation was per institutional practices. CRS and ICANS were graded according to the American Society for Transplantation and Cellular Therapy criteria. Results: Of 280 brexu-cel recipients in the ROCCA database, 73 (26%) were ≥60 yo, of which 58 (79%) were between 60-69 yo and 15 (21%) were ≥70 yo. Among pts ≥60 yo, the median age at infusion was 65 (range 60-81). Pts were heavily pretreated with a median of 3 prior lines of therapy (range 2-9). Prior therapies included: allogeneic HSCT (38%), inotuzumab ozogamicin (41%), and blinatumomab (62%). Forty pts (55%) had Ph-negative B-ALL, 24 (33%) had Ph+ B-ALL and 9 (12%) had Ph-like B-ALL. When grouped by HCT-CI equal to 0, 1-2 or ≥3, a higher proportion of pts ≥60 yo had HCT-CI ≥3 (19% vs. 7% in <60 yo; p=0.004). Pre-apheresis, 33 pts (45%) had active disease (>5% marrow blasts or extramedullary disease), 34 (47%) were in CR (of whom 14 were MRD-negative) and 6 had unknown disease status. Following brexu-cel, 43 (59%) achieved MRD-negative CR, 20 (27%) had MRD + or CR with unknown MRD status, 6 (8%) had refractory disease and 5 had no disease evaluation available. The ORR was similar between pts 60-69 and ≥70 yo (MRD-negative CR rate: 58% vs 61%, r/r to brexu-cel: 9% vs 6%) and was comparable to pts <60 yo (MRD-negative CR 66%; r/r disease of 9%). The rate of all grade ICANS was higher in pts ≥70 (77%) than in pts 60-69 (47%) or pts <60 (49%), with grade 1-2 ICANS occurring at a significantly higher rate in pts ≥70 (44% vs. 20% in 60-69 and 20% in <60, p=0.049). Grade 3-4 ICANS were similar between the groups: 33%, 27% and 29% in the ≥70, 60-69, and <60 groups, respectively. Conversely, rates of CRS were similar across age groups (80-84%). There was no statistically significant difference in the rate of grade 3-4 CRS which was 17% in pts ≥70, 4% in pts 60-69, and 11% in pts <60 yo. With a median follow-up of 332 days (range 8-936 days) from infusion, pts ≥60 yo had a median PFS of 395 days compared to 547 days in pts <60 yo. Median PFS was lower in the ³70 yo (231 days) compared to 677 in the 60-69 yo cohort. No statistically significant difference was found between the <60 and ≥60groups in 6- and 12-month PFS rates (6 months PFS: 66% vs 64%, p=0.77 and 12 months PFS: 57% vs 57%, p=1.00). When pts ≥60 yo were stratified by age, pts ≥70 yo had similar 6-month PFS compared to other age groups but significantly lower 12-month PFS (38%; vs. 64% in pts 60-69and 57% in pts <60, p=0.001). Median OS was not reached in any of the age groups, and there was no statistically significant difference in 6-month OS (72% in ≥ 70 vs. 82% in the 60-69 vs. 82% in <60, p=0.14) or 12-months OS (61% in ≥ 70 vs. 69% in 60-69 vs. 73% in <60, p=0.18). Conclusion: This is the largest study to date of older B-ALL pts receiving CAR-T cells. We observed that older pts, particularly those aged 60-69, have similar outcomes to younger pts. However, pts ≥70 yo had lower median and 12-month PFS when compared to younger patients. Additionally, pts ≥70 yo had higher rates of grades 1-2 ICANS. An important limitation of this analysis is the potential selection bias among clinicians when selecting older patients for this treatment. Longer follow-up, including inclusion of additional pts ≥70 yo is needed to confirm these results, and further studies are needed to identify the optimal approach for use of CAR T-cell therapy in patients in this age group.

Background: Polatuzumab vedotin (Pola) is an antibody drug conjugate targeting CD79b that incorporates the microtubule disrupting monomethyl auristatin E payload. Pola was approved in 2023 for the upfront treatment of diffuse large B cell lymphoma (DLBCL) in combination with rituximab, cyclophosphamide, doxorubicin, and prednisone (polaRCHP) based on the POLARIX trial. However, the activity of pola appears to vary based on DLBCL cell of origin (COO) subtype, with greater efficacy in activated B cell (ABC) DLBCL compared to germinal center B cell (GCB) DLBCL (Russler-Germain Blood 2023). When outcomes in POLARIX are stratified by COO, polaRCHP demonstrated progression free survival (PFS) and overall survival (OS) benefits over RCHOP in patients with ABC but not GCB subtype DLBCL (PFS HR 0.34 ABC vs 1.03 GCB, OS HR 0.27 ABC vs 1.64 GCB; Morschhauser ASH 2023 and FDA data). Most prospective studies of pola used gene expression to assess COO, which is not readily clinically available. This study aims to examine if COO subtype by Hans algorithm (based on CD10, BCL6, and MUM1 expression by immunohistochemistry) is predictive of pola responses and outcomes in patients with large B cell lymphoma (LBCL). Methods: We conducted a retrospective, multicenter observational study of adults with LBCL who received pola (monotherapy or in combination) from 2015-2024 with Hans algorithm COO data and response assessment available. Patients were stratified by receipt of pola in the frontline vs relapsed/refractory (R/R) setting. The primary endpoint was overall response rate (ORR) to pola-based treatment in GCB vs non-GCB subtypes. Secondary endpoints included complete response rate (CRR), PFS, and OS. For time to event endpoints, patients responding to pola who received CAR T or stem cell transplantation prior to progression were censored at time of cellular therapy. Demographics were summarized by descriptive statistics. Comparative and survival analyses used Chi squared/Fischer exact tests and Kaplan Meier analysis. Data cutoff was July 1, 2024. Results: 718 patients were included. Median follow-up was 15 months (interquartile range [IQR] 8-32). Median age at LBCL diagnosis was 66 years (IQR 56-74); 62% were men; 69 (10%) had double hit lymphoma (DHL); 129 (18%) had underlying low grade lymphoma. Pola was used in the frontline setting in 293 (41%) patients, of whom 139 (47%) had GCB vs 154 (53%) non-GCB COO. Of the 426 patients receiving pola for R/R LBCL (including one patient receiving pola retreatment), 224 (53%) had GCB vs 202 (47%) non-GCB COO. Among patients receiving pola-based regimens in the R/R setting (GCB vs non-GCB: pola monotherapy = 7% vs 4%, pola + R = 26% vs 26%, pola + BR = 55% vs 61%, pola + other = 12% vs 9%; p = 0.44), the ORR in GCB vs non-GCB LBCL was 36% vs 61% (p < 0.001), while CRR in GCB vs non-GCB was 17% vs 36% (p < 0.001). COO remained a significant component of logistic multivariate regression models of ORR (p < 0.001) and CRR (p < 0.001) when incorporating IPI at original LBCL diagnosis, histology, DHL status, and refractory status to frontline therapy. Despite this, no significant PFS or OS differences by COO were seen, potentially due to approximately 1/4 patients being censored due to receiving subsequent cellular therapy (e.g. CAR T) prior to progression. In patients receiving frontline pola-based regimens (of which 275 [94%] included an anthracycline), ORR and CRR were similar in GCB vs non-GCB (ORR 89% vs 88% p > 0.5; CRR 76% vs 77% p > 0.5). While PFS and OS were similar between COO groups in the frontline cohort, follow-up and cohort size were limited. Conclusion: Based on this real-world evidence, COO classification by Hans algorithm is a strong predictor of the activity of pola-containing therapy in R/R LBCL, with significantly higher ORR and CRR in patients with non-GCB compared to GCB COO LBCL. This aligns with the cumulative existing evidence. ORR and CRR to pola-containing therapy in the frontline setting did not differ significantly by COO subtype, but longer follow-up of larger cohorts is needed to clarify the predictive role of COO by Hans algorithm in this setting, especially considering the PFS advantage with polaRCHP in POLARIX was not associated with significant differences in ORR or CRR. Overall, clinicians should consider factoring COO subtype into treatment decisions regarding pola-containing regimens, and studies of pola-based therapies should stratify patients and report outcomes by COO subtype.

Background: Erdheim-Chester disease (ECD) manifests as multi-organ infiltration of clonal histiocytes with mutations primarily in the mitogen-activated protein kinase (MAPK) pathway. The revised classification of histiocytosis (2016) categorizes ECD with typical bilateral, symmetric osteosclerosis of the lower extremity long bones as classical (C) and as non-classical (NC) if otherwise. The clinical and biological significance of this classification is unclear. This study compared the clinical and genotypic findings of the 2 subtypes within a large cohort of ECD patients. Methods: We included patients seen at our institution since 1990 meeting the following criteria: A) had an ECD diagnosis based on the revised criteria by Haroche J, et al. (Blood 2020;135:1311-1318); B) completed whole-body imaging studies including long bones of the legs. Classification as C-ECD required symmetric osteosclerosis of the distal femur and/or proximal tibia/fibula. Results: A total of 145 patients were enrolled, comprising a male-to-female ratio of 2:1 (66.2% male). C-ECD was diagnosed in 77.2% of cases, and NC-ECD in 22.8%. The median age at diagnosis was similar with 58.5 years (range, 18-82) in C-ECD and 55 years (range, 20-81) in NC-ECD, (p=0.65). The most frequently affected systems included skeletal (81.4%), renal (60.0%), vascular (45.5%), cardiac (40.0%), central nervous (38.6%), sinus (37.2%), pulmonary (36.6%), and adrenal (32.4%). The numbers of organs involved were significantly higher in C-ECD compared to NC-ECD (median 5 vs 3, p<0.01). Higher rates of skeletal (100% vs. 18.2%, p<0.01), adrenal gland (37.5% vs. 15.2%, p=0.02), and sinus (44.6% vs. 12.1%, p<0.01) involvement were observed in C-ECD. Arginine vasopressin deficiency (AVP-D) was exclusively observed in C-ECD (20.7% vs. 0%, p<0.01). NC-ECD had a higher rate of cardiac involvement (69.7% vs. 31.3%, p<0.01). No significant differences were found in other systems. The overall median time between onset of the first symptoms/signs to diagnosis was 15 months with no significant difference between C-ECD and NC-ECD (17.5 vs. 12 months, p=0.18). The median time to diagnosis of ECD in patients with AVP-D was 38.5 months, compared to 12 months without AVP-D (p=0.09). Genetic testing was conducted in 86.2% of patients and B-Raf proto-oncogene (BRAF) alterations were identified in 59.2% of the tested cases. BRAFV600E was more prevalent in C-ECD (61.3% vs. 21.9%, p<0.01), whereas non-V600 mutations were more commonly found in NC-ECD (12.5% vs. 1.1%, p<0.01). There was no significant difference in the frequency of BRAF fusions. NC-ECD patients exhibited a higher rate of MAP2K1 mutations (25.0% vs. 5.4%, p<0.01). Other frequently mutated genes included KRAS (4.0%), NRAS (2.4%), and CSF1R (2.4%), although no significant difference was observed in their frequency between C-ECD and NC-ECD. Testicular involvement appeared to be more common in patients with MAP2K1 mutations (23.1% vs. 8%, p=0.08). Two patients with pathogenic CSF1R mutations both had central nervous system (CNS) involvement. Among C-ECD patients, BRAFV600E conferred a higher rate of CNS involvement (50.9% vs. 25%, p=0.01). No significant difference was observed in NC-ECD patients (71.4% vs 36%, p=0.09). Among NC-ECD cases, MAP2K1 mutations conferred a reduced risk of cardiac involvement (37.5% vs. 79.2%, p=0.03) and no such difference was observed in patients with C-ECD (40% vs 34.1%, p=0.79). The median numbers of organs involved in patients with BRAF, MAP2K1, and KRAS/NRAS mutations were 5, 3, and 3, respectively, with no significant difference. Conclusions: C-ECD affects more organs and more frequently involves bones, adrenal glands, and sinuses. AVP-D was exclusively observed in C-ECD. Conversely, NC-ECD showed a higher prevalence of cardiac involvement. BRAFV600E was more commonly identified in C-ECD, whereas non-V600 mutations and MAP2K1 mutations were more prevalent in NC-ECD. Among C-ECD patients, BRAFV600E was correlated with a greater likelihood of CNS involvement. Conversely, NC-ECD patients with MAP2K1 mutations had a reduced risk of cardiac involvement. This study highlights the distinct clinical and molecular features of C-ECD and NC-ECD, underscoring the importance of subclassifying ECD into classical and non-classical forms. Further studies are needed to explore differences in the clinical outcomes between the 2 forms.

Introduction Venetoclax + rituximab resulted in a 2-year progression-free survival estimate of 85% in the mostly 2nd-line, post-chemotherapy setting of the MURANO clinical trial (Seymour NEJM 2018). Short remissions with venetoclax in patients (pts) with prior cBTKi treatment (tx) for CLL are reported. However, these cohorts have included heavily pre-treated pts. Here, we report outcomes with venetoclax-based regimens in a contemporary cohort with cBTKi-exposed CLL and no prior chemotherapy. Methods We conducted a retrospective study of pts who received venetoclax for relapsed CLL after prior cBTKi tx at Mayo Clinic and across 8 centers in France. Pts with any prior chemotherapy tx were excluded. Pts were grouped as cBTKi-resistant (CLL disease progression on cBTKi) and cBTKi-exposed (any prior cBTKi tx but without disease progression). Overall survival (OS) was analyzed as the time from initiation of venetoclax until date of death or last known to be alive. Time to next therapy or death (TTNTD) after venetoclax was defined as the time from venetoclax initiation until the earliest date of next tx or death. Cox proportional hazards regression models were used to estimate associations of factors with OS and TTNTD. Results A total of 85 pts received venetoclax, including: venetoclax monotherapy (n=13, 15%), venetoclax + rituximab (n=45, 53%), and venetoclax + obinutuzumab (n=27, 32%). Patient characteristics at the time of venetoclax start were as follows: median age 69 years (interquartile range [IQR] 62-77), 59 (69%) male, 45% (33/73 evaluated) with TP53 disruption (del(17p) or TP53 mutation), 82% (46/56 evaluated) with unmutated IGHV, and 41% (15/37 evaluated) with complex karyotype (CK; ≥3 clonal structural or numerical abnormalities on karyotype). The median prior lines of therapy was 1 (IQR 1, 2); 32 (38%) pts had received prior anti-CD20 monoclonal antibody and 8 (9%) pts had received 2 prior cBTKi. Prior cBTKi tx was stopped for a reason other than disease progression in 46 (54%) pts (cBTKi-exposed) and due to CLL progression in 39 (46%) pts (cBTKi-resistant). TP53 disruption, unmutated IGHV, and CK were more common in the cBTKi-resistant subgroup. Among pts with cBTKi-resistant CLL, 60% (12/20 evaluated) had a BTK and/or PLCG2 mutation. Median follow-up from start of venetoclax-based therapy was 20 months. The median TTNTD and OS for the entire cohort was 36 (95% CI 29-not evaluable [NE]) and 68 (95% CI 39-NE) months, respectively. Among the 46 pts with cBTKi-exposed CLL, the median duration of prior cBTKi tx was 6.7 months (IQR 1.8, 23.7). The median TTNTD and OS from venetoclax start were both 78 months in pts with cBTKi-exposed CLL. The 24-month TTNTD and OS estimates were 73% and 81%, respectively. Among the 39 pts with cBTKi-resistant CLL, the median duration of prior cBTKi tx was 42.3 months (IQR 23.4, 60.1). The median TTNTD from venetoclax start in pts with cBTKi-resistant CLL was 30 months. The 24-month TTNTD estimate was 65% in the cBTKi-resistant subgroup, 53% with venetoclax monotherapy (n=5), 62% with venetoclax + rituximab (n=30), and 100% venetoclax + obinutuzumab (n=4). The median OS from venetoclax initiation was 39 months overall in pts with cBTKi-resistant CLL. The 24-month OS estimate was 84% in the cBTKi-resistant subgroup overall, 53% with venetoclax monotherapy, 87% with venetoclax + rituximab, and 100% with venetoclax + obinutuzumab. On a univariate analysis in the whole cohort, only TP53 disruption was associated with shorter TTNTD (HR 2.23; 95% CI 1.02-4.87; P=0.04) and only older age was associated with shorter OS (HR 1.05; 95% CI 1.007-1.095, P=0.02). On a univariate analysis in the cBTKi-resistant subgroup, only TP53 disruption was associated with shorter TTNTD (HR 6.68; 95% CI 1.51-29.46; P=0.01) and OS (HR 7.95; 95% CI 1.02-61.97; P=0.04). Duration of prior cBTKi exposure (as a continuous variable) was not associated with survival outcomes in the cBTKi-resistant subgroup. Conclusions Pts with chemotherapy-naïve, cBTKi-treated CLL had worse than expected outcomes with venetoclax-based tx in a mostly 2nd-line tx cohort, particularly pts with cBTKi-resistant CLL. The frequency of high-risk disease features, shorter duration of disease control with their initial cBTKi tx, and small cohort size warrant caution in generalizing these results to all pts with cBTKi-resistant disease. Novel tx trial strategies in 1st- and 2nd-line settings remain a high priority for high-risk pts.

Background Bispecific antibodies (bsAbs) have gained momentum during the last several years in the treatment of hematological malignancies. Their novel mechanism of action has resulted in improvement in outcomes of patients with hematological malignancies refractory and/or relapsing after conventional therapies. This resulted in 7 regulatory approvals of bsAbs by the US FDA to treat hematological malignancies. Excluding blinatumomab, all have gained accelerated approval through phase II trials to treat relapsed/refractory (R/R) non-Hodgkin lymphoma (NHL); primarily diffuse large B-cell lymphoma (DLBCL and follicular lymphoma (FL), and R/R multiple myeloma (MM). Although these agents are associated with overall response rates (ORR) of greater than 50% in heavily treated patients, the real-world eligibility and response to these therapies in the United States is not known. Methods We aimed to estimate the number of US patients with NHL and MM who are eligible for and may respond to FDA approved bsAbs for R/R NHL and MM. A person was considered to be eligible for treatment with a bsAb if they had the FDA approved indication and inclusion criteria. We defined response based on the best available response rate for that indication from the FDA drug label. We used the incidence rate of NHL and MM from American Cancer Society's Cancer Facts and Figures during the years each bsAb had an approval. We made assumptions to estimate eligibility by incorporating attrition rates between lines of therapy according to what is published in the literature. For NHL, we assumed 75% of NHL diagnoses are DLBCL, while 20% are FL. For DLBCL, we assumed that 30% (10% primary refractory and 20% in relapse) of newly diagnosed DLCBL would receive a second-line therapy; of these patients, we assumed that 50% would proceed to receive a bsAb as third-line therapy. For FL, we assumed that 75% of newly diagnosed FL patients are grade 1-3A; of these, 85% will require first-line treatment, and 13% of these patients will eventually relapse to receive a bsAb as third-line therapy. For MM, we assumed that 14% of newly diagnosed MM will eventually be triple class refractory (refractory to a proteasome inhibitor, an immunomodulatory drug, and a monoclonal antibody) patients potentially eligible to receive a bsAb. The calculated number of people eligible was multiplied by the overall response rate (ORR) reported in the trial that led to the bsAb approval for each year a therapy had an approval, using the highest calculated response, to estimate the population who would potentially benefit of these therapies. Results Six bsAbs were approved in the US since 2022 to treat NLH and MM: epcoritamab and glofitamab in 2023 to treat R/R DLBCL and other mature B-cell neoplasms, mosunetuzumab in 2022 and epcoritamab in 2024 to treat R/R grade 1-3A FL, and for MM, teclistamab in 2022, and elranatamab and talquetamab in 2023. All of them were authorized via accelerated approval after a phase II trial. There were 80550 and 80620 new NHL cases in 2023 and 2024, respectively, and 12640, 12590, and 12540 new MM cases in 2022, 2023, and 2024, respectively. Of these, we estimated 21033 DLCBL patients would be potentially eligible to receive bsAbs since 2023, 2733 FL patients potentially eligible to receive bsAbs since 2023, and 5666 MM patients potentially eligible to receive bsAbs since 2022. The percentage of patients per year that were potentially eligible for bsAbs was 13% for DLCBL, 8.5% for FL, and 15% for MM. Based on best available response rates from registration trials, we estimated that 9.6% and 10.5% newly diagnosed NHL and MM patients, respectively, would potentially benefit from bsAbs. Conclusions Even though CR and ORR of bsAbs are high for highly pretreated patients, we found the percentage of newly diagnosed NHL and MM patients who would become potentially eligible and would respond to these therapies to be quite low (approximately only 1 out of 10). Even though these conclusions are driven by best-case scenario assumptions and have a risk of bias, they provide insights of the actual impact and reach of these newer therapies.