Citations

Introduction: Epcoritamab, a novel subcutaneously administered CD3xCD20 bispecific antibody (bsAb) being developed as a core therapy across several lymphoma subtypes, is currently approved for the treatment of adults with different types of R/R LBCL after ≥2 systemic therapies. The combination of epcoritamab with standard treatments has been shown to be safe and efficacious; epcoritamab in combination with gemcitabine and oxaliplatin (Epcor+GemOx) has provided deep and durable responses with favorable survival benefits in a transplant-ineligible R/R DLBCL study population, of which 99% was from the United States and Europe (EPCORE NHL-2; NCT04663347). The rituximab plus gemcitabine and oxaliplatin (R-GemOx) regimen has been a widely used treatment for patients with R/R DLBCL ineligible for transplant, albeit with suboptimal efficacy outcomes. In the absence of direct comparisons of these regimens, this study assessed the comparative efficacy of Epcor+GemOx vs R-GemOx in patients with R/R DLBCL ineligible for transplant. Methods: Individual patient-level data (IPD) from EPCORE NHL-2 arm 5 were compared to 2 sources of clinical practice data for patients with R/R DLBCL treated with R-GemOx: published data from Cazalles et al (2021) and IPD from the US-based COTA electronic health record database. The Cazalles study reports the results of a large retrospective analysis of patients with R/R DLBCL treated in 2 academic centers in France. The COTA database includes de-identified IPD with demographic and clinical information from numerous academic and community clinical sites in the US. For the comparison to Cazalles, logistic propensity score models were used to weight the Epcor+GemOx cohort to create match-adjusted distributions of baseline characteristics with the R-GemOx cohort in Cazalles. For the comparison to COTA, inverse probability of treatment weighting was employed to balance covariates between the Epcor+GemOx and R-GemOx cohorts. Analyses were restricted to chimeric antigen receptor T-cell therapy (CAR T)-naive patients from EPCORE NHL-2, as the comparator cohorts did not include patients treated with CAR T. Overall response rate (ORR), complete response (CR) rate, progression-free survival (PFS), and overall survival (OS) were compared for Epcor+GemOx vs R-GemOx. Results: A total of 74 patients treated with Epcor+GemOx (median follow-up: 13.2 months) were compared to 196 R-GemOx-treated patients from Cazalles et al (median follow-up: 22 months). After match-adjustment, Epcor+GemOx (ORR 86.8%) demonstrated significantly higher ORR, corresponding to a 48.5% advantage over R-GemOx (ORR 38.3%) with an odds ratio (OR) of 2.3 (95% CI 1.8-2.9; P<0.0001). Adjusted CR rate was also significantly higher with Epcor+GemOx vs R-GemOx (71.2% vs 32.7%; 38.6% difference; OR 2.2 [95% CI 1.6-3.0]; P<0.0001). Median PFS was significantly longer with Epcor+GemOx (26.7 months) vs R-GemOx (4.8 months; hazard ratio [HR] 0.38 [95% CI 0.22-0.67]; P<0.001). Median OS was not reached (NR) for Epcor+GemOx vs 10.0 months with R-GemOx (HR 0.54 [95% CI 0.29-1.0]; P=0.05), corresponding overall to a 62% reduction in the risk of a progression event and a 46% reduction in the risk of mortality with Epcor+GemOx vs R-GemOx. A total of 72 patients were treated with R-GemOx in COTA (median follow-up: 7.5 months) and compared to 74 Epcor+GemOx patients. After adjustment, ORR was significantly higher with Epcor+GemOx vs R-GemOx (88.5% vs 35.6%; OR 2.5 [95% CI 1.8-3.4]; P<0.0001). Adjusted CR rate was also significantly higher with Epcor+GemOx (63.9% vs 10.2%; OR 6.3 [95% CI 3.1-12.7]; P<0.0001). Adjusted median PFS was significantly longer with Epcor+GemOx (11.2 months) vs R-GemOx (2.4 months; HR 0.23 [95% CI 0.15-0.36]; P<0.0001). Adjusted median OS was also significantly longer with Epcor+GemOx (21.6 vs 8.3 months; HR 0.47 [95% CI 0.30-0.74]; P=0.002), corresponding overall to a 77% reduction in the risk of a progression event and a 53% reduction in the risk of mortality with Epcor+GemOx vs R-GemOx. Conclusions: In this indirect treatment comparison analysis,Epcor+GemOx provided significantly superior efficacy benefits in terms of ORR, CR, PFS, and OS vs standard-of-care R-GemOx. While subject to the limitations of comparisons outside of controlled trials, findings indicate the compelling efficacy of Epcor+GemOx as a novel therapeutic option for transplant-ineligible patients with R/R DLBCL.

Abstract Background Hypomagnesemia has been correlated with inferior outcomes in patients with large B cell lymphoma (LBCL) undergoing stem cell transplants. As T-cell and myeloid cell dysfunction have been associated with low magnesium conditions, we investigated whether serum magnesium (Mg) levels could predict clinical outcomes in LBCL patients who received chimeric antigen receptor T-cell therapy. Methods Patients with LBCL who received axi-cel under the ZUMA-1 trial or as FDA approved therapy at Mayo Clinic were examined. Serum samples were obtained at specified time points and cytokine analysis was performed. Single cell RNA sequencing was performed on peripheral blood mononuclear cells. The Student T-test, Kruskal Wallis, or Fisher's Exact Tests were used to compare differences in demographics across Mg levels. Survival curves were plotted using the Kaplan-Meier methodology and compared using the Wilcoxon test. Results We found that hypomagnesemia before lymphodepletion chemotherapy predicted for inferior progression-free and overall survival in the pivotal study ZUMA-1 (NCT02348216). These results were validated in an independent cohort of LBCL patients receiving axicabtagene ciloleucel (axi-cel) at Mayo Clinic. Hypomagnesemia correlated with increased inflammatory serum markers and cytokine levels including ferritin, IL-6, IL1Ra, IL-8, and MIP1a. scRNAseq analysis unveiled altered immune interactions between monocytes and T cells with a concordant immune suppressive transcriptome. Conclusions Hypomagnesemia at the time of CAR-T infusion associates with an unfavorable inflammatory profile and decreased response and survival in LBCL patients receiving axi-cel. These findings suggest a potentially actionable prognostic factor for patients with large cell lymphoma undergoing CAR-T.

283 Background: Infertility can be a devastating consequence for adolescent or young adult (AYA) patients, posing distinct challenges for healthcare providers striving to deliver high-quality, equitable cancer care. The rising incidence of cancer and growing population of AYA cancer survivors necessitates innovative, streamlined, and efficient processes to promote fertility preservation. While guidelines from organizations like American Society of Clinical Oncology (ASCO) and Agency for Healthcare Research and Quality (AHRQ) provide valuable recommendations, ensuring consistent adherence to these standards remains an ongoing challenge. Methods: The aim of this quality improvement project was to increase fertility preservation counseling and documentation, by 20% within 6 months without delaying chemotherapy start for newly diagnoses AYA patients (age 18-39) within a large academic medical center. Utilizing a Define, Measure, Analyze, Improve, Control (DMAIC) methodology, interventions were conducted through a series of Plan-Do-Study-Act (PDSA) cycles that included provider and staff education, referral process standardization, implementation of a best practice advisory (BPA) within the electronic health record (EHR), revision of organizational policy, and establishment of nurse touchpoints to facilitate communication. Results: The percentage of counseling and documentation in AYA cancer patients (n=83) increased by 52%, exceeding the project aim. Statistical significance was calculated using a chi-square test. Contrary to initial concerns of potential delays in beginning chemotherapy while awaiting preservation, the average time to starting chemotherapy decreased by 43%. Conclusions: Fertility preservation counseling is a critical aspect of quality outcomes for AYA cancer patients. Strategic planning of automated methods to facilitate documentation and referral was an ideal method of building quality into a large healthcare system. Establishing methods of process improvement engrained best practices, allowing for enrichment of data collection, while driving continuous quality improvement. Increased utilization of the BPA facilitated tracking of quality metrics, while promoting a patient-centered approach to fertility preservation. Interdisciplinary collaboration between physicians, nurses, and reproductive specialists fosters holistic care to enhance long-term survivorship. Fertility preservation counseling and documentation Results. Month Month Count (%) QuarterlyCount (%) 95% CI Change 95% CI P Mean days to begin chemotherapy Baseline 17 of 41 (41%) 17 of 41 (41%) 0.27 to 0.58 42 October 19 of 20 (95%) November 10 of 12 (83%) December 9 of 14 (64%) 38 of 46 (83%) 0.68 to 0.92 0.41 0.20 to 0.62 <0.001 January 10 of 12 (83%) February 7 of 7 (100%) March 12 of 12 (100%) 29 of 31 (94%) 0.77 to 0.99 0.52 0.32 to 0.72 <0.001 24 April 6 of 6 (100%)

Abstract Unirradiated patients with relapsed/refractory (R/R) B-cell non-Hodgkin lymphoma (NHL) who undergo anti-CD19 chimeric antigen receptor T-cell therapy (CART) have a predominant localized pattern of relapse, the significance of which is heightened in individuals with limited/localized disease before CART. This study reports on the outcomes of patients with R/R NHL and limited (&lt;5 involved sites) disease bridged with or without radiotherapy. A multicenter retrospective review of 150 patients with R/R NHL who received CART with &lt;5 disease sites before leukapheresis was performed. Bridging treatment, if any, was administered between leukapheresis and CART infusion. Study end points included relapse-free survival (RFS), event-free survival (EFS), and overall survival. Before CART infusion, 48 patients (32%) received bridging radiotherapy (BRT), and 102 (68%) did not. The median follow-up was 21 months. After CART infusion, BRT patients had higher objective response (92% vs 78%; P = .046) and sustained complete response rates (54% vs 33%; P = .015). Local relapse in sites present before CART was lower in the BRT group (21% vs 46%; P = .003). BRT patients had improved 2-year RFS (53% vs 44%; P = .023) and 2-year EFS (37% vs 34%; P = .039) compared with patients who did not receive BRT. The impact of BRT was most prominent in patients who had ≤2 pre-CART involved disease sites, with 2-year RFS of 62% in patients who received BRT compared with 42% in those who did not (P = .002). BRT before CART for patients with limited (&lt;5 involved disease sites) R/R NHL improves response rate, local control, RFS, and EFS without causing significant toxicities.

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7080 Background: Primary mediastinal large B-cell lymphoma (PMBCL) is an uncommon type of aggressive B-cell non-Hodgkin lymphoma. PMBCL has distinct clinicopathologic features compared to diffuse large B-cell lymphoma but shares some clinical and biologic features with nodular sclerosis classic Hodgkin lymphoma (cHL). Central nervous system (CNS) relapse is exceedingly rare in cHL, therefore one may expect that CNS relapse in PMBCL is also uncommon. Herein, we examined the incidence of CNS relapse in patients with PMBCL. Methods: Patients with newly diagnosed PMBCL seen at Mayo Clinic between 1/2002 and 4/2023 were identified from the Mayo Clinic Lymphoma Database. Clinical features, treatment details and outcomes were abstracted from medical records. The CNS relapse rate was calculated using a competing risk model, with death considered as a competing risk. Results: A total of 154 PMBCL cases were identified. The median age at diagnosis was 38 years (range 18-77) and 60.4% were female. The distribution of CNS-IPI was low-risk in 80 (51.9%) patients, intermediate-risk in 43 (27.9%), and high-risk in 3 (1.9%), and data were missing for 28 patients (18.2%). 78 patients (50.6%) received R-CHOP and 76 patients (49.4%) received R-DA-EPOCH as frontline therapy. High-dose methotrexate (HD-MTX) for CNS prophylaxis was administered to 5 patients (all treated with R-CHOP). 20 patients received intrathecal (IT) chemotherapy (methotrexate and/or cytarabine) for CNS prophylaxis (4 with R-CHOP [1 received HD-MTX too],16 with R-DA-EPOCH). The median follow-up was 39 months (95% CI 28.2-49.8). Only 3 patients had CNS relapse, all associated with systemic relapse (1 concurrent, 1 had CNS relapse 8.8 months after systemic relapse, 1 had CNS relapse 2 months before systemic relapse). The cumulative incidence of CNS relapse for the entire cohort was 1.43% (95% CI 0.3%-4.6%) at 1 year and 2.21% (95% CI 0.6%-5.8%) at both 2 and 5 years. For those who did not receive CNS prophylaxis (n=130), the incidence was 0.86% (95% CI 0.1%-4.3%) at 1 year and 1.82% (95% CI 0.4%-5.8%) at both 2 and 5 years. All 3 patients who experienced CNS relapse had R-CHOP as frontline therapy; two patients did not receive any CNS prophylaxis, while 1 patient received IT CNS prophylaxis. Conclusions: The risk of isolated CNS relapse in PMBCL appears to be very low, even in patients who did not receive CNS prophylaxis. While some patients may experience CNS relapse associated with systemic relapse, the overall incidence was low (1.43% at 1 year and 2.21% at 2 and 5 years). The rarity of isolated CNS relapse in PMBCL suggests that routine CNS prophylaxis may not be necessary as part of initial therapy.

7038 Background: While chimeric antigen receptor T-cell (CAR-T) therapy has transformed treatment for hematological malignancies, severe (≥ grade 3,Gr 3, CTCAE) cytopenias post CAR-T and therapy related myeloid neoplasms (t-MN) are particularly difficult to manage. Survival after diagnosis of t-MN is dismal. Management of ≥Gr 3 cytopenias that do not recover by month 3 after CAR-T require frequent monitoring and transfusion support. Growth factor and thrombopoietin mimetics have variable success, with stem cell boost emerging as having more consistent success. Evaluation for CAR-T eligibility, prior to leukapheresis, is the critical timepoint where factors identified at this time could inform risks and benefits of CAR-T versus alternative treatment and for consideration of stem cell collection in patients who may benefit from stem cell boost to treat severe cytopenia post CAR-T. Methods: We conducted a retrospective analysis comparing clinical data of patients (pts) with lymphoma (NHL) and multiple myeloma (MM) treated with FDA-approved and investigational CAR-T between 01/2016 – 06/2022 at Mayo Clinic. Prolonged cytopenias were defined as hemoglobin (Hg)<8 g/dL, absolute neutrophil count (ANC)<0.5 x 109/L, and/or platelet count (PLT)<50 x 109/L at 3 months after CAR-T. Pts with progressive disease were excluded from cytopenia analysis. Logistic regression to identify factors correlated with cytopenia and t-MN. Results: Among the 186 pts who received CAR-T, 42 (22%) patients developed severe cytopenia (26/102, 25%, in NHL; 16/84, 19% in MM); 15/186 (8%) had more than 1 concurrent cytopenia. Univariate analysis identified that baseline ferritin and CAR-HEMATOTOX score correlated with cytopenia. Multivariate analysis showed that advanced age (≥ 65 years) (HR 2.69, 95%CI 1.17 – 6.40, P = 0.02) and thrombocytopenia (HR 4.01, 95%CI 1.77 – 9.34, P = 0.001) were associated with severe cytopenia. Twenty (10.7%) patients [8 (40%) males] developed t-MN at a median of 9.5 months (IQR 4.8 – 19.3 months) after CAR-T (14/102, 13% in NHL; 6/84, 7% in MM). Univariate analysis identified ferritin and CAR-HEMATOTOX score correlated with t-NM. Multivariate logistic regression showed advanced age (HR 5.03; 95%CI 1.59-18.7, P= 0.009), hemoglobin ≤ 10 g/dl (HR 3.63, 95%CI 1.04-13.30, P = 0.04), and thrombocytopenia (HR 4.06, 95%CI 1.32-14.2, P 0.02) are significantly associated with development of post-CART t-MN. Conclusions: Advanced age, anemia and thrombocytopenia at the time of evaluation for CAR-T eligibility, prior to leukapheresis, are associated with the development of post-treatment severe cytopenia and t-MN. Larger, multi-center studies are needed to validate these findings.

Abstract Chimeric antigen receptor T‐cell (CAR‐T) therapy, despite being a potentially curative therapy in relapsed or refractory (RR) large B‐cell lymphoma (LBCL), remains underutilized in older patients due to limited clinical data. We therefore studied the safety and efficacy of CAR‐T therapy in older patients with RR LBCL in the real‐world setting. Patients aged ≥65 years with RR LBCL, treated with anti‐CD19 CAR‐T therapy at 7 US institutions were included in this multicenter, retrospective, observational study. In total, 226 patients were included. Median age at infusion was 71 years (range 65–89). Best objective and complete response rates were 86% and 62%, respectively. Median follow‐up after infusion was 18.3 months. The median progression‐free survival (PFS) was 6.9 months, with 6‐ and 12‐month PFS estimates of 54% and 44%, respectively. The nonrelapse mortality (NRM) rate was 10.9% at day 180, primarily due to infections, and not impacted by the age groups. Grade ≥3 cytokine release syndrome and neurotoxicity occurred in 7% and 26%, respectively. In univariate analysis, no significant difference in PFS was seen regardless of the age groups or CAR‐T type, whereas ECOG PS ≥2, elevated LDH, bulky disease, advanced stage, extranodal involvement, the need for bridging therapy, and prior bendamustine exposure were associated with shorter PFS. These findings support the use of CAR‐T in older patients, including those aged ≥80 years. The age at CAR‐T therapy did not influence safety, survival, and NRM outcomes. Older patients should not be excluded from receiving CAR‐T therapy solely based on their chronological age.

The emergence of CD19-directed chimeric antigen receptor T-cell (CAR-T) therapy has revolutionized the treatment paradigm for R/R B-cell NHLs. However, challenges persist in accurately evaluating treatment response and detecting early relapse, necessitating the exploration of novel biomarkers. Circulating tumor DNA (ctDNA) via liquid biopsy is a non-invasive tool for monitoring therapy efficacy and predicting treatment outcomes in B-NHL following CAR-T therapy. By overcoming the limitations of conventional imaging modalities, ctDNA assessments offer valuable insights into response dynamics, molecular mechanisms of resistance, and early detection of molecular relapse. Integration of ctDNA monitoring into clinical practice holds promise for personalized therapeutic strategies, guiding the development of novel targeted therapies, and enhancing patient outcomes. However, standardization of assay methodologies and consensus on clinical response metrics are imperative to unlock the full potential of ctDNA in the management of B-NHL. Prospective validation of ctDNA in clinical trials is necessary to establish its role as a complementary decision aid.

Abstract Background Although CAR T-cell therapy has achieved remarkable response in patients (pts) with B-cell non-Hodgkin’s lymphoma (NHL), 20-30% of pts still have primary refractory disease (PD1), and another 30-40% relapse (PD2). We and others have shown that monocytes can modulate T-cell functions and impact clinical response to chemoimmunotherapy in NHL. Given that monocytes nadir and recovery kinetics differ from lymphocytes post lymphodepletion chemotherapy, we hypothesize that monocyte phenotype at peak CAR-T expansion and in the early month post CAR-T can modulate immune responses. Methods scRNAseq were performed on peripheral blood mononuclear cells of NHL pts prior to lymphodepletion chemotherapy (pre), at peak CAR-T expansion (peak), and one month following CAR-T (M1). Seurat v4.3.0 was used for unsupervised hierarchical clustering analysis. Lugano criteria was used to determine clinical responses which were categorized as CR (complete remission), PD1, or PD2. Results We analyzed 129,981 monocytes from 77 samples of 32 pts (16 CR, 4 PD1, 12 PD2) and 5 healthy controls. Unsupervised hierarchical clustering analysis identified 13 monocyte clusters: 4 classical monocyte (CM) clusters with transcriptome profiles for enriched signaling in IL-6, TGFβ, EMT, and p53; 2 intermediate monocyte (IM) clusters enriched for IL-1 or CD38 signaling; 2 non-classical monocytes (NM), one with increased CD36 expression; 3 monocytic MDSC clusters with enrichment of TGFβ, SIRPα, and HIF1α signaling; and 2 lymphoma-associated monocytes, expressing CD163 or CD169. At Pre and Peak, the distribution of the monocyte clusters was similar in pts with CR, PD2, or PD1, with only a slight decrease in the percent of NM in the PD2 group at Pre and slight increase of CD36 NM in PD1 at Peak. Compared to Pre, all pts had increased percent of CD36 NM and IL-1 IM at Peak. Interestingly, while the distribution of monocyte clusters was similar at Pre and Peak across clinical responses, GSEA showed that monocytes in CR pts, compared to PD1 and PD2, had gene expression enrichment of MYC target V2 pathway at Pre and TGFβ pathway at Peak. At M1, pts in PD1 had increased percent of p53 and TGFβ CM and decreased percent of NM. In contrast, pts with CR had decreased percent of IL-6 CM, p53 CM, TGFβ CM, IL-1 IM and increased percent of NM. Notably, as pts with CR and PD2 may appear similar clinically at M1, pts with PD2, compared to CR, have increased IL-6 CM, IL-1 IM, and decreased NM. In addition, GSEA showed that PD2 pts had increased IFNα response. Our results demonstrate that monocyte phenotype differences at Pre and Peak could be associated with CAR-T clinical response, and that persistent inflammatory monocyte signaling at M1 in pts with clinical response is associated with relapse. These data suggest a role for development of monocyte biomarkers to predict response and therapeutic targeting. Citation Format: Andre de Menezes Silva Corraes, Panwen Wang, Radhika Bansal, Henan Zhang, Zuoyi Shao, Kevin Regan, Eider Moreno Cortes, Arushi Khurana, Nora Bennani, Yucai Wang, Paul Hampel, Jonas Paludo, Patrick Johnston, Hemant Murthy, Madiha Iqbal, Stephen Ansell, Javier Munoz, Allison Rosenthal, Mohamed Kharfan-Dabaja, Januario Castro, Saad Kenderian, Haidong Dong, Ying Li, Yi Lin. Monocyte transcriptome profiles associated with clinical response in patients with B-cell non-Hodgkin’s lymphoma receiving CD19-directed CAR-T therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4001.