Moustafa, Muhamad Alhaj

Introduction: The treatment of older patients with advanced stage classical Hodgkin lymphoma (cHL) is challenging and outcomes remain poor compared to younger patients (pts). A subgroup analysis of older pts (aged ≥ 60 years) enrolled in the SWOG S1826 study showed the Nivolumab-AVD regimen was better tolerated and improved progression free survival (PFS) compared to concurrent brentuximab vedotin-AVD (Bv-AVD). The sequential administration of Bv before and after AVD chemotherapy (seq Bv-AVD-Bv) is a commonly used approach to minimize the toxicity of Bv-AVD in older pts based on the tolerability and efficacy shown in a phase II study (Evens, et al. J Clin Oncol 2018). There is limited data on clinical outcomes with seq Bv-AVD-Bv in the real-world setting. We report our multicenter study of sequential Bv-AVD-Bv administration in older patients with cHL. Methods: This retrospective study included a total of 40 older pts with cHL treated with sequential Bv-AVD-Bv in 6 cancer centers. Descriptive statistics were used to depict patient demographics and disease characteristics prior to treatment initiation. Responses to therapy were assessed using the Lugano criteria. Response evaluable patients were those who received at least one cycle of chemotherapy with AVD. PFS and overall survival (OS) were estimated using log-rank testing with the Kaplan Meier curves. Results: The majority (n=23, 57.2%) of patients were male; median age was 72.5 years (range, 57-86 years); 10 (25%) pts were Hispanic, and 18 (45%) pts were Caucasian; performance status by ECOG was 0-2 in 33 (82.5%) pts. In terms of disease characteristics 19 (47.5%) pts had cHL NOS, 10 (25%) had nodular sclerosing subtype; stage III/IV in 35 (87.5%), stage II in 5 (12.5%) pts; B- symptoms in 21 (52.5%); extranodal disease in 19 (47.5%), with bone marrow involvement in 10 (25%) pts. Among the 38 response-evaluable patients the ORR and CR rates were 97.4% and 71.1%, respectively. Bv dose reductions or interruptions were reported in 14 (35.9%) pts. Treatment discontinuation (Td) occurred in 16 (40%) pts. The most common any grade adverse events were hematological toxicities (HT) in 28 (70%) pts and peripheral neuropathy in 24 (60%) pts. Forty-five percent of patients experienced grade 3 or higher HT. The overall incidence of grade 2 or higher peripheral neuropathy was 15%. The main reasons for treatment discontinuation were toxicity (n=9) and disease progression (n=4). During treatment, 1 (2.5%) pt reported loss of basic activities of daily living (ADLs) and 5 (12.5%) had loss of instrumental ADLs (iADLs). G-CSF prophylaxis was used in most (n=33, 82.5%) pts. At a median follow up of 25.7 months (range, 2.6 - 58.9) the 2 years PFS was 62.6% (95% CI: 46.1-79.1) and the 2 years OS was 83.3% (95% CI: 67-99.6). On univariate analysis, the median PFS correlated with the depth of response (CR: not reached; PR: 11.4 months; SD/PD: 3.9 months; P=0.0001); and with treatment discontinuation (No Td: not reached; Td: 21.6 months; P=0.007). There was no correlation between age, sex, institution, B- symptoms, bone marrow involvement, ADL/iADLs, or disease stage with treatment discontinuation. Conclusion: Sequential Bv-AVD-Bv in older patients with cHL can help minimize the toxicity associated with the concurrent administration of Bv-AVD. This sequential approach has shown comparable efficacy in real-word setting as seen in clinical trials. Our findings suggest seq Bv-AVD-Bv remains a feasible option for older fit patients with cHL outside clinical trials. Further randomized studies in older cHL pts are needed.

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: In the ZUMA2 study, a higher peak chimeric antigen receptor (CAR) T cell expansion correlated with better outcomes in patients with relapsed/refractory (R/R) mantle cell lymphoma (MCL) receiving brexucabtagene autoleucel (brexu-cel). However, in clinical practice, peak CAR T cell expansion is not routinely assessed for. Since patients receive lymphodepleting agents prior to CAR T cell infusion, it is hypothesized that peak absolute lymphocyte count (ALC), which can be easily measured, in the first two weeks after CAR T cell infusion represents peak CAR T cell expansion. Our group previously showed that peak ALC was associated with response durability and outcomes in patients with R/R large B-cell lymphoma receiving axicabtagene ciloleucel. In this retrospective study, we assessed the association of peak ALC with clinical outcomes after brexu-cel infusion in patients with R/R MCL. Methods: Patients with R/R MCL who received brexu-cel between March 2020-March 2024 at Mayo Clinic were included in this analysis. Peak ALC was defined as maximum ALC value in the first 14 days after CAR T cell infusion. Progression-free survival (PFS) was defined as time from CAR T cell infusion to lymphoma relapse, progression, or death, and overall survival (OS) was defined as time from to CAR T cell infusion to death. The optimal cutoff point for peak ALC that correlated with PFS was determined by the log-rank method using the Cutoff Finder application, a computational method which fits Cox proportional hazard models to the dichotomized variable and survival. The optimal cutoff was the point with the most significant PFS split by log-rank test. Results: A total of 43 patients were identified. The median age at time of CAR T cell infusion was 68 years (IQR 58, 73). 34 (79%) were male, 28 (74%) had Ki-67 >30%, 14 (33%) had blastoid or pleomorphic histology, and 19 (44%) had TP53 mutation or deletion. Median number of prior lines of therapy was 3 (IQR 2, 4) and 13 (30%) received prior autologous stem cell transplant. 32 (74%) received bridging therapy prior to CAR T cell infusion. All patients received fludarabine plus cyclophosphamide for lymphodepletion. The best overall response rate was 88%, with a complete response rate of 84%. After a median follow-up of 25.6 months (95% CI 14.4-31.4), the median PFS and OS were 16.6 (95% CI 8.6-NE) and 35.1 (95% CI 24.5-NE) months, respectively. The incidence of cytokine release syndrome (CRS) was 95% (4.7% grade ≥3). The median time to initial CRS and maximum grade CRS onset was 4.5 days (IQR 1, 6.25) and 5.5 days (IQR 2.75, 7), respectively. The incidence of immune effector cell-associated neurotoxicity syndrome (ICANS) was 65% (18% grade ≥ 3). The median time to initial and maximum grade ICANS onset was 9 days (IQR 6, 11) and 10.5 days (IQR 7, 12), respectively. The median ALC at time of CAR T cell infusion was 0.03 x109/L (IQR 0.02, 0.05). Among 37 patients with identifiable ALC peaks, the median ALC peak was 0.84 (IQR 0.41, 2.45) and the median time to peak ALC was 12 days (IQR 9, 12). 6 patients had no identifiable peak ALC due to no frequent CBC differentials post CAR T cell infusion. A peak ALC of ≥0.45 × 109/L correlated significantly with PFS, with median PFS not reached for the group with peak ALC of ≥0.45 × 109/L (n=27) compared to 9.3 months for the group with peak ALC of <0.45 × 109/L (n=10) and a 1-year PFS rate of 68% vs 33% (p=0.02). OS was also significantly higher in patients with a peak ALC of ≥0.45 × 109/L (median OS not reached vs 11 months, 1-year OS rate of 84% vs 44%, p=0.01). The incidence of ICANS was significantly higher (74% vs 30%, p=0.02) in patients with a peak ALC of ≥0.45 × 109/L. Numerically, the group with peak ALC of ≥0.45 × 109/L had a later onset of initial and maximum grade ICANS, but the difference was not statistically significant. Peak ALC was not associated with ICANS severity. There was a trend towards higher incidence of CRS (100% vs 80%, p=0.07) and earlier CRS onset (3 vs 5 days, p=0.07) in the high peak ALC group. There was no difference in CRS severity. Conclusion: Peak ALC after CAR T cell infusion was significantly associated with better PFS and OS and higher incidence of ICANS in patients with R/R MCL receiving brexu-cel. Peak ALC may serve as a surrogate measure for peak CAR T cell expansion in routine practice, but confirmatory studies are needed. Larger studies are warranted to confirm the association of peak ALC with PFS, OS and toxicities in patients with R/R MCL receiving brexu-cel.

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.

Background Mantle cell lymphoma (MCL) is more common in males, with a male to female ratio of approximately 3:1. However, it is unclear whether disease characteristics and survival outcomes differ by sex. Additionally, the impact of race and ethnicity in MCL is understudied due to underrepresentation of minorities in clinical studies and trials. In this study, we utilized the National Cancer Database (NCDB) to examine patient and disease characteristics and survival outcomes of MCL by sex, race and ethnicity. Methods Patients diagnosed with MCL in 2004-2020 were identified from NCDB. Patient and disease characteristics were compared between groups using Chi-squared tests. Overall survival (OS) analysis was performed using the Kaplan-Meier method and the Cox proportional hazards model. Results A total of 35,135 patients was included. The median follow-up was 83.0 months (95% CI 81.9-84.1). 24,980 (71.1%) patients were male and 10,155 (28.9%) were female. Females had more elderly (age ≥65: 65.9% vs 59.0%; p<0.001), lower Charlson-Deyo Score (CDS ≥2: 7.0% vs 8.6%; p<0.001) and fewer stage III-IV diagnoses (80.5% vs 82.6%; p<0.001). Females were less likely to receive upfront treatment (80.7% vs 85.3%; p<0.001), treatment at academic centers (36.8% vs 40.9%; p<0.001) or transplant (11.0% vs 13.7%; p<0.001). Compared to males, females were more likely to live in metropolitan areas (83.7% vs 81.6%; p<0.001), had similar incomes, had more Medicare (60.4% vs 53.1%) and fewer private insurance (33.2% vs 38.6%; p<0.001). Female patients had better OS, with a median OS of 76.0 (95% CI 72.4-79.6) vs 67.8 months (95% CI 65.9-69.6; p<0.001). In the multivariable Cox model adjusting for age, race, ethnicity, CDS, stage, upfront treatment (vs surveillance or no treatment), facility (academic vs nonacademic), transplant, residence (metropolitan vs urban or rural) and insurance, female sex remained associated with superior OS (HR 0.84, 95% CI 0.793-0.890; p<0.001). For race, 32,399 (92.2%) patients were White, 1,465 (4.2%) were Black, 942 (2.7%) were others and 329 (0.9%) were unknown. Compared to White patients, Black patients had fewer elderly (52.9% vs 61.7%; p<0.001), higher CDS (≥2: 11.4% vs 7.9%; p<0.001), similar stage III-IV (80.7% vs 82.1%; p=0.276) and upfront treatment (84.7% vs 84.0%; p=0.074), were more likely to be treated at academic centers (50.6% vs 38.9%; p<0.001), were less likely to receive transplant (11.1% vs 13.0%; p=0.042), were more likely to live in metropolitan areas (91.0% vs 81.5%; p<0.001), had lower income, had more uninsured (4.4% vs 2.0%) and Medicaid (9.8% vs 3.7%) and fewer Medicare (47.4% vs 56.0%; p<0.001). Black and White patients had similar OS, with a median of 67.9 (95% CI 57.5-78.2) vs 69.6 months (95% CI 67.8 vs 71.3; p=0.697). In the multivariable Cox model, Black vs White race was not associated with OS (HR 1.086, 95% CI 0.952-1.240; p=0.219). For ethnicity, 31,717 (90.3%) patients were non-Hispanic, 1,894 (5.4%) were Hispanic and 1,534 (4.3%) were unknown. Hispanics had fewer elderly (51.3% vs 61.5%; p<0.001), lower CDS (≥2: 6.4% vs 8.2%; p=0.018), similar stage III-IV (81.2% vs 82.1%; p=0.467), were more likely to receive upfront treatment (86.0% vs 83.9%; p<0.001), more likely to be treated at academic centers (49.9% vs 39.5%; p<0.001), equally likely to receive transplant (13.0% vs 13.1%; p=0.943), more likely to live in metropolitan areas (95.4% vs 81.6%; p<0.001), had lower income, had more uninsured (9.6% vs 1.8%) and Medicaid (15.2% vs 9.6%) and fewer Medicare (40.3% vs 55.9%; p<0.001). Hispanics had better OS, with a median OS of 84.4 (95% CI 71.7-97.1) vs 70.5 months (95% CI 68.7-72.2; p<0.001). However, in the multivariable Cox model, Hispanic ethnicity was not associated with OS (HR 0.952, 95% CI 0.839-1.080; p=0.448). Conclusion This study is the first of its scale to demonstrate that female MCL patients have superior survival outcomes compared to males. It also demonstrated that neither Black race nor Hispanic ethnicity appears to be associated with worse survival outcomes. Despite its size, the NCDB is limited in the treatment information and disease characteristics it provides, including MIPI score, Ki-67, blastoid/pleomorphic morphology, and TP53 status. Thus, additional real-world dataset studies are needed to gain a deeper understanding of potential differences in sex, race and ethnicity with regards to disease characteristics and survival outcomes.

Introduction: Bispecific antibodies (BsAbs) epcoritamab (Epco) and glofitamab (Glofit) are approved in the US for the treatment of patients (pts) with relapsed or refractory (r/r) large B-cell lymphomas (LBCLs) based upon high response rates and manageable toxicity profiles reported in pivotal trials. However, data on outcomes for pts treated with BsAbs outside of clinical trials are limited. As such, we sought to investigate the safety and efficacy of Epco and Glofit for the treatment of pts with r/r LBCLs in real-world settings. Methods: We performed a retrospective study including 19 US centers evaluating pts with r/r LBCLs receiving commercially available Epco or Glofit between 2023 and 2024. Baseline characteristics and outcomes were extracted from medical records. Efficacy outcomes 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. Key safety outcomes included cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Results: As of May 31, 2024, a total of 209 pts with r/r LBCLs were treated with Epco (n=139) or Glofit (n=70). Median age at BsAb start was 67 years (interquartile range [IQR] 58-76). Most were male (62.2%), and the most common histology was diffuse large B-cell lymphoma (n=155 [74.2%]). Of pts with molecular testing (n=168), 34 (20.2%) had double/triple hit lymphoma. Most (78.9%) had Ann Arbor stage III-IV disease and 91% had an ECOG performance status of ≤1. Median number of lines of treatment before BsAb was 3 (range 1-12). Of pts with known response assessment following front-line therapy, 54 (32.1%) had primary refractory disease, defined as failure to achieve PR or CR to front-line therapy. Most pts (n=126 [60.3%]) received prior chimeric antigen receptor (CAR) T-cell therapy and 21 (10.0%) received prior autologous hematopoietic progenitor cell transplant. CD20 expression was assessed in 106 biopsies (50.7%) prior to BsAb and was positive in 90 (84.9%). A total of 172 pts were response-evaluable. The best ORR was 50.6%, with CR in 41 (23.8%), PR in 46 (26.7%), stable disease in 10 (5.8%), and progressive disease in 75 (43.6%). The ORR and CR rates were 49% and 23% for Epco, and 53% and 25% for Glofit, respectively. With a median follow-up of 5 months, the median PFS was 2.7 months (95% CI 2.0, 3.9) and median OS was 7.2 months (95% CI 6.1, not reached [NR]). The estimated PFS and OS at six months were 35% (95% CI 29%-43%) and 59% (95% CI 52%-67%), respectively. For pts who relapsed after CAR T-cell therapy, the median PFS and OS were 2.5 (95% CI 1.8, 4.7) and 7.8 (95% CI 6.2, NR) months, respectively. Pts without detectable CD20 expression via immunohistochemistry or flow cytometry prior to BsAb therapy had significantly inferior outcomes (PFS 1.1 vs 3.4 months, P < 0.001 and OS 1.3 vs 13 months, P < 0.001) compared to pts with detectable CD20. CRS of any grade occurred in 82 pts (39.2%), corresponding to 51.1% and 28.6% of pts treated with Epco and Glofit, respectively. Grade ≥3 CRS occurred in 9 (4.3%), all of whom received Epco. CRS was treated with tocilizumab in 43 pts (53.1%). ICANS occurred in 24 (11.5%) pts; any grade ICANS occurred in 13.7% and 7.1% of pts treated with Epco and Glofit, respectively. Grade ≥3 ICANS occurred in 6 pts (2.9%), 5 of which received Epco (3.6%). Of those experiencing ICANS, 66.0% were treated with corticosteroids. Two pts had deaths attributed to ICANS and one to CRS. A total of 122 (58.4%) pts discontinued therapy after a median of 3 cycles (range 0-48), 91 (74.6%) due to disease progression and 31 (25.4%) due to adverse events (15 due to infection, 3 due to ICANS, 2 due to CRS, and 11 for other reasons). Conclusions: In this heavily pretreated group with adverse disease features and high rate of CAR T exposure, the response rates, PFS, and OS following BsAb therapy were lower compared to pivotal trials. Poor outcomes were observed for those without detectable CD20. Rates of ICANS and grade ≥3 CRS were higher than reported in pivotal trials, as was the rate of discontinuation of therapy due to adverse events. Future efforts to improve outcomes may include intensified dose escalation protocols to more rapidly achieve disease control, combination therapies, and characterization of clinicopathologic factors that predict response to BsAb to identify subgroups of pts who can derive maximal benefit from these agents.

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 (<5 involved sites) disease bridged with or without radiotherapy. A multicenter retrospective review of 150 patients with R/R NHL who received CART with <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 (<5 involved disease sites) R/R NHL improves response rate, local control, RFS, and EFS without causing significant toxicities.

7006 Background: Rituximab maintenance (RM) after first-line (1L) bendamustine and rituximab (BR) in MCL did not improve progression-free survival in the MAINTAIN trial (Rummel et al, ASCO 2016) but was associated with improved survival outcomes in a North American observational study (Martin et al, JCO 2023). We sought to examine the potential benefit of RM after BR using a large observational cohort from 26 US academic centers. Methods: Patients with MCL who received 1L BR (without stem cell transplant) outside of clinical trials were included. At the landmark of 3 months after the end of BR, patients who achieved a complete response (CR) or partial response (PR) to BR and had no evidence of progressive disease (PD) or second-line (2L) therapy were deemed eligible for RM. Event-free survival (EFS) was defined as time from landmark to progression, relapse, retreatment, or death. EFS2 was defined as time from landmark to progression, relapse, or retreatment following 2L therapy or death. RM was not considered a line of therapy for either endpoint. OS was defined as time from landmark to death. Survival analysis was done with Kaplan-Meier methods and Cox regression models adjusting for sex and simplified MIPI. Results: Among 796 patients who received 1L BR in 2007-2020, 693 achieved a CR or PR. At the 3-month post-BR landmark, 613 had no evidence of PD, among whom 318 (52%) received RM and 295 did not. The RM group was younger (median age 70 vs 72, p = 0.010) and more predominantly male (78% vs 69%, p = 0.047). There was no statistical difference in stage, simplified MIPI, histology (blastoid or pleomorphic vs classic), Ki-67, TP53 alteration, complex karyotype, year of BR start, or best response to BR between the two groups. The median follow-up after the 3-month post-BR landmark was 61.3 months (95% CI 62.6-70.4). The median number of doses of RM was 10 (IQR 5-12). RM was associated with improved EFS (median 47.1 vs 29.7 months, adjusted HR 0.59, 95% CI 0.48-0.73), EFS2 (median 89.1 vs 48.3 months, adjusted HR 0.63, 95% CI 0.50-0.81), and OS (median 136.1 vs 74.3 months, adjusted HR 0.57, 95% CI 0.44-0.75) (all p values < 0.001). In patients with CR to 1L BR (n=527), 271 (51%) received RM, for a median of 11 (IQR 6-12) doses. In this subgroup, RM was associated with improved EFS (median 60.6 vs 31.5 months, adjusted HR 0.56, 95% CI 0.44-0.71), EFS2 (median 89.1 vs 48.3 months, adjusted HR 0.62, 95% CI 0.48-0.81), and OS (median 136.1 vs 75.6 months, adjusted HR 0.59, 95% CI 0.44-0.79) (all p values < 0.001). Analysis in patients with PR to 1L BR was limited by the sample size (n=86, 47 received RM). The numeric differences in median EFS (20.8 vs 11.5, log-rank p = 0.370), EFS2 (48.9 vs 30.3, log-rank p = 0.210) and OS (87.3 vs 46.9, log-rank p = 0.067) were not statistically significant. Conclusions: In this large multicenter study, RM after 1L BR was associated with improved EFS and OS, supporting its use in routine practice for patients with newly diagnosed MCL.

e19075 Background: Orbital diffuse large B-cell lymphoma is a rare entity accounts for less than 1% of all non-Hodgkin lymphoma cases. Large-scale studies describing and evaluating the effect of different type of treatments on survival outcome are lacking. Methods: The National Cancer Database (NCDB) was queried for patients diagnosed with primary orbital DLBCL between 2004 and 2020. All patients aged ≥ 18 years diagnosed with primary orbital DLBLC were included. We excluded patients with unknown chemotherapy and radiation therapy status or lost to follow-up (unknown vital status of last contact). Kaplan-Meier and multivariate Cox regression were used in the analyses. Results: The total cohort consisted of 404 patients with primary orbital DLBCL. Out of whom 233 (58%) were females, 326 (81%) were White non-Hispanic, 29 (7%) were White Hispanic and 16 (4%) were African Americans. 113 (28%) received chemotherapy only, 76 (19%) received radiation only, 113 (28%) received chemoradiation, 79 (20%) did not receive any treatment and 23 (6%) had unknown treatment status. The median age at diagnosis was 71 years (range 28-90). The median follow-up time was 132 months (95%CI 117-147), the median overall survival (mOS) for the whole cohort was 110 months (95%CI 82-138). Among patients with known treatment status and vital status of last contact (N=381), patient who received chemoradiation had significantly better mOS compared to patients who received radiation only (169 vs 67 months, P=0.002), but there was no statistically significant difference in mOS between chemoradiation and chemotherapy only (169 vs 124 months, P=0.068) or between chemotherapy only and radiation only (124 vs 67 months, P=0.213). On multivariate analysis, older age and Charlson-Deyo score of 2 were associated with worse OS (HR 1.072 95%CI 1.055-1.089; P<0.001, HR 2.292 95%CI 1.099-4.778; P=0.027, respectively). Compared to no treatment, only chemoradiation was associated with better OS (HR 0.509 95%CI 0.332-0.778; P=0.002), whereas chemotherapy only and radiation only did not add a survival benefit (HR 0.909 95%CI 0.598-1.381; P=656 and HR 0.766 95%CI 0.496-1.185; P=0.231). Conclusions: This large real-world analysis shows a survival benefit with combined treatment of chemoradiation in primary orbital DLBCL compared to single treatment modality.

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.