Prior Autologous Stem Cell Transplant Research Articles

Reduced Intensity Conditioning Prior Autologous Stem Cell Transplantation in Elderly DLBCL Patients.

High-dose chemotherapy (HDCT) followed by autologous stem cell transplantation (ASCT) is widely used in patients with diffuse large B-cell lymphoma. HDCT/ASCT is associated with increased morbidity in elderly/unfit patients. We retrospectively evaluated the use of reduced intensity conditioning in DLBCL patients. Our study included 146 patients aged 60 years and older treated at our institution between 2005 and 2019; 86 patients received standard intensity conditioning (SI group) with BEAM or TEAM (BCNU or thiotepa, etoposide, cytarabine, melphalan). Sixty patients received reduced intensity high-dose conditioning (RI group) with BM (BCNU, melphalan, 43.3%), TM (thiotepa, melphalan, 16.7%), BCNU or busulfan thiotepa (38.4%), or bendamustine melphalan (1.7%). Median follow-up was 62.4 months. We observed comparable toxicities in the SI and RI groups. The cumulative incidence of relapse at 3 years was higher in the RI group (30.8% vs. 23.4%, p = 0.034). There was no difference in nonrelapse mortality (NRM). In univariate analyses, SI vs. RI conditioning resulted in superior progression-free survival (PFS) (HR 1.80 CI 1.11-2.92, p = 0.017) but not in superior overall survival (OS) (HR 1.48 CI 0.86-2.56, p = 0.152). On multivariate analysis, we observed no difference in PFS (HR 0.74 CI 0.40-1.38, p = 0.345) and a trend toward better OS with RI conditioning (HR 0.45 CI 0.22-0.94, p = 0.032). Age 60-69 versus ≥ 70 years and remission prior to ASCT were the only factors predicting better PFS. Factors associated with better OS were RI conditioning, age 60-69 versus ≥ 70 years, ECOG 0 versus ≥ 1 performance status, bulky disease, and prior lines 1 versus ≥ 2. In conclusion, RI conditioning prior to ASCT may be feasible in elderly patients and led to a comparable outcome when corrected for several significant confounders.

Subcutaneous epcoritamab + GemOx in patients with relapsed or refractory DLBCL: Updated results from EPCORE NHL-2.

7037 Background: Gemcitabine + oxaliplatin (GemOx) is commonly used with rituximab to treat relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL); however, outcomes are suboptimal: 33% complete response (CR) rate; 5 mo median progression-free survival (PFS); 10 mo median overall survival (OS; Cazelles et al, Leuk Lymphoma 2021). We report additional efficacy and safety results of epcoritamab + GemOx in difficult-to-treat R/R DLBCL (EPCORE™ NHL-2 phase 1/2 trial, NCT04663347). Methods: Adults with R/R CD20+ DLBCL who failed or were ineligible for autologous stem cell transplant (ASCT) enrolled to receive subcutaneous (SC) epcoritamab (2 step-up doses followed by 48-mg full doses) in 28-d cycles (C): QW, C1–3; Q2W, C4–9; Q4W, C≥10 until unacceptable toxicity or disease progression. GemOx was given Q2W in C1–4. The primary endpoint was overall response rate (ORR) per Lugano criteria. Subgroup analyses by prior treatment (tx) and response were performed. Results: As of Sept 1, 2023, 97 pts with ≥6 mo of follow-up had received epcoritamab 48 mg + GemOx (median follow-up, 9.7 mo). Pts had a median of 2 prior lines of tx (pLOT; range, 1–6); 55% had primary refractory disease, 38% had bulky disease (>6 cm), 30% had prior CAR T, and 9% had prior ASCT. Median age was 72 y, with 34% of pts ≥75 y. A median of 7 cycles of epcoritamab and 4 cycles of GemOx were initiated. At data cutoff, tx was ongoing in 46% of pts. ORR was 78% and CR rate was 55%. Median time to CR was 1.7 mo; median duration of CR was 13.3 mo. Additional efficacy outcomes are shown in the Table. Safety was consistent with previous reports. The most common tx-emergent AEs (TEAEs) of any grade (G) were hematologic AEs (68% thrombocytopenia; 59% neutropenia [6% febrile neutropenia]; 51% anemia) and CRS (51%). CRS was primarily low grade (27% G1, 23% G2), with only 1 pt experiencing G3 CRS; all events resolved and none led to tx discontinuation. ICANS was reported in 3 pts (G1, n=2; G3, n=1); all events resolved, but 1 pt discontinued tx. There were 13 fatal TEAEs; in 3 cases, the contribution of epcoritamab + GemOx could not be ruled out: COVID-19, multiple organ dysfunction syndrome, and small intestinal perforation. Conclusions: These long-term results continue to demonstrate that SC epcoritamab in combination with GemOx leads to deep, durable responses, which translate to high rates of PFS and OS in challenging-to-treat, high-risk pts with R/R DLBCL. CR rates were consistently high across prespecified subgroups. Higher CR rates in pts with 1 vs ≥2 pLOT indicate that earlier use may further improve outcomes. No new safety signals were identified. The benefit-risk profile of this combination supports the combinability of epcoritamab in R/R DLBCL. Clinical trial information: NCT04663347 . [Table: see text]

Talquetamab (Tal) therapy in relapsed/refractory (R/R) multiple myeloma (MM): Assessing weight loss and dysgeusia.

e19514 Background: Tal, a bispecific antibody targeting CD3 and GPRC5D receptors, has shown high response rates in heavily pretreated R/R MM patients. This study aimed to evaluate adverse events (AEs), specifically dysgeusia and weight loss in MM patients treated with tal. Methods: Patients treated at the University of Arkansas for Medical Sciences who received at least one dose of tal were included. Common Terminology Criteria for Adverse Events (CTCAE) was used to grade AEs. The body mass index (BMI)-adjusted weight loss grading system (WLGS) was used to capture weight loss trends over duration of treatment. Weight loss based on BMI was graded based on the BMI-WLGS. Results: 17 patients were included in our analysis. Nine patients (53%) were male. Ten patients (59%) were African American. Median age at diagnosis was 62 (range: 51-75years). Six patients (35%) had Eastern Cooperative Oncology Group (ECOG) performance status ≥2. The median number of prior lines of therapy was seven (range: 3-12). Fourteen patients (82%) received at least one prior autologous hematopoietic stem cell transplant. The median number of tal doses received was 14.8 (range: 2-29). Median time on treatment (ranging from 1.15 to 15.84) was 4.36 months (range: 1.2-15.8 months). Overall response rate (ORR) for was 76%. Cytokine release syndrome occurred in 12 patients (70.6%), with 5 patients (29.4%) in grade 2 or higher CRS. Immune effector cell-associated neurotoxicity syndrome (ICANS) in four patients (23.6%), and 2 patients (11.8%) had grade 2 ICANS. Fourteen patients (82%) developed significant weight loss during treatment with tal. The median weight loss was 11.6 lbs., and median decrease in BMI was 1.85. Median percentage of weight loss was 6.1% from weight prior to tal ranging from 0% to 14.3%. Two patients had grade I, five patients had grade II, six patients had grade III, and one patient had grade IV weight loss per the BMI-WLGS grading system. Fourteen patients (82%) reported dysgeusia during tal treatment. Eight of these patients had grade I dysgeusia, and six patients had grade II dysgeusia. Two patients had persistent dysgeusia even after discontinuation of tal treatment at time of last follow up. Eight patients had weight gain after tal discontinuation (n = 8/14, 57%), with 5 returning to their baseline weight or higher. Six of these patients had dysgeusia during tal, and all six had resolution of dysgeusia after tal discontinuation. Conclusions: In this study, tal resulted in weight loss and dysgeusia in the majority of patients with most cases of dysgeusia resolving after tal discontinuation. Patients, on average, lost 6% of their initial weight during tal treatment. More than two-thirds of patients treated with tal developed BMI-adjusted WLGS grade ≥II. Weight loss persisted in approximately half of the patients after discontinuation of tal. Such AEs need to be discussed with patients and monitored during treatment.

Abstract 6327: Impact of G-CSF on safety and efficacy of CAR T-cell therapy in non-Hodgkin lymphoma

Abstract Introduction: Chimeric antigen receptor T-cell (CAR-T) therapy is an established treatment modality for the management of refractory and/or relapsed non-Hodgkin lymphoma (NHL). Despite restrictions on granulocyte colony-stimulating factor (G-CSF) use in registration clinical trials due to potential worsening of cytokine release syndrome (CRS), G-CSF is often prescribed for neutrophil recovery post-CAR-T in clinical practice. We conducted a retrospective study to assess the association between G-CSF use and the safety and efficacy of CAR-T. Methods: Following Institutional Review Board approval, we retrospectively analyzed NHL patients receiving commercial CD19-targeted CAR-T across Mayo Clinic sites (Arizona, Florida, and Minnesota) between October 2017 and May 2023. Demographics, labs, and post CAR-T events were collected. Electronic medical records were reviewed for G-CSF exposure within Day 1 - 100 post-CAR T. Differences by G-CSF status were examined using a Chi-square test and Kruskal Wallis tests. Hazard ratios (HR) and 95% confidence intervals (CI) for overall survival (OS) were calculated using Cox model. Results: Among 270 CAR-T patients; 106 received G-CSF within 30 days and 164 did not. Median age was 56.9 with G-CSF and 58.3 without G-CSF. Most were male (75.2% G-CSF, 62.6% no G-CSF). Diffuse large B cell lymphoma was the predominant NHL subtype (67.0% G-CSF, 65.2% no G-CSF). G-CSF within 30 days was not associated with reduced incidence of neutropenic fever (11.7% G-CSF vs 9.9% no G-CSF, p = 0.6593) or documented infection (22.1% vs 18.3%, p = 0.4439). G-CSF correlated with decreased profound neutropenia duration (ANC < 100 μL, 0 vs 2 days, p < 0.0001) and incidence within 30 days ( 31.7% vs 60.4%, p < 0.0001) as well as incidence of protracted profound neutropenia (> 7 days, 3.8% vs 22.8%, p < 0.0001). G-CSF was associated with a higher incidence of cytopenias between days 30 -100: severe neutropenia (ANC < 500/uL, 28.8% vs 15.2%, p = 0.0075), severe anemia (Hb < 8 g/dL, 21% vs 9.7%, p = 0.0114), and severe thrombocytopenia (Plt < 50 g/L, 35.2% vs 20.9%, p = 0.0099). Logistic regression analysis showed that none of the examined covariates, including prior autologous stem cell transplant, ECOG PS score, and receipt of bridging therapy, were associated with severe neutropenia likelihood. G-CSF was associated with a higher CRS incidence (89.6% vs 79.9%, p = 0.0343), but grade 3 CRS or higher (4.7% vs 3.7%, p = 0.6675) was no different. No difference in complete response rates (66% vs 61.1%, p = 0.4707) or 2-year OS (p = 0.523) was observed between the 2 groups. Conclusion: G-CSF within 30 days was associated with reduced duration and incidence of profound neutropenia without a significant impact on incidence of neutropenic fever or documented infections. There was a signal of association between G-CSF and increased incidence of low-grade CRS and delayed cytopenias (day 30-100) that warrants confirmation in larger studies. Citation Format: Lay She Ng, Claire I. Yee, Radhika Bansal, Mohamed A. Kharfan-Dabaja, Grzegorz S. Nowakowski, Allison C. Rosenthal, Javier Munoz, Januario Castro, Wern Lynn Ng, Hemant S. Murthy, Yi Lin, Matthew R. Buras, Madiha Iqbal, Yucai Wang, Talal Hilal. Impact of G-CSF on safety and efficacy of CAR T-cell therapy in non-Hodgkin lymphoma [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 6327.

Matching-Adjusted Indirect Comparison of Brexucabtagene Autoleucel (ZUMA-2) and Pirtobrutinib (BRUIN) in Patients with Relapsed/Refractory Mantle Cell Lymphoma Previously Treated with a Covalent Bruton Tyrosine KinaseInhibitor.

Patients with relapsed/refractory (R/R) mantle cell lymphoma (MCL) often require multiple lines of treatment and have a poor prognosis, particularly after failing covalent Bruton tyrosine kinase inhibitor (cBTKi) therapy. Newer treatments such as brexucabtagene autoleucel (brexu-cel, chimeric antigen receptor Tcell therapy) and pirtobrutinib (non-covalent BTKi) show promise in improving outcomes. Without direct comparative evidence, an unanchored matching-adjusted indirect comparison was conducted to estimate the relative treatment effects of brexu-cel and pirtobrutinib for post-cBTKi R/R MCL. Using logistic propensity score models, individual patient-level data from ZUMA-2 brexu-cel-infused population (N = 68) were weighted to match pre-specified clinically relevant prognostic factors based on study-level data from the BRUIN cBTKi pre-treated cohort (N = 90). The base-case model incorporated the five most pertinent factors reported in ≥ 50% of both trial populations: morphology, MCL International Prognostic Index, number of prior lines of therapy, disease stage, and prior autologous stem cell transplant. A sensitivity analysis additionally incorporated TP53 mutation and Ki-67 proliferation. Relative treatment effects were expressed as odds ratios (ORs) or hazard ratios (HRs) with 95% confidence intervals (CIs). In the base-case model, brexu-cel was associated with higher rates of objective response (OR 10.39 [95%CI 2.81-38.46]) and complete response (OR 10.11 [95%CI 4.26-24.00]), and improved progression-free survival (HR0.44 [95%CI 0.25-0.75]), compared to pirtobrutinib. Overall survival and duration of response favored brexu-cel over pirtobrutinib but the differences crossed the bounds for statistical significance. Findings were consistent across the adjusted and unadjusted analyses. Findings suggest that brexu-cel may offer clinically and statistically significant benefits regarding objective response, complete response, and progression-free survival compared to pirtobrutinib among patients with R/R MCL after prior cBTKi therapy. Given the short follow-up and high degree of censoring in BRUIN, an analysis incorporating updated BRUIN data may provide more definitive overall survival results.

Efficacy of Selinexor in Relapsed/Refractory Multiple Myeloma (RRMM) Patients with del17p and Other High-Risk Abnormalities (A Retrospective Single-Center Study).

Selinexor (Seli) is a first-in-class, oral selective inhibitor of the nuclear export protein, exportin-1 (XPO1). Seli exhibits its antitumor effect through the blockage of XPO1, which increases nuclear retention of tumor suppressor proteins (TSPs), including p53, thereby limiting the translation of oncogenes, triggering cell cycle arrest and the death of malignant cells. Multiple Myeloma (MM) patients with del17p are deficient in TP53 and have a particularly poor prognosis. Given its unique mechanism of action, we investigated whether Seli has increased efficacy in RRMM patients with del17p compared to other high-risk cytogenetics (OHRC). This is an IRB-approved observational study of RRMM patients with high-risk cytogenetics (del17p, t (4;14), t (14;16) or gain 1q) or standard-risk cytogenetics treated at the Levine Cancer Institute (LCI) with a Seli-based regimen between January 2019 and December 2022. Time-to-event endpoints (PFS, OS) were evaluated using Kaplan-Meier (KM) methods. Log-rank tests compared time-to-event endpoints between cohorts [del17p vs. OHRC vs. standard risk]. We identified 40 RRMM patients with high-risk cytogenetics, including 16 patients with del17p and 24 patients with OHRC, as well as 20 with standard-risk cytogenetics. The median age was 62.5 vs. 69 vs. 65.5 years (del17p group vs. OHRC vs. standard risk). The median prior line of therapies was five (range: 3-16) with similar rates of prior autologous stem cell transplant in all arms (68.8% vs. 62.5% vs. 70.0%). The most frequently used regimens were Seli-Pomalidomide-dexamethasone(dex) or Seli-Carfilzomib-dex (Seli-Kd) in the del17p group and Seli-Kd in the OHRC and standard-risk groups. The median time to start the Seli-based regimen after initial MM diagnosis was 5.6 years for the del17p group, 4.1 years in OHRC, and 4.8 years in the standard-risk group. The median follow-up time after the start of the Seli-based regimen was 10.5 months (mos) in the del17p group, 8.4 mos in OHRC, and 10.3 mos in the standard-risk group. In the del17p group, 50% had an objective response, 41.7% in the OHRC, and 35% in the standard-risk group (p = 0.71). Depth of response was also similar across the arms (12.5% vs. 12.5% vs. 10.0% VGPR p = 0.99). The median OS was 10.9 mos in the del17p group, 10.3 mos in the OHRC, and 10.3 mos in the standard-risk group (p = 0.92). The median OS was 15.5 mos for patients who received Seli as a bridging therapy versus 9 mos for Seli use for other reasons rather than as a bridge. Overall, Seli-based regimens showed promising responses even in this heavily pretreated population. Our analysis suggests that Seli-based regimens lead to similar outcomes among RRMM patients with del17p, OHRC, and standard-risk cytogenetics. This contrasts with previously reported outcomes using combinations of novel therapies in this population, where the del17p patients often have a poorer prognosis. Interestingly, our data suggest that Seli is a particularly effective bridging modality for patients preparing for CAR-T cell therapies in our population. Further investigation into this population is warranted, including in earlier lines of therapy, in hopes of seeing a more durable response.

Treatment-Related Risk Factors for Adverse Outcomes of COVID-19 in Patients Treated for Lymphoid Malignancies in the Pre-Omicron Era-A Study of KroHem, the Croatian Group for Hematologic Diseases.

Patients with lymphoid malignancies are at increased risk of death or prolonged infection due to COVID-19. Data on the influence of different antineoplastic treatment modalities on outcomes are conflicting. Anti-CD20 monoclonal antibodies increase the risk of prolonged infection. It is unclear whether this risk is affected by the choice of the antibody (rituximab vs. obinutuzumab). To elucidate the role of antineoplastic therapy on COVID-19 outcomes, KroHem collected data on patients with lymphoid malignancies diagnosed with COVID-19 between October 2020 and April 2021. A total of 314 patients were identified, 75 untreated, 61 off treatment and 178 on treatment. The mortality rate in untreated and off-treatment patients was 15% and 16%; 9% and 10% had prolonged infection. In the on-treatment group, 3% were still prolonged positive at time of data collection, 62% recovered and 35% died; 42% had prolonged infection. Disease type, use of anti-CD20 monoclonal antibodies, prior autologous stem-cell transplantation (ASCT) and line of treatment did not significantly affect mortality. Mortality was higher in older patients (p = 0.0078) and those treated with purine analogues (p = 0.012). Prolonged COVID-19 was significantly more frequent in patients treated with anti-CD20 monoclonal antibodies (p = 0.012), especially obinutuzumab, and purine analogues (p = 0.012). Age, prior ASCT and treatment line did not significantly affect risk of prolonged infection. These data suggest that increased age and use of purine analogues are main risk factors for increased mortality of COVID-19 in patients with lymphoid malignancies. Obinutuzumab further increases the risk of prolonged disease, but not of death, in comparison to rituximab. Epidemiological considerations should be taken into account when choosing the appropriate antineoplastic therapy for patients with lymphoid malignancies.

Bendamustine, Prednisone and Bortezomib (BPV) Induction Therapy Prior Autologous Stem Cell Transplantation (ASCT) in 135 Newly Diagnosed Multiple Myeloma Patients: Comparison Between Patients with Normal and Impaired Renal Function

Bendamustine, Prednisone and Bortezomib (BPV) Induction Therapy Prior Autologous Stem Cell Transplantation (ASCT) in 135 Newly Diagnosed Multiple Myeloma Patients: Comparison Between Patients with Normal and Impaired Renal Function

Long-Term Outcomes from the Phase 3 OCEAN (OP-103) Study: Melflufen and Dexamethasone (Dex) Versus Pomalidomide (Pom) and Dex in Relapsed Refractory Multiple Myeloma (RRMM)

Background/Introduction: Melphalan flufenamide (melflufen) is a first-in-class peptide-drug conjugate that targets aminopeptidases resulting in rapid release of alkylating agents inside tumor cells. Based on the phase 2 HORIZON study and supported by the phase 3, randomized, controlled OCEAN study, melflufen was approved in Europe for use in patients (pts) with triple-class refractory RRMM with ≥3 prior lines of therapy (LoTs) and without prior autologous stem cell transplantation (ASCT) or with a time to progression (TTP) >36 mo after prior ASCT. In the OCEAN study (NCT03151811), melflufen + dex showed superior progression-free survival (PFS) compared with pom + dex (6.8 vs 4.9 mo; hazard ratio [HR]: 0.79; P=0.032); PFS benefit in the melflufen + dex group was mainly driven by pts who had not received prior ASCT. Overall survival (OS) trended in favor of melflufen + dex in pts without prior ASCT and favored pom + dex in pts with prior ASCT (Schjesvold et al. Lancet Haematol. 2022;9:e98). Post-hoc analyses of OCEAN and HORIZON demonstrated that a TTP <36 mo after prior ASCT was a negative prognostic factor for OS with melflufen + dex (Sonneveld et al. Clin Lymphoma Myeloma Leuk. 2023;S2152). Here, we present long-term OS and safety data from the final analysis of the OCEAN study. Methods: Pts with RRMM (2-4 prior LoTs including lenalidomide [len] and a proteasome inhibitor) refractory to len and last LoT were randomized 1:1 (stratified by age, no. of prior LoTs, and International Staging System score) to receive 28-day (d) cycles of melflufen 40 mg intravenously on d1 or pom 4 mg orally (PO) daily on d1 to 21. All pts received dex 40 mg (20 mg for pts ≥75 y) PO on d1, 8, 15, and 22. Pts received therapy until disease progression or unacceptable toxicity. The primary endpoint was PFS, as assessed by independent review committee per IMWG Uniform Response Criteria, and key secondary endpoints were overall response rate, OS, and safety. Results: As of 3 Feb 2023, 495 pts were randomized (246 to melflufen; 249 to pom); median age was 68 y (range, 39-91) and median prior LoTs was 3. In the intent-to-treat (ITT) melflufen and pom populations, median OS was 20.2 mo vs 24.0 mo (HR, 1.09 [95% CI, 0.88-1.35]), at a median follow-up of 40.3 mo and 38.1 mo, respectively. In the target subgroup of the melflufen and pom groups (pts without a prior ASCT or TTP >36 mo after an ASCT), median OS was 23.6 mo vs 19.1 mo (HR, 0.88 [95% CI, 0.67-1.16]); in the non-target population (pts with TTP <36 mo after ASCT), median OS was 15.7 mo vs 27.5 mo (HR, 1.60 [95% CI, 1.15-2.21]), respectively. While any grade hematologic toxicities were more common with melflufen, the occurrence of non-hematologic toxicities was similar in the 2 groups. Grade 3/4 (G3/4) treatment-emergent adverse events (TEAEs) in the safety population (melflufen [n=228] and pom [n=246]) occurred in 90% vs 76% of pts, respectively; most commonly thrombocytopenia (78% vs 13%; occurring with G3/4 hemorrhage in 1% vs 0%), neutropenia (64% vs 50%; occurring with G3/4 infections in 4% vs 7%), anemia (43% vs 19%), and infection and infestations (14% vs 24%). Serious AEs occurred in 43% vs 50% of pts (including pneumonia [6% vs 9%], COVID-19 pneumonia [5% vs 6%], and anemia [4% vs 2%]), and fatal AEs in 14% vs 15% (including COVID-19 pneumonia [4% vs 2%] and pneumonia [2% vs 2%]) in the melflufen and pom groups, respectively. With melflufen and pom, TEAEs led to dose reductions in 52% vs 28% of pts (most frequently thrombocytopenia [32% vs 2%] and neutropenia [12% vs 8%]), and discontinuations in 30% vs 24% of pts, respectively. Deaths occurred in 74% vs 68% of pts in the melflufen and pom groups, with AEs being the primary cause of death ≤30 d after last dose in 8% and 11%, respectively. Conclusion: Long-term results were consistent with those of previous analyses (Schjesvold, et al. Lancet Haematol. 2022;9:e98-e110). While OS trended in favor of pom in the ITT population, OS outcomes continued to be more favorable with melflufen in pts with no prior ASCT or with TTP >36 mo after ASCT. No new safety signals were reported, and AEs were manageable with dose modifications, consistent with previous reports. This long-term follow-up of OCEAN confirms the favorable safety and OS outcomes of melflufen + dex in the target population and supports its continued use as an alternative treatment choice for pts with RRMM who have received ≥2 prior LoT and who have not received ASCT.

Outcomes in Patients with Classical Hodgkin Lymphoma Refractory or Intolerant to Brentuximab Vedotin and Anti-PD-1 Therapy: Real World Analysis from 14 U.S. Academic Centers

Background: Brentuximab vedotin (BV) and anti-PD-1 therapies (nivolumab and pembrolizumab) have changed the therapeutic landscape for patients (pts) with classical Hodgkin lymphoma (cHL) over the past decade. Although first proven to be beneficial in relapsed and refractory cHL, these therapies have moved earlier in the treatment algorithm given superior response rates and survival compared to cytotoxic chemotherapy alone. However, there is limited data regarding outcomes in pts who progress after both BV and anti-PD-1 therapies (double refractory, DR) or become intolerant (INT) of these therapies. Knowledge of outcomes in this subset of pts is important as BV and anti-PD-1 therapies are increasingly used in front-line treatment and early relapsed cHL. Methods: We conducted a retrospective study of adult pts from 14 U.S. academic medical centers who developed DR cHL or became INT of BV and/or anti-PD-1 therapy between January 2011 and December 2021. DR was defined as treatment failure (evidence of progression by imaging or biopsy) during therapy or within 3 months of the last dose of both BV and anti-PD-1 therapy. INT was defined as any toxicity limiting further cycles of BV or anti-PD-1 therapy. Pts with INT were either intolerant to both BV and anti-PD-1 or intolerant and refractory to BV or anti-PD-1. The primary endpoint was assessment of overall survival from time of cHL diagnosis (OS-1) and from DR or INT (OS-2). Secondary endpoints included description of pt characteristics developing DR or INT cHL, estimate of OS comparing DR versus INT, and estimate of OS stratified by prior autologous stem cell transplant (ASCT) at the time of DR/INT. Time-to-event analyses were evaluated by Kaplan-Meier methodology. INT pts were not included in time to progression (TTP) analysis for initial BV or anti-PD-1 therapy. Results: 158 pts were eligible. Clinical characteristics at diagnosis included median age 33 years (range 16-89), 61% male, 77% white race, 66% nodular sclerosing subtype, 47% stage IV, and 56% with B symptoms. Front-line treatment was ABVD/AVD in 122 pts (77%) and BV or anti-PD-1 therapy in 28 pts (18%). 60% had primary refractory cHL (n=94). Table 1 describes pt characteristics in detail. Initial BV treatment was after a median of 2 lines of therapy (LOT) (range 0-7). The majority (60%, n=94) were treated with BV monotherapy and 15% (n=24) were treated with BV combined with anti-PD-1 therapy. Median TTP of BV refractory pts was 168 days (95%CI 138-190). Initial anti-PD-1 therapy was after a median of 3 LOT (range 0-12). Nivolumab was the most commonly used (72%) anti-PD-1 therapy. Median TTP of anti-PD-1 refractory pts was 223 days (95%CI 166-271). DR cHL was observed in 119 pts (75%), while 39 pts (25%) were INT. The median time from cHL diagnosis to DR/INT was 3.3 years (95%CI 0.5-23.1). At the time of DR/INT, 47% (n=75) had prior ASCT. The majority (87%, n=137) received subsequent LOTs after DR/INT (median 2, range 0-14). Table 1 describes DR/INT in detail. The median OS from the time of cHL diagnosis (OS-1) in all pts was 15.0 years (95%CI 9.4-20.9). There was no difference in OS-1 between DR and INT pts (log-rank p=0.83) or primary refractory and front-line relapsed pts (log-rank p=0.94). Pts who developed DR/INT at any time after ASCT had a significantly longer OS-1 compared to DR/INT without prior ASCT with a median OS of 19.1 years (95%CI 19.1-NR) versus 8.6 years (95%CI 5.3-15.0), respectively (log-rank p<0.001, Figure 1). Comparing pts with prior ASCT and no prior ASCT, the median age at DR/INT was 35 (range 20-75) versus 49 (range 18-90) years, Fisher's exact p=0.01. Adjusting for age at DR/INT did not impact the association between prior ASCT and improved OS, Cox proportional hazard ratio 0.48 (95%CI 0.25-0.90, p=0.02). Median OS from time of DR/INT (OS-2) was 7.4 years (95%CI 4.1-NR). OS-2 was not different between DR and INT pts (log-rank p=0.33). Conclusion: To our knowledge, this is the largest cohort of pts refractory to, or intolerant of BV and anti-PD-1 therapy. OS was longer than anticipated both from diagnosis and from time of DR/INT. Pts who were DR/INT after ASCT had a significantly longer OS. Further investigation is needed to determine if OS differences by ASCT may be due to disease biology or sequencing of therapies. Importantly, OS-2 serves as a benchmark for future clinical trials evaluating DR/INT cHL pts.

Real-World Multicenter Study of PD-1 Blockade in HIV-Associated Hodgkin Lymphoma across the United States

Background: Despite a 5 to 20-fold higher risk of Hodgkin lymphoma (HL) in people with HIV (PWH) than the general population, PWH were excluded from clinical trials that led to the approval of anti-PD-1 agents (PD-1) in HL. PD-1 have overall response rates (ORR) of 65-70% in the general population and are used in all lines of HL therapy. Several prospective and retrospective studies have shown PD-1 are safe in PWH, but they remain underutilized in HIV-associated HL (HIV-HL) where data are limited. Methods: Patients (pts) with HIV-HL were identified from the retrospective, international database, “Cancer Therapy using Checkpoint inhibitors in PWH-International (CATCH-IT)” consortium, that is maintained at the Dana-Farber Cancer Institute (DFCI) and approved by DFCI and local institutional review boards. Pts who received either nivolumab or pembrolizumab, alone or in combination with other agents were included. Records were reviewed for demographics, HL and HIV characteristics, and treatment data. Safety was evaluated by the occurrence of immune-related adverse events (irAEs) per Common Terminology Criteria for Adverse Events (CTCAE) v5.0. Response to treatment was evaluated using descriptive statistics, and immune reconstitution was measured by changes in CD4 + T cell counts (CD4) from prior to end of PD-1 therapy via paired t-tests. ORR was defined as the proportion of pts with partial or complete response (PR/CR) per the 2014 Lugano classification for HL. Duration of response (DOR) was defined as the time from the date of the first CR or PR to the date of progressive disease (PD) or death. Progression-free survival (PFS) was defined as the time from PD-1 initiation to disease progression, death, or censored on the date of the last follow-up. Overall survival (OS) was defined as the time from PD-1 initiation to death or censored at the last follow-up. DOR, PFS, and OS were evaluated by Kaplan-Meier methodology. Results: We identified 23 pts with HIV-HL from 12 institutions in the United States: 20 cisgender men, 3 cisgender women; 10 Black,10 White, and 10 Hispanic; median age 48 years [interquartile range (IQR): 36-58]. At HL diagnosis, 19 (83%) pts had advanced stage disease, and in 20 pts where EBV status of the tumor was known, all were positive. Nine (39%) pts had primary refractory disease. The median number of prior systemic therapies was 2 (IQR: 1-3). One pt had PD-1 as 1 st-line therapy, 6 had PD-1 as 2 nd-line therapy, and 16 had PD-1 as ≥3 rd-line therapy. Fourteen (61%) pts received doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) as 1 st-line therapy. Two pts had prior autologous stem cell transplant (ASCT). At the time of PD-1 initiation, 22 pts (96%) had advanced stage disease, 17 (46%) had extranodal disease, and the median ECOG performance status was 1 (IQR: 0-2). Seventeen (74%) pts received PD-1 monotherapy, 5 (22%) received nivolumab + brentuximab vedotin, and 1 received nivolumab + ifosfamide, carboplatin, and etoposide. Four pts had uncontrolled HIV at the time of PD-1 initiation (HIV viral load range=10,000-2,000,000 copies/mL). All pts received antiretroviral therapy during treatment. Median baseline CD4 was 155 cells/µL (IQR: 66-297) and CD8 was 429 cells/µL (IQR: 158-716). Median CD4 and CD8 increased to 310 and 653 cells/µL at the end of PD-1 treatment (P=0.0084, P=0.32). The median number of PD-1 cycles was 6 (IQR: 4-21). Three (13%) pts had irAEs (all grade 3): hypothyroidism, autoimmune pancreatitis, and pneumonitis. None required PD-1 discontinuation. The ORR was 83% in the overall cohort. Sixteen pts (70%) had CR, 3 (13%) PR, and 4 (17%) PD as best response. Among the 19 pts with CR or PR, the median DOR was 19.7 months; 8 had PD after initial response and 11 had ongoing CR at data cut-off. Ten pts received consolidation with ASCT after PD-1, 6 of whom had received PD-1 at ≥3 rd line treatment. All pts who received ASCT had ongoing CR at data cut-off. Median PFS was 21.2 months in the overall cohort. Among pts with CD4 <200 and >200 cells/µL, PFS was not statistically different (17.3 vs 29 months; P=0.95). At data cut-off, 17 pts (74%) were alive and 6 (26%) had died due to HIV-HL. Median OS was 23.6 months in the overall cohort. Conclusion: In HIV-HL, PD-1 blockade was safe, had a high ORR and CR rate, and allowed for immune reconstitution in pts across a wide range of CD4 counts and HIV viral loads. These data add to the evidence that anti-PD-1 agents are effective in PWH and should be used in HIV-HL.

French Early Nationwide Idecabtagene Vicleucel (Ide-Cel) Chimeric Antigen Receptor (CAR) T-Cell Therapy Experience in Patients with Relapsed/Refractory Multiple Myeloma (FENIX): Update of the IFM Study from the Descar-T Registry

Introduction Prognosis of patients with relapsed/refractory multiple myeloma (RRMM) is poor, particularly in triple-class refractory patients (refractory to a proteasome inhibitor, an immunomodulatory drug and an anti-CD38 monoclonal antibody). Idecabtagene vicleucel (Ide-Cel) is the first chimeric antigen receptor (CAR) T-cell therapy targeting the B-cell maturation antigen (BCMA) approved by both the European Medicines Agency and the US FDA and the only one available in France through the Early Access Program for treatment (≥ 3 lines) of RRMM. Here we present an update of characteristics and outcome of patients enrolled in this program. Methods We conducted a multicenter, retrospective, observational study that included all consecutive patients with RRMM registered in the DESCAR-T database of patients treated with CAR T therapy, who underwent apheresis up to November 2022 to be treated by commercial Ide-Cel in France. The main objective was to analyze efficacy in terms of response rates, progression free survival (PFS) and overall survival (OS). Secondary objectives included evaluation of safety in terms of cytokine release syndrome (CRS), neurotoxicity, cytopenia, infections and management of relapse including subsequent anti myeloma therapies (sAMT). Results From June 2021 to November 2022, 207 patients were registered in DESCAR-T and underwent leukapheresis to be treated with Ide-cel, 164 (79%) were infused; 43 were not infused: 13 due to rapidly progressive disease or death and 5 due to manufacturing failure. Fifty seven (28%) patients did not meet KarMMa inclusion criteria: cytopenia (n=23), kidney failure (n=13), performance score (PS) >1 (n=15), prior anti BCMA drug conjugate antibody (n=8), prior allograft (n=5). Median age of the 164 patients was 60.5 years (range 34-82), 59% were male, median number of prior treatment lines was 4 (range 2-12) including prior autologous stem cell transplantation in 147 (90%); 130 (80%) were triple-refractory, 47 (29%) were penta-refractory. At diagnosis, 12 (16%) patients had R-ISS stage III disease (89 missing). High tumor burden (> 30% BMPCs) was present in 71 patients (54%) (33 missing). High risk cytogenetic abnormalities defined by del(17p) or t(4;14) were present in 63 patients (58%) (56 missing) and 15 (23%) had extramedullary disease (EMD) (98 missing). One hundred and forty-two (87%) received bridging therapy of which 39 (27%) responded: 25 had partial response (PR); 8 very good partial response (VGPR); 6 complete response (CR). Median time from apheresis to infusion was 62 days. Median follow-up after infusion was 6.2 months. In the first 3 months, overall response rate was 82% (n=134), best achieved response was CR, VGPR and PR in 60 (38%), 36 (23%) and 38 (24%) respectively. Median PFS was 11.6 months (95% CI (7.1; NA)). The 12-month OS was 73% (95% CI (64; 84)). In the first 6 months post-infusion, MRD was analyzed for 45 patients and reached negativity rate in 77%. In univariate analysis, only EMD had a significant impact on PFS: median PFS was 6.3 months (95% CI (3; NA)) for patients with EMD (p = 0.003; HR 3.5, 95% CI (1.55; 7.9)). CRS occurred in 146 (89%) patients, with only 3 cases (2%) of grade ≥ 3. Neurotoxicity occurred in 19 (12%) patients (5 with grade ≥ 3). Ninety-eight (60%) patients received tocilizumab, and 37 (23%) received steroids. Persistent grade ≥ 3 thrombocytopenia, anemia and neutropenia at M1 were observed in 55 (34%), 20 (12%) and 90 (55%) patients, respectively. Forty (24%) patients presented infections grade ≥ 3 in the first six months after infusion. Fifty-two patients progressed during follow-up. 34/52 patients (65%) received a sAMT. Median time from relapse to first administration of sAMT was 0.6 months. Eighteen received bispecific antibodies including 12 anti-BCMA and 6 anti-GPRC5D. Among these 34 patients, a total of 13 (38%) died. Overall, at data cut-off, 26 patients had died, including 9 after disease progression, 4 of acute toxicity and 2 of sepsis. Conclusion This updated study confirms safety and efficacy of Ide-cel in patients with RRMM in real world settings. Response rates and safety were comparable to those reported in the registration trial (Munshi et al., 2021) and American real world study (Hansen et al., 2023). Importantly, patients with EMD had a significant lower PFS. Prognosis data at relapse following ide-cel require a longer follow up and will be presented at ASH.

A Propensity Score-Matched Analysis on the Outcomes of Brexucabtagene Autoleucel from Zuma-2 Study and Allogeneic Stem Cell Transplantation from the EBMT Database in Relapsed and Refractory Post-Btki Mantle Cell Lymphoma

Introduction Brexucabtagene autoleucel (brexu-cel), an autologous anti-CD19 CAR T-cell therapy, is approved in the US for the treatment of relapsed/refractory (r/r) mantle cell lymphoma (MCL) and in Europe for r/r MCL after ≥2 prior lines of therapies, including Bruton's tyrosine kinase inhibitor (BTKi). The pivotal ZUMA-2 trial demonstrated very good efficacy of brexu-cel in r/r MCL and tolerable safety including cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome (Wang et al. J Clin Oncol. 2022). Allogeneic stem cell transplantation (alloSCT) is potentially curative but is associated with high treatment related mortality (TRM) and clinically significant graft-versus-host disease (GvHD). The optimal choice of treatment between brexu-cel and alloHCTs is unclear. We conducted a propensity score matched (PSM) analysis of brexu-cel and alloSCT in patients (pts) with r/r MCL. Methods Pts from ZUMA-2 were matched with alloSCT pts from the EBMT database. Selection criteria to identify pts in the EBMT registry were: r/r MCL diagnosis and receipt of alloSCT from 2010 to 2020, age ≥18 years, prior treatment with anti-CD20, prior anthracycline- or bendamustine containing regimens, and prior BTKi. We performed a 1:1 nearest neighbor matching without replacement, balanced for 5 baseline parameters: age, sex, number of prior treatment lines, time from diagnosis to cellular immunotherapy, and prior autologous stem cell transplantation (autoSCT). The primary endpoint was overall survival (OS) from cellular immunotherapy. The following secondary endpoints were analyzed: progression-free survival (PFS), TRM, defined as incidence of deaths which are related to the treatment and occurred in absence of disease progression, and rate of GvHD. Competing risks were defined as relapse, progression or treatment-unrelated death for TRM, and death for GvHD. The EBMT registry includes pts who actually underwent alloSCT. To characterize the dropout rate prior to cellular therapy, we conducted a multicenter intent-to-treat (ITT) analysis and identified 77 pts with r/r MCL for whom an unrelated donor search was initiated and an alloSCT was intended. Results Sixty-four of 68 pts from the ZUMA-2 cohort were included in the study; 4 pts were excluded because of inability to anonymize. A total of 270 pts who had undergone alloSCT and met eligibility criteria were identified in the EBMT registry. Patient characteristics between the brexu-cel and the alloSCT cohorts were imbalanced. Brexu-cel pts were older (p<0.001), had more prior lines of treatment (median 3 vs 2, p<0.001), had less prior autoSCT (41% vs 71%, p<0.001), and had longer time between diagnosis and treatment (53 vs 40 months, p=0.01). After 1:1 PSM matching, criteria were well balanced between cohorts. Median follow-up time was 36.5 and 46.4 months for the brexu-cel and the matched alloSCT cohort, respectively. PFS and long-term OS were similar between both cohorts (Fig. 1A). However, the risk of death within the first 12 months was significantly lower in the brexu-cel cohort vs the alloSCT cohort (logistic regression with inverse probability of censoring weighting, risk ratio=0.5, 95% confidence interval [CI] 0.3-0.9, p=0.02). This was mainly attributable to the significantly higher TRM rate in the alloSCT cohort (alloSCT vs brexu-cel: cause specific hazard ratio=7.7, 95% CI 1.9-31.6, p=0.005, Fig. 1B). The cumulative incidence of acute GvHD grade ≥3 at 3 months and chronic GvHD at 24 months was 17.9% (95% CI 9.1-29.0%) and 44.3% (95% CI 30.6-57.2%), respectively. In our ITT analysis, the dropout rate was significantly higher in the cohort intended to receive alloHCT (23%, [18/77]) vs the cohort intended to receive brexu-cel (8% [6/74]; Fisher test, p=0.01). For alloSCT, failure to proceed to cellular therapy was related to progression in 13%, change of patient's preference in 5% and ineligibility in 4%; in the brexu-cel cohort this was due to manufacturing failures in 4% and progression in 3%. Conclusion Brexu-cel is an effective treatment in pts with r/r MCL post-BTKi with a superior safety profile compared with alloSCT, as indicated by lower 12-month mortality, lower TRM, and absence of chronic GVHD-related morbidity. Despite efforts to match pts between the cohorts, the inherent limitations of this study, such as incongruent data sources and case selection bias, have to be considered. Additional analyses will be presented.

Lisocabtagene Maraleucel in Relapsed/Refractory Large B-Cell Lymphoma: Real World Analysis from the Cell Therapy Consortium

Introduction Lisocabtagene maraleucel (liso-cel) is an autologous CD19-directed CAR T cell therapy approved for the treatment of relapsed/refractory (R/R) large B-cell lymphoma (LBCL) based on the TRANSCEND (Abramson et al, Lancet 2020), TRANSFORM (Kamdar et al, Lancet 2022), and PILOT studies (Sehgal et al, Lancet Oncol 2022). Extending clinical trial results for liso-cel to the real-world setting, we performed a multicenter retrospective study to evaluate the safety and efficacy of liso-cel in standard of care practice. Methods Patients (pts) aged ≥18 years with LBCL who received commercial liso-cel infusion between February 2021 (time of FDA approval) and June 2023 at 7 academic US medical centers were identified from the Cell Therapy Consortium registry. Pt and treatment characteristics were summarized descriptively, and the Kaplan Meier method was used for survival outcomes. Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) were graded per ASTCT consensus criteria. Tumor response was assessed per Lugano criteria locally by the treating clinician. Results As of 6/10/2023, 101 pts underwent liso-cel infusion. Detailed baseline pt characteristics are shown in Table 1. Median age at apheresis was 71 years (range: 30-85) with 35% of pts ≥75 years, 60% were male, 16% had an ECOG PS of ≥2 at apheresis, and 11% had active secondary CNS involvement. By histology, 86% of pts had DLBCL, 7% HGBL, 5% TFL, and 2% PMBCL. Baseline comorbidities included diabetes (18%), stage IV chronic kidney disease (5%), cerebrovascular disease (5%), impaired cardiac ejection fraction (2%), pulmonary dysfunction (2%), impaired hepatic function (2%), and active infection (3%), with 68% having a Charlson Comorbidity Index score of ≥3. Due to comorbidities, 30% of pts would have been ineligible for the TRANSCEND clinical trial. The median number of prior therapies was 3 (range: 1-8) and 16% of pts underwent prior autologous stem cell transplant. Bridging therapy was used in 62% of pts including 41% receiving polatuzumab-based treatment, 24% chemoimmunotherapy, and 21% radiation therapy. Seven (7%) pts received liso-cel on an expanded access trial (NCT04400591) due to a non-conforming product. Median time from apheresis to CAR T-cell infusion was 39 days (IQR: 34-43) and 85% of CAR T-cell infusions occurred inpatient. Any Grade CRS occurred in 49% (3% were Grade ≥3) and any Grade ICANS occurred in 26% (10% were Grade ≥3). Median onset of CRS and ICANS was 4 and 6 days following liso-cel infusion, respectively. Tocilizumab was administered in 31% and 31% of pts received steroids for toxicity management. Nine deaths (9%) unrelated to lymphoma progression occurred at a median of 1.2 months (range: 0.3-4.3) with 2 due to infectious complications, 2 due to other malignancy, 1 due to grade 5 neurologic toxicity, 1 due to concurrent grade 5 neurologic toxicity and grade 5 CRS, 1 due to accidental death, and 2 due to unknown causes. The 6-month incidence of non-relapse mortality was 8% (95% CI, 3.4% - 15%). The overall response rate (ORR) to bridging therapy, as assessed prior to lymphodepletion, was 45% with 17% achieving a complete response (CR). Following liso-cel infusion, response assessment was performed at day 30 and/or day 90 according to treating center practice, or in those determined to have clinical progression. Of the 89 pts evaluable at day 30, the ORR was 81% with 63% achieving a CR. Among 76 pts evaluable at day 90, the ORR was 63% with 58% achieving a CR. With a median follow-up of 10.3 months (range 0.3-22.8), month 6 outcomes were 62.7% (95% CI, 52.8% - 74.3%) for progression-free survival, 71.6% (95% CI, 60.9% - 84.1%) for duration of response, and 77.1% (95% CI, 68.4% - 86.9%) for overall survival ( Figure 1). Conclusions These analyses confirm that efficacy and safety are similar or superior to those of patients enrolled in liso-cel prospective clinical trials for R/R LBCL. Notably, these outcomes were achieved in pts predominately of advanced age and with a significant comorbid burden, recognizing that one-third would have been ineligible for TRANSCEND. These results also likely reflect advancements in patient selection and toxicity management including the real world utilization of novel bridging therapy to temporize and debulk disease. Follow-up is ongoing and updated data will be presented at the meeting.

Indirect Comparison of Efficacy of Zanubrutinib Versus Orelabrutinib in Patients with Relapsed or Refractory Mantle Cell Lymphoma (R/R MCL): An Updated Analysis with Long-Term Follow up

Introduction Zanubrutinib and orelabrutinib, both the next generation Bruton's tyrosine kinase inhibitors (BTKis), are used in China as treatment options for R/R MCL. A further evaluation to understand the differences between these two novel BTKis is helpful for future study. Our previously indirect comparison has suggested a favorable PFS trend in zanubrutinib over orelabrutinib in R/R MCL patients (Song Y, et al. Invest New Drugs 2023). Here, we conducted an updated analysis to indirectly compare the long-term efficacy between zanubrutinib (median follow up: 35.3 months) and orelabrutinib (median follow up: 23.8 months) in patients with R/R MCL. Methods Individual patient data from zanubrutinib study (BGB-3111-206, n=86; NCT03206970) were adjusted to match the patients population profile of the orelabrutinib study (ICP-CL-00102, n=106; NCT03494179). As both trials were single-arm and were not linked through a common control arm, an unanchored matching-adjusted indirect comparison (MAIC) was performed to adjust for effect modifiers and prognostic variables. The baseline characteristics included in population adjustment were identified from literature review and clinical experts' assessment, which were sex, bulky disease, bone marrow involvement, disease stage, simplified Mantle Cell Lymphoma International Prognostic Index, prior autologous stem cell transplantation, and the number of prior lines of treatment. The efficacy outcomes included investigator-assessed progression free survival (PFS), overall survival (OS), and overall response rate (ORR). After matching, a weighted Cox model or a weighted logistic model will be employed to analyze the PFS and OS through hazard ratio (HR) or to analyze the ORR through odds ratio (OR). Response evaluations were only CT-based assessment in orelabrutinib study, while PET- and CT-based assessment were both performed in zanubrutinib study. Thus, the PFS assessed by PET and CT of zanubrutinib study were used to compare with the PFS assessed by CT of orelabrutinib study, respectively. Results After matching, the baseline characteristics were balanced between zanubrutinib and orelabrutinib, with the (effective) sample size of 70 and 106 in zanubrutinib and orelabrutinib, respectively (Table). PFS assessed by CT was significantly longer in the zanubrutinib versus the orelabrutinib (median PFS: not estimable [NE] vs. 22.0 months; HR, 0.54 [95% CI: 0.34-0.86]; P = 0.009) (Figure). Additionally, PFS assessed by PET of zanubrutinib was also significantly longer than the PFS assessed by CT of orelabrutinib (median PFS: NE vs. 22.0 months; HR, 0.63 [95% CI: 0.40-0.99]; P = 0.044). There are clinically meaningful differences observed for both the PFS (assessed by CT or PET) of zanubrutinib versus the PFS assessed by CT of orelabrutinib and the 24-month PFS rate (assessed by CT or PET) in the zanubrutinib versus that assessed by CT in the orelabrutinib (67.3% vs. 46.5% and 62.2% vs. 46.5%, respectively). Due to very limited number of OS events, the analysis of OS was not powered enough to detect a statistical meaningful difference between two groups (median OS: NE vs. NE; HR, 0.68 [95% CI: 0.36-1.27]; P = 0.223). However, the 24-month OS rate was numerically higher in the zanubrutinib than the orelabrutinib (83.7% vs. 74.3%). ORR was comparable between zanubrutinib and orelabrutinib (85.5% vs. 82.1%; OR, 1.28 [95% CI: 0.56-2.94]; P = 0.556). Conclusions MAIC results demonstrated that zanubrutinib had significantly longer PFS compared with orelabrutinib in the treatment of R/R MCL patients.

Efficacy and Safety of a Third Generation CD20 CAR-T (MB-106) for Treatment of Relapsed/Refractory Indolent B-Cell Non-Hodgkin Lymphoma: Phase-1 Results from a Multicenter Trial

Background: Indolent B-cell non-Hodgkin lymphomas (NHL) remain incurable despite multiple therapeutic options, including chemoimmunotherapy, targeted therapies, bispecific antibodies, and CD19-targeted chimeric antigen receptor T (CAR-T) cells. MB-106, a fully human 3 rd-generation CD20-targeted CAR-T product with both 4-1BB and CD28 costimulatory domains, had high overall response rate (100%) and complete response (CR) rate (91%) in follicular lymphoma (FL) patients at doses ≥ 3.3×10 6 cells/kg in a single institution trial (Shadman et al., 17-ICML, 2023). We seek to replicate the favorable efficacy and safety profile of MB-106 in a multicenter trial with centralized manufacturing. Methods: MB-106 is being evaluated in a Phase 1/2, open label, multicenter study utilizing a 3+3 dose-escalation design in R/R B-cell NHL patients with confirmed CD20 expression. Prior treatment with CD19-targeted CAR-T therapy is permitted. Following lymphodepletion (cyclophosphamide 300 mg/m 2/day and fludarabine 30 mg/m 2/day for 3 days), MB-106 is administered to patients with indolent B-cell NHL at one of two dose levels (DL): DL1, 3.3×10 6; and DL2, 1.0×10 7 cells/kg. MB-106 is infused in the outpatient setting if allowed by the institution, except for the first patient in each dose level cohort (overnight observation). Dose-limiting toxicities (DLT) are monitored through day 28. The treatment response is assessed on day 28 and on subsequent visits, and best overall response is reported here. CAR-T persistence is assessed by both flow cytometry and qPCR in peripheral blood mononuclear cells. Results: Three patients with indolent NHL (2 FL, 1 Waldenström macroglobulinemia [WM]) received MB-106 at DL1. In addition, one patient with hairy cell leukemia variant (HCL-v) received non-conforming material (drug product that failed to meet release criteria) at DL1, following FDA authorization. These four patients were heavily pre-treated with a median of 5.5 prior lines of treatment. High-risk features included progression of disease within 24 months of first-line treatment (POD24, n=1), prior autologous stem cell transplant (n=1) and prior CD19-targeted CAR-T therapy (n=1). No DLTs were observed at DL1. Three patients experienced Grade 1 cytokine release syndrome. There have been no occurrences of immune effector cell-associated neurotoxicity syndrome (ICANS). The 2 FL patients achieved CR by both PET-CT and bone marrow biopsy, one of whom had been previously treated with CD19-targeted CAR-T. The WM patient, who had nine prior treatments, including autologous stem cell transplant, and high disease burden, achieved very good partial response, with complete metabolic response by PET-CT, morphologic clearance of lymphoma in bone marrow, and resolution of the IgM paraprotein. The patient with HCL-v, who had been transfusion dependent, continues to have stable disease with decreased disease in the bone marrow, and achieved complete transfusion independence which is ongoing at 6 months. All patients displayed MB-106 expansion with peak levels between 7-14 days post-infusion. Persistence of CAR T-cells is ongoing at 6 months. Conclusion: Treatment with MB-106, a third generation CD20 targeting CAR-T, resulted in responses, including CRs, and CAR-T persistence in patients with R/R indolent NHL and was associated with favorable safety profile with no occurrence of Grade 3 or Grade 4 cytokine release syndrome and no ICANS of any grade. CRs have been observed in patients previously treated with CD19-targeted CAR-T in both this multicenter trial and the original single institution trial. Dosing is ongoing in the final dosing level (1.0×10 7 cells/kg) to establish the recommended Phase 2 dose for a planned pivotal trial in WM. It is anticipated that the complete data set from the Phase 1 indolent NHL arm will be presented.

Flat Dose Intravenous Immunoglobulin Primary Infection Prophylaxis in Multiple Myeloma Patients on Bispecific Antibody Therapy: Vanderbilt Experience

BACKGROUND Bispecific antibodies (BsAbs) are novel immunotherapeutic agents with prolific anti-multiple myeloma (MM) efficacy in highly relapsed/refractory disease (RRMM). They have been associated with profound and prolonged hypogammaglobinemia which represents a unique challenge regarding increased risk of serious (sometimes fatal) infections. Though IVIG has historically been dosed at 0.4g/kg for secondary prophylaxis, there is still uncertainty in optimal timing, schedule and frequency of supplementation in MM patients. At Vanderbilt University Medical Center, we have adopted a flat dose 10g IVIG prophylaxis schedule, which on average delivers ~36% of historical, weight-based dosing. At present, expert recommendations advise IVIG replacement every 4 weeks in recipients of BsAb starting the second month of therapy and continuing until the end of therapy or until serum IgG levels reach > 400 mg/dL, whichever is longer ( Mohan M et al. Br J Haematol.2023;00:1-11). Considering that MM BsAbs are currently used with continued dosing schedule, adoption and anticipated new BsAb approvals are increasing, IVIG has previously been on national/global shortage (occasionally unavailable), IVIG replacement during hypogammaglobulinemia represents a crucial aspect of adequate infection prophylaxis in MM, we explored the impact of our institutional 10g IVIG prophylaxis on infection rates in RRMM patients receiving BsAbs. Prior studies with comparable BsAbs reported Grade (G) ≥3 infection rate of 32-45% and 18%, in anti-BCMA and anti-GPRC5D BsAbs, respectively. In these trials, overall, 14-53% of patients received IVIG prophylaxis. METHODS We performed a retrospective review using electronic medical record of RRMM patients receiving anti-BCMA or anti-GPRC5D BsAbs from Jan 2019 to Dec 2022, either on clinical trials or as a standard of care at our institution. The inclusion criteria were minimum of two months of BsAb therapy, and the use of at least one month of monthly IVIG prophylaxis for serum IgG < 400 mg/dL. All patients were also on baseline valacyclovir, trimethoprim-sulfamethoxazole and levofloxacin prophylaxis. Routine disease and treatment specifics as well as infection rates and grades were collected. Infections were defined as mild (infections treated outpatient), moderate (required hospital admission) or severe (hospital admission with intensive care unit level of care), next to also being graded by CTCAE v5 with the rest of hematologic and non-hematologic adverse events (AEs). RESULTS A total of 30 patients with RRMM were identified. Table 1 illustrates the demographic and disease specifics: 79% received a median (range) of 4 (2-7) lines of prior therapy, over half were penta-class exposed, 27% were triple and quad refractory, 67% received a prior autologous stem cell transplant and 17% underwent prior treatment with BCMA targeting CAR-T therapy. All except 2 patients received BsAb therapy on clinical trials. Anti-GPRC5D BsAb was used to treat 60% of patients, while the rest (40%) received anti-BCMA BsAb, all of which were given for a median of 27 (12-45) months (Table 1). Overall, 30% of patients had one infectious episode, while 43% had ≥2. Viral infections (57%) were twice as common as bacterial (30%) (Table 2). Infections were mild in 60%, moderate in 23%, and severe in 6.6% of patients. We observed 27% rate of G ≥3 infectious complications. Patients had a median (range) IgG at diagnosis of 1284(196-5431), and 499(210-2246) at the time of onset of first infection (IgG values at the start of BsAb therapy, at first and at ≥2 infections are outlined in Table 2). The rate of G ≥3 neutropenia and lymphopenia was 6.6% and 30% respectively. There were 2 (6.6%) sepsis related deaths, one each with anti-BCMA and anti-GPRC5D BsAbs. Table 2 also describes severity and the rates of cytokine release syndrome and neurotoxicity. CONCLUSIONS We observed relatively lower rate of severe or ≥ G3 infectious events with 10g flat IVIG dosing schedule. While our results represent a small, single-institutional cohort of predominantly anti-GPRC5D treated RRMM patients and require prospective validation in a randomized (IVIG 10g vs 0.4g/kg body weight) fashion, they demonstrate feasibility of reduced level dosing of a critical resource such as IVIG, in the fast expanding, national/global BsAb-based MM armamentarium.

Isatuximab-Based Regimens As Salvage Therapy for Patients with Multiple Myeloma: Sardinian, Multicenter, Retrospective Clinical Practice Experience with 27 Cases Outside of Controlled Clinical Trials

Introduction: Isatuximab (Isa), a humanized monoclonal antibody directed against the surface antigen CD38, has been available in Italy since October 2021 for the treatment of relapsed or refractory Multiple Myeloma (RRMM) in combination with Pomalidomide (P) and Dexamethasone (d) (IsaPd) after two lines of therapy with lenalidomide and a proteosome inhibitor, and from April 2022 in combination with carfilzomib (K) after one line of treatment. Patients eligible for these therapies must not be refractory to Daratumumab. Here, we report preliminary efficacy and safety data for Isatuximab in a Sardinian study of RRMM patients treated with IsaPd and IsaKda as salvage therapy outside of controlled clinical trials. The primary objective of this study was to evaluate the toxicity profile and quality of response to Isatuximab-based regimens administered as salvage therapy in a real-world setting. Methods: The 2 cohorts included 27 patients with RRMM from 4 Sardinian centers who received at least one cycle of IsaPd (16 patients) or IsaKd (11 patients) as salvage therapy between January 2022 and March 2023. Patients received Isa 10 mg/kg IV weekly for the first 4 weeks (wks), then every 2 weeks in combination with Pomalidomide and Dexamethasone (4mg PO days 1-21; 40mg [20mg at > 75 years] PO or IV weekly) every 28 days for the IsaPd regimen. The IsaKd regimen consisted of administration of 10 mg/kg Isatuximab intravenously once weekly in the first cycle, then once every 2 weeks in subsequent cycles. Both arms received Carfilzomib at a dose of 20 mg/m2 on days 1 and then 56 mg/m2 on days 8, 9, 15, and 16 of the first cycle, then 56 mg/m2 on days 1, 2, 8, 9, 15, and 16 in subsequent cycles, while 20 mg of Dexamethasone was administered on days 1, 2, 8, 9, 15, 16, 22, and 23 of each cycle. Results: The median age of the 16 IsaPd-treated patients was 67.5 years (range 48-89 years) and 61 years (range 49-84 years) for the IsaKd population; 44% and 64% were male, respectively (Table 1). The median number of prior therapies was 2 (range 2-4) for the IsaPd and 1 (range 1-4) for the IsaKd cohort; 11 (68.75%) and 9 (82%) received prior autologous stem cell transplantation (ASCT), respectively. Four patients in both populations started treatment because of biochemical relapse, and no refractory patients were recorded in the IsaKd cohort. Three patients (2 in the IsaPd population and 1 in the IsaKd cohort) had creatinine clearance ≤30 mL/min. Among the IsaKd-cohort, 5 (46%) had R-ISS 2 stage and three had a 17p deletion. At the last data collection, 13 cases in the IsaPD population were evaluable for response. The median number of courses administered to date was 4 (range, 1-14). The overall response rate (ORR) was 69%, with 2 stringent complete remissions (sCR) (15%) and 1 very good partial remissions (VGPRs) (7.7%). The median time to first response was 1 month, while the median time to best response was 2 months. In the IsaKd population, 10 patients were evaluable with an overall response rate (ORR) of 100%, with 1 complete remission (sCR) (10%), 1 complete remission (10%), and 5 very good partial remissions (VGPRs) (50%). A median time to first response of 1 month was also recorded in this population, whereas the median time to best response was 3 months. Renal insufficiency and age > 70 years had no significant impact on the likelihood of achieving a response in either population.In the IsaPd cohort, after a median follow-up of 6 months (range 1-14 months), 9 patients discontinued treatment, 7 due to disease progression, 1 due to toxicity, and 1 due to patient choice) Six patients died (5 patients from progressive disease and 1 from secondary acute myeloid leukemia). Common grade 3 or 4 adverse events were fatigue (57%), thrombocytopenia (35%), neutropenia (57%), lymphocytopenia (15.9%), anemia (29%), and infection (21%). Infusion reactions occurred in only 2 patients (12.5%) and were grade 1 or 2 without treatment discontinuation. In the IsaKd population, the median follow-up time was 4 months (range 1-8 months). 1 patient discontinued treatment and died due to disease progression. Grade 3 or 4 adverse events were fatigue (18%), thrombocytopenia (18%), neutropenia (18%), anemia (36%), and infection (63%) No infusion reactions occurred. Conclusions: Despite the limited number of cases, our preliminary real-world data confirm that Isa-based treatment is an effective and safe therapy for RRMM patients, broadly consistent with results from controlled clinical trials.

A Phase 2 Study of Daratumumab in Combination with Thalidomide and Dexamethasone in Relapsed and / or Refractory Myeloma: A Report from the Asian Myeloma Network

Introduction Myeloma is a plasma cell dyscrasia characterised by a relapsing remitting course. Patients with relapsed / refractory myeloma (RRMM) with prior exposure to proteosome inhibitor and an immunomodulatory agent have a poor prognosis. In the last few years, CD38 antibodies such as daratumumab and isatuximab have revolutionised the treatment of multiple myeloma. They appear synergistic with immunomodulatory drugs; triplet combinations with lenalidomide 1 (DRd) or pomalidomide 2 (DPd) and dexamethasone have been approved for treatment of RRMM. However, patients face high out-of-pocket costs when attempting to access these drugs. There is hence a pressing need to develop combinations which harness the therapeutic potential of CD38 antibodies while preserving synergistic action of triplet combinations. Methods This was a multi-national, multi-centre, single arm, phase 2 trial of daratumumab in combination with thalidomide and dexamethasone. Patients with myeloma diagnosed according to the International Myeloma Working Group criteria with measurable disease and relapsing after / refractory to at least one prior line of treatment were eligible for enrolment. Satisfactory organ function (neutrophil count ≥ 1,000/mm 3, platelet ≥ 50,000/mm 3, bilirubin ≤ 1.5 x the upper limit of the normal range (ULN). Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 3 x ULN and creatinine clearance ≥ 30ml/min) were pre-requisites for inclusion. Patients with plasma cell leukaemia and those with prior CD38 antibody exposure were excluded. Patients received daratumumab IV 16mg/kg weekly for weeks 1 - 8, every 2 weeks from weeks 9 - 24 and every 4 weeks from week 25 onwards, thalidomide 100mg daily and dexamethasone 20mg twice a week. Treatment was continued for as long as tolerated and clinically indicated, based on physician assessment, or until disease progression. Thromboprophylaxis was allowed but not mandated. The primary outcome measure was progression-free survival (PFS), defined as the time from commencement of treatment to disease progression or death from any cause, whichever occurred first. Secondary outcome measures included overall response rate (ORR, the percentage of patients achieving a partial response (PR) or better), overall survival (OS), duration of response (DOR, the time from first evidence of PR or better till disease progression or death, whichever occurred first) and safety, assessed by the frequency and severity of adverse events. Results 70 patients were recruited. The median age was 66.8 (range 39 - 81) years with 62.7% males. 95.5% of patients had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. The median number of prior therapies was 2 (range 1 - 6). 91% of patients had prior exposure to bortezomib, while 88% had prior exposure to thalidomide, lenalidomide or both. 50.7% had a prior autologous stem cell transplant. 67 patients completed at least one cycle of treatment. Two died prior to completion of the first cycle, while one withdrew consent and was excluded. Patients were treated for a median of 15.9 (interquartile range, IQR 5.1 - 23) months. 67 (95.7%) patients suffered 544 adverse events, of which 256 (47%) were related to the study treatment, 103 (19%) grades 3-4 and 8 (1%) were fatal. The most common adverse event was infection, which occurred in 26 patients; 4 were fatal. 27 patients had peripheral neuropathy, 25 of which were grade 1 - 2. 14 patients had an infusion reaction, 3 of which required hospitalisation. One patient had a deep vein thrombosis. At a median follow-up of 22.0 (IQR, 9.9 - 31.0) months, the median PFS was 16.3 (95% CI, 12.8 - 24.6) months (Figure 1). The median OS was 32.5 (95% CI, 25.4 - not reached) months. The ORR was 82.1% (95% CI, 70.8 - 90.4). This ORR was comparable to DRd and DPd (Table 2). Of these, 43 (78%) of patients achieved a very good partial response (VGPR) or better, with 9 (16%) of patients achieving a stringent complete response (sCR). The median DOR was 19.3 (95% CI, 12.2 - 36.5) months. Conclusion The combination of daratumumab, thalidomide and dexamethasone is effective in RRMM patients. Thalidomide and dexamethasone are cost-effective drugs which can improve the accessibility of daratumumab-based triplet combinations.

Second Line Treatment and Outcomes of Patients with Multiple Myeloma: A Real World Multi-Institutional Report from the Canadian Myeloma Research Group (CMRG) Database

Introduction: The treatment of multiple myeloma (MM) has evolved rapidly, with various combinations of immunomodulators (IMiDs), proteasome inhibitors (PIs), corticosteroids and autologous stem cell transplantation (ASCT) utilized in newly diagnosed (ND) patients; in some jurisdictions, monoclonal antibodies (MABs) are also incorporated in first-line treatment. Over the last decade, the standard of care in Canada for NDMM in fit younger patients has consistently been induction (CyBorD/more recently RVD) followed by ASCT and maintenance lenalidomide (len) until progression. In transplant-ineligible patients, bortezomib- or len-based treatments in doublets or triplets have been used frontline. At relapse, options have included re-induction followed by 2nd ASCT or doublet/triplet combinations until progression. Limited comparative data are available to support any one approach. The aim of this retrospective study was to assess the treatment patterns and outcomes of MM patients treated at 1st relapse in a real-world setting. This data may be useful to myeloma stakeholders when evaluating the potential impact of even newer novel immunotherapeutic agents in patients in who have had 1 prior line of treatment. Methods: We performed a retrospective observational study using the Canadian Myeloma Research Group Database (CMRG-DB), which is a prospectively maintained disease-specific database with ≥ 9000 patients enrolled from 16 academic sites across Canada. All MM patients who initiated second-line therapy between 01/12/2010 - 30/06/2022 were included and results were analyzed up to 23/05/2023. We aimed to evaluate the following outcomes for each second-line regimen: overall response rate (ORR), progression-free survival (PFS) and overall survival (OS), calculated from the start of second-line therapy. Survival was estimated using Kaplan-Meier methods and compared between groups using the log rank test. Results: A total of 3569 patients were identified: 1638 (45.9%) who had prior ASCT and 1931 (54.1%) non-ASCT patients. 2715 (76%) patients were bortezomib-exposed in first line, 1052 (30%) were lenalidomide-exposed; 22% had high-risk cytogenetics. The most commonly used second-line regimens were Rd in 1325 (37%) of patients, DRd in 346 (10%), CyBorD in 291 (8%), 2nd ASCT in 270 (8%), RVd in 201 (6%) and DVd in 167 (5%). Outcomes including ORR, ≥ VGPR rate, PFS and OS from second-line treatment for regimens with >50 patients are presented in Table 1. Among all patients, the highest ORRs were seen with DRd (90%), 2nd ASCT (89%), Kd/KCd (79%), RVd (78.1%) and KRd (74%); DRd had the highest ≥ VGPR rate (66%). In patients who had received bortezomib-based first line treatment, the second line ORRs were 96%, 98% and 95% for VRd, KRd and DRd, respectively, with a corresponding median PFS of 20 months (VRd), 19 months (KRd) and 28 months (DRd). For patients who had len-based first line treatment, the second line ORRs were 80% for Kd/KCd and 95% for DVd with a median PFS of 16 months (Kd/KCd) and 11 months (DVd), respectively. The median PFS was 41 months after 2 nd ASCT; of these patients, 68% were exposed to bortezomib in first line and 34% were len exposed in first line. The median PFS was 30 months in those who had len maintenance after their 1 st transplant compared to 60 months in those with no initial maintenance. Conclusion: In this real-world observational study we demonstrate that Canadian patients achieved results comparable those noted in prospective clinical trials leading to the approval of these agents in the second-line setting. Triplet combinations with an IMID backbone, including DRd, KRd and Ixa-Rd, had high response rates, with DRd offering the longest PFS. Patients undergoing 2 nd ASCT had ORRs and PFS comparable to DRd, although these results were likely influenced by selection of a population with a favorable response to 1st ASCT . Given the expanding use of IMID, PI and MAB combinations in first-line, our results highlight the need for better modalities at the time of 1 st relapse. Earlier integration of “novel” agents, including CAR-T therapy, bi-specifics, conjugated antibodies and CEL-MoDs-even in the second-line setting–is likely required to improve on these outcomes. The current analysis provides efficacy benchmarks to guide their implementation. Financial Support: CMRG received financial support from Janssen Inc. for the conduct of this study