Richards, Alicia

Abstract Introduction Ciltacabtagene autoleucel (cilta-cel) has demonstrated unprecedented response rates and progression-free survival (PFS) in relapsed/refractory multiple myeloma (RRMM), but a proportion of patients experience early relapse. Identifying these patients is essential to guide future therapeutic strategies, such as enhanced bridging therapy or consolidation, while avoiding overtreatment in those likely to achieve durable disease control. Methods We conducted a multi-center study of patients treated with cilta-cel at 15 U.S. academic centers. Outcomes were evaluated based on high-risk (HR) features, including functional HR disease (FHR; relapse within 18 months of first-line therapy initiation), true extramedullary disease (EMD), traditional HR cytogenetics as defined in CARTITUDE-1 [deletion 17p, t(4;14), t(14;16)], and a 2024 IMS-IMWG-adapted HR definition (deletion 17p; t(4;14) or t(14;16) with gain 1q or deletion 1p; and gain 1q with deletion 1p). Multivariable Cox regression was used to examine the association of HR features (FHR, adapted IMS-IMWG HR, and EMD, individually and collectively) with PFS while adjusting for baseline ferritin, prior BCMA, and ECOG performance status (PS ≥2). Among patients with ≥18 months of follow-up, we evaluated predictors of early relapse (≤18 months post infusion) using logistic regression. Results Our cohort included 598 patients treated with cilta-cel between 5/2022 and 12/2024 who had available data on all HR features. The median age was 65 years (range 33-83), and the median prior lines of therapy (pLOT) was 5 (range: 1-18, 84% with >3 pLOT); 8% had received prior BCMA-directed therapy, and 27% were penta-refractory. Most patients (88%) received bridging therapy and 30% achieved ≥ partial response. In our cohort, 33% (n=195) had FHR, 43% (n=258) had traditional HR cytogenetics, 42% (n=253) had adapted IMS-IMWG HR disease, and 11% (n=64) had EMD. Median follow up was 10.6 months (range 0.4-34.1). Overall response rate (ORR) and complete response (CR) rates were lower in patients with vs without HR features: FHR (ORR: 89% vs 94%, CR: 61% vs 75%), traditional HR (ORR: 90% vs 94%, CR: 65% vs 74%), adapted IMS-IMWG HR (ORR: 91% vs 94%, CR: 64% vs 75%) and EMD (ORR: 77% vs 94%, CR: 61% vs 71%). Corresponding 12-month PFS was also lower in patients with vs without HR features: FHR (55% vs 79%), traditional HR (63% vs 78%), adapted IMS-IMWG HR (61% vs 80%) and EMD (59% vs 73%). ORR, CR rate, and 12-month PFS in patients without any HR features compared to those with ≥1 HR feature were 96% vs 90%, 81% vs 64%, and 83% vs 65%, respectively. In multivariable models, each HR feature (FHR, adapted IMS-IMWG HR, and EMD) was independently associated with inferior PFS after adjusting for baseline ferritin, prior BCMA, and ECOG PS ≥ 2. However, because early relapse cannot always be identified a priori based on traditional risk factors, we sought to identify predictors of relapse within 18 months of cilta-cel in a subset of patients with ≥18 months of follow-up (N=247; infused by 12/2023). Notably, while FHR (OR=3.04, 95% CI=1.59-5.89) and adapted IMS-IMWG HR (OR=2.07, 95% CI=1.10-3.89) were independently associated with odds of relapse within 18 months, EMD was not (OR=0.90, 95% CI=0.32, 2.40) when accounting for prior BCMA, ECOG PS ≥ 2, and baseline ferritin. We also used a time-varying Cox model to examine each HR feature associated with PFS at two time periods, <18 and ≥18 months, while adjusting for baseline ferritin, ECOG PS, and prior BCMA. We confirmed that FHR and adapted IMS-IMWG HR were both associated with relapse <18 months (HR=2.05, 95% CI=1.48-2.83 and HR=1.56, 95% CI=1.11-2.19) but not in the ≥18-month time period (HR=0.70, 95% CI=0.19-2.59 and HR=0.76, 95% CI=0.24-2.40). The magnitude of the association for EMD with PFS was similar across both time periods (<18 months HR=1.67, 95% CI=1.09-2.57 and ≥18 months HR=2.17, 95% CI=0.45-10.40). Conclusion While cilta-cel leads to high response rates and durable PFS in RRMM, a subset of patients with FHR and adapted IMS-IMWG HR remains at increased risk for early relapse. In this large multi-center cohort, we describe PFS outcomes across high-risk subgroups and identify key predictors of relapse within 18 months of cilta-cel. These findings inform risk-adapted therapeutic strategies and interventional trials, including bridging, consolidation, or maintenance approaches, to improve outcomes in the highest-risk RRMM patients.

PURPOSE Idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel), two B-cell maturation antigen–directed chimeric antigen receptor (CAR) T-cell therapies have demonstrated remarkable efficacy in relapsed/refractory multiple myeloma (RRMM). We compare safety, efficacy, and survival among patients with RRMM treated with standard-of-care (SOC) ide-cel or cilta-cel. METHODS Data were from a retrospective chart review of patients with RRMM leukapheresed by December 31, 2022, with the intent to receive SOC ide-cel or cilta-cel at 19 institutions. An inverse probability of treatment weighting (IPTW) approach was used to compare outcomes by therapy type. RESULTS A total of 641 patients were leukapheresed by December 31, 2022, with ide-cel (n = 386) and cilta-cel (n = 255). Five hundred eighty-six patients were infused (n = 350 for ide-cel; n = 236 for cilta-cel) with a median follow-up of 12.6 and 13.0 months for ide-cel and cilta-cel, respectively. After IPTW, patient characteristics were well balanced. Cilta-cel was associated with higher likelihood of grade ≥3 cytokine release syndrome (CRS; odds ratio [OR], 6.80 [95% CI, 2.28 to 20.33]), infections (OR, 2.03 [95% CI, 1.41 to 2.92]), second primary malignancies (OR, 1.77 [95% CI, 0.89 to 3.56]), and delayed neurotoxicity (OR, 20.07 [95% CI, 4.46 to 90.20]). Cilta-cel was also associated with better treatment responses (≥complete response: OR, 2.42 [95% CI, 1.63 to 3.60]), longer progression-free survival (hazard ratio [HR], 0.48 [95% CI, 0.36 to 0.63]), and longer overall survival (HR, 0.67 [95% CI, 0.46 to 0.97]). No associations were observed between therapy type and immune effector cell–associated neurotoxicity syndrome, any CRS, severe cytopenia at days 30 and 90, or nonrelapse mortality. We observed consistent findings when repeating the analyses restricting the ide-cel cohort to patients infused during the same time period as Food and Drug Administration approval for cilta-cel (≥March 2022). CONCLUSION Cilta-cel demonstrated superior efficacy and survival, with higher incidence of certain toxicities, compared with ide-cel.

*Authors contributed equally. Introduction. Two chimeric antigen receptor (CAR) T-cell therapies have been FDA approved for patients with relapsed/refractory multiple myeloma (RRMM): idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel). Prior work from our consortium identified racial and ethnic differences in safety and response to ide-cel among patients treated in the standard of care (SOC) setting; despite these differences, survival was similar across race and ethnicity. Here, we extend this work to investigate racial and ethnic differences in safety, efficacy, and outcomes in a larger cohort of patients treated with SOC ide-cel with longer follow-up and patients treated with SOC cilta-cel. Methods. Data for RRMM patients who underwent leukapheresis by 12/31/2022 and were treated with SOC ide-cel or cilta-cel were pooled across 19 institutions in the U.S. Multiple Myeloma Immunotherapy Consortium. We compared Non-Hispanic White, Non-Hispanic Black, and Hispanic (any race) patients, excluding other racial and ethnic groups due to small sample sizes that precluded sub-group investigations. Separately for each CAR T-cell therapy, racial and ethnic differences in baseline patient characteristics, safety, and treatment responses were examined using chi-square and Kruskal-Wallis rank sum tests. Kaplan-Meier survival curves and log-rank tests were used to examine progression-free survival (PFS) and overall survival (OS) by race and ethnicity. Results. Among 332 RRMM patients treated with ide-cel, Non-Hispanic Black and Hispanic patients comprised 17% and 10% of the cohort, respectively. Hispanic patients were younger at infusion compared to Non-Hispanic Black and Non-Hispanic White patients (55.5 vs. 63 vs. 66 years, p<0.001). Non-Hispanic Black patients had a higher disease burden (≥ 50% bone marrow plasma cell percentage) compared to Non-Hispanic White and Hispanic patients (35% vs. 20% vs. 19%, p=0.05), while a higher proportion of Non-Hispanic White patients had high-risk cytogenetics compared to Non-Hispanic Black and Hispanic patients (37% vs. 23% vs. 10%, p=0.003). Non-Hispanic Black patients were more likely to develop severe (≥ grade 3) cytopenia at day 30 (p<0.001) and day 90 (p=0.01) post-infusion, and these differences were particularly driven by higher rates of severe neutropenia among Non-Hispanic Black patients at these time points. Non-Hispanic White patients were more likely to achieve a best response of partial response (PR) or better (82%) compared to Non-Hispanic Black (75%) and Hispanic patients (63%, p=0.02). No other racial and ethnic differences in baseline patient characteristics (including cytopenias), safety, PFS, and OS were observed (p>0.05). Among 222 RRMM patients treated with cilta-cel, Non-Hispanic Black and Hispanic patients comprised 12% and 9% of the cohort, respectively. At baseline, Non-Hispanic Black and Hispanic patients were more likely to have anemia (p=0.01), and Non-Hispanic Black patients were more likely to have thrombocytopenia (p=0.02) and neutropenia (p=0.06) compared to Non-Hispanic White patients. No other differences in baseline patient characteristics were observed by race and ethnicity. While not statistically significant, a higher rate of severe (≥ grade 3) cytopenia at day 90 post-infusion was observed among Non-Hispanic Black and Hispanic patients compared to Non-Hispanic White patients (33% vs. 44% vs. 21%, p=0.07), similar to the ide-cel cohort. This finding was primarily driven by higher rates of severe neutropenia among Non-Hispanic Black patients and higher rates of anemia among Hispanic patients. No other racial and ethnic differences in safety, responses to cilta-cel, PFS, or OS were not observed in the cilta-cel cohort (p>0.05). Conclusion. In a large cohort of RRMM patients treated with SOC ide-cel or cilta-cel, we observed a higher rate of cytopenias post-infusion and inferior ide-cel responses among racial and ethnic minority patients compared to Non-Hispanic White patients. Despite these differences, survival was similar across race and ethnicity, suggesting that both available CAR T-cell therapies for RRMM patients can be utilized across all populations. Future studies that include larger patient cohorts of racially and ethnically diverse patients should be conducted to confirm these findings and additionally evaluate long-term outcomes.

Background: The FDA package inserts for all approved chimeric antigen receptor T-cell (CAR-T) therapies state that patients should universally refrain from driving for 8 weeks following infusion. However, there are no clear data to support this recommendation, particularly in multiple myeloma (MM) which all CAR-T therapies use 4-1BB as opposed to CD28 costimulatory domains. Specifically, no seizures were reported in the KarMMa, KarMMa-3, CARTITUDE-1, or CARTITUDE-4 trials. Because patients typically return to their referring oncologists after Day (D) +28 following CAR-T infusion, an additional month of driving restrictions can create confusion for referring oncologists, impose significant burdens for patients and caregivers, and potentially even affect the choice of MM therapy for patients living in remote areas. Methods: We conducted a two-part study within the US MM Immunotherapy Consortium. Firstly, we analyzed data from commercial idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel) recipients (leukapheresis cutoff December 31, 2023) to identify the prevalence of CRS, ICANS, or death between Weeks 5-8 (D+29 to D+56) following CAR-T (Day 0). Patients with index hospital stays lasting over 4 weeks and patients with <8 weeks of post-CAR-T follow-up were excluded. Secondly, we surveyed Consortium members about the prevalence of impaired driving risk (defined as “anything that could impair a patient's ability to drive safely, e.g. seizures, altered mental status, blindness, etc.”) and used 1-5 Likert scales to gauge the perceived importance of driving restrictions (assuming no FDA guidance existed) during Weeks 0-4 vs 5-8. This anonymous IRB-exempted survey was distributed via email to 63 CAR-T-prescribing physicians within the Consortium. Results: Of 553 analyzed patients, 41% (n=224) had received cilta-cel and 59% (n=329) ide-cel. The median age was 64 (IQR 58-70), 42% (n=231) were female, 78% White (n=434), 13% (n=72) Black, and 9% (n=51) Hispanic. ECOG PS at infusion was ≥2 in 11% (n=63) of patients, and 5% (n=28) had had previous CNS co-morbidities such as prior strokes. One patient (0.2%) developed Grade 2 CRS during Weeks 5-8 (onset D+47, resolution one day later); no patients had de novo ICANS after D+28. There were 16 cases of non-ICANS neurotoxicity (including 2 cases of Parkinsonism) diagnosed a median of 24 days after CAR-T (range: 17-147 days), of which 3 cases (all non-Parkinsonian) were first diagnosed during Weeks 5-8. There were 10 deaths (2%) during Weeks 5-8, one due to infection and the remainder from progressive MM. The survey was completed by 45 oncologists (71% response rate), 41 of whom had managed both >5 ide-cel and >5 cilta-cel recipients. Regarding impaired driving during Weeks 0-4, 20% of physicians felt this was never a risk, 36% a risk for 1-2% of patients, 29% a risk for 3-10% of patients, and 16% a risk for >10% of patients. The distribution was significantly different (p < 0.01) for Weeks 5-8: 49% never a risk, 36% a risk for 1-2% of patients, 16% a risk for 3-10% of patients, while no respondents felt this remained a risk for >10% of patients. For Weeks 0-4, 73% agreed that patients should be advised not to drive while 9% disagreed. In contrast, for Weeks 5-8, 14% of physicians agreed with driving restrictions while 78% disagreed (p < 0.01 compared to Weeks 0-4). Discussion: Our two-part study demonstrates that driving restrictions following Week 4 after CAR-T therapy in MM may not be required. The incidence of de novo CRS or any-type neurotoxicity being diagnosed during Weeks 5-8 was <1%, and - if such toxicities developed - patients and physicians could be expected to set appropriate restrictions at that juncture. While 73% of CAR-T-prescribing oncologists agreed that patients should refrain from driving during Weeks 0-4, 78% disagreed with this recommendation during Weeks 5-8. These findings complement other real-world studies (Wesson, Dima, et al, TCT 2024; Ahmed et al, Blood Advances 2024) reporting the rarity of CRS and ICANS after the first month in both MM and lymphoma. Our study is limited by a lack of patient-reported data, which was done intentionally to avoid asking patients about activities undertaken against medical advice. Nevertheless, we believe that narrowing universal driving restrictions to Weeks 0-4 following CAR-T therapy would constitute an evidence-based modification to the package inserts for ide-cel and cilta-cel.

Introduction. Ciltacabtagene autoleucel (cilta-cel) and idecabtagene vicleucel (ide-cel), two anti-B-cell maturation antigen (BCMA) CAR T therapies, have demonstrated remarkable responses and improved survival among patients with relapsed/refractory multiple myeloma (RRMM) in the clinical trials and standard of care (SOC) setting. Here, we compare safety, efficacy, and survival for patients treated with SOC ide-cel and cilta-cel. Methods. Data were from a retrospective chart review of RRMM patients leukapheresed by 12/31/2022 with the intent to receive SOC ide- or cilta-cel at 19 institutions in the US Multiple Myeloma Immunotherapy Consortium. An inverse probability of treatment weighting (IPTW) approach was used to compare outcomes by therapy type (cilta- vs. ide-cel), balancing on age, sex, race and ethnicity, performance status, extramedullary disease, high-risk cytogenetics, prior BCMA therapy, bone marrow plasma cells, penta-refractory status, lymphodepleting chemotherapy, baseline ferritin, low cell dose, and bridging therapy response. Logistic regression and Cox proportional hazard models were used to examine the association of treatment type with safety, efficacy, and survival accordingly, while adjusting for IPTW weights. We employed propensity score matching utilizing the same covariates to identify the association of treatment type with progression-free survival (PFS) within relevant patient sub-groups. Results. A total of 641 patients were leukapheresed by 12/31/2022 with ide-cel (n=386) and cilta-cel (n=255). 586 patients were infused (n=350 for ide-cel; n=236 for cilta-cel) with a median follow-up of 13.0 and 12.6 months, respectively. After IPTW, patient characteristics were well-balanced. Patients treated with cilta-cel were more likely to have grade ≥ 3 cytokine release syndrome (CRS) (OR=5.52, 95% CI=1.76-17.30, p=0.004), infections (OR=2.07, 95% CI=1.44-2.97, p<0.001), and delayed neurotoxicity (NT) (OR=20.97, 95% CI=4.75-92.42, p<0.001) compared to patients treated with ide-cel. In the cilta-cel cohort, 24 patients (10%) experienced delayed NT compared to 2 patients (1%) in the ide-cel cohort. Although not statistically significant, patients treated with cilta-cel were more likely to have any second primary malignancies (SPMs) (OR=1.87, 95% CI=0.94-3.71, p=0.08) and any SPMs excluding non-melanoma skin cancers (OR=1.78, 95% CI=0.78-4.10, p=0.2) but no association was observed for odds of hematologic SPMs (OR=0.98, 95% CI=0.26-3.61). No association was observed for therapy type with any or severe immune effector cell-associated neurotoxicity syndrome, any CRS, severe cytopenias, and non-relapse mortality. Compared to ide-cel, cilta-cel was associated with better treatment responses of ≥ complete response (OR=2.38, 95% CI=1.61-3.51, p<0.001) and ≥ partial response (OR=1.74, 95% CI=0.99-3.05, p=0.06). Patients treated with cilta-cel had a longer PFS and overall survival (OS) than ide-cel (HR=0.47, 95% CI=0.35-0.62, p<0.001 and HR=0.63, 95% CI=0.42-0.93, p=0.02, respectively), and these findings were similar in the intention to treat cohort (PFS: HR=0.44, 95% CI=0.34-0.55, p<0.001; OS: HR=0.55, 95% CI=0.41-0.73, p<0.001, respectively). We observed consistent findings when repeating the analyses restricting the ide-cel cohort to patients infused during the same time-period as FDA approval for cilta-cel (≥ March 2022), restricting to patients with data on all covariates, and restricting to sites that contributed data for both products. In a propensity matched population, (n=380; n=190 for cilta-cel and n=190 for ide-cel), patients treated with cilta-cel had superior PFS compared to those treated with ide-cel in most subgroups with respect to age and disease characteristics including extramedullary disease, high-risk cytogenetics, and elevated baseline ferritin (p<0.05). Conclusion. Our results suggest superior efficacy of cilta-cel with a higher incidence of certain toxicities compared to ide-cel in the SOC setting. This study provides valuable information for patient counseling and guiding the selection of CAR T-cell therapy for specific patient populations. Further validation through similar large-scale real-world experiences or prospective studies is needed to confirm our results and enhance applicability in the clinical setting. *DH, LP, & DD are co-first authors * YL, KP, & SS are co-last authors