Safety and Efficacy of Standard of Care Ciltacabtagene Autoleucel for Relapsed/Refractory Multiple Myeloma.

Ciltacabtagene autoleucel (cilta-cel) CAR-T therapy was approved in 2022 for patients with relapsed/refractory multiple myeloma (RRMM). We report outcomes with cilta-cel in the standard-of-care setting. Patients with RRMM who underwent leukapheresis for cilta-cel manufacturing between 3/1/2022-12/31/2022 at 16 US academic medical centers were included. RESULTS: 255 patients underwent leukapheresis and 236 (92.5%) received cilta-cel. Of leukapheresed patients, 56% would not have met CARTITUDE-1 trial eligibility criteria. Manufacturing failure rates at first attempt and overall were 6% and 1%, respectively. Median prior lines of therapy were 6. In treated patients (N=236), cytokine release syndrome was seen in 75% (>= grade 3: 5%), immune effector cell-associated neurotoxicity syndrome in 14% (>= grade 3: 4%), and delayed neurotoxicity in 10%. Best overall and >= CR rates were as follows: infused patients (N=236): 89% and 70%; patients receiving conforming CAR-T product (N=191) 94% and 74%; conforming CAR-T product with fludarabine/cyclophosphamide lymphodepletion (N=152): 95% and 76%, respectively. Non-relapse mortality was 10%, most commonly from infection. After median follow-up of 13 months from CAR-T, median progression-free survival (PFS) was not reached, with 12- month estimate being 68% (95% CI: 62-74%). High ferritin levels, high-risk cytogenetics, and extramedullary disease were independently associated with inferior PFS, with a signal for prior BCMA-TT (p=0.08). Second primary malignancies (SPMs) excluding non-melanoma skin cancers were seen in 5.5% and myeloid malignancies/acute leukemia in 1.7%. We observed a favorable efficacy profile of standard of care cilta-cel in RRMM despite more than half the patients not meeting CARTITUDE-1 eligibility criteria.

Clinical outcomes after idecabtagene vicleucel in older patients with multiple myeloma: a multicenter real-world experience.

ABSTRACT: The safety and efficacy of chimeric antigen receptor T-cell therapy is not well described in older patients, a population that has higher frailty and comorbidities. In this multicenter retrospective study, we evaluated clinical outcomes along with frailty and geriatric characteristics such as comorbidities, polypharmacy, falls, neuropathy, organ dysfunction, and performance status in younger (aged <65 years) vs older (aged ≥65 years) patients who received commercial idecabtagene vicleucel (ide-cel). A total of 156 patients (n = 75, aged ≥65 years) were infused with ide-cel by data cutoff. In older patients (median age: 69 years; range, 65-83; 66.7% frail; 77.3% did not meet KarMMa eligibility criteria), with a median follow-up duration of 14.2 months, best overall response rate (ORR) was 86.7%, which was comparable with pivotal KarMMa study results (ORR: 73%). Median progression-free survival and overall survival in older patients were 9.1 months and 26.5 months, respectively. Grade ≥3 cytokine-release syndrome and immune effector cell-associated neurotoxicity syndrome were observed in 1% and 4% of older patients, respectively. Compared with younger patients, the older patients had significantly higher prevalence of frailty, geriatric characteristics such as polypharmacy (≥5 drugs; 97%), ≥4 comorbidities (69%), and organ dysfunction (35%; P < .05). The safety and efficacy of ide-cel therapy were similar in younger and older patients. Frailty and geriatric characteristics such as polypharmacy, comorbidities, and organ dysfunction in older patients did not confer an inferior overall outcome.

Mechanisms and management of CAR T toxicity.

Chimeric antigen receptor (CAR) T cell therapies have dramatically improved treatment outcomes for patients with relapsed or refractory B-cell acute lymphoblastic leukemia, large B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, and multiple myeloma. Despite unprecedented efficacy, treatment with CAR T cell therapies can cause a multitude of adverse effects which require monitoring and management at specialized centers and contribute to morbidity and non-relapse mortality. Such toxicities include cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, neurotoxicity distinct from ICANS, immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome, and immune effector cell-associated hematotoxicity that can lead to prolonged cytopenias and infectious complications. This review will discuss the current understanding of the underlying pathophysiologic mechanisms and provide guidelines for the grading and management of such toxicities.

Real-world experience of patients with multiple myeloma receiving ide-cel after a prior BCMA-targeted therapy.

Most patients with multiple myeloma experience disease relapse after treatment with a B-cell maturation antigen-targeted therapy (BCMA-TT), and data describing outcomes for patients treated with sequential BCMA-TT are limited. We analyzed clinical outcomes for patients infused with standard-of-care idecabtagene vicleucel, an anti-BCMA chimeric antigen receptor (CAR) T-cell therapy, at 11 US medical centers. A total of 50 patients with prior BCMA-TT exposure (38 antibody-drug conjugate, 7 bispecific, 5 CAR T) and 153 patients with no prior BCMA-TT were infused with ide-cel, with a median follow-up duration of 4.5 and 6.0 months, respectively. Safety outcomes between cohorts were comparable. The prior BCMA-TT cohort had a lower overall response rate (74% versus 88%; p = 0.021), median duration of response (7.4 versus 9.6 months; p = 0.03), and median progression-free survival (3.2 months versus 9.0 months; p = 0.0002) compared to the cohort without prior BCMA-TT. All five patients who received a prior anti-BCMA CAR T responded to ide-cel, and survival outcomes were best for this subgroup. In conclusion, treatment with ide-cel yielded meaningful clinical responses in real-world patients exposed to a prior BCMA-TT, though response rates and durability were suboptimal compared to those not treated with a prior BCMA-TT.

Antibody Drug Conjugates in Multiple Myeloma.

ABSTRACT: Antibody-drug conjugates (ADCs) have emerged as a treatment option for patients with relapsed/refractory multiple myeloma with the regulatory approval of the first-in-class B-cell maturation antigen (BCMA) ADC belantamab mafodotin. Other BCMA and non-BCMA ADCs are currently in clinical development. Whereas ADCs allow antigen-specific delivery of a chemomoiety to myeloma cells, on-target and off-target effects related to antigen target, antibody, linker, and chemomoiety can also limit these approaches. We review the clinical development of belantamab mafodotin and ongoing efforts to enhance its efficacy while mitigating ocular toxicity. The landscape of other ADCs being evaluated clinically in patients with multiple myeloma will also be reviewed.