High rates of durable complete responses are reported at the 2021 ASCO Annual Meeting with ciltacabtagene autoleucel in patients with relapsed or refractory multiple myeloma.
Patients who had received 1 to 3 prior lines of therapy for multiple myeloma experienced early and deep responses when treated with a single infusion of ciltacabtagene autoleucel (cilta-cel), according to data from the phase 2 CARTITUDE-2 study (NCT04133636) that was presented during the 2021 ASCO Annual Meeting.
Treatment with a target dose of cilta-cel at 0.75 x 106/kg resulted in an overall response rate (ORR) of 95% (95% CI, 75%-100%) with a stringent complete response rate (sCR) of 75% (95% CI, 51%-91%), and a very good partial response rate or better of 85% (95% CI, 62%-97%).
After a median follow-up of 5.8 months, the median time to first response with cilta-cel was 1 month (range, 0.7–3.3) and the median time to best response was 1.9 months (0.9–5.1). As of the January 2021 data cutoff, a median duration of response had not yet been reached.
Cilta-cel, formerly JNJ-68284528, is a second-generation CAR T-cell therapy with 2 BCMA-targeting, single-domain antibodies designed to confer avidity. Previous data that were published from the phase 1b/2 CARTITUDE-1 (NCT03548207) trial demonstrated that single infusion of cilta-cel was associated with deep and durable response among heavily pretreated patients with relapsed/refractory disease.
The primary objective of this cohort of the CARTITUDE-2 trial was to assess minimal residual disease (MRD) negativity at 10–5 threshold among patients who were refractory to lenalidomide or relapsed after one to three prior lines of therapy. Additional secondary outcomes included ORR, duration of response (DOR), time and duration of MRD negativity and incidence and severity of adverse events (AEs).
Patients received the targeted dose of cilta-cel 5 to 7 days after the beginning of lymphodepletion (daily cyclophosphamide at 300 mg/m2 and fludarabine at 30 mg/m2 for 3 days).
A total of 20 patients (median age, 60 years; 65% male) received the single-infusion CAR T-cell therapy. One of the patients was treated in an outpatient setting. Twelve of the patients had received fewer than 3 lines of therapy, and the remaining 8 received 3 prior lines of therapy.
All the patients had been previously treated with a proteasome inhibitor (PI), an immunomodulatory drug (IMiD) and dexamethasone. Almost all (95%) of the patients were exposed to alkylating agents and 65% received daratumumab (Darzalex).
All patients (n = 4) with MRD-evaluable samples were MRD negative at the January 2021 cutoff and more samples are being evaluated.
In terms of safety, hematologic AEs that occurred in 20% or more of the patients included neutropenia (95%), thrombocytopenia (80%), anemia (65%), lymphopenia (60%) and leukopenia (55%). Moreover, cytokine release syndrome occurred in 85% of patients, of which 10% were considered grade 3 or 4.
“The safety profile was manageable, including in the one patient that was treated in the outpatient setting,” said study author Mounzer E. Agha, MD, director, Mario Lemieux Center for Blood Cancers, clinical director of Hematopoietic Stem Cell Transplantation, UPMC Hillman Cancer Center, during a recorded presentation of the data. “There were no cases of movement and neurocognitive adverse events.”
Agha noted that one death occurred 100 days after the infusion of cilta-cel due to COVID-19 infection and was assessed as treatment-related by the investigators.
“Early and deep responses were observed with a single infusion of cilta-cel in lenalidomide refractory patients with multiple myeloma who received one-to three prior lines of therapy,” he concluded.
The CAR T-cell therapy is being evaluated in other cohorts of the CARTITUDE-2 in earlier line settings, as well as in the phase 3 CARTITUDE-4 (NCT04181827) study in patients with one to three prior lines of therapy.
Agha ME, Cohen AD, Madduri D, et al. CARTITUDE-2: Efficacy and safety of ciltacabtagene autoleucel (cilta-cel), a BCMA-directed CAR T-cell therapy, in patients with progressive multiple myeloma (MM) after one to three prior lines of therapy. J Clin Oncol. 2021;39(suppl 15): abstract 8013.