|The following article features coverage from the American Society of Clinical Oncology 2020 meeting. Click here to read more of Cancer Therapy Advisor‘s conference coverage.|
Administration of chimeric antigen receptor (CAR) T-cell (CAR-T) therapy JNJ-4528 to heavily pretreated patients with relapsed/refractory multiple myeloma (RRMM) resulted in high response and progression-free survival (PFS) rates, according to results from a phase 1b trial presented at the ASCO20 Virtual Scientific Program. JNJ-4528 contains 2 anti–B-cell maturation antigen (BCMA) single-domain antibodies.
“CARTITUDE-1 is a phase 1b/2 study,” Jesus G. Berdeja, MD, of the Sarah Cannon Research Institute in Nashville, Tennessee, and lead author and presenter of the study, said. “The primary objective of the phase 1 is to characterize the safety and confirm the phase 2 dose as informed by the LEGEND-2 study.”
The phase 1 study treated 29 patients with RRMM with JNJ-4528 with a median dose of 0.73 x 106 CAR T cells/kg. Patients had received 3 or more prior regimens or were double-refractory to a proteosome inhibitor (PI) or immunomodulatory (IMiD) agent and had received a prior anti-CD38 antibody. All patients underwent lymphodepletion with cyclophosphamide and fludarabine, and 79% received bridging therapy.
At baseline, the median patient age was 60 years, and 52% of patients were female. Patients received a median of 5 (range, 3-18) prior lines of therapy, and 86% were triple-refractory and 28% were penta-refractory. Nearly all patients were refractory to their last line of treatment. Extramedullary disease was present in 10% of patients and 27% had high-risk cytogenetics.
All patients responded to treatment, with an ORR of 100%. The stringent complete response (sCR) rate was 86%, 10% of patients had a very good partial response, and 3% had a partial response. The median time to complete response was 3 months.
During a median follow-up of 11.5 months, the 9-month PFS was 86% (95% CI, 67%-95%) and 76% of patients remained alive and progression free.
“The majority of patients continue to show [minimal residual disease] MRD-negative response rates beyond 28 days,” Dr Berdeja said. Among patients who achieved a CR, 81% were MRD-negative at 10-5 or 10-6.
The most common grade 3 or higher adverse events (AEs) were neutropenia (100%), thrombocytopenia (69%), and leukopenia (66%). Cytokine release syndrome (CRS) occurred in 93% of patients, including 1 grade 3 case and 1 grade 5 case, but all patients received medications to manage the inflammatory condition. Neurotoxicity occurred in 10% of patients, including 1 grade 3 event.
CAR T-cell expansion peaked between day 10 to 14, and at 6 months; most patients (79%) did not have detectable CAR T-cells in their peripheral blood. This suggests that “CAR-T persistence in peripheral blood did not seem to correlate with deepening of response,” Dr Berdeja said.
Dr Berdeja added that JNJ-4528 treatment “induced early, deep, and durable responses in heavily pretreated patients.” He noted that the phase 2 portion of CARTITUDE-1 is fully enrolled and additional phase 2 and phase 3 studies have been initiated.
Read more of Cancer Therapy Advisor‘s coverage of the ASCO 2021 meeting by visiting the conference page.
Berdeja JG, Madduri D, Usmani SZ, et al. Update of CARTITUDE-1: A phase Ib/II study of JNJ-4528, a B-cell maturation antigen (BCMA)-directed CAR-T-cell therapy, in relapsed/refractory multiple myeloma. Presented at: ASCO20 Virtual Scientific Program. J Clin Oncol. 2020;38(suppl):abstr 8505.