ASH 2021: Early-Phase Trial of Idecabtagene Vicleucel in Resistant Multiple Myeloma
Posted: Wednesday, December 15, 2021
The phase I CRB-402 trial, performed by Noopur S. Raje, MD, of Mass General Hospital Cancer Center, Boston, and colleagues, assessed idecabtagene vicleucel (also known as bb21217)—a B-cell maturation antigen (BCMA)-directed chimeric antigen receptor (CAR) T-cell therapy with an added PI3K inhibitor—for duration of response in patients with resistant multiple myeloma. Their results, which were presented during the 2021 American Society of Hematology (ASH) Annual Meeting & Exposition (Abstract 548), concluded that outcomes of this treatment appear to be promising with consistent toxicities.
“Efficacy results are encouraging, with a median duration of response estimate of 17 months; complete response rate continues to mature,” stated the investigators. “Patients with higher levels of proliferative, less differentiated memory-like CAR-positive T cells at peak expansion are more likely to experience prolonged duration of response, continuing to support the hypothesis that the memory-like T-cell phenotype associated with bb21217 results in a prolonged duration of response.”
This multicenter trial enrolled 72 patients with relapsed or refractory multiple myeloma who received at least three prior lines of therapy. Participants underwent lymphodepletion with cyclophosphamide and fludarabine and then received a single infusion of bb21217 at 150 (n = 12), 300 (n = 14), or 450 (n = 46) x 106 CAR-positive T cells.
The median follow-up was 9.0 months, and the median number of prior therapy lines was six. The majority (75%) of patients developed cytokine-release syndrome of grade 1/2 (n = 51) or 3 (n = 1), with a median onset of 2 days; neurotoxicity was reported in 11 patients, with a median onset of 7 days.
CAR-positive T cells were detectable in 81% and 60% of patients at 6 and 12 months, respectively. Of 15 participants evaluable for measurable residual disease (MRD) who experienced a complete response, 14 achieved MRD negativity. Notably, individuals with a higher number of CD8-positive CAR-positive T cells demonstrated a significantly longer duration of response (P = .0024) compared with those exhibiting lower numbers.
Disclosure: For full disclosures of the study authors, visit ash.confex.com.
