Phase I Study Findings With bb2121 in Resistant Myeloma
Posted: Monday, June 24, 2019
After preclinical work indicated that bb2121, a chimeric antigen receptor (CAR) T-cell therapy that targets B-cell maturation antigen, could potentially treat multiple myeloma, Noopur Raje, MD, of Massachusetts General Hospital Cancer Center in Boston, and colleagues have found through a 33-patient phase I trial that the agent does indeed have antitumor activity. The trial’s primary endpoint was safety, and all adverse events were reported in the study’s account in The New England Journal of Medicine.
All participants (median age, 60 years) had relapsed or refractory disease and had received at least three previous lines of therapy, including a proteasome inhibitor and an immunomodulatory agent, or were refractory to both drug classes. Each patient received a single infusion of bb2121 in this open-label study, although the doses varied.
The objective response rate was 85%, and 15 patients (45%) achieved a complete response (6 of whom have since relapsed). The median progression-free survival was 11.8 months. Sixteen patients who had a partial or complete response appeared to be negative for minimal residual disease.
“The results observed with bb2121 indicate a favorable safety profile,” the authors reported. All patients experienced at least one adverse event, including 28 (85%) who experienced a grade 4 event. The grade 3 or higher events that occurred most frequently were hematologic in nature: neutropenia (85% of patients), leukopenia (58%), anemia (45%), and thrombocytopenia (45%).
“CAR T-cell expansion was associated with responses, and CAR T cells persisted up to 1 year after the infusion,” declared Dr. Raje and her colleagues.
Disclosure: The study authors’ disclosure information can be found at nejm.org.