bb21217 is a new treatment being investigated in myeloma that belongs to a type of immunotherapy known as chimeric antigen receptor T-cell (CAR-T) therapy. This involves T-cells being taken from the patient and being changed to find myeloma cells more easily. bb21217 is similar to its predecessor (bb2121) but this new construct includes a phosphoinositide 3-kinase inhibitor, whose addition is designed to make the cells more potent and enable them to persist longer.
December 05, 2020
“Regarding safety and tolerability, the most common adverse event [AE] was grade 3/4 cytopenias,” said Alsina, an associate professor of medicine in the Blood and Marrow Transplant Program and head of the Multiple Myeloma Transplant Program, both at Moffitt Cancer Center in Tampa, Florida. “These were not dose related,” she added.
Median time to recovery for grade 3/4 neutropenia and grade 3/4 thrombocytopenia was 2.0 months and 2.2 months, respectively. Grade 3/4 infection was reported in 26% of patients, with 1 death from infection reported within 6 months, but in the absence of disease progression.
There were 2 deaths reported within 8 weeks of the bb21217 infusion, both attributed to cytokine release syndrome (CRS).
Regarding CRS, the median time to onset was 2 days (range, 1-20) with 70% of patients reporting any grade CRS. The majority of patients reported 65% of grade 1/2 CRS, 1% reported grade 3 and 3% reported grade 5. To alleviate CRS symptoms, 31 patients received tocilizumab (Actemra) and 10 patients received the combination of tocilizumab and corticosteroid.
The objective response rate (ORR) was reported as 68% with a stringent complete response (sCR)/CR of 29% and a very good partial response (VGPR) of 25%. Median time to first response was 1 month.