Photo © ASCO/David Eulitt 2017
Poster session at ASCO 2017
CHICAGO—A new type of chimeric antigen receptor (CAR) T cell, one that is specific for the B-cell maturation antigen (BCMA), has produced durable remissions in patients with multiple myeloma (MM), according to research reported at the 2017 ASCO Annual Meeting (abstract LBA3001).
BCMA is a cell surface antigen universally expressed on malignant plasma cells. It plays a role in the progression of MM and is turning out to be a highly selective antigen to target in novel treatments for MM.
This trial of LCAR-B38M is one of the first clinical trials of CAR T cells to target BCMA.
“[W]hat makes our CAR T different from other CAR T all over the world is we are truly a bispecific CAR T modality,” Frank (Xiaohu) Fan, MD, PhD, explained in a media briefing, “especially our antigen-binding units compared to single domain antibodies.” Dr Fan is CSO of Nanjing Legend Biotech in China, the developer of LCAR-B38M.
“We believe targeting BCMA alone should be enough to get a good efficacy,” he said.
To date the objective response rate is 100%.
The investigators treated 35 relapsed/refractory MM patients thus far with LCAR-B38M. Patients received the modified CAR T cells in 3 doses, on days 0, 2, and 6.
The investigators reported on 19 patients who they followed for more than 4 months, a criterion established by the International Myeloma Working Group for full efficacy evaluation.
Efficacy
Of the 19 patients, 14 (74%) achieved a stringent complete response (sCR), 4 (21%) a very good partial response (VGPR), and 1 (5%) a PR.
One patient who achieved a VGPR relapsed due to an extramedullary lesion.
Investigators observed no evidence of relapse among patients who achieved sCR.
Five patients have been followed for more than a year and all have maintained sCR.
Safety
Safety is a major issue with CAR T-cell therapies, with a frequent and major adverse event being cytokine release syndrome (CRS).
Of the 35 patients treated, 6 experienced no CRS, 17 had grade 1, 10 had grade 2, and 2 had grade 3 CRS. No patient experienced grade 4 CRS or any grade 5 event.
Because LCAR-B38M demonstrates “outstanding” efficacy with a “great” safety profile, the investigators believe this technology raises the hope of cure for MM patients.
A clinical trial of LCAR-B38M is planned in the United States.
