Regeneron Pharmaceuticals announced initial clinical data for REGN5458, a BCMAxCD3 bispecific antibody, in patients with relapsed or refractory multiple myeloma.
REGN5458 is designed to bind to BCMA on multiple myeloma cells and the CD3 receptor on T-cells, bridging them together and activating T-cell killing of the cancer cell. Results were presented today at the American Society of Hematology Annual Meeting from the first two dose groups.
Patients had a median of seven lines of prior systemic therapy, and all had failed CD38 antibody treatment. Responses were observed in 4 of 7 patients, including 3 of 4 in the 6 mg dose group. In the 6 mg dose group, 2 patients were also minimal residual disease negative, meaning that no cancer cells were detectable in their bone marrow.
“We are encouraged to see promising, rapid clinical activity even at the initial two doses of REGN5458 in heavily pretreated patients with multiple myeloma. Two patients achieved the high bar of MRD negativity, and another patient attained a very good partial response despite entering the trial with difficult-to-treat plasmacytomas outside of the bone marrow,” said Israel Lowy, Senior Vice President and Head of Clinical and Translational Sciences for Oncology at Regeneron. “We are actively recruiting patients into higher dose groups in this trial and look forward to sharing further results in 2020. In addition, we have also initiated a clinical trial for our second BCMAxCD3 bispecific, REGN5459, which has different binding characteristics.”