ASH 2018: Novel Agent for Resistant Multiple Myeloma Under Study
Posted: Tuesday, December 18, 2018
The early results of a first-in-human, phase I, dose-escalation study of AMG 420 in patients with relapsed or refractory multiple myeloma were presented at the 2018 American Society of Hematology (ASH) Annual Meeting & Exposition in San Diego (Abstract 1010).
AMG 420 is an anti–B-cell maturation antigen (BCMA) bispecific T-cell engager antibody construct. Specifically, according to lead author Max S. Topp, MD, of the University Hospital of Würzburg, Germany, and colleagues, AMG 420 binds BCMA on tumor cells and plasma cells and CD3 on T cells, “resulting in T-cell–mediated lysis of BCMA-positive cells.”
A total of 35 eligible patients, all with progression of relapsed or refractory multiple myeloma after at least 2 prior treatment lines, received AMG 420 in doses ranging from 0.2 µg/day to 800 µg/day for up to five 6-week cycles; one cycle included 4 weeks of continuous intravenous infusion, 2 weeks off.
According to the investigators, 6 patients had complete responses to AMG 420; three received 6.5, 100, and 200 µg/day and three received 400 µg/day. In fact, the complete responders at the 400-µg/day dose were minimal residual disease–negative. “Responses are ongoing for these last three (≥ 4.6 months). There also were two partial remissions, a partial response at 50 µg/day, and a very good partial response at 800 µg/day.”
As for safety, two of the three patients who were given 800 µg/day experienced dose-limiting toxicities. Since no such toxicities were observed at up to 400 µg/day, Dr. Topp and colleagues recommend the 400-µg/day dose for further investigation.