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Shaji K. Kumar, MD
Prashant Kapoor, MD, FACP
Shaji K. Kumar, MD
Prashant Kapoor, MD, FACP
Posted: Friday, January 21, 2022
According to early research findings from a phase I/II trial, REGN5458 (a BCMA x CD3 bispecific antibody) appears to show an acceptable safety and tolerability profile in patients with relapsed or refractory multiple myeloma. Jeffrey A. Zonder, MD, of the Karmanos Cancer Institute, Detroit, and colleagues also reported that “early, deep, and durable” responses were seen in triple- to penta-refractory patients with resistant multiple myeloma. These findings were presented at the 2021 American Society of Hematology (ASH) & Exposition (Abstract 160).
Patients with progressive relapsed or refractory multiple myeloma (51% of whom were penta-refractory) or who were intolerant to prior lines of systemic therapy were included in the study. The study measured the safety, tolerability, and occurrence of dose-limiting toxicities of REGN5458. Additionally, the study tested a recommended phase II dose regimen.
As of data cutoff in June 2021, 68 patients were treated with REGN5458 in the dose-escalation cohort, with full doses ranging from 300 to 400 mg for 16 weeks. The median duration of follow-up was 2.4 months.
The response rate of patients treated at the 96-mg and 200-mg doses was 73.3% (11 of 15). Across all dose levels, 92.6% (n = 25) of all responders achieved at least a very good partial response, and 48.1% (n = 13) of responders had a complete response or stringent complete response. Patients without extramedullary plasmacytomas responded more frequently than those with extramedullary plasmacytomas.
The safety profile was consistent across all dose levels, and there was no apparent correlation between cytokine-release syndrome and the full dose of REGN5458. Treatment-related adverse events were reported in 56 patients (82.4%). The most frequent hematologic treatment-related adverse event was neutropenia in 11 patients (16.2%), with grade 3 events observed in 9 of these patients (13.2%).
Disclosure: For full disclosures of the study authors, visit ash.confex.com.
2021 ASH Annual Meeting & Exposition
