Cevostamab Associated With Clinical Benefits for Certain Patients With Relapsed/Refractory Multiple Myeloma

Updated results from an ongoing phase 1 study evaluating cevostamab monotherapy in patients with heavily pre-treated relapsed/refractory multiple myeloma (RRMM) found that cevostamab continues to show clinically meaningful activity in a large cohort of these patients. According to the trial results, presented at the American Society of Hematology’s 2021 Annual Meeting and Exposition, these responses appear durable, with a target dose-dependent increase in overall response rate (ORR) without any increase in the rate of cytokine release syndrome (CRS).

Study participants have RRMM for which no established therapy is available or appropriate, according to the investigators. Cevostamab is administered to these patients intravenously in 21-day cycles and continued for a total of 17 cycles, barring progressive disease or unacceptable toxicity. Patients are split between 2 dosing schedules: step-up (SS) dosing, in which a step dose is given on day 1 of the first cycle followed by the targeted dose on day 8, and double step-up (DS) dosing, in which step doses are given on days 1 and 8, followed by the targeted dose on day 15. Initial data demonstrated manageable safety and promising activity.

According to the investigators, the data suggest a target dose-dependent increase in clinical efficacy, with responses observed at the 20–198 mg target dose levels. Median time to response was 29 days, with a range from 20 to 179 days. After opening 2 dose-expansion cohorts, the investigators found that ORR was higher at the 160 mg dose level at 54.5% compared to 36.7% in the 90 mg dose level cohort.

A total of 160 patients with a median of 6 prior lines of therapy were enrolled in the study at the time of data cut-off. The median follow-up in exposed patients was 6.1 months.

Almost all patients in the study had 1 or fewer adverse event, with the most common being CRS, occurring in 80% of patients. Immune effector cell-associated neurotoxicity syndrome associated with CRS was observed in 13.1% of patients and 16.1% of CRS events.

REFERENCE

Trudel S, Cohen AD, Krishnan AY, et al. Cevostamab monotherapy continues to show clinically meaningful activity and manageable safety in patients with heavily pre-treated relapsed/refractory multiple myeloma (RRMM): updated results from an ongoing phase I study. Presented at: ASH Annual Meeting and Exposition 2021. Accessed December 9, 2021. https://ash.confex.com/ash/2021/webprogram/Paper147983.html