Phase 2 Study of Cemsidomide Plus Dexamethasone in Relapsed/Refractory Multiple Myeloma

The primary objective is to determine the antitumor activity of cemsidomide in combination with dexamethasone in subjects with relapsed/refractory multiple myeloma, which is clinically relevant for assessing disease control in a heavily pretreated population. The secondary objectives are to evaluate additional antitumor activity, to characterize safety and tolerability, and to assess the pharmacokinetics of cemsidomide in this setting.

The trial enrolled 55 participants with relapsed/refractory multiple myeloma. The study population included male and female patients, and the age range was not specified in the source data. Participants were selected from patients with a documented diagnosis of multiple myeloma and measurable disease at enrollment, with prior exposure to at least three anti-myeloma regimens, including an immunomodulatory drug, a proteasome inhibitor, an anti-CD38 antibody, and a T-cell engager or CAR-T therapy when available per local standard of care. Additional requirements included adequate organ function and resolution of prior treatment-related toxicities to grade 1 or lower. Relevant lifestyle-related restrictions included contraception requirements for men and women of childbearing potential, avoidance of pregnancy and breastfeeding, and refraining from sperm, ova, and blood donation during the study period and for a defined period afterward.

This is a Phase 2, open-label, single-arm, multicenter interventional study evaluating cemsidomide in combination with dexamethasone in subjects with relapsed/refractory multiple myeloma. The main objective is to determine antitumor activity, with efficacy assessed by overall response rate according to International Myeloma Working Group Response Criteria and independent review. The study is planned to run from 2026-06-15 to 2030-03-31. Study participation begins with a screening visit to confirm eligibility, including informed consent, documented diagnosis, measurable disease, prior treatment history, adequate organ function, and resolution of prior toxicities. Eligible subjects then enter the treatment period, during which study treatment is administered and safety, response, and plasma concentrations are assessed at follow-up visits. An end-of-study visit is performed at treatment completion or discontinuation to document final assessments. Expected participant involvement extends from screening through the treatment and follow-up assessments until the end-of-study visit. Early termination may occur if eligibility criteria are not met, if disease progression, unacceptable toxicity, or other adverse events occur, if treatment is interrupted or discontinued, or if a subject withdraws consent or otherwise cannot continue study procedures.

Cemsidomide was administered as an oral tablet at a dose of 100 micrograms once daily. In the study, it was used as the investigational treatment in combination with dexamethasone for subjects with relapsed/refractory multiple myeloma. The dosing regimen and route of administration were defined for clinical trial use.

Dexamethasone was used as a non-experimental concomitant treatment in the study. No additional details on its formulation, dose, or administration schedule were provided in the source data. The study was open-label and single-arm, and no placebo or comparator treatment was described. Information on drug administration procedures, dose modifications, or participant compliance monitoring was not provided.

Overall response rate per International Myeloma Working Group (IMWG) Response Criteria by an Independent Review Committee (IRC) is the primary efficacy endpoint. Secondary efficacy endpoints include duration of response, complete response rate, time to response, progression-free survival, and overall survival. Plasma concentrations of cemsidomide are also assessed.