Circularly permuted TRAIL plus thalidomide and dexamethasone versus thalidomide and dexamethasone for relapsed/refractory multiple myeloma: a phase 2 study

Purpose Circularly permuted TRAIL (CPT) has exhibited promising efficacy as a mono-therapy or in combination with thalidomide for patients with multiple myeloma (MM). In this phase 2 study, the safety and efficacy of CPT in combination with thalidomide and dexamethasone (CPT + TD) was evaluated in patients with pretreated relapsed/refractory MM (RRMM). Methods Patients who received at least two previous therapies for MM were randomly assigned at a 2:1 ratio to receive treatment with CPT + TD or thalidomide and dexamethasone (TD). The primary endpoint was the overall response rate (ORR), and the secondary endpoints included progression-free survival (PFS), duration of response (DOR) and safety. Results Overall, 47 patients were assigned to the CPT + TD group, and 24 patients were recruited to the TD group. The ORR in the CPT + TD group was 38.3 vs. 25.0% in the TD group. The median PFS time was 6.7 months for the CPT + TD group and 3.1 months for the TD group. The median DORs for the CPT + TD and TD groups were 7.1 and 3.2 months, respectively. Most of the adverse effects (AEs) were grade 1 or 2. Serious AEs were reported in 19.7% of the patients. No treatment-related deaths were reported. Conclusion CPT plus TD could serve as a new therapeutic strategy for patients with RRMM. A randomized, double-blind, placebo-controlled confirmatory study is currently under way.