Recombinant Circularly Permuted TRAIL (CPT) for the Treatment of Relapsed or Refractory Multiple Myeloma: An Open-Label, Multicenter Phase II Clinical Trial

Circularly permuted TRAIL (CPT) is a recombinant mutant of human Apo2L/TRAIL developed by Beijing Sunbio Biotech Co., Ltd. as a targeted therapy for multiple myeloma and other hematologic malignancies. CPT is a dual pro-apoptotic receptor agonist that directly activates both pro-apoptotic receptors TRAIL-R1 (DR4) and TRAIL-R2 (DR5). CPT selectively induces apoptosis in a variety of cancer cells, while sparing most normal cells in preclinical models.

CPT has shown preliminary activities for patients with relapsed or refractory multiple myeloma (Rel/Ref MM) in phase I study. The aim of this phase II study is to investigate the effect and safety of CPT for Rel/Ref MM patients.

In this multi-center, open-label, single arm phase II study, twenty-seven Rel/Ref MM patients were enrolled to receive CPT treatment alone at the dose of 2.5 mg/kg/day intravenously, once daily for 14 consecutive days of each 21-day cycle. Clinical responses to CPT after 2 cycle's treatment were assessed by an independent review committee according to the criteria of the European Group for Blood and Marrow Transplantation (EBMT).

Among the 27 patients, one patient (3.7%) achieved near complete response (nCR) and eight patients (29.63%) exhibited partial response (PR). The overall response rate (ORR) was 33.3%. The median PFS was not reached within 2 cycle's treatment. The drug related adverse events (≥10%) included fever, AST/ALT elevation, leucopenia, neutropenia, rash, thrombocytopenia, and LDH elevation. The severe adverse events were occurred in 3 patients (11%), one of them was CPT-related liver injury. Anti-drug antibodies were detected in 6 patients without reduced efficacy or increased toxicities.

The CPT is a very effective and well-tolerated new agent for Rel/Ref MM, and it is worthy to be further studied.

Yang:Beijing Sunbio Biotech Co. Ltd.: Employment. Cui:Beijing Sunbio Biotech Co. Ltd.: Employment.