Cellectar Biosciences, Inc. was granted Fast Track Designation by the FDA for CLR 131 in fourth line or later relapse/refractory multiple myeloma. CLR 131 is the company’s small-molecule radiotherapeutic phospholipid drug conjugate (PDC) designed to deliver cytotoxic radiation directly and selectively to cancer cells and cancer stem cells. It is currently being evaluated in Cellectar’s ongoing CLOVER-1 Phase II study in patients with relapsed or refractory multiple myeloma and other select B-Cell lymphomas.

“Fast Track Designation furthers our efforts to expeditiously develop CLR 131 as a new, innovative therapy for patients with relapse/refractory multiple myeloma,” said James Caruso, president and chief executive officer of Cellectar. “Patients with third line or later relapsed/refractory multiple myeloma have a poor prognosis and low rates of survival as a result of limited effective treatment options. Based on data in the initial patient cohort from our ongoing CLOVER-1 trial where patients showed a 30% response rate after receiving a single 25.0 mCi/m2 dose as a seventh line of therapy on average, we are optimistic that CLR 131 has the potential to provide a meaningful treatment option for these patients.”

Fast Track Designation is granted to drugs for the treatment of serious or life-threatening diseases or conditions where there is an unmet medical need. The purpose of the Fast Track Designation is to help facilitate development and expedite the review of drugs to treat serious and life-threatening conditions.

Sponsors of drugs that receive Fast Track Designation have the opportunity for more frequent interactions with the FDA. Additionally, these products may be eligible for priority review of a New Drug Application (NDA) and the FDA may consider reviewing portions of an NDA before the sponsor submits the complete application (Rolling Review).

CLOVER-1 is a Phase II study of CLR 131 being conducted in approximately 10 leading cancer centers in the U.S. in patients with relapsed or refractory B-cell hematologic cancers. The hematologic cancers being studied in the trial include multiple myeloma (MM), chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), lymphoplasmacytic lymphoma (LPL), marginal zone lymphoma (MZL), mantle cell lymphoma (MCL), and diffuse large B-cell lymphoma (DLBCL).  

The study’s primary endpoint is clinical benefit response (CBR), with additional endpoints of overall response rate (ORR), progression free survival (PFS), median overall survival (OS) and other markers of efficacy.