FDA grants CLR 131 fast track designation for the treatment of patients with lymphoplasmacytic lymphoma/Waldenström’s macroglobulinemia

On May 26, 2020, CLR 131, a radiotherapeutic phospholipid drug conjugate, was granted fast track designation by the U.S. Food and Drug Administration for the treatment of patients with lymphoplasmacytic lymphoma/Waldenström’s macroglobulinemia (LPL/WM) who received ≥ 2 prior treatment regimens.¹

The fast track designation was based on the ongoing phase II CLOVER-1 trial (NCT02952508) which is evaluating CLR 131 in patients with relapsed/refractory B-cell malignancies, including LPL/WM and multiple myeloma.¹ The dose-exploration portion of the study, Part A, demonstrated 100% overall response rates in patients with LPL/WM at 50 mCi (n = 2) and 75 mCi (n = 2) total body doses.²  The expansion cohort portion of the study, Part B, evaluating 100 mCi total body dose of CLR 131, showed that all patients (n = 4) with LPL/WM achieved 100% of overall response rate. One patient achieved a complete response rate,¹ which is continuing for approximately 27 months.²

CLR 131 was previously granted Orphan Drug designation in LPL, and a fast track designation for the treatment of patients with relapsed or refractory diffuse large B-cell lymphoma.