Cellectar Biosciences announced updated and mature 12-month follow-up data from its Phase 2b CLOVER WaM clinical trial evaluating iopofosine I 131 in patients with relapsed or refractory Waldenstrom macroglobulinemia, the company announced today.

According to a release, 83.6% of patients responded, and a 61.8% major response rate was achieved in a heavily pretreated population with a median duration of response of 17.8 months.

“Importantly, the durability of response continues to improve over time, and the consistency of activity in post-BTKi patients reinforces the potential of iopofosine to address a critical unmet need in the second-line setting and beyond,” Cellectar Biosciences President and CEO James Caruso said in a statement. “We remain committed to providing iopofosine I 131 to the thousands of patients who can benefit from treatment and plan to initiate our confirmatory study in the fourth quarter of this year.”

Cellectar Biosciences will present the full data sets at upcoming medical congresses or scientific meetings.