Cellectar's Iopofosine I 131 Posts 79.2% Major Response Rate in BTK-Refractory Waldenström Macroglobulinemia
核心洞察
A Phase 2 CLOVER WaM subset analysis of iopofosine I 131 (搜索) in BTK (搜索) inhibitor-refractory or resistant Waldenström macroglobulinemia (搜索) showed a 79.2% major response rate and 87.5% overall response rate.
Duration of response exceeded 16 months in patients who received iopofosine I 131 (搜索) immediately after BTK (搜索) inhibitor therapy and at least two prior lines of treatment.
Cellectar plans to dose patients in a confirmatory Phase 3 trial in early 2027 and file a New Drug Application for accelerated approval in the first half of 2027.
Cellectar Biosciences reported that a subset analysis of its Phase 2 CLOVER WaM trial showed a major response rate of 79.2% and an overall response rate of 87.5% with iopofosine I 131 (搜索) in patients with Waldenström macroglobulinemia (搜索) (WM) who are refractory or resistant to BTK (搜索) inhibitor therapy. Duration of response exceeded 16 months in the subset of patients treated with iopofosine I 131 immediately after BTK inhibitor therapy.
The analysis evaluated patients who received iopofosine I 131 (搜索) immediately following BTK (搜索) inhibitor therapy after at least two prior lines of treatment. Cellectar described this as a particularly challenging, heavily pretreated population.
"We are pleased to present these data from the CLOVER-WaM study at IWWM and share additional evidence supporting the potential of iopofosine I 131 (搜索) to address a significant unmet need for patients with WM," said Jarrod Longcor, chief operating officer at Cellectar Biosciences.
Presentation at IWWM 2026
The data will be highlighted in a poster presentation at the International Workshop for Waldenström Macroglobulinemia (搜索) (IWWM), taking place October 14 to 16, 2026, in Palm Springs, California. The poster, titled "Iopofosine I 131 (搜索) After BTK (搜索) Inhibitors in Waldenström Macroglobulinemia: CLOVER-WaM Subgroup Efficacy and Safety," is scheduled for Session 14 on October 15, 2026, at 4:00 PM in Sierra-Ventura Hall. Longcor will present.
Regulatory Path and Timeline
Cellectar said it remains on target to dose patients in the confirmatory Phase 3 clinical trial in early 2027 and to file a New Drug Application for accelerated approval in the first half of 2027. Because iopofosine I 131 (搜索) holds Breakthrough Therapy Designation, the company expects a six-month review with a potential approval by the end of 2027.
"We remain on-target to dose patients in the confirmatory Phase 3 clinical trial in early 2027 and to file our New Drug Application for accelerated approval in the first half of 2027," Longcor said.
Mechanism and Development Program
Iopofosine I 131 (搜索) is an investigational targeted radiotherapy built on Cellectar's Phospholipid Drug Conjugate (PDC) delivery platform, which is designed to deliver iodine-131 (搜索) (radioisotope) to cancer cells. The company states the platform aims to improve efficacy and safety through fewer off-target effects.
The agent has been tested in Phase 2b trials in relapsed or refractory WM, relapsed or refractory multiple myeloma (搜索), and central nervous system lymphoma (搜索). The CLOVER-2 Phase 1b study is evaluating iopofosine I 131 (搜索) in pediatric patients with high-grade gliomas (搜索), for which Cellectar is eligible to receive a Pediatric Review Voucher from the FDA upon approval.
The FDA has granted iopofosine I 131 (搜索) Breakthrough, six Orphan Drug, four Rare Pediatric Drug and two Fast Track Designations across various cancer indications, and the EMA has granted it PRIority MEdicines (PRIME) designation.
Broader Pipeline
Cellectar is also developing CLR 121125 (CLR 125), an iodine-125 Auger-emitting program targeted at solid tumors including triple negative breast cancer (搜索), lung cancer and colorectal cancer. CLR 125 is being evaluated in a Phase 1b study in triple negative breast cancer that will determine the recommended dose for the subsequent Phase 2 trial; the company reports it has been well tolerated in vivo and has shown preclinical data of reduction or inhibition of solid tumor growth.
The company is additionally developing CLR 121225 (CLR 225), an actinium-225 based program targeting solid tumors in indications with significant unmet need, such as pancreatic cancer (搜索), along with proprietary preclinical PDC chemotherapeutic programs and multiple partnered PDC assets.