Cellectar Biosciences (NASDAQ: CLRB), a late-stage clinical biopharmaceutical company based in Florham Park, New Jersey focused on targeted oncology therapies, announced an oversubscribed financing of up to USD 140 million through a registered direct offering and concurrent private placement, comprising approximately USD 35 million in upfront proceeds and USD 105 million in milestone-based securities.
The round was led by Nantahala Capital Management, with participation from Balyasny Asset Management, Caligan Partners, Janus Henderson Investors, SilverArc Capital Management, Stonepine Capital Management, Empery Asset Management LP, StemPoint Capital LP, other dedicated healthcare funds, and members of the company's executive management team. Ladenburg Thalmann & Co. Inc. served as exclusive placement agent. Cellectar said proceeds will support a confirmatory study and NDA filing for accelerated US FDA approval of iopofosine I 131 in Waldenström macroglobulinemia (WM), with a global confirmatory trial initiation targeted for Q4 2026. Funding will also advance CLR 125, the company's Auger-emitting program targeting solid tumors including triple-negative breast cancer (TNBC). In connection with the financing, Andrew Gu of Nantahala Capital Management will join Cellectar's board of directors upon closing.
Cellectar's lead candidate, iopofosine I 131, is built on the company's proprietary Phospholipid Drug Conjugate (PDC) platform, which is designed to deliver radioisotopes and other cytotoxic payloads selectively to cancer cells by exploiting the altered lipid metabolism of malignant tissue. Iopofosine I 131 delivers iodine-131 via this mechanism and has been evaluated in Phase II studies across relapsed or refractory WM, multiple myeloma, and CNS lymphoma. The US FDA has granted the molecule Breakthrough Therapy designation, six Orphan Drug designations, four Rare Pediatric Drug designations, and two Fast Track designations across various cancer indications. The European Medicines Agency has granted PRIME designation.
The company is also running the CLOVER-2 Phase Ib study, which is evaluating iopofosine I 131 in pediatric patients with high-grade gliomas. Cellectar said it is eligible to receive a Pediatric Review Voucher from the US FDA upon approval in this indication. CLR 125, an iodine-125 Auger electron-emitting PDC candidate targeting solid tumors including TNBC, lung, and colorectal cancer, is currently in a Phase Ib study for TNBC to determine a recommended dose for a subsequent Phase II trial. Earlier in the pipeline, CLR 225 is an actinium-225-based program targeting solid tumors in indications such as pancreatic cancer, alongside additional preclinical PDC chemotherapeutic and partnered programs.