Cellectar Biosciences Stock Price, News & Analysis

Cellectar Biosciences, Inc. (NASDAQ: CLRB) is a late-stage clinical biopharmaceutical and radiopharmaceutical company focused on the discovery and development of proprietary drugs for the treatment of cancer. According to its SEC filings and corporate disclosures, the company’s core objective is to leverage its proprietary Phospholipid Drug Conjugate™ (PDC™) delivery platform to create cancer cell-targeting treatments designed to deliver improved efficacy and better safety through fewer off‑target effects.

Cellectar is incorporated in Delaware and classified under the pharmaceutical preparation manufacturing industry. The company reports a single operating segment centered on utilizing its PDC platform to develop drugs for oncology indications. Its common stock trades on the Nasdaq Capital Market under the ticker symbol CLRB.

Phospholipid Drug Conjugate (PDC) Platform

Cellectar’s PDC platform is based on proprietary phospholipid ether chemistry that is designed to selectively target tumor cells. Company disclosures state that this platform has demonstrated delivery of a variety of radioisotopes directly to tumor cells across a broad range of cancers. By concentrating therapeutic payloads in malignant tissue and limiting exposure in normal tissue, the platform is intended to support cancer treatments with more favorable safety profiles.

The company develops PDC-based radiotherapeutics both independently and through research and development collaborations. Its programs span beta-emitting, Auger-emitting and alpha-emitting radioisotopes, reflecting a strategy to match isotope characteristics to specific tumor types and clinical needs.

Lead Program: Iopofosine I 131

Cellectar’s lead asset is iopofosine I 131, a PDC designed to provide targeted delivery of the beta-emitting radioisotope iodine‑131 to cancer cells. Company materials describe iopofosine I 131 as a potential first‑in‑class, novel cancer-targeting radioconjugate monotherapy.

Iopofosine I 131 has been studied in multiple clinical settings, including:

• Waldenstrom’s macroglobulinemia (WM): A Phase 2b CLOVER WaM study in relapsed or refractory WM, including patients who are post‑Bruton tyrosine kinase inhibitor (BTKi) refractory. Company data summarized in SEC and news disclosures report that the trial met its primary endpoint, with high overall and major response rates and durable responses in a heavily pretreated population.
• Multiple myeloma (MM), non‑Hodgkin’s lymphomas and CNS lymphoma: Iopofosine I 131 has been evaluated in Phase 2b trials in relapsed or refractory MM, non‑Hodgkin’s lymphomas and central nervous system lymphoma.
• Pediatric high‑grade gliomas (pHGG): The CLOVER‑2 Phase 1b study in inoperable relapsed or refractory pediatric high‑grade glioma has generated interim data showing extended progression‑free survival and overall survival, disease control in all evaluable patients at certain dose levels, and a safety profile consistent with prior experience.
• Head and neck cancer (HNC): An investigator‑initiated Phase 1 study combining iopofosine I 131 with external beam radiation therapy in recurrent head and neck cancer reported complete remissions and tumor control in a majority of patients in the treated cohort, alongside hematologic toxicities consistent with prior safety data.

Regulatory agencies have recognized iopofosine I 131 with multiple designations. The U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy, Orphan Drug, Rare Pediatric Disease and Fast Track designations across various cancer indications, as disclosed in company news releases and filings. In Europe, the European Medicines Agency (EMA) has granted PRIME and orphan drug designations for WM. Following scientific advice from the EMA’s Scientific Advice Working Party (SAWP), Cellectar has been advised that filing for a Conditional Marketing Authorization (CMA) for iopofosine I 131 in post‑BTKi refractory WM patients could be acceptable, and the company has stated its intention to pursue a CMA submission.

Auger-Emitting Program: CLR 121125 (CLR 125)

CLR 121125 (CLR 125) is Cellectar’s iodine‑125 Auger‑emitting PDC program targeting solid tumors. Company disclosures describe CLR 125 as an Auger‑emitting radiotherapeutic candidate for cancers such as triple‑negative breast cancer (TNBC), lung cancer and colorectal cancer. Auger emitters have extremely short path lengths, and Cellectar reports that CLR 125 has shown tumor uptake with minimal end‑organ toxicity in preclinical models, particularly in TNBC.

The company has prepared a Phase 1b dose‑finding clinical study of CLR 125 in TNBC and has entered into a partnership with Evestia Clinical, a specialist contract research organization, to provide full CRO services for this trial. Cellectar has also identified a Mayo Clinic Network site as a treatment center and named a lead investigator, reflecting its focus on advancing CLR 125 into clinical development for difficult‑to‑treat solid tumors.

Alpha-Emitting Program: CLR 121225 (CLR 225)

CLR 121225 (CLR 225) is an actinium‑225 based alpha‑emitting PDC program targeting solid tumors with significant unmet need, including pancreatic ductal adenocarcinoma (PDAC), colorectal cancer and breast cancer. Company presentations and SEC disclosures state that CLR 225 has completed Investigational New Drug (IND)‑enabling studies and has demonstrated robust anti‑tumor activity, selective biodistribution and high tumor uptake in multiple pancreatic cancer xenograft models.

In preclinical studies, CLR 225 was observed to provide either tumor stasis or tumor volume reduction depending on dose, with potential survival benefit and no reported toxicities at the highest doses tested in animal models. Cellectar has also entered into strategic supply agreements with radioisotope manufacturers, including Ionetix and ITM Isotope Technologies Munich, to secure clinical and potential commercial‑scale supplies of actinium‑225 and other isotopes to support CLR 225 and related alpha‑emitting programs.

Pipeline Scope and Collaborations

Beyond its lead radiotherapeutic candidates, Cellectar reports a broader pipeline that includes:

• Proprietary preclinical PDC chemotherapeutic programs.
• Multiple partnered PDC assets developed through research and development collaborations.
• Additional PDC‑based radiotherapeutics in preclinical and IND‑enabling stages, including next‑generation Auger‑ and alpha‑emitting candidates.

The company’s disclosures emphasize both independent development and collaborations as key elements of its strategy to expand the application of its PDC platform across hematologic malignancies and solid tumors.

Regulatory and Clinical Strategy

Cellectar’s stated strategic priorities, based on its news releases and SEC filings, include:

• Pursuing conditional marketing approval in Europe for iopofosine I 131 in post‑BTKi refractory WM, following EMA scientific advice.
• Advancing a New Drug Application (NDA) strategy with the FDA for accelerated approval of iopofosine I 131 in WM, supported by the CLOVER WaM Phase 2b data and planned confirmatory trials.
• Continuing development of iopofosine I 131 in pediatric high‑grade gliomas through the CLOVER‑2 program, where interim data have shown extended progression‑free and overall survival with a tolerable safety profile.
• Initiating and conducting clinical studies of CLR 125 in TNBC and preparing CLR 225 for first‑in‑human trials in pancreatic cancer.

Company communications also highlight the potential eligibility for a Pediatric Review Voucher from the FDA upon approval of iopofosine I 131 in certain pediatric indications, reflecting the regulatory significance of the pediatric glioma program.

Capital Markets and Corporate Actions

Cellectar has used public equity offerings and warrant transactions to fund its operations and clinical programs. SEC filings detail:

• Registration statements on Form S‑1 and S‑1/A covering unit offerings of common stock, pre‑funded warrants and common warrants.
• A one‑for‑thirty reverse stock split of its common stock, effective June 24, 2025, intended to adjust the share count and trading price while leaving the par value unchanged.
• Warrant inducement transactions in which existing warrant holders exercised warrants for cash in exchange for new inducement warrants, providing additional gross proceeds to the company.

These capital markets activities, described in detail in the company’s S‑1 and 8‑K filings, are positioned as supporting pipeline development, regulatory submissions and general corporate purposes.

Risk and Development Stage

Cellectar describes itself as a late‑stage clinical company. Its drug candidates are in clinical and preclinical development and have not yet received full marketing approval. The company’s SEC filings and news releases emphasize that drug discovery and development involve a high degree of risk, and forward‑looking statements are subject to uncertainties related to regulatory outcomes, clinical trial results, partnering, and financing.

FAQs

• What does Cellectar Biosciences do?
  Cellectar Biosciences is a late‑stage clinical biopharmaceutical and radiopharmaceutical company focused on discovering and developing proprietary drugs for the treatment of cancer. It develops targeted radiotherapeutics based on its Phospholipid Drug Conjugate (PDC) platform.
• What is the core technology behind Cellectar’s pipeline?
  The company’s core technology is its proprietary phospholipid ether‑based PDC platform, which is designed to selectively deliver radioisotopes and other payloads to cancer cells, aiming to improve efficacy and safety by reducing off‑target effects.
• What are Cellectar’s main drug candidates?
  Key disclosed candidates include iopofosine I 131, an iodine‑131 PDC for hematologic and solid tumors such as Waldenstrom’s macroglobulinemia and pediatric high‑grade gliomas; CLR 121125 (CLR 125), an iodine‑125 Auger‑emitting program for solid tumors including triple‑negative breast, lung and colorectal cancers; and CLR 121225 (CLR 225), an actinium‑225 based alpha‑emitting program targeting solid tumors with significant unmet need, such as pancreatic cancer.
• What regulatory designations has iopofosine I 131 received?
  According to company disclosures, iopofosine I 131 has received Breakthrough Therapy, multiple Orphan Drug, Rare Pediatric Disease and Fast Track designations from the FDA for various cancer indications. The EMA has granted PRIME and orphan drug designations for WM.
• What is Cellectar’s strategy in Waldenstrom’s macroglobulinemia?
  Cellectar has conducted the CLOVER WaM Phase 2b trial of iopofosine I 131 in relapsed or refractory WM, including post‑BTKi refractory patients. Based on scientific advice from the EMA’s SAWP, the company plans to file for a Conditional Marketing Authorization in Europe for this population and is preparing an NDA pathway with the FDA under an accelerated approval framework.
• How is Cellectar addressing pediatric cancers?
  The company is evaluating iopofosine I 131 in pediatric high‑grade gliomas through the CLOVER‑2 Phase 1b trial. Interim data have shown extended progression‑free survival, overall survival and disease control in children, adolescents and young adults with relapsed or refractory disease, and the program has received Rare Pediatric Disease and Orphan Drug designations.
• What is CLR 125 and which cancers is it targeting?
  CLR 121125 (CLR 125) is an iodine‑125 Auger‑emitting PDC targeting solid tumors. Company disclosures highlight its planned evaluation in triple‑negative breast cancer and its preclinical activity in TNBC and other solid tumor models, with a Phase 1b dose‑finding study in TNBC being prepared and supported by a CRO partnership.
• What is CLR 225 and what data support its development?
  CLR 121225 (CLR 225) is an actinium‑225 based alpha‑emitting PDC program targeting solid tumors such as pancreatic ductal adenocarcinoma. Preclinical studies presented at scientific conferences and summarized in company releases show tumor growth inhibition or reduction and potential survival benefit in multiple pancreatic cancer xenograft models, along with favorable biodistribution and tolerability in animals.
• How does Cellectar fund its research and development?
  Cellectar raises capital through public equity offerings, warrant exercises and related transactions, as detailed in its S‑1 and 8‑K filings. It also benefits from grants, such as National Cancer Institute SBIR funding for pediatric studies, and pursues collaborations and potential partnerships to support its programs.
• Is Cellectar Biosciences a multi‑segment company?
  The company reports one operating and reportable segment focused on utilizing its PDC platform to develop drugs for the treatment of cancer.