This section highlights FDA-related milestones and regulatory updates for drugs developed by Cellectar Biosciences (CLRB).
Over the past two years, Cellectar Biosciences has reported clinical trial outcomes, regulatory submissions, approvals, and other FDA events for drugs and therapies such as
Iopofosine, CLR, and CLR. For definitions of regulatory abbreviations such as NDA, BLA, or PDUFA, see the event status legend.
Select a button below to view the list of FDA events for that drug.
Iopofosine I-131 FDA Regulatory Timeline and Events
Iopofosine I-131 is a drug developed by Cellectar Biosciences for the following indication: Pediatric Brain and Solid Tumors.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- Iopofosine I-131
- Announced Date:
- May 5, 2026
- Indication:
- Pediatric Brain and Solid Tumors
Announcement
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 (r/r) Waldenström macroglobulinemia (WM).,
AI Summary
Cellectar Biosciences reported mature 12-month follow-up data from its Phase 2b CLOVER WaM trial of iopofosine I 131 in relapsed or refractory Waldenström macroglobulinemia. In the per-protocol population (n=55) the overall response rate was 83.6% and the major response rate (MRR) was 61.8%, with a median duration of response of 17.8 months, showing deep and durable responses in a heavily pretreated group.
Results were consistent in patients previously treated with BTK inhibitors: in BTKi-exposed patients (n=39) MRR was 64.1% with median DoR 18.2 months and median PFS 15.9 months; in BTKi-refractory patients (n=33) MRR was 63.6% with median DoR 18.2 months and median PFS 14.8 months. The regimen is time-limited—four approximately 30-minute infusions—and responses often deepened over follow-up.
Safety was predictable and manageable, with cytopenias as the most common events, low infection rates (<10%), mostly low-grade non-hematologic toxicities, and no significant bleeding events. The ≥12-month dataset strengthens regulatory positioning, supports initiation of a confirmatory randomized study in 4Q26, and is backed by an oversubscribed financing up to $140 million to support the confirmatory trial and potential filings.
Read Announcement- Drug:
- Iopofosine I-131
- Announced Date:
- October 27, 2025
- Indication:
- Pediatric Brain and Solid Tumors
Announcement
Cellectar Biosciences, announced the U.S. Food and Drug Administration (FDA) has granted rare pediatric drug designation (RPDD) for iopofosine I 131 in inoperable relapsed or refractory pediatric high-grade glioma (r/r pHGG).
AI Summary
Cellectar Biosciences announced the FDA granted rare pediatric disease designation for iopofosine I 131 to treat inoperable relapsed or refractory pediatric high-grade glioma (r/r pHGG). Iopofosine I 131 is a novel radioconjugate that uses a phospholipid ether to deliver iodine-131 directly to cancer cells and could become a first-in-class targeted therapy.
Interim results from the Phase 1b CLOVER-2 trial showed that patients receiving at least 55 mCi experienced median progression-free survival of 5.4 months and overall survival of 8.6 months. Additional dosing cycles further extended disease control and produced some objective responses. The safety profile was manageable, with predictable blood-related side effects.
The rare pediatric disease designation supports development of therapies for serious conditions in children. If the drug is approved, Cellectar may qualify for a Priority Review Voucher to speed future FDA reviews and help deliver this treatment to patients faster.
Read Announcement- Drug:
- Iopofosine I-131
- Announced Date:
- October 6, 2025
- Indication:
- Pediatric Brain and Solid Tumors
Announcement
Cellectar Biosciences announced that after a scientific advice procedure, the Scientific Advice Working Party (SAWP) of the European Medicines Agency (EMA) advised that filing for a Conditional Marketing Authorization (CMA) for iopofosine I 131 as a treatment for post-Bruton Tyrosine Kinase inhibitor (BTKi) refractory patients with Waldenstrom macroglobulinemia (WM) could be acceptable for a CMA.
AI Summary
In October 2025, Cellectar Biosciences announced that after a scientific advice procedure, the Scientific Advice Working Party (SAWP) of the European Medicines Agency (EMA) advised that filing a Conditional Marketing Authorization (CMA) for iopofosine I-131 as a treatment for post-BTKi refractory Waldenstrom macroglobulinemia patients could be acceptable.
Iopofosine I-131 is a potential first-in-class radioconjugate monotherapy that uses Cellectar’s proprietary phospholipid ether platform. It has already received PRIME designation from the EMA for patients who have received at least two prior treatments.
Cellectar expects to submit the CMA application in early 2026 and, if approved, hopes to launch iopofosine I-131 in 2027 across the 30 countries represented by the EMA.
This recommendation addresses a serious unmet need in Europe, where 35,000 to 45,000 people live with Waldenstrom macroglobulinemia and few options exist after BTKi failure. CMA status could speed access for these patients.
Read Announcement- Drug:
- Iopofosine I-131
- Announced Date:
- September 30, 2025
- Indication:
- Pediatric Brain and Solid Tumors
Announcement
Cellectar Biosciences, announced that Jarrod Longcor, chief operating officer of Cellectar, delivered an oral presentation followed by a 55-minute panel discussion with other experts in the field at the American Association for Cancer Research (AACR) Special Conference on Pediatric Cancer that took place September 25-28 in Boston, Massachusetts.
AI Summary
Cellectar Biosciences announced that Jarrod Longcor, COO, delivered an oral presentation and led a 55-minute expert panel at the AACR Special Conference on Pediatric Cancer in Boston, drawing pediatric oncologists and researchers.
He shared interim results from the Phase 1b study of iopofosine I-131 in relapsed or refractory pediatric high-grade glioma. Patients receiving at least 55 mCi had an average progression-free survival of 5.4 months and overall survival of 8.6 months. Those with four or more infusions saw progression-free survival of 8.1 months and overall survival of 11.5 months, including two objective responses.
Two case studies showed a 25-year-old male with more than 50% tumor shrinkage and ongoing survival beyond 18 months, and a 15-year-old female with lesion reduction and survival over 17 months. Treatment was well tolerated with mainly manageable blood-related side effects, reinforcing Cellectar’s commitment to providing new options.
Read Announcement- Drug:
- Iopofosine I-131
- Announced Date:
- August 27, 2025
- Indication:
- Pediatric Brain and Solid Tumors
Announcement
Cellectar Biosciences, Inc. announced the acceptance of an abstract for oral presentation followed by a 55-minute panel discussion with other experts in this area at the American Association for Cancer Research (AACR) Special Conference on Pediatric Cancer taking place September 25-28 in Boston, Massachusetts.
AI Summary
Cellectar Biosciences announced that an abstract has been accepted for an oral presentation followed by a 55-minute panel discussion at the American Association for Cancer Research (AACR) Special Conference on Pediatric Cancer. The event runs September 25–28 in Boston, Massachusetts.
The oral presentation highlights interim data from the Phase 1b dose and regimen optimization study of iopofosine I-131 in inoperable relapsed or refractory pediatric high-grade glioma. It is scheduled for Plenary Session 3: From Targets to Trials: Rethinking How We Design Child-First Medicine on September 26, 2025, at 2:50 pm Eastern.
Jarrod Longcor, Chief Operating Officer of Cellectar, said he is honored by the AACR peer review process and encouraged by the initial findings from the CLOVER-2 trial. He believes these results support the clinical potential of iopofosine I-131 for treating aggressive cancers in patients with limited options.
Read Announcement- Drug:
- Iopofosine I-131
- Announced Date:
- June 11, 2025
- Indication:
- Pediatric Brain and Solid Tumors
Announcement
Cellectar Biosciences, announced initial results as of June 10, 2025, from the CLOVER-2 Phase 1 clinical trial evaluating iopofosine I 131 in relapsed/refractory pediatric high-grade glioma (pHGG) patients.
AI Summary
Cellectar Biosciences announced initial results from its CLOVER-2 Phase 1 trial evaluating iopofosine I 131 in relapsed/refractory pediatric high-grade glioma (pHGG) patients. The trial involved children with aggressive brain tumors, including diffuse midline gliomas, DIPG, and anaplastic ependymomas.
Patients who received a minimum total dose of 55 mCi experienced an average progression free survival of 5.4 months and overall survival of 8.6 months. Notably, those who received at least four infusions had longer averages of 8.1 months of progression free survival and 11.5 months of overall survival, with two patients achieving an objective response. The treatment was well tolerated, showing manageable hematologic side effects without significant cardiovascular, renal, or liver toxicities. These results provide promising evidence of iopofosine I 131’s potential as a new option for pediatric patients with limited treatment choices.
Read Announcement- Drug:
- Iopofosine I-131
- Announced Date:
- June 4, 2025
- Indication:
- Pediatric Brain and Solid Tumors
Announcement
Cellectar Biosciences, announced that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation for iopofosine I 131, a potential first-in-class, novel cancer targeting agent utilizing a phospholipid ether as a radioconjugate monotherapy, for the treatment of relapsed/refractory Waldenstrom macroglobulinemia (r/r WM).
AI Summary
Cellectar Biosciences announced that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation to iopofosine I 131, a potential first-in-class cancer targeting agent. This novel treatment uses a unique phospholipid ether radioconjugate as a monotherapy and is aimed at treating patients with relapsed or refractory Waldenstrom macroglobulinemia (r/r WM), a subtype of lymphoplasmacytic lymphoma with few effective treatment options. The FDA’s decision is based on promising clinical data, which suggest that iopofosine I 131 could offer significant improvements in patient outcomes compared to current therapies. This designation is intended to expedite the development and review process, potentially leading to a faster path toward regulatory approval and making a meaningful treatment difference for patients with this challenging form of cancer.
Read Announcement- Drug:
- Iopofosine I-131
- Announced Date:
- March 13, 2025
- Indication:
- Pediatric Brain and Solid Tumors
Announcement
Cellectar Biosciences, provided a corporate update.
AI Summary
Cellectar Biosciences provided a corporate update focusing on important progress with its leading candidate, iopofosine I 131. The company has achieved alignment with the FDA on a regulatory pathway toward potential accelerated approval for iopofosine I 131 as a treatment for relapsed/refractory Waldenström macroglobulinemia (WM). CEO James Caruso emphasized the positive clinical data, which showed high response rates and a safe, manageable toxicity profile. This regulatory clarity has generated significant interest in potential collaborations, which may offer non-dilutive funding opportunities.
Additionally, Cellectar outlined its plans for advancing other radiotherapeutic compounds. The company has received IND clearance for an Auger-emitting radioconjugate and plans to file an IND for an alpha-emitting radioconjugate. These initiatives are expected to support Phase 1 clinical studies in triple-negative breast cancer and pancreatic cancer by mid-2025.
Read Announcement - Drug:
- Iopofosine I-131
- Announced Date:
- June 27, 2024
- Indication:
- Pediatric Brain and Solid Tumors
Announcement
Cellectar Biosciences, announced it will host an event on July 24, 2024, at 8:00 a.m., EDT, to provide a comprehensive overview of recent data from its pivotal trial of iopofosine I 131 in Waldenstrom's macroglobulinemia, the current treatment landscape, unmet needs for patients with this disease, and opportunities to improve patient outcomes.
AI Summary
Cellectar Biosciences announced it will host an event on July 24, 2024, at 8:00 a.m. EDT to discuss promising advancements in treating Waldenström’s macroglobulinemia. The company’s leaders and key investigators will review recent data from their pivotal trial of iopofosine I 131, focusing on the full results of the CLOVER WaM study. They will examine the current treatment landscape for this B-cell malignancy, emphasizing existing unmet needs as many patients do not achieve durable responses with current therapies. The discussion will cover how this novel treatment option could improve patient outcomes, especially for those with relapsed or refractory disease who have limited alternatives. This event underscores Cellectar Biosciences’ commitment to developing innovative, targeted therapies that may offer a safer, more effective approach to managing and ultimately transforming the treatment paradigm for this difficult-to-treat condition.
Read Announcement- Drug:
- Iopofosine I-131
- Announced Date:
- May 29, 2024
- Indication:
- Pediatric Brain and Solid Tumors
Announcement
Cellectar Biosciences, announced that a strategic partnership with City of Hope Cancer Center, one of the largest cancer research and treatment organizations in the United States.
AI Summary
Cellectar Biosciences announced a strategic partnership with City of Hope Cancer Center, one of the nation’s largest cancer research and treatment organizations. This collaboration focuses on expanding the clinical development of Cellectar’s lead radioconjugate asset, iopofosine I-131, for patients with mycosis fungoides—a rare type of non-Hodgkin’s lymphoma that typically affects the skin and may spread to internal organs and the blood.
The investigator-sponsored trial, led by experts at City of Hope, will evaluate the potential of iopofosine as a systemic targeted radiotherapeutic. The drug’s unique delivery platform may offer advantages over traditional external beam radiotherapy by targeting tumor cells throughout the body and reducing the chance of systemic progression. This effort aims to provide new treatment options for patients with limited therapies available and high unmet medical needs.
Read Announcement
CLR 121225 FDA Regulatory Events
CLR 121225 is a drug developed by Cellectar Biosciences for the following indication: For pancreatic cancer.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- CLR 121225
- Announced Date:
- April 14, 2026
- Indication:
- For pancreatic cancer
Announcement
Cellectar Biosciences, announced that the first patient has been enrolled in the Phase 1b trial of CLR 121125 (CLR 125) for the potential treatment of triple negative breast cancer (TNBC).
AI Summary
Cellectar Biosciences announced that the first patient has been enrolled in the Phase 1b trial of CLR 121125 (CLR 125) for the potential treatment of triple negative breast cancer (TNBC). This marks the start of an early-stage clinical study that will begin testing the agent in patients with a hard-to-treat form of breast cancer. Enrollment of the first patient is an important step that lets researchers begin collecting human safety and activity data.
Alongside CLR 125, Cellectar is developing CLR 121225 (CLR 225), an actinium-225–based program aimed at solid tumors with high unmet need, such as pancreatic cancer. The company also continues to advance proprietary preclinical PDC chemotherapeutic programs and multiple partnered PDC assets, expanding its pipeline of targeted cancer approaches.
If early results are promising, these programs could provide new treatment options for patients with aggressive tumors that lack effective therapies today.
Read Announcement- Drug:
- CLR 121225
- Announced Date:
- October 14, 2025
- Indication:
- For pancreatic cancer
Announcement
Cellectar Biosciences, announced that Jarrod Longcor, chief operating officer of Cellectar, presented positive preclinical data in a poster at the American Association for Cancer Research (AACR) Special Conference on Pancreatic Cancer Research that took place from September 28 through October 1, 2025, in Boston, Massachusetts.
Read Announcement
CLR 125 FDA Regulatory Events
CLR 125 is a drug developed by Cellectar Biosciences for the following indication: For the treatment of relapsed TNBC.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- CLR 125
- Announced Date:
- September 24, 2025
- Indication:
- For the treatment of relapsed TNBC.
Announcement
Cellectar Biosciences, Inc. have entered into an agreement whereby Evestia will provide Cellectar with full CRO services for their upcoming Phase 1b study evaluating CLR 125 for the treatment of triple-negative breast cancer (TNBC).
AI Summary
Cellectar Biosciences and Evestia Clinical have signed an agreement in which Evestia will provide full CRO services for Cellectar’s Phase 1b trial of CLR 125. The study will test CLR 125 as a treatment for triple-negative breast cancer.
CLR 125 is an iodine-125 Auger-emitting drug candidate designed to target and kill solid tumors. In this Phase 1b study, the focus will be on triple-negative breast cancer, a subtype with few therapy options and a high relapse rate.
This contract leverages Evestia’s expanded global capabilities since its merger with Atlantic Research Group (ARG). The combined team has led over 300 oncology trials in adult and pediatric populations, works with top centers like the Mayo Clinic, and offers a tailored approach to support trial success.
Cellectar chose a Mayo Clinic Network site for the trial and appointed Pooja Advani, MBBS, MD, as lead investigator. This collaboration ensures patients will receive care from experienced clinicians committed to advancing cancer treatments.
Read Announcement- Drug:
- CLR 125
- Announced Date:
- June 24, 2025
- Indication:
- For the treatment of relapsed TNBC.
Announcement
Cellectar Biosciences, announced that the company has submitted a protocol with the U.S. Food and Drug Administration (FDA) for a Phase 1b Dose Finding study of its Auger emitting radiopharmaceutical, CLR 125, for the treatment of relapsed TNBC. CLR 125 is an iodine-125 Auger-emitting drug candidate targeting solid tumors, such as triple negative breast, lung and colorectal cancers.
AI Summary
Cellectar Biosciences has submitted a protocol to the FDA for a Phase 1b dose-finding study of its Auger-emitting radiopharmaceutical, CLR 125. This innovative drug candidate uses iodine-125 to target solid tumors, specifically focusing on relapsed triple-negative breast cancer (TNBC), as well as lung and colorectal cancers. The study is designed to evaluate three different dosing regimens in patients with relapsed TNBC, including metastatic cases, aiming to determine the optimal dose for safety and effectiveness.
The study will use imaging to assess tumor uptake and involves 15 patients per dosing arm. By leveraging its phospholipid drug conjugate delivery system, CLR 125 is designed to deliver the therapeutic isotope directly to cancer cell nuclei and mitochondria, potentially enhancing its tumor-killing ability while reducing harmful side effects. This marks a significant step in developing a new treatment option for patients with challenging cancers.
Read Announcement
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