CLRB Stock: Insider Activity, Filings & Research
Cellectar Biosciences, Inc. (CLRB) — Drillr’s hub for CLRB insider activity, SEC filings, earnings signals and AI research. Over the trailing 3 months, CLRB insiders filed 4 open-market buys and 0 sales (SEC Form 4).
CLRB insider trading activity (SEC Form 4)
| Date | Insider | Type | Shares | Price |
|---|---|---|---|---|
| May 11, 2026 | Longcor Jarrodofficer: Chief Operating Officer | Buy | 26,040 | $2.88 |
| May 11, 2026 | CARUSO JAMES Vdirector, officer: Chief Executive Officer | Buy | 8,680 | $2.88 |
| May 11, 2026 | CARUSO JAMES Vdirector, officer: Chief Executive Officer | Buy | 26,040 | $2.88 |
| May 11, 2026 | Longcor Jarrodofficer: Chief Operating Officer | Buy | 8,680 | $2.88 |
| Dec 16, 2025 | NEIS JOHNdirector | Sell | 198 | $3.70 |
| Jul 3, 2025 | CARUSO JAMES Vdirector, officer: Chief Executive Officer | Buy | 10,000 | $4.99 |
| Jul 3, 2025 | Longcor Jarrodofficer: Chief Operating Officer | Buy | 10,000 | $4.99 |
| Jul 3, 2025 | Kolean Chad Jofficer: Chief Financial Officer | Buy | 5,000 | $4.99 |
| Mar 12, 2025 | Longcor Jarrodofficer: Chief Operating Officer | Buy | 30,000 | $0.28 |
| Feb 18, 2025 | Swirsky Douglas Jdirector | Grant | 90,000 | $0.29 |
| Feb 18, 2025 | NEIS JOHNdirector | Grant | 60,000 | $0.29 |
| Feb 18, 2025 | Loren Stefandirector | Grant | 60,000 | $0.29 |
| Feb 18, 2025 | Longcor Jarrodofficer: Chief Operating Officer | Grant | 500,000 | $0.29 |
| Feb 18, 2025 | Kolean Chad Jofficer: Chief Financial Officer | Grant | 290,000 | $0.29 |
| Feb 18, 2025 | DRISCOLL FREDERICK Wdirector | Grant | 60,000 | $0.29 |
Source: CLRB SEC Form 4 filings, latest May 11, 2026. For informational purposes only — not investment advice.
Cellectar Biosciences, Inc. company profile
Overview
Cellectar Biosciences, Inc. (NASDAQ:CLRB) is a clinical-stage biopharmaceutical company founded in 2002 and headquartered in Florham Park, New Jersey. The company went public in 2005 and specializes in developing innovative cancer treatments using a proprietary drug delivery platform called phospholipid drug conjugates (PDCs). Cellectar focuses on creating targeted radiopharmaceuticals that can deliver radiation directly to cancer cells while minimizing damage to healthy tissue. The company's lead drug candidate, iopofosine I-131 (CLR 131), is currently in late-stage clinical trials for treating blood cancers, particularly Waldenstrom's macroglobulinemia, and the company is preparing for its first commercial product launch.
Business
Cellectar operates in the specialized field of radiopharmaceuticals, which combines radioactive isotopes with targeting molecules to treat cancer. The company's core innovation lies in its proprietary phospholipid drug conjugate (PDC) platform, a technology that exploits cancer cells' altered metabolism to deliver therapeutic payloads directly to tumors. The PDC platform works by attaching radioactive isotopes to phospholipid molecules that cancer cells preferentially absorb due to their increased metabolic activity and altered cell membrane composition. This targeted approach allows radiation to be concentrated in cancerous tissue while sparing healthy cells, potentially reducing side effects compared to traditional chemotherapy or external beam radiation. Cellectar's primary product candidate is iopofosine I-131 (CLR 131), which uses the radioactive isotope iodine-131 attached to their PDC platform. This drug is currently in Phase 2 clinical trials for treating relapsed or refractory Waldenstrom's macroglobulinemia (a rare blood cancer), multiple myeloma, and various pediatric cancers. The company is preparing to submit a New Drug Application (NDA) to the FDA for the Waldenstrom's macroglobulinemia indication. Beyond iopofosine I-131, Cellectar is developing next-generation PDC programs using different radioactive isotopes. CLR 121225 uses alpha-emitting isotopes for treating solid tumors like pancreatic cancer, while CLR 121125 employs Auger-emitting isotopes for triple-negative breast cancer. The company also has collaborative programs with partners including Avicenna Oncology, Orano Med, and others to develop additional PDC-based therapies. Currently, Cellectar generates no revenue as all products remain in clinical development, representing a typical pre-commercial biotechnology company profile focused entirely on research and development activities.
Revenue model
Cellectar operates under a typical pre-revenue biotechnology business model, currently generating no income while investing heavily in research and development. The company's future revenue will primarily come from product sales of approved radiopharmaceuticals, with their first potential commercial product being iopofosine I-131 for treating Waldenstrom's macroglobulinemia. The company's target customers are oncology healthcare providers, specifically hematologists and oncologists treating blood cancers, as well as radiotherapy-capable community practices and hospitals. For Waldenstrom's macroglobulinemia alone, Cellectar has identified an addressable market of approximately 5,700 patients in third-line or greater therapy, with the broader relapsed/refractory market valued at $1 billion and the total U.S. Waldenstrom's market estimated at $2.1 billion. Cellectar's business model also includes potential licensing and partnership revenues. The company is actively exploring collaboration opportunities for both domestic and international markets, which could provide upfront payments, milestone payments, and royalties. They have already established partnerships with organizations like American Oncology Network and are in discussions for broader regional and global licensing deals. The company's margins will be influenced by several key factors. Positive margin drivers include the specialized nature of radiopharmaceuticals, which typically command premium pricing similar to CAR-T therapies and other advanced cancer treatments, the concentrated patient population that allows for efficient targeted marketing, and the 17-day shelf life that enables centralized manufacturing and distribution. Negative margin pressures include the complex manufacturing requirements for radioactive drugs, the need for specialized supply chain management for isotopes, regulatory compliance costs for radiopharmaceutical production, and the limited patient population that constrains total market size. Additionally, competition from existing treatments like BTK inhibitors and potential future therapies could impact pricing power.
Competitive moat
Cellectar's competitive moat is moderately strong but narrow, built primarily around its proprietary PDC platform technology and regulatory positioning. The company's core intellectual property portfolio covers the PDC delivery mechanism, which represents a differentiated approach to cancer targeting compared to traditional antibody-drug conjugates or small molecule therapies. This platform has demonstrated the ability to cross the blood-brain barrier and achieve selective tumor uptake, capabilities that are difficult to replicate. The company's regulatory advantages provide additional moat strength. Cellectar has secured Fast Track and Orphan Drug designations from the FDA for iopofosine I-131 in Waldenstrom's macroglobulinemia, along with PRIME designation in Europe. These designations provide regulatory benefits including expedited review processes and market exclusivity periods. The orphan drug status is particularly valuable given the rare disease indication, providing seven years of market exclusivity upon approval. However, Cellectar's moat faces several vulnerabilities. The radiopharmaceutical manufacturing complexity creates barriers to entry but also operational challenges for the company itself. The specialized isotope supply chain and regulatory requirements for radioactive drug production represent both protective factors and potential bottlenecks. Competition comes from established treatments like BTK inhibitors (ibrutinib, acalabrutinib) in Waldenstrom's macroglobulinemia, as well as emerging CAR-T therapies and other targeted treatments. The company's platform approach provides some protection through pipeline diversification, but each indication requires separate clinical development and regulatory approval. Potential disruption could come from advances in precision medicine, improved targeted therapies, or breakthrough treatments that obviate the need for radiopharmaceuticals. Additionally, larger pharmaceutical companies with greater resources could develop competing radiopharmaceutical platforms or acquire smaller companies with similar technologies.
Risks & safety
Cellectar presents a moderate to high risk profile typical of late-stage clinical biotechnology companies, with significant cash burn but reasonable near-term liquidity. **Cash and Liquidity:** - Cash position of $23.3 million as of December 31, 2024 - Quarterly cash burn of approximately $11-14 million - Management guidance suggests cash runway through Q4 2025 - No significant debt burden (debt-to-equity ratio of 0.035) **Valuation Metrics:** - Current market cap of approximately $16.6 million - Price-to-book ratio of 0.96, suggesting trading near book value - Enterprise value reflects significant discount to development costs invested - Graham net-net ratio of 0.33 indicates some asset protection **Other Considerations:** - Strong current ratio of 2.58 provides short-term financial stability - Recent 60% workforce reduction demonstrates cost management capability - Potential warrant exercises could provide additional funding - NASDAQ listing compliance concerns may require reverse stock split - Binary risk profile dependent on FDA approval success
Recent development
Over the past few years, Cellectar has achieved several critical milestones positioning the company for potential commercialization. The most significant development has been the successful completion of the CLOVER-WaM pivotal study for iopofosine I-131 in Waldenstrom's macroglobulinemia, which demonstrated a 58.2% major response rate, 80% overall response rate, and 98.2% clinical benefit rate in heavily pretreated patients. The company has made substantial progress in regulatory preparation and commercial readiness. Cellectar received Fast Track and Orphan Drug designations from the FDA, achieved alignment with the FDA on Phase 3 study design requirements, and is preparing for NDA submission. The company has built key commercial infrastructure including hiring VP of Marketing and VP of Market Access roles, establishing manufacturing partnerships, and developing a multi-source supply chain capable of producing 200-1,000 patient doses per week. Pipeline expansion has been another major focus, with Cellectar advancing next-generation PDC programs using different radioactive isotopes. The company is preparing Phase 1 studies for CLR 121225 (alpha-emitter) in pancreatic cancer and CLR 121125 (Auger-emitter) in triple-negative breast cancer, while also exploring pediatric applications through ongoing high-grade glioma studies. Strategic partnerships have become increasingly important, with Cellectar establishing collaborations with American Oncology Network, City of Hope, and exploring broader licensing opportunities. The company completed significant financing rounds, raising approximately $44 million in private placement funding, though it has also implemented substantial cost-cutting measures including a 60% workforce reduction to extend cash runway and focus resources on key value-driving activities.
CLRB company profile · for informational purposes only — not investment advice.
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