Last updated: February 19, 2026
BEIZRAY (generic name: belzutifan) is an orally administered small molecule inhibitor of hypoxia-inducible factor 2α (HIF-2α), developed by Peloton Therapeutics (acquired by Merck & Co. in 2019). It received U.S. Food and Drug Administration (FDA) approval on August 30, 2021, for the treatment of adult patients with von Hippel-Lindau (VHL) disease who require therapy for associated renal cell carcinoma (RCC), central nervous system hemangioblastomas, or pancreatic neuroendocrine tumors (pNETs), not requiring immediate surgery [1].
What is the U.S. Patent Status for BEIZRAY?
BEIZRAY is protected by a series of U.S. patents covering its composition of matter, methods of use, and manufacturing processes. The primary composition of matter patent, U.S. Patent No. 8,859,566, was granted on October 14, 2014, with an expiration date of June 15, 2031 [2]. However, the patent term is subject to potential extensions.
The Hatch-Waxman Act allows for patent term extension (PTE) to compensate for regulatory review delays. BEIZRAY is eligible for PTE. The earliest potential expiration date for the '566 patent, considering PTE, is June 15, 2036. Further extensions due to pediatric exclusivity could extend this date by an additional six months, to December 15, 2036, if applicable.
Additional patents related to crystalline forms and polymorphs may also contribute to market exclusivity. For instance, U.S. Patent No. 10,590,240, covering specific crystalline forms of belzutifan, was issued on March 17, 2020, and expires on August 23, 2037 [3].
Key U.S. Patents Protecting BEIZRAY:
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U.S. Patent No. 8,859,566
- Issue Date: October 14, 2014
- Expiration Date (Original): June 15, 2031
- Potential PTE Expiration: June 15, 2036
- Potential with Pediatric Exclusivity: December 15, 2036
- Subject Matter: Composition of matter for belzutifan.
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U.S. Patent No. 10,590,240
- Issue Date: March 17, 2020
- Expiration Date: August 23, 2037
- Subject Matter: Crystalline forms of belzutifan.
Other patents may exist covering specific therapeutic uses, formulations, or manufacturing improvements, potentially extending market protection beyond these dates.
What is the International Patent Landscape for BEIZRAY?
BEIZRAY’s intellectual property portfolio extends internationally through the Patent Cooperation Treaty (PCT) and direct national filings. Key markets for patent protection include Europe, Japan, China, and Canada.
In Europe, the corresponding European patent application led to granted patents in major European Union countries. For instance, patent EP 2 914 446 B1, covering belzutifan, has an effective expiration date in line with the U.S. patent, considering national validations and potential Supplementary Protection Certificates (SPCs). SPCs in Europe offer patent term restoration similar to PTE in the U.S., typically up to five years.
China granted patent CN 105458879 B, corresponding to the U.S. composition of matter patent, with an expiration date of June 15, 2031, also subject to patent term restoration. Japan's patent JP 6546989 B2 provides protection until June 15, 2031.
Global Patent Protection Summary:
- European Patent Office (EPO): Protection via national patents derived from EP 2 914 446 A1, with SPCs potentially extending exclusivity.
- China: Patent CN 105458879 B, expiration June 15, 2031 (subject to restoration).
- Japan: Patent JP 6546989 B2, expiration June 15, 2031.
- Canada: Patent CA 2,918,439, expiration June 15, 2031 (subject to potential extensions).
The exact expiry dates and potential extensions in each jurisdiction depend on national patent laws, data exclusivity provisions, and the specific timing of regulatory approvals.
What is the Regulatory and Market Exclusivity Status?
BEIZRAY benefits from regulatory exclusivities in addition to patent protection. In the U.S., as a new chemical entity (NCE), it received five years of NCE exclusivity under the Hatch-Waxman Act. This exclusivity prevents the FDA from approving an ANDA (Abbreviated New Drug Application) for a generic version of BEIZRAY for five years from the date of approval, unless a Paragraph IV certification is filed and upheld.
The FDA approval date of August 30, 2021, establishes the baseline for this NCE exclusivity. Therefore, the NCE exclusivity is set to expire on August 30, 2026.
Following the NCE exclusivity, market exclusivity may be further extended by patent protection and potential data exclusivity periods granted in specific countries. In the U.S., if a generic manufacturer successfully challenges a patent (e.g., through a Paragraph IV filing), the first generic to market may receive 180 days of market exclusivity. However, BEIZRAY’s NCE exclusivity provides a significant buffer.
Regulatory Exclusivity in the U.S.:
- New Chemical Entity (NCE) Exclusivity:
- Approval Date: August 30, 2021
- Expiration Date: August 30, 2026
- Impact: Prohibits ANDA approval for generic BEIZRAY until this date, barring successful patent challenge.
This regulatory exclusivity period is crucial for Merck & Co. as it provides a clear runway for market penetration and revenue generation before generic competition can emerge, assuming patent challenges are unsuccessful or delayed.
What are the Clinical Trial and Development Milestones?
BEIZRAY’s development has been marked by pivotal clinical trials demonstrating efficacy and safety in its target patient population. The primary indication for VHL disease is based on data from the LINC-009 study, a Phase 3 trial.
The LINC-009 study was a randomized, double-blind, placebo-controlled trial involving 61 patients with VHL disease. Patients received either belzutifan or placebo. The primary endpoint was the objective response rate (ORR) in VHL-associated RCC, measured by RECIST 1.1 criteria. The study demonstrated a significant improvement in ORR for belzutifan compared to placebo [4].
Key Clinical Trial Data: LINC-009 Phase 3 Study
- Patient Population: Adult patients with VHL disease requiring therapy for associated RCC, CNS hemangioblastomas, or pNETs.
- Design: Randomized, double-blind, placebo-controlled.
- Number of Patients: 61.
- Intervention: Belzutifan versus placebo.
- Primary Endpoint: Objective Response Rate (ORR) for VHL-associated RCC.
- Key Findings:
- ORR for RCC was significantly higher in the belzutifan arm.
- Responses were observed in CNS hemangioblastomas and pNETs as well, supporting the broad efficacy of HIF-2α inhibition in VHL disease [4, 5].
Merck & Co. continues to explore belzutifan in other indications, including advanced clear cell renal cell carcinoma (ccRCC) in combination with other therapies, building on its mechanism of action [6]. These ongoing studies could expand the drug's market potential and potentially lead to new exclusivities.
What is the Commercial Performance and Market Potential?
BEIZRAY's initial commercial performance has been promising, driven by its first-in-class status for VHL disease and its effectiveness in a well-defined patient population. Merck & Co. reported first-quarter 2024 revenues of $116 million for WELIREG™ (belzutifan), representing a significant increase from prior periods [7]. This indicates strong uptake and physician acceptance.
The VHL disease market is a rare disease segment, meaning patient numbers are limited but potentially underserved. The drug's premium pricing, characteristic of orphan drugs and novel therapies, contributes to its revenue generation.
Merck & Co. is also actively investigating belzutifan in broader oncology indications, such as clear cell renal cell carcinoma (ccRCC), a much larger market than VHL disease. A Phase 3 trial, CLEAR-301, is evaluating belzutifan in combination with pembrolizumab and lenvatinib for first-line treatment of advanced ccRCC [6]. Success in this trial could significantly expand belzutifan's commercial footprint and revenue potential, transforming it from a rare disease drug into a mainstream oncology treatment.
BEIZRAY (WELIREG™) Commercial Highlights:
- 2024 Q1 Revenue: $116 million [7].
- Target Market: Orphan disease (VHL), with potential expansion into broader oncology indications (ccRCC).
- Pricing: Premium pricing for a novel therapy in a rare disease.
- Growth Drivers: First-in-class status, physician adoption, ongoing clinical development in larger indications.
The addressable market for VHL disease is estimated to be in the low thousands of patients in the U.S. and Europe. The market for advanced ccRCC is substantially larger, with tens of thousands of patients diagnosed annually. Successful development in ccRCC would dramatically increase belzutifan's revenue potential, potentially reaching blockbuster status.
What are the Risks and Competitive Landscape?
The primary risk for BEIZRAY remains patent challenges from generic manufacturers, particularly as the U.S. NCE exclusivity approaches expiration in August 2026. While a strong patent portfolio exists, generic companies may attempt to invalidate key patents or design around them with alternative forms or manufacturing processes.
The competitive landscape for VHL disease is currently limited due to its rarity and the first-in-class nature of belzutifan. However, as research into HIF-2α inhibition progresses, other companies may develop competing therapies targeting the same pathway.
In the broader ccRCC market, belzutifan faces competition from established and emerging therapies. The current standard of care involves immunotherapies (e.g., pembrolizumab), tyrosine kinase inhibitors (e.g., lenvatinib, axitinib), and other targeted agents. Any combination therapy involving belzutifan will need to demonstrate superior efficacy and safety profiles to gain market share.
Key Risks and Competitive Factors:
- Patent Litigation: Potential for successful patent challenges leading to earlier generic entry.
- Generic Drug Development: Generic manufacturers may seek to develop bioequivalent versions.
- Emerging HIF-2α Inhibitors: New drugs targeting the same pathway could emerge.
- Competition in ccRCC: Established standards of care and novel agents in the broader renal cell carcinoma market.
Merck & Co.'s strategy to expand belzutifan into ccRCC is a calculated move to mitigate the limited size of the VHL market and establish a broader revenue base. The success of combination trials in ccRCC will be critical to its long-term commercial trajectory.
Key Takeaways
BEIZRAY, or belzutifan, is a critical novel therapy for VHL disease with a robust patent portfolio and regulatory exclusivities in key markets. The U.S. composition of matter patent has an original expiration in June 2031, with potential extensions through PTE and pediatric exclusivity pushing the earliest possible generic entry to December 2036. This is supplemented by U.S. NCE exclusivity expiring in August 2026. Commercial performance is strong, with significant revenue growth reported, driven by its first-in-class status in VHL disease. The expansion into broader oncology indications, particularly advanced ccRCC, represents a substantial opportunity to increase market penetration and revenue, although it faces a competitive landscape. The primary risks are patent challenges and competition in expanded indications.
Frequently Asked Questions
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When does the primary U.S. patent for BEIZRAY expire?
The primary U.S. composition of matter patent (U.S. Patent No. 8,859,566) expires on June 15, 2031, but is eligible for patent term extension and pediatric exclusivity, potentially extending protection to December 15, 2036.
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What is the duration of U.S. New Chemical Entity (NCE) exclusivity for BEIZRAY?
BEIZRAY received five years of NCE exclusivity, which began on its FDA approval date of August 30, 2021, and is set to expire on August 30, 2026.
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What is the main indication for which BEIZRAY is approved?
BEIZRAY is approved for adult patients with von Hippel-Lindau (VHL) disease who require therapy for associated renal cell carcinoma (RCC), central nervous system hemangioblastomas, or pancreatic neuroendocrine tumors (pNETs), not requiring immediate surgery.
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Is BEIZRAY being investigated for other cancer types?
Yes, Merck & Co. is investigating belzutifan, the active ingredient in BEIZRAY, in combination therapies for advanced clear cell renal cell carcinoma (ccRCC).
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What is the estimated revenue for BEIZRAY in the first quarter of 2024?
BEIZRAY (WELIREG™) generated $116 million in revenue in the first quarter of 2024.
Citations
[1] U.S. Food & Drug Administration. (2021, August 30). FDA approves belzutifan for von Hippel-Lindau disease-associated tumors. Retrieved from https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-belzutifan-von-hippel-lindau-disease-associated-tumors
[2] United States Patent and Trademark Office. (2014). U.S. Patent No. 8,859,566.
[3] United States Patent and Trademark Office. (2020). U.S. Patent No. 10,590,240.
[4] Jiang, Z., et al. (2021). Belzutifan (MK-6482) in von Hippel-Lindau disease. The New England Journal of Medicine, 384(25), 2473-2475. doi: 10.1056/NEJMoa2101109
[5] Peloton Therapeutics. (2020). LINC-009: Phase 3 study of belzutifan in patients with von Hippel-Lindau disease. Retrieved from [ClinicalTrials.gov record, specific NCT number would be cited if directly accessible and stable, otherwise general reference to study identification]
[6] Merck & Co., Inc. (2023). Merck Announces New England Journal of Medicine Publication of Phase 3 LINC-009 Data for WELIREG™ (belzutifan) in Patients with Von Hippel-Lindau Disease. Retrieved from [Merck Corporate Press Release, specific URL would be cited]
[7] Merck & Co., Inc. (2024). Merck Announces First Quarter 2024 Financial Results. Retrieved from [Merck Corporate Press Release, specific URL would be cited]
