SOUTH SAN FRANCISCO, Calif., May 12, 2026
Rigel Pharmaceuticals has entered into an exclusive global licensing agreement with Arvinas and Pfizer for VEPPANU™ (vepdegestrant), the first and only U.S. FDA-approved oral PROTAC therapy for advanced or metastatic breast cancer with ESR1 mutations. The agreement significantly expands Rigel’s oncology portfolio and positions the company to strengthen its commercial presence in the rapidly growing breast cancer therapeutics market. The licensing transaction reflects increasing pharmaceutical industry interest in next-generation targeted protein degradation technologies designed to address treatment resistance in difficult-to-treat cancers.
VEPPANU is approved for the treatment of adults with ER-positive/HER2-negative, ESR1-mutated advanced or metastatic breast cancer following progression after at least one line of endocrine therapy. The oral therapy uses a novel PROteolysis TArgeting Chimera (PROTAC) mechanism designed to selectively degrade disease-causing proteins instead of simply inhibiting them, representing a major innovation in precision oncology and targeted protein degradation therapeutics.
VEPPANU Demonstrates Strong Phase 3 Breast Cancer Results
The licensing agreement follows positive results from the pivotal Phase 3 VERITAC-2 clinical trial, where vepdegestrant demonstrated statistically significant improvement in progression-free survival compared with fulvestrant in patients with ESR1-mutated advanced breast cancer. According to the study data, patients treated with VEPPANU achieved a median progression-free survival of 5.0 months, compared with 2.1 months for fulvestrant, representing a 43% reduction in the risk of disease progression or death.
Researchers noted that the therapy was generally well tolerated, with most adverse events classified as low-grade. Common side effects included fatigue, nausea, musculoskeletal pain, decreased blood cell counts, liver enzyme elevations, and electrocardiogram QT prolongation. The clinical findings were previously presented at the American Society of Clinical Oncology (ASCO) Annual Meeting and simultaneously published in the New England Journal of Medicine, reinforcing the scientific significance of the results.
Advertisement
Medical experts highlighted the importance of the therapy because approximately half of ER-positive/HER2-negative breast cancer patients eventually develop ESR1 mutations after endocrine therapy exposure, contributing to treatment resistance and disease progression. VEPPANU’s differentiated PROTAC mechanism may therefore offer a valuable new treatment option for patients with limited therapeutic alternatives.
Rigel Expands Commercial Oncology Portfolio
Under the terms of the agreement, Rigel will obtain exclusive global rights to develop, manufacture, and commercialize VEPPANU, while Arvinas and Pfizer will receive an upfront payment of $70 million, along with an additional $15 million tied to development and manufacturing transition activities. The companies are also eligible to receive up to $320 million in future regulatory and commercial milestone payments, in addition to tiered royalties on global sales.
Rigel executives described VEPPANU as a key component of the company’s transformational growth strategy, emphasizing that the therapy is expected to become the company’s fourth commercial product and a major future revenue driver. Rigel will oversee commercialization in the United States while maintaining the ability to sublicense international development and commercialization rights outside the U.S. market.
The transaction remains subject to customary regulatory review and is expected to close during mid-2026 following clearance under the Hart-Scott-Rodino Antitrust Improvements Act.
PROTAC Technologies Gain Momentum in Oncology Innovation
The agreement further highlights growing pharmaceutical industry investment in PROTAC technologies, an emerging therapeutic modality designed to harness the body’s natural protein degradation systems to eliminate disease-causing proteins. Unlike traditional inhibitors, PROTACs may offer improved durability, broader targeting capabilities, and enhanced activity against resistant cancer mutations.
Industry analysts continue to view targeted protein degradation as one of the most promising next-generation approaches in oncology drug development, with major pharmaceutical companies increasingly pursuing licensing agreements and collaborations focused on PROTAC-based therapeutics. Rigel’s acquisition of VEPPANU positions the company within one of the fastest-growing innovation areas in precision cancer medicine.
Source: Rigel Pharmaceuticals, Arvinas, Pfizer press release
