Rigel Pharmaceuticals (Nasdaq: RIGL) is acquiring exclusive global rights to Veppanu (vepdegestrant), the first US FDA-approved oral PROTAC, in a deal that brings a newly approved oncology asset into its commercial portfolio and marks a strategic exit by Arvinas (Nasdaq: ARVN) and Pfizer (NYSE: PFE) from direct commercialization of the drug. Under the licensing agreement, Rigel will take over development, manufacturing, and commercialization of vepdegestrant, an estrogen receptor-targeting degrader approved on May 1, 2026, for adults with ER+/HER2-, ESR1-mutated advanced or metastatic breast cancer who have progressed on at least one line of endocrine therapy.
Rigel will pay USD 70 million upfront and an additional USD 15 million upon completion of defined development and manufacturing transition activities. Rigel will also contribute up to USD 40 million toward certain ongoing development activities over four years, during which Arvinas and Pfizer retain responsibility for current development programs. Arvinas and Pfizer are eligible for tiered royalties on net sales ranging from mid-teens to mid-twenties percent, up to USD 320 million in regulatory and commercial milestones, and a share of sublicensing revenue Rigel generates outside the US. The breakdown of the USD 320 million between regulatory and commercial triggers was not disclosed. The deal is subject to Hart-Scott-Rodino antitrust clearance and is expected to close in mid-June 2026.
Deal context
Vepdegestrant is an orally bioavailable small molecule that functions as a PROteolysis TArgeting Chimera, or PROTAC — a bifunctional degrader that simultaneously binds estrogen receptor alpha and recruits the E3 ubiquitin ligase cereblon, directing the receptor for proteasomal degradation. This mechanism differs from selective estrogen receptor degraders such as fulvestrant, which inhibit receptor signaling without eliminating the protein. By degrading ERα, vepdegestrant is described by Arvinas as capable of addressing both wild-type and ESR1-mutant receptor variants, the latter of which emerge in approximately 50% of patients following exposure to endocrine therapy and confer resistance to standard agents.
The US FDA approval was based on data from VERITAC-2 (NCT05654623), a global, randomized, open-label Phase III trial comparing vepdegestrant to fulvestrant in patients with ER+/HER2-, ESR1-mutated advanced or metastatic breast cancer. Among 270 patients with confirmed ESR1 mutations, vepdegestrant reduced the risk of disease progression or death by 43% relative to fulvestrant, with a median progression-free survival of 5.0 months versus 2.1 months (hazard ratio 0.57; 95% CI: 0.42, 0.77; p=0.0001). Overall survival data were immature at the time of the PFS analysis, with 16% of events observed. The National Comprehensive Cancer Network added vepdegestrant as a Category 2A treatment option in May 2026 for HR+/HER2-, ESR1-mutated advanced or metastatic breast cancer after at least one line of endocrine therapy plus a CDK4/6 inhibitor.