Arvinas, Pfizer find new partner for ‘Protac’ breast cancer drug

An article from Arvinas, Pfizer find new partner for ‘Protac’ breast cancer drug A deal with Rigel Pharmaceuticals ends months of uncertainty about the future of Veppanu, a first-of-its-kind, newly approved medicine with a murky financial outlook. Published May 12, 2026 Delilah Alvarado Reporter Share Copy link Email LinkedIn X/Twitter Facebook Print License Add us on Google Biotechnology firm Arvinas and partner Pfizer have struck a long-awaited licensing deal for their newly approved breast cancer drug. The companies on Tuesday inked an agreement transfering ownership of that medicine, Veppanu, to San Francisco-based biotech Rigel Pharmaceuticals.

Arvinas and Pfizer will receive $75 million upfront, another $15 million after certain “transition” activities are completed, and are eligible for another $320 million in future payouts as well as sales royalties. In return, Rigel will get global rights to Veppanu, which includes the ability to partner off non-U.S. ownership.

Formerly known as vepdegestrant, Veppanu earlier this month was approved in the U.S. as a treatment for certain people with a common form of breast cancer. In winning that clearance, Veppanu became the first drug of its kind — a protein-trashing medicine known for short as a “PROTAC” — to get to market.

Arvinas and Pfizer had originally hoped Veppanu could help a broad group of breast cancer patients in multiple lines of care. However, the drug proved most beneficial in breast cancer patients with mutations to a gene called ESR1. Study data also didn’t clearly separate Veppanu from other, similar hormone-degrading cancer drugs recently approved for breast tumors, such as Eli Lilly's Inluriyo and Menarini’s Orserdu.

Those factors led the partners to dial back their projections for Veppanu and look to offload the medicine rather than sell it. They’d aimed to complete a deal before a regulatory approval was issued, though Arvinas CEO Randy Teel reassured investors the companies were “well-situated” if an alliance hadn’t been struck by then. The transaction effectively enables Arvinas to move forward with a pipeline that’s now built around other programs.

“It's not the blue-sky deal I would’ve hoped for,” but “the most important part of the deal is that it’s done, and focus can now fully move on,” wrote Evercore ISI analyst Jon Miller, in a Tuesday note to clients. Founded in 1996, Rigel is best known for Tavalisse, a medicine used to treat a rare autoimmune disease known as chronic immune thrombocytopenia. With the addition of Veppanu, the company now has three other marketed cancer medicines as well.

“With its novel mechanism of action designed to address a key driver of resistance, Veppanu represents a compelling treatment option within this setting," said Rigel CEO Raul Rodriguez, in a separate statement. Rodriguez said the therapy is “expected to contribute strong revenue growth” and has the potential to become a key revenue driver for the company going forward. Add us on Google Share Copy link Email LinkedIn X/Twitter Facebook Print purchase licensing rights Filed Under: Pharma, Deals