Philochem AG has agreed to license global rights to its investigational prostate cancer agent OncoACP3 to RayzeBio, a Bristol Myers Squibb company, in a deal that could reach $1.35 billion in total value, the companies announced last week.

The agreement includes a $350 million up-front payment, with an additional $1 billion tied to development, regulatory, and commercial milestones. Philochem will also receive royalties ranging from the mid-single to low double digits on global net sales of both therapeutic and diagnostic versions of the drug.

OncoACP3 is a small molecule radiopharmaceutical that targets acid phosphatase 3 (ACP3), a protein under investigation as a novel marker in prostate cancer. The compound is currently being evaluated as a diagnostic tool in a Phase I trial (NCT06840535), with preliminary results showing tumor-specific uptake and minimal accumulation in healthy tissues. IND-enabling activities are underway to support the launch of a therapeutic study using actinium-225-labeled OncoACP3.
“The partnership will focus on the development and commercialization of OncoACP3 for both diagnostic and therapeutic applications in prostate cancer,” said professor Dario Neri, CEO and chief scientific officer of the Philogen Group, which owns Philochem. “This collaboration reflects our shared commitment to translating scientific innovation into meaningful clinical solutions.”

Ben Hickey, president of RayzeBio, added, “OncoACP3, with its initial encouraging safety profile, provides a differentiated entry for Bristol Myers Squibb and RayzeBio into the prostate cancer arena.”

The Otelfingen, Switzerland-based Philochem retained Centerview Partners UK LLP as financial advisor and Cooley LLP as legal counsel on the transaction. The deal is expected to close in the third quarter of 2025, pending regulatory approval and customary closing conditions.

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