RayzeBio, a wholly-owned subsidiary of Bristol Myers Squibb, has secured exclusive worldwide rights to develop and commercialize OncoACP3, a clinical-stage radiopharmaceutical targeting prostate cancer, through a licensing agreement with Philochem AG worth up to $1.35 billion. The deal, announced on June 10, 2025, represents a significant expansion of Bristol Myers Squibb's oncology portfolio into the rapidly advancing radiopharmaceuticals sector.
Novel Target Shows Early Promise
OncoACP3 is a small molecule ligand engineered with high affinity and specificity for Acid Phosphatase 3 (ACP3), representing a novel therapeutic target in prostate cancer treatment. The compound is currently under evaluation in a company-sponsored Phase I trial (NCT06840535), with initial data from the first patient cohort demonstrating encouraging results.
The diagnostic version of OncoACP3 has shown selective tumor uptake and long residence time with minimal healthy tissue uptake, according to early clinical data. These characteristics are critical for effective radiopharmaceutical therapy, as they indicate the potential for targeted cancer cell destruction while minimizing damage to healthy tissues.
Dual Therapeutic and Diagnostic Applications
The OncoACP3 platform encompasses both therapeutic and diagnostic applications, positioning it as a theranostic agent. IND-enabling activities are currently ongoing to support the application for a Phase I therapeutic study using 225Ac-OncoACP3, an actinium-based radiopharmaceutical therapeutic approach.
Prof. Dr. Dario Neri, CEO and CSO of Philogen, emphasized the compound's potential: "OncoACP3 is a best-in-class targeting agent with the potential to become a breakthrough treatment in this field. This collaboration reflects our shared commitment to translating scientific innovation into meaningful clinical solutions, making OncoACP3 therapies widely available to patients in need."
Strategic Value for Bristol Myers Squibb
The acquisition aligns with RayzeBio's strategy to advance best-in-class radiopharmaceutical therapeutic (RPT) candidates. Ben Hickey, President of RayzeBio, noted that the collaboration "enhances our leadership in the rapidly advancing radiopharmaceuticals space" and "provides a differentiated entry for Bristol Myers Squibb and RayzeBio into the prostate cancer arena, building on our leadership in actinium-based RPT development."
The deal structure includes a $350 million upfront payment to Philochem, with additional payments of up to $1.0 billion tied to development, regulatory, and commercial milestones. Philochem will also receive mid-single to low double-digit royalties on global net sales of both therapeutic and diagnostic versions of OncoACP3.
Transaction Timeline and Regulatory Path
The transaction is subject to regulatory approvals and other customary closing conditions, with both parties expecting completion in the third quarter of 2025. Centerview Partners UK LLP serves as exclusive financial advisor to Philochem, while Cooley LLP acts as exclusive legal counsel.
This licensing agreement represents a significant milestone for both companies, with RayzeBio gaining access to a potentially transformative prostate cancer therapy while Philochem secures substantial financial backing for continued development of its radiopharmaceutical platform.
