Instead of homing in on PSMA—currently the most validated target in prostate cancer—BMS and Philochem will instead collaborate on an early-stage molecule that binds to a novel marker called ACP3.
Bristol Myers Squibb is trying to unlock an alternative pathway to treating prostate cancer. The company’s radiopharma-focused subsidiary RayzeBio has fronted $350 million to partner with Italian-Swiss biotech Philochem to advance an early-stage small-molecule radiotherapeutic targeting a novel biomarker.
BMS is also promising up to $1.35 billion in development, regulatory and commercial milestones, plus mid-single to low-double-digit royalties on global net sales. BMS and Philochem expect to close the transaction in the third quarter, pending customary clearances and approvals.
Philogen, Philochem’s parent company, surged 20% on Wednesday morning.
The star of Wednesday’s agreement is OncoACP3, a small-molecule radiotracer that targets a biomarker called ACP3. According to Philochem, ACP3 is highly expressed in prostate cancer—but not in healthy tissue—and at levels that match or exceed that of PSMA, which is currently the prevailing target of choice for prostate cancer therapies. “A side-by-side comparison between ACP3 and PSMA . . . has shown that ACP3 is more abundantly expressed in prostate cancer than PSMA,” the biotech wrote on its website.
OncoACP3 is a small-molecule ligand that has high affinity for the ACP3 protein. Notably, it can carry both Lutetium-177 and Actinium-225—both currently the most common payloads for radiopharmaceuticals.
In a statement on Wednesday, RayzeBio president Ben Hickey said that by potentially opening an alternative pathway to PSMA, the Philochem partnership “provides a differentiated entry” for BMS “into the prostate cancer arena.”
The decision to zero in on a novel prostate cancer target could also help BMS distinguish itself in a radiopharma field that is becoming increasingly crowded. Currently leading the pack is Novartis, which owns two FDA-approved therapies: Lutathera, indicated for gastroenteropancreatic neuroendocrine tumors, and Pluvicto, which targets PSMA and is approved for prostate cancer.
Another pharma trying to catch Novartis is AstraZeneca, which entered the ring in March 2024 with the $2.4 billion acquisition of Fusion Pharmaceuticals, which gave the pharma its lead radiopharma asset FPI-2265, an actinium-based radioconjugate that is being developed for prostate cancer—and targets PSMA.
Also in the running is Eli Lilly, which spent $1.4 billion to buy Point Biopharma in October 2023 and $1.1 billion for Aktis Oncology in May 2024. Anchoring its radiopharma pipeline is PNT2002, another PSMA-targeting candidate for prostate cancer.
