Prothena: BMS ends PRX019 license, removing up to $617.5 million in milestone payments
Bristol Myers Squibb told Prothena on October 28, 2026 that it will not advance PRX019 further in the clinic, and the PRX019 license agreement will terminate on January 28, 2027. Under the terminated agreement, Prothena would have been eligible for up to $617.5 million in milestones and tiered royalties, and Bristol Myers Squibb will owe none of these payments. Prothena's separate moponetug collaboration with Bristol Myers Squibb continues.
Key points
- Bristol Myers Squibb decided not to advance PRX019 after an internal strategic review, notified Prothena on October 28, 2026.
- The PRX019 Global License Agreement, signed in May 2024 with an $80 million upfront payment, terminates on January 28, 2027.
- Up to $617.5 million in development, regulatory and sales milestones, plus royalties, will not be paid to Prothena.
- Bristol Myers Squibb continues developing moponetug, for which Prothena has received $135 million and is eligible for up to $562.5 million more.
The filing
Written by AI on Nov 9, 2026, 8:38 AM ET, from this filing only. Written later: this filing was briefed after the fact, when past filings were added to the site, so the brief may be read with hindsight; the filing itself is the record of what was known on October 29, 2026.
Briefs are written by AI from the filing text and can contain mistakes — open the filing before acting on anything. Impact (1-5) and tone are the AI's reading of the filing for shareholders, not a price forecast. Not investment advice.