Bristol Myers Squibb halts clinical development of Prothena’s PRX019
PRTA•Bristol Myers Squibb notified Prothena on October 28 that it would stop clinical development of PRX019 after a strategic review. The license will terminate January 28, 2027, ending Prothena’s eligibility for up to $617.5 million in milestones and tiered royalties.
1. License termination
Bristol Myers Squibb notified Prothena on October 28, 2026, that it would stop clinical development of PRX019 following a strategic review. The license, signed in May 2024 with an $80 million upfront payment, will terminate on January 28, 2027.
2. Milestones and other trial
Termination eliminates Prothena’s eligibility for up to $617.5 million in development, regulatory and sales milestones, as well as tiered royalties. Previously reported Phase 1 results from the first half of 2026 showed favorable safety and tolerability and met prespecified biological-response targets. Bristol Myers Squibb continues moponetug’s Phase 2 Alzheimer’s trial, with up to $562.5 million in regulatory and sales milestones remaining available.
