Eli Lilly notified Rigel on April 16, 2026, of its decision to terminate the entire License and Collaboration Agreement signed February 18, 2021, effective June 15, 2026.128
The agreement covered ocadusertib (previously R552) and other RIPK1 inhibitors for non-CNS and CNS diseases, with potential milestone payments and royalties to Rigel.125
This follows an earlier termination of the CNS portion effective November 2025, eliminating all future milestones and royalties for Rigel.14
Rigel will regain full rights to the programs and is evaluating the impact.125
Ocadusertib was in a phase 2a trial for severe rheumatoid arthritis as of December 2025.2
Sources:
1. https://www.stocktitan.net/sec-filings/RIGL/8-k-rigel-pharmaceuticals-inc-reports-material-event-a9ac6023488a.html
2. https://www.gurufocus.com/news/8807571/eli-lilly-ends-collaboration-with-rigel-pharmaceuticals-lly
4. https://www.panabee.com/news/eli-lilly-terminates-rigel-ripk1-partnership-rights-revert-to-company
5. https://www.investing.com/news/sec-filings/rigel-pharmaceuticals-to-regain-rights-to-ocadusertib-after-eli-lilly-ends-agreement-93CH-4627501
8. https://www.streetinsider.com/Corporate+News/Rigel+Pharmaceuticals+regains+rights+as+Lilly+terminates+license+deal/26344506.html