Biogen and Denali end LRRK2 Parkinson’s program after phase 2b setback
Biogen and Denali terminated BIIB122 (DNL151), a LRRK2 inhibitor for idiopathic Parkinson’s, after a phase 2b trial failed to meet its primary endpoint despite strong target engagement (about 90% peripheral LRRK2 inhibition and a ~30% CSF biomarker decrease). The decision ends the idiopathic program, though Denali will continue a phase 2a trial in LRRK2-associated Parkinson’s, and the deal’s upfront cost ($400 million in 2020) and earlier phase 3 cutbacks underscore the challenge of translating target activity into clinical benefit in Parkinson’s disease.