Biogen and Denali Halt Parkinson’s Drug Development After Phase 2b Trial Failure — Denali Therapeutics Inc.

Event summary

Biogen and Denali Therapeutics discontinued development of BIIB122 (DNL151) for idiopathic Parkinson’s disease after Phase 2b LUMA study failed to meet primary and secondary endpoints.
The Phase 2b LUMA study involved 648 participants with early-stage Parkinson’s disease and lasted up to 144 weeks.
Denali will continue the Phase 2a BEACON study independently, focusing on carriers of a pathogenic LRRK2 variant.
Data from the BEACON study is anticipated in the first half of 2027.

The big picture

The failure of BIIB122 in idiopathic Parkinson’s disease highlights the challenges in developing effective treatments for this complex neurodegenerative disorder. While Denali continues to explore LRRK2 inhibition in genetically defined subsets, the broader biotech industry will watch closely to see if this pathway can yield meaningful therapeutic benefits. The discontinuation underscores the high risk and uncertainty inherent in drug development, particularly for diseases with heterogeneous underlying biology.

What we're watching

LRRK2 Target Viability: Whether LRRK2 inhibition remains a viable therapeutic target for Parkinson’s disease, given the failure in idiopathic cases but continued exploration in genetic variants.
BEACON Study Outcomes: The pace at which Denali can generate and analyze data from the BEACON study to inform future development strategies.
Pipeline Adjustments: How Biogen and Denali will adjust their pipelines in response to this setback, particularly in neurodegenerative disease research.