Denali Therapeutics Inc. and Biogen Inc. announced that dosing has commenced in the global Phase 2b LUMA study to evaluate the efficacy and safety of BIIB122 (DNL151), as compared to placebo in approximately 640 participants with early-stage Parkinson's disease. LUMA is a Phase 2b multi-center, randomized, double-blind, placebo-controlled study to evaluate safety and efficacy of BIIB122 in people with early-stage Parkinson's disease between the ages of 30 and 80. The primary endpoint of LUMA is Time to Confirmed Worsening in Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) parts II and III combined score over the treatment period.

Participants will be randomized to receive oral BIIB122 or placebo once daily. BIIB122 is an investigational small molecule inhibitor of LRRK2 that was discovered and developed by Denali. Denali and Biogen are co-developing and co commercializing BIIB122 for the potential treatment of Parkinson's disease.

The BIIB122 clinical development program includes both the LUMA Phase 2b study and the Phase 3 LIGHTHOUSE study in individuals with Parkinson's disease with LRRK2 pathogenic variants. Following discovery of the LRRK2 mutation as a pathogenic genetic factor for Parkinson's disease, further research has uncovered that it has the potential to be a novel therapeutic target for Parkinson's disease. Mutations in leucine-rich repeat kinase 2 (LRRK2) account for 4-5% of familial and 1-2% of sporadic Parkinson's disease.

BIIB122 is a selective, central nervous system-penetrant small molecule inhibitor of LRRK2 that is hypothesized to improve lysosomal dysfunction. BIIB122 is an investigational drug that is not approved by any regulatory authority, and its safety and efficacy have not been established.