Key Takeaways
Biogen Inc. (BIIB) and Denali Therapeutics Inc. (DNLI) will discontinue development of their experimental Parkinson’s drug, BIIB122, after it failed to slow disease progression in a 648-patient Phase 2b study, a significant setback for a promising therapeutic target.
"While these are not the results we hoped for, these data provide important information to the Parkinson’s community and will be presented at an upcoming scientific conference,” Diana Gallagher, Head of Neurodegeneration Clinical Development at Biogen, said in a statement.
The LUMA study did not meet its primary endpoint, defined as the Time to Confirmed Worsening in the modified Movement Disorder Society Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) Part II and III combined score. Secondary endpoints also showed no benefit. While the drug achieved its biological goal, demonstrating over 90% inhibition of the LRRK2 protein in the blood and sustained levels in cerebrospinal fluid, this did not translate to a clinical benefit for patients with early-stage idiopathic Parkinson's disease.
The failure deals a blow to the hypothesis that inhibiting the LRRK2 protein could benefit all Parkinson's patients, a theory that gained traction after mutations in the LRRK2 gene were linked to rare, inherited forms of the disease. Shares of Biogen fell more than 1% in after-hours trading following the news.
Despite the LUMA study's outcome, Denali Therapeutics will continue its independent Phase 2a BEACON study. This trial is evaluating BIIB122 specifically in patients who carry a pathogenic LRRK2 gene variant, which is associated with increased activity of the LRRK2 kinase. Data from that study is expected in the first half of 2027.
“We believe the LUMA study was a robust test of LRRK2 inhibition,” said Peter Chin, Chief Medical Officer at Denali. “We look forward to further analysis of the LUMA data and the results from BEACON to inform next steps for development.”
The outcome for BIIB122 underscores the immense difficulty in developing drugs for neurodegenerative conditions like Parkinson's disease, which affects more than 10 million people worldwide. The focus for the LRRK2 inhibitor now narrows to a genetically-defined patient population, with the BEACON study results serving as the next major catalyst for the program.
This article is for informational purposes only and does not constitute investment advice.
