Annexon's Interim Mid-Stage Results On Huntington's Disease Candidate Fails To Cheer

Annexon Inc ANNX posted interim data from its ongoing Phase 2 trial of ANX005 in patients with Huntington's disease (HD) who completed the 24-week treatment period. 

• Annexon is developing ANX005, its lead monoclonal antibody candidate, for a range of complement-mediated disorders, including HD.
• Results showed that relative to baseline after six months of treatment, improvement in mean Composite Unified Huntington's Disease Rating Scale (cUHDRS) was observed in more than half of all evaluable patients.
• Additionally, as of the cutoff date, 56% of patients showed improvement from baseline in cUHDRS and several subdomains of cUHDRS over six months of treatment.
• Also, 75% of evaluable patients demonstrated excess complement activity at baseline.
• The open-label trial of ANX005 enrolled 28 participants. The most common adverse events reported were infusion-related reactions.
• The Company anticipates reporting complete data from all patients enrolled, including data from the three-month follow-up period, in Q2 of 2022. 
• Pending results from the entire dataset, Annexon plans to evaluate the opportunity for a Phase 3 trial of ANX005 in HD patients.
• Price Action: ANNX shares closed 22.8% lower at $8.50 during after-hours trading on Tuesday.