Annexon Says Tanruprubart Met The Primary Endpoint; Demonstrates Rapid, Durable Recovery and Superior Efficacy In First Placebo-Controlled Phase 3 GBS Trial, Showing Significant Improvement In Motor Function, Mobility, and Disability Measures Over Placebo with No New Safety Signals"

First Placebo-Controlled Phase 3 Trial for GBS Presented in AAN Oral Presentation

In the Phase 3 pivotal trial of 241 patients, tanruprubart met the primary endpoint with consistent outcomes and rapid, more complete functional recovery versus placebo across multiple time points and clinical efficacy measures. The primary endpoint, GBS-Disability Scale (DS), showed that after a single infusion of tanruprubart at 30 mg/kg dose, patients had a statistically significant 2.4-fold higher likelihood of being in a better state of health than placebo at Week 8 (p=0.0058).

Highlights from the oral presentation at AAN include:

• New efficacy findings consistently demonstrated rapid recovery and durable benefits of tanruprubart across muscle strength, mobility and disability measures:
  
  
  
  • At Week 1, treated patients rapidly gained motor function and were 14-fold more likely to perform the Timed Up and Go (TUG) test, a standardized measure of mobility, balance and lower limb capacity
    
     
  • At Week 1, treated patients rapidly gained motor ability and showed more than a 2-point improvement on the Overall Neuropathy Limitation Scale (ONLS), a tool used to assess limitations in everyday activities of the upper and lower limbs
    
     
• New efficacy findings at Week 26 also demonstrated that the benefit of tanruprubart was durable, with twice the number of treated patients having no limitations on the ONLS compared to placebo
   
• The new findings build upon previously reported Phase 3 trial results that showed an improvement in the primary endpoint of GBS-DS at Week 8, as well as that twice the number of patients treated with tanruprubart fully recovered to normal (GBS-DS = 0) at Week 26, compared to placebo
• Treatment with tanruprubart enabled patients to walk independently and be off ventilation (for those requiring it) approximately a month earlier
   
• Patients treated with tanruprubart also spent approximately a week less time in intensive care
   
• Tanruprubart was well tolerated, with no new safety signals or off-target effects  
   

Results of the Phase 3 trial are reinforced by a Real World Evidence (RWE) study that matched tanruprubart-treated patients from the pivotal Phase 3 study with a Western world patient population treated with current standards of care, intravenous immunoglobulin (IVIg) or plasma exchange (PE). In the RWE study, tanruprubart showed a rapid increase in muscle strength with more complete recovery over IVIg or PE, consistent with benefits shown in the Phase 3 trial. The RWE study is planned for presentation at upcoming conferences.