Annexon announces topline results from RWE study of ANX005 in GBS

Annexon (ANNX) announced topline results from a real-world evidence study supporting ANX005 as a potential treatment for Guillain-Barre Syndrome. GBS is a rapid-onset and acute neuromuscular disease with no U.S. Food and Drug Administration-approved treatments. ANX005, the most advanced targeted immunotherapy in development for GBS, is designed to rapidly block C1q and complement activity with a single dose to halt disease progression during the critical progressive phase of the disease. Working in collaboration, the IGOS investigators and Annexon established a cohort of 79 real-world patients from the IGOS global patient registry that was matched based on key prespecified prognostic factors to the cohort of 79 patients treated with ANX005 30 mg/kg from Annexon’s completed Phase 3 study conducted outside the United States. Patients in the ANX005 Phase 3 population had moderate to severe disease, and the matching level demonstrates that the Phase 3 population is represented within the global GBS patient spectrum captured in IGOS. Patients treated with ANX005 showed faster and greater improvement in muscle strength and disability compared to patients in the matched IGOS cohort treated with IVIg or PE. The comparison also showed that fewer patients treated with ANX005 required mechanical ventilation. Further, ANX005-treated patients were observed to spend less time on ventilation and less time in the intensive care unit. These findings indicate that ANX005 may decrease the overall burden of GBS care. Key findings comparing ANX005 30 mg/kg to IVIg or PE: By week 1, patients treated with ANX005 showed more than a 10-point improvement in muscle strength over patients treated with IVIg or PE, a clinically meaningful benefit as measured by Medical Research Council sumscore and an indicator for future recovery potential; Patients treated with ANX005 were approximately twice as likely to be in a better state of health than patients on IVIg or PE on the GBS-Disability Scale at multiple timepoints throughout the study, including at week 8, the primary endpoint for the Phase 3 trial; Approximately half the number of patients treated with ANX005 required mechanical ventilation compared with patients treated with IVIg or PE; ANX005-treated patients were observed to spend fewer days on mechanical ventilation and fewer days in the ICU.