Annexon reports early data from first 10 GBS FORWARD study patients

Annexon, Inc. announced on August 6, 2026 that initial results from the first ten U.S. and European patients enrolled in its ongoing, open-label FORWARD study of tanruprubart in Guillain-Barré syndrome (GBS) showed rapid clinical responses in the first week of treatment.

The initial cohort data showed clinically meaningful and rapid improvement in strength and reduced disability within days of a single 30 mg/kg infusion of tanruprubart, with all treated patients showing rapid muscle strength improvement within four days.¹ Among specific outcomes, four patients who were bedbound early in the course of disease were able to walk with or without assistance between day two and eight¹, and the one patient who needed ventilation early in the disease course came off the ventilator within four days¹. The remaining five patients showed marked functional gains within 48 hours.¹

Safety in this cohort tracked prior data: the drug was generally well tolerated, and the most common adverse events were related to GBS itself or its complications, consistent with earlier Phase 3 results.¹ The cohort spanned a wide range of patients: both male and female patients aged 12 to 78 were enrolled, representing moderate to severe disease.¹ The company said these outcomes align with the Phase 3 study, where about 90% of patients showed rapid, clinically meaningful improvement by day 8.¹

Looking ahead, Annexon said FORWARD data will be shared at upcoming medical meetings and are expected to support consistent clinical benefit across global patient populations, feeding into a planned Biologics License Application targeted for the fourth quarter of 2026.¹ Separately, a Marketing Authorisation Application for tanruprubart is currently under review by the European Medicines Agency.¹ Tanruprubart already holds Fast Track and Orphan Drug designations from the FDA and orphan drug designation from the EMA for GBS.¹