The interim analysis of the Phase 3 FORTIFY trial evaluated oral BBP-418 in individuals with LGMD2I/R9, showing a rapid reduction in serum CK with 59.6% achieving levels within twice the ULN and 38.3% normalizing CK by month 12. BBP-418-treated participants completed the 100-meter timed test approximately 31 seconds faster than placebo and improved 10-meter walk speed by 0.13 m/s versus a 0.10 m/s decline in the placebo arm, with consistent benefits across genotype, age, and baseline pulmonary function subgroups.

BBP-418 was generally well tolerated, with treatment-emergent adverse events reported in 93.2% of treated individuals versus 100% on placebo; grade ≥3 events occurred in 5.4% versus 5.3%. Common mild-to-moderate events included diarrhea (39.2% vs. 52.6%), procedural pain (20.3% vs. 10.5%), and nausea (16.2% vs. 7.9%), with no treatment-related serious adverse events or deaths and no laboratory or cardiac safety signals.

Based on these positive interim results, BridgeBio intends to submit a new drug application to the FDA in the first half of 2026, targeting a U.S. launch in late 2026 or early 2027. If approved, BBP-418 would become the first therapy for LGMD2I/R9 and potentially the first for any limb-girdle muscular dystrophy subtype.