New data reveal how Bayer's asundexian failed to prevent strokes, imperiling $5.5B blockbuster hopes

Bayer suspended the phase 3 trial for its factor XIa inhibitor asundexian late last year after the drug showed “inferior efficacy” at preventing strokes in patients with atrial fibrillation compared to Bristol Myers Squibb and Pfizer’s Eliquis. The full picture of what that “inferior efficacy” looks like has now come into focus: Patients receiving asundexian actually suffered strokes or systemic embolisms at a higher rate than those receiving Eliquis.