Enanta advances zelicapavir into Phase 2b/3 RSV trial following FDA meeting

Enanta Pharmaceuticals announced advancement of zelicapavir into a registrational Phase 2b/3 clinical trial for high-risk RSV adults, with Phase 2b data expected in 2027, plus a pediatric Phase 2b trial starting in Q3 2026. The company estimates the oral RSV antiviral market opportunity exceeds $2 billion globally, positioning zelicapavir as a potential first-to-market antiviral therapy for RSV.