Moderna's mRNA-1403 Norovirus Vaccine Misses Phase 3 Interim Efficacy Bar

Moderna disclosed alongside its Q2 2026 earnings (Jul 31) that mRNA-1403, its experimental norovirus vaccine, failed to meet the pre-specified statistical threshold for early success at a planned Phase 3 interim analysis. The ongoing NOVA 301 trial has enrolled nearly 38,000 participants and remains blinded; Moderna is recruiting an additional cohort and adding a third enrollment season (winter 2026) to strengthen statistical power. President Stephen Hoge said the company "will need additional cases from a further cohort to strengthen that statistical analysis." The setback was disclosed alongside Q2 revenue of $145M (beating consensus) and vaccine sales of $94M (topping the $74M consensus); Moderna reaffirmed its target of up to 10% revenue growth versus 2025's $1.94B.