Moderna's CMV Vaccine Fails in Phase 3 Trial

Moderna, Inc. announced that its investigational CMV vaccine, mRNA-1647, did not meet the primary efficacy endpoint in a Phase 3 trial. The study aimed to prevent CMV infection in seronegative women of childbearing age. As a result, Moderna will halt its congenital CMV program.

The trial involved approximately 7,500 participants across 13 countries. The vaccine's efficacy ranged between 6% to 23%, significantly below expectations. Despite this setback, Moderna will continue exploring mRNA-1647's potential in bone marrow transplant patients through an ongoing Phase 2 study.

The company does not foresee any impact on its 2025 financial guidance or breakeven expectations for 2028, as mRNA-1647 was projected minimal revenue at launch. Moderna remains committed to advancing mRNA technologies despite this challenge.