Moderna Halts Development of CMV Vaccine After Phase 3 Failure

Moderna's investigational vaccine for cytomegalovirus (CMV), called mRNA-1647, failed its Phase 3 trial, leading the company to discontinue development for this indication1 3 5 7 11.

The vaccine demonstrated an efficacy rate of just 6% to 23% in preventing CMV infection among women aged 16–40, far below Moderna's target and insufficient for advancement1 3 5.

The pivotal Phase 3 trial, known as the CMVictory study, enrolled nearly 7,500 women globally between 16 and 40 years old1 2 3 5.

No significant safety concerns were identified with the vaccine, and it was generally well tolerated by participants2 3 5 7.

Moderna's CEO and President acknowledged disappointment and highlighted the continued unmet need for a congenital CMV vaccine but confirmed sharing forthcoming trial data with the scientific community to aid future research1 3 5 7 9.

Congenital CMV is the leading infectious cause of birth defects in the U.S., causing serious disabilities, but there remains no approved vaccine for prevention1 4 5 11.

Moderna will continue a Phase 2 study of mRNA-1647 in bone marrow transplant patients, but its program for congenital CMV prevention is discontinued1 3 7.