Moderna announces CMV vaccine study did not meet primary endpoint

Moderna (MRNA) announced topline results from a Phase 3 pivotal trial evaluating the efficacy of mRNA-1647, the company’s investigational cytomegalovirus vaccine. The study did not meet its primary efficacy endpoint of preventing CMV infection in seronegative female participants of childbearing age. Moderna will discontinue its congenital CMV clinical development program. mRNA-1647 was found to be generally well-tolerated regardless of CMV serostatus, with a safety profile consistent with earlier studies. No safety concerns have been raised by the Data and Safety Monitoring Board. The company plans to continue its study of mRNA-1647 in bone marrow transplant patients, which is currently in a Phase 2 trial. Moderna does not anticipate any impact to its 2025 financial guidance or its expectation of achieving breakeven in 2028. Moderna anticipated minimal initial revenue contribution from mRNA-1647 given necessary investments in market building and launch, and expected the product to be cash-flow negative in 2028. “Today’s announcement is disappointing for families and healthcare professionals who have been eagerly awaiting a CMV vaccine to prevent congenital CMV, a leading infectious cause of birth defects,” said Stephane Bancel, CEO of Moderna. “The majority of the data from this trial is still forthcoming, and we will share our full results with the scientific community in hopes that our learnings can contribute to the continued pursuit of a CMV vaccine. I am grateful for our dedicated team, our partners at clinical trial sites, and all the trial participants who made this research possible.”