Moderna begins Phase 3 H5N1 vaccine trials

Moderna said on April 21 that the first participants in the United States and Britain had been dosed in a Phase 3 study of its experimental H5 pandemic influenza vaccine, mRNA-1018. The Cambridge, Massachusetts, company said the trial will test safety and immunogenicity in about 4,000 adults age 18 and older in the two countries. Britain’s National Institute for Health and Care Research said on April 22 that the U.K. portion had given its first dose and would recruit about 3,000 volunteers across 26 sites. The study puts Moderna’s bird flu program into a late-stage human trial as health agencies continue to track H5 viruses in birds and other animals. The company said the candidate is designed as an mRNA-based pandemic influenza vaccine rather than a seasonal flu shot. CEPI, the Coalition for Epidemic Preparedness Innovations, said in December it would invest up to $54.3 million to help move the program toward licensure. (feeds.issuerdirect.com) ### When did this trial actually start? April 21 is the date Moderna used for the trial start announcement, saying the first participants in the U.S. and U.K. had been dosed. April 22 is the date NIHR used for its own announcement of the first U.K. dose. Those are the key dates tied to the launch, not May 14. (feeds.issuerdirect.com) Britain’s announcement added a location detail that was missing from some brief reports: the study is being run through community clinics across England and Scotland as part of a U.K. government strategic partnership managed by the U.K. Health Security Agency. NIHR said the trial is sponsored by Moderna and supported by CEPI. (feeds.issuerdirect.com) ### What is Moderna testing in Phase 3? mRNA-1018 is Moderna’s investigational A(H5) pandemic influenza vaccine candidate. Moderna said the Phase 3 study will evaluate safety and immunogenicity in healthy adults, meaning the main readouts are whether the shot is tolerated and whether it produces an immune response. NIHR used similar language, saying the trial will assess safety and immune response against A(H5) strains with pandemic potential. (nihr.ac.uk) ClinicalTrials.gov shows Moderna previously ran a Phase 1/2 study, NCT05972174, in 1,504 adults to generate the safety and immunogenicity data needed to move one selected candidate into a large Phase 3 trial. That earlier study tested several pandemic influenza constructs before narrowing to a single H5 candidate. ### Why are Britain and the United States central to this study? (feeds.issuerdirect.com) NIHR said about 75% of the roughly 4,000 planned participants will be recruited in Britain, or about 3,000 people. The agency said there are 26 U.K. sites and that the work is being delivered through community clinics rather than only hospital settings. (clinicaltrials.gov) Moderna said only that the study is taking place in the U.S. and U.K., but the British rollout gives a clearer picture of how much of the enrollment is expected to come from that country. Southampton has been identified in outside reports as one of the U.K. locations, though NIHR’s announcement described the study more broadly as a multi-site national effort. (nihr.ac.uk) ### Who is paying for it, and what has Moderna promised? CEPI said on Dec. 17 it would provide up to $54.3 million to support the pivotal Phase 3 trial. Moderna and CEPI said the agreement is intended to help advance mRNA-1018 to licensure. Moderna said that if the vaccine is licensed and an influenza pandemic occurs, it will allocate 20% of its H5 pandemic vaccine manufacturing capacity to low- and middle-income countries at affordable pricing under its CEPI agreement. (feeds.issuerdirect.com) That commitment is contingent on licensure and a pandemic scenario; it is not a statement that supply is available now. (cepi.net) ### What comes next before any vaccine could be used? Moderna said any global regulatory submissions for mRNA-1018 would also be supported by positive data from the company’s Phase 3 seasonal flu vaccine trial, mRNA-1010. The company said that seasonal flu candidate has been accepted for review in the United States, European Union, Canada and Australia. (feeds.issuerdirect.com) Recruitment is continuing now. NIHR directs potential volunteers to its Be Part of Research service, and Moderna’s trial registry lists the study as mRNA-1018-P301. (nihr.ac.uk) (feeds.issuerdirect.com)