Moderna Phase III Covid-19 vaccine study to enroll 30,000 participants starting next month

The company said Thursday that it had finalized the design of the protocol for its upcoming randomized, placebo-controlled trial of its closely watched messenger RNA-based vaccine, mRNA-1273.

One of the companies in the lead to develop a vaccine against the virus that causes Covid-19 has finalized the design of its protocol for the Phase III study slated to begin next month.

Cambridge, Massachusetts-based Moderna gave details Thursday about the design of the protocol of the upcoming Phase III study, based on discussions with the Food and Drug Administration. Its vaccine against SARS-CoV-2, mRNA-1273, is currently in two clinical trials: a Phase I study sponsored by the National Institute of Allergy and Infectious Diseases and a Phase II study that the company itself is running.

Shares of Moderna rose 6.3% on the Nasdaq after markets opened following the news.

The Phase III trial, which Moderna will conduct under a collaboration with NIAID, will be randomized and placebo-controlled, enrolling about 30,000 participants in the U.S. Its primary endpoint will be prevention of symptomatic Covid-19 disease, while prevention of severe disease and of infection by SARS-CoV-2 will be secondary endpoints. Dosing is expected to start in July, and participants will receive a dose of 100 micrograms, the dose determined based on results of the Phase I study.

Swiss contract manufacturer Lonza will produce the vaccine, supplying 500 million to 1 billion doses annually starting next year. The Department of Health and Human Services’ Biomedical Advanced Research and Development Authority is funding the vaccine’s development.

Meanwhile, the Phase II study finished enrolling the first cohort of 300 younger adults – those aged 18-54 – while also enrolling a sentinel group of 50 older adults, aged 55 and older. That study is set to enroll 600 participants total, including 250 additional older adults.

The other company that is most advanced in development of its Covid-19 vaccine is Tianjin, China-based CanSino Biologics, whose vaccine is in a clinical development program centered on China that has recently also expanded into Canada. That company bears the distinction of having the first published data, with a paper that appeared in The Lancet last month.

Moderna also announced data from its Phase I study, showing that participants developed antibodies, though the data only included a very small number of subjects and did not show whether those antibodies would lead to immunity against SARS-CoV-2.

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