Novavax takes RSV vaccine into Phase III ahead of schedule

Novavax ($NVAX) has been on a roll with its RSV (respiratory syncytial virus) vaccine lately, landing an $89 million Gates Foundation grant, reporting promising Phase II results in infants and launching a Phase III trial in older adults. Now, the Gaithersburg, MD-based biotech is starting a second Phase III trial in pregnant women to gauge the vaccine's efficacy in infants through maternal immunization.

The global trial, dubbed Prepare, comes slightly ahead of schedule. Following positive Phase II data, the company initially announced in September that it would launch the Phase III trial in 2016.

It will be randomized, observer-blinded and placebo-controlled, said Novavax in a statement. It will use a group sequential design, which allows flexibility in the size of the trial. Between 5,000 and 8,255 pregnant women will be recruited for the trial, which will last between two and four years. Trial participants will be vaccinated ahead of the 2015-2016 RSV season in each region.

Novavax CEO Stanley Erck

"We believe that maternal immunization offers the optimal way of protecting young infants, who are among the most susceptible populations to RSV disease," said Novavax CEO Stan Erck in the statement. "Initiation of this trial builds on our groundbreaking Phase II clinical data in this important population, and incorporates discussions with experts in the field and the FDA."

No vaccine for RSV exists, and developing one has been a priority for decades. The FDA fast-tracked Novavax's candidate in November 2014 and did the same for AstraZeneca's ($AZN) candidate in April this year. And in August, Bavarian Nordic initiated Phase I trials for its RSV vaccine in the U.S.

- here's the release