With promising RSV data in hand, Novavax wins $89M Gates grant for PhIII

Immunizing pregnant women with an RSV vaccine charged up levels of antibodies that should be able to protect infants during the first few months of their lives, Novavax reported Tuesday morning, adding that the Bill & Melinda Gates Foundation followed up with an $89 million grant to fund a pivotal study.

Investigators recruited 50 pregnant women for the Phase II study, which they say provided evidence of a 14-fold rise in anti-F IgG, a 29-fold rise in palivizumab-competing antibody titers, and a twofold rise in microneutralization titers.

The news wasn't good enough to overcome the downward draft of a bear biotech market, with Novavax's ($NVAX) stock dropping several points in early trading.

Novavax's Dr. Gregory Glenn

"Maternal immunization is an elegant and accepted approach to protect infants in the first few months of life, the time period when they are most vulnerable to RSV," said Gregory Glenn, the SVP of R&D at Gaithersburg, MD-based Novavax. "These data are consistent with immune responses observed in our earlier trials of women of child-bearing age. As anticipated, infants received a significant bolus of all anti-RSV antibodies via transplacental transfer. Half of all hospitalizations due to RSV occur within the first three months of life and, based on these data, the RSV F Vaccine demonstrates the potential to protect infants when they are most at risk of infection."

The latest Phase II study comes just weeks after another successful study in which Novavax demonstrated that their vaccine helped guard against the respiratory disease in older adults. That study enrolled 1,600 older subjects divided between a placebo arm and the adjuvanted vaccine arm.

RSV has proven to be a devilishly difficult virus to block. And now Novavax will launch a Phase III program in early 2016 to see if they can take the lead in finally accomplishing the task.

Novavax is by no means the only company in the field. Both MedImmune, a subsidiary of AstraZeneca ($AZN) which has spent years working in this field, and Bavarian Nordic have fast-track status at the FDA with their rival programs.

- here's the release