Novavax offers hype and hope with an RSV 'breakthrough'

Novavax's Dr. Gregory Glenn

Novavax shares ($NVAX) surged today on the news that its vaccine for respiratory syncytial virus (RSV) proved effective in a large midstage study that company officials billed as a "historic" achievement.

Long an elusive goal in development circles after inactivated vaccines proved dangerous in the '60s, Novavax is angling to launch a late-stage program for the RSV vaccine later in the year, company execs tell Bloomberg. And CEO Stanley Erck previewed the company's blockbuster commercial expectations with Reuters yesterday, telling the news service that it could be "the largest selling vaccine in the history of vaccines in terms of revenue."

That may be, but the vaccine provided significantly less than universal protection against the virus, which is a mortal threat to a host of infants and the elderly every year. Investigators for Novavax noted that the big Phase II study demonstrated that their vaccine was 46% effective in preventing lower respiratory tract infections and 44% effective against all symptoms of RSV disease.

The company's stock jumped about 10% on the news, which was timed to coincide with Novavax's quarterly report.

Bolstered with $1 billion peak sales projections in the U.S. alone, Novavax isn't tempering the hype around this program.

"These efficacy data represent a historic advance for the field," said Novavax R&D chief Gregory Glenn in a statement. "This is also an important confirmation of the burden of RSV disease in older adults and highlights the high rate of lower respiratory tract symptoms in those infected by RSV in a large, prospective trial. It is clear that our RSV F Vaccine provided statistically significant efficacy in older adults, a population that historically has been difficult to protect. The reduction in symptomatic RSV, RSV with lower respiratory tract illness and RSV associated with difficulty breathing are breakthrough results."

"It could be a major breakthrough," Andrew Pavia, a spokesman for the Infectious Diseases Society of America, tells the AP. But he adds that these results need to be confirmed in Phase III before the celebrations can begin. "It's not time to break out the champagne."

A big market awaits Novavax if it proves successful. The CDC notes that with no vaccine to stop infection, 100,000 infants are hospitalized each year, with 177,000 hospitalizations and 14,000 deaths among adults over 65.

It's not unusual for a vaccine to provide significantly less than universal protection, but with fewer than half of the population protected against the common virus, Novavax still has some major league competition to consider.

Moncef Slaoui, who was moved from head of R&D at GlaxoSmithKline ($GSK) to chief of the enlarged vaccines business--which swelled with a vaccine/cancer drug portfolio flip with Novartis ($NVS)--recently noted that their RSV vaccine had completed Phase I and was headed into a Phase II among pregnant women. Novartis also cleared early studies with their vaccine and then presumably handed it over to GSK. AstraZeneca's ($AZN) MedImmune, a neighbor of Novavax in Rockville, MD, won fast-track status for their early-stage effort last spring. And Bavarian Nordic has reviewed its own preclinical results in RSV.

Vaccine development tends to be fast during an epidemic and a grinding, slow slog otherwise. But with Novavax taking the lead in such a big field, with global implications, regulators are more likely to provide an assist in getting this vaccine through Phase III at a more rapid pace.

- here's the release
- here's the AP report