Novavax’s flu vaccine for older adults shows early promise against Sanofi’s Fluzone

Novavax's recombinant flu vaccine candidate NanoFlu returned with positive topline clinical data in older adults. (Pixabay)

As the unsatisfactory performance posted by this season’s flu vaccines draws conversation around better prophylactic options, Novavax hopes to show that it’s new candidate could become one for older adults, who usually suffer the most from influenza.

The company released positive early data from a phase 1/2 trial on its NanoFlu recombinant flu vaccine. It reported that the vaccine candidate elicited significantly higher antibody responses against multiple flu strains—especially the nasty H3N2 strains—in adults 60 of age or older compared to Sanofi Pasteur’s licensed Fluzone high-dose.

NanoFlu combines Novavax’s Matrix-M adjuvant platform with recombinant nanoparticle technology, which Novavax says can display the virus’s conserved antigenic regions unaffected by surface shifts to offer broad protection against a range of strains.

Recent studies have suggested that the widely adopted egg-based production process, as used in Fluzone, might cause structural changes to the vaccine strain and hence affect vaccine efficacy. FDA Commissioner Scott Gottlieb, M.D., citing preliminary finding from the Centers for Medicare & Medicaid Services data, also recently said the cell-based flu vaccine “appears to have somewhat better effectiveness” than the egg-based vaccine.

Novavax grabbed the opportunity by stressing that its NanoFlu is produced in insect cells instead of eggs.

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The FDA is currently in the process of understanding why effectiveness of this year’s flu vaccines against H3N2 was only 25% overall, and it plans to apply the lessons learned to “considering whether greater investment in alternative processes such as cell-based or recombinant approaches to vaccine development are required.”

For Novavax, it still has a ways to go to prove NanoFlu’s worth. A phase 2 trial of the vaccine is expected to begin in the third quarter of 2018. But it has arguably been benefiting from renewed interest in novel flu vaccines amid one of the worst flu seasons in years. Without any major announcement, its stock price climbed from about $1.30 when 2018 began to a high of around $2.40 mid-February.

The Gaithersburg, Maryland-based company has been on quite a roller coaster. Although the topline flu results sent shares upward, the announcement had actually been scheduled for last December. When the company postponed it to February, its stock price dropped dramatically.

Data from a phase 2 trial on its once-flopped RSV F vaccine also failed to excite investors last July. The company is currently testing that candidate as a maternal immunization in a phase 3 supported by a grant from the Bill & Melinda Gates Foundation and a fast-track designation from the FDA.