Phase 1 randomized, placebo-controlled, dose-escalating study to evaluate OVX836, a nucleoprotein-based influenza vaccine: intramuscular results

J Infect Dis. 2021 Oct 15;jiab532. doi: 10.1093/infdis/jiab532. Online ahead of print.


Background: OVX836 is a recombinant protein vaccine targeting the highly conserved influenza nucleoprotein (NP), which could confer broad-spectrum protection against this disease.

Methods: This was a randomized, placebo-controlled, double-blind, dose-escalating, single center first-in-human study, conducted in 36 healthy adults aged 18-49 years. Twelve subjects per cohort (9 vaccine and 3 placebo) received two OVX836 intramuscular administrations on Days 1 and 28 at the dose level of 30 µg, 90 µg or 180 µg. Safety and immunogenicity were assessed after each vaccination and for 150 days in total.

Results: OVX836 was safe and well tolerated at all dose-levels, with no difference in solicited local and systemic symptoms, and unsolicited adverse events between the 1 st and 2 nd administration, or between dose levels. All subjects presented pre-existing NP-specific immunity at baseline. OVX836 induced a significant increase in NP-specific interferon-gamma T-cells and anti-NP immunoglobulin G at all dose levels after the 1 st vaccination. The 2 nd vaccination did not further increase the response. There was a trend for a dose-effect in the immune response.

Conclusions: The safety and reactogenicity profile, as well as the humoral and cellular immune responses encourage further evaluation of OVX836 in a larger Phase 2a study.

Keywords: OVX836; Phase 1; healthy volunteers; immunogenicity; influenza; intramuscular; nucleoprotein; safety; universal vaccine.