The NanoFlu influenza vaccine was well-tolerated and elicited vigorous immune responses to the four flu strains included in the vaccine, according to top-line results of a Phase 2 clinical trial by Novavax Inc.
The Ph2 trial compared the safety and immune responses of various quadrivalent formulations of NanoFlu, with or without Novavax’ Matrix-M adjuvant, with two US-licensed influenza vaccines in 1,375 healthy adults 65 years of age and older.
In addition, Matrix-M adjuvant resulted in significant enhancement of immune responses when compared to the unadjuvanted formulation.
NanoFlu is a differentiated flu vaccine, as evidenced by significantly superior hemagglutination inhibition (HAI) antibody responses against wild-type A(H3N2) viruses, including drifted strains, when compared to Fluzone High-Dose, the leading flu vaccine in older adults. Improved response included:
- 45% increase against vaccine-homologous virus, A/Singapore.
- 22% increase against a historic drifted virus, A/Switzerland (p=0.014)
- 42% increase against a forward drifted virus, A/Wisconsin (p<0.001)
Based on the results, Novavax has advanced NanoFlu to a Phase 3 clinical trial and commercialization.
“The superior immunogenicity against wild-type H3N2 viruses holds promise that NanoFlu will more effectively address the mismatch between circulating viruses and the strains included in most commercial vaccines due to genetic drift and vaccine virus egg adaptation,” said Gregory Glenn, M.D., President of Research and Development of Novavax. “Older adults experienced the brunt of the serious health consequences of this mismatch, with H3N2 driving the majority of influenza hospitalizations and death during 2017-2018, the worst flu season in four decades. Over the past several years, influenza vaccine effectiveness has been suboptimal in this population, and there is broad agreement that better vaccines are needed. These confirmatory data from the second clinical trial of NanoFlu further justify continued rapid development of an improved vaccine.”
As Novavax previously announced, the US Food and Drug Administration (FDA) acknowledged that the accelerated approval pathway may be available for NanoFlu, which could allow for licensure of NanoFlu in a shorter timeframe. Novavax will again meet with the FDA in the first half of 2019 to discuss the Phase 2 clinical trial data, the proposed Phase 3 trial design, and the use of accelerated approval for licensure.
“The Phase 2 clinical trial results with NanoFlu demonstrate the potential impact our vaccine can make in preventing serious disease caused by influenza in older adults, a high-risk population that has proven difficult to protect in recent years,” said Stanley C. Erck, President and Chief Executive Officer of Novavax. “Our goal remains to advance to the market an improved vaccine that addresses the serious global public health threat that exists for older adults, and ultimately to make NanoFlu available to all populations.”