Sanofi Pasteur, the vaccines division of Sanofi has reported topline results of a large-scale, multi-centre efficacy trial in people 65 years of age and older showing a superior clinical benefit of Fluzone High-Dose (Influenza Virus Vaccine) relative to the standard dose of Fluzone vaccine in preventing influenza.

This results will reflect the positive findings related to the primary endpoint for the study population. Further data analyses of secondary endpoints are ongoing, including an evaluation of the relative efficacy based on the match of the vaccine strains to circulating influenza virus strains. Sanofi Pasteur anticipates submitting the full clinical study report to the FDA for review by early 2014 and will seek a modification to the label for Fluzone High-Dose vaccine reflecting the superior efficacy data in adults 65 years of age and older.

“We are pleased that this study demonstrates the superior relative efficacy of Fluzone High-Dose vaccine compared to Fluzone vaccine in preventing influenza in older adults,” said David P Greenberg, MD, vice president, US Scientific and Medical Affairs, Sanofi Pasteur. “This efficacy trial complements the previous evidence of superior immune responses for Fluzone High-Dose vaccine compared to Fluzone vaccine and reaffirms the phase III safety data in this population that were the basis for FDA licensure of Fluzone High-Dose vaccine in 2009.”

In the study, Fluzone High-Dose vaccine was 24.2 per cent more effective in preventing influenza in adults 65 years of age and older than Fluzone vaccine.  The results met the pre-specified primary objective of the study, demonstrating statistically superior efficacy for Fluzone High-Dose vaccine. Additionally, the study results suggested consistent clinical benefit across the study years,  influenza virus types, clinical illness definitions, and laboratory methods of influenza confirmation. This large, multi-year trial also reaffirmed the safety of Fluzone High-Dose vaccine as demonstrated in previous studies.

“Influenza vaccines have been shown to offer public health benefits in preventing influenza and its complications in all age groups; however, older adults still have the highest rates of influenza-related hospitalization and death despite having high immunization rates,” said John Shiver, senior vice president, Research and Development, Sanofi Pasteur. “This led Sanofi Pasteur to develop Fluzone High-Dose vaccine, which this trial has confirmed provides better protection against influenza compared to Fluzone vaccine in people 65 years of age and older.”

Fluzone High-Dose vaccine was licensed in the United States by the Food and Drug Administration (FDA) in December 2009 based on the vaccine’s safety profile and superior immunogenicity compared to Fluzone vaccine. Immunogenicity (the ability of a vaccine to trigger the body to produce antibodies against an infectious agent) is commonly used to evaluate vaccines in clinical trials. Fluzone High-Dose vaccine contains 60 mcg of hemagglutinin  antigen per strain of influenza virus in the vaccine as compared to 15 mcg of influenza virus hemagglutinin antigen per strain of influenza virus in standard dose Fluzone vaccine. Fluzone High-Dose vaccine was licensed by the FDA  under an accelerated approval process to address the medical need in older adults. As a requirement of the accelerated approval pathway, Sanofi Pasteur embarked on this large-scale, two-season, confirmatory efficacy trial, involving more than 30,000 participants 65 years of age and older, to evaluate the clinical benefit of Fluzone High-Dose vaccine compared to Fluzone vaccine in the prevention of influenza disease.

Research has shown that the immune system weakens as people age. Older adults are not only more susceptible to infections, but also less responsive to vaccination. When infected with the influenza virus, they are less able to mount an effective immune response to neutralize the attack. Compared to younger adults, people 65 years of age and older suffer disproportionately from seasonal influenza disease and its complications, including severe illness leading to hospitalization and death. Although this group comprises only 15 per cent of the US population, on average it accounts for 65 per cent of the estimated 226,000 hospitalizations and 90 per cent of the 3,000 to 49,000 deaths attributed to seasonal influenza and its complications each year. The first baby boomers began to turn 65 in 2011 and, by the year 2030, the number of adults 65  years of age and older  is anticipated to double and surpass 70 million people, comprising 20 per cent of the US population. Thus, better prevention of influenza in older adults can have a significant impact on public health, quality of life, and healthcare costs.

Sanofi, an integrated global healthcare leader, discovers, develops and distributes therapeutic solutions focused on patients’ needs. Sanofi has core strengths in the field of health care with seven growth platforms: diabetes solutions, human vaccines, innovative drugs, consumer healthcare, emerging markets, animal health and the new Genzyme.