Additional data from Sanofi's quadrivalent inactivated influenza vaccine study

Sanofi Pasteur, the vaccines division of Sanofi (EURONEXT: SAN and NYSE: SNY), announced today the results of a new study evaluating the immunogenicity and safety of an investigational quadrivalent inactivated influenza vaccine (QIV) among adults 65 years of age and older. Currently licensed influenza vaccines target only three influenza virus strains anticipated to circulate in a given year. The data were presented at the 49th Annual Meeting of the Infectious Diseases Society of America (IDSA) on October 21, 2011.

This study affirms the findings of a previous study on QIV presented last year at IDSA in adults 18 years of age and older. The results of the Phase II study indicated that the addition of an alternate-lineage B strain does not adversely affect the safety or immunogenicity profile of QIV compared to the currently licensed trivalent inactivated vaccine (TIV), Fluzone® (Influenza Virus Vaccine). In addition to the data in elderly adults presented today, a Phase III study in children 6 months through 18 years of age also is underway with data anticipated later this year.   

"The QIV development program supports Sanofi Pasteur's strategy to develop new vaccine options tailored to individual segments of the population to better support health-care providers in the public health fight to reduce overall morbidity and mortality caused by influenza," said David Greenberg, M.D., Senior Director U.S. Scientific and Medical Affairs, Sanofi Pasteur.

Currently, the annual influenza vaccine formulation targets the three influenza virus strains anticipated to circulate in a given year. This annual vaccine formulation includes two A strains, A(H1N1) and A(H3N2), and one of the two currently circulating B strains. However, since influenza B Victoria lineage re-emerged worldwide in 2001-2002, both Victoria and Yamagata lineages have circulated with varying prevalence, making it difficult to predict the next season's dominant lineage. Even in years when there was a good match to one B lineage strain, some influenza disease was caused by the other B lineage omitted from the vaccine. This led to the addition of a second B lineage strain in a quadrivalent formulation which may reduce influenza morbidity and mortality.

"The clinical significance of influenza B, the second most common cause of influenza-related complications and death after H3N2, is often overlooked," said Greenberg. "The results of our investigational studies to date continue to suggest that QIV has the potential to be a useful alternative to currently licensed influenza vaccines by including both B lineages that have been in circulation for the past decade. Thus, Sanofi Pasteur is continuing its clinical development program for this new vaccine which we believe will offer public health benefits."