FDA files MedImmune's sBLA for quadrivalent intranasal nasal influenza vaccine, FluMist

MedImmune has received confirmation from the U.S. Food & Drug Administration (FDA) that the Agency has filed the Company's supplemental Biologics License Application (sBLA) for a quadrivalent (four-strain) version of FluMist® (Influenza Vaccine Live, Intranasal). The company submitted the sBLA early in the second quarter of this year.

Currently licensed seasonal influenza vaccines are trivalent, containing three strains (two strains of type A influenza (A/H1N1 and A/H3N2) and one B lineage strain).  However, as influenza B strains from 2 different lineages have circulated in recent years (B/Yamagata and B/Victoria) the quadrivalent vaccine contains four strains: A/H1N1, A/H3N2, and B strains from both of the B lineages.  The quadrivalent vaccine is designed to offer protection against a broader range of B strains and reinforces MedImmune's commitment to innovation within the infectious disease area.

Historically, seasonal flu vaccines have contained three strains recommended by the FDA's Vaccines and Related Biological Products Advisory Committee (VRBPAC). Their recommendation is based on global public health officials' best prediction nearly 8 months prior to the start of the influenza season as to which strains will predominate during the upcoming season and therefore are most likely to pose the greatest public health risk.

"According to the Centers for Disease Control and Prevention (CDC), since the 2001-2002 season, influenza B viruses from both lineages have co-circulated during most influenza seasons in the USA, and it has been difficult to accurately predict the correct lineage to include in the seasonal vaccine," said Robert Belshe, M.D., director of the Center for Vaccine Development  Saint Louis University. "In fact, in the United States, in a recent 10 year interval of influenza seasons, the predominant circulating influenza B lineage was different in 5 seasons from the one selected for inclusion in the vaccine."

In pivotal clinical studies conducted in adults and children, the quadrivalent live attenuated influenza vaccine (Q/LAIV) was compared to two trivalent formulations of MedImmune's licensed seasonal influenza vaccine, FluMist (Influenza Vaccine Live, Intranasal).  The quadrivalent vaccine induced immune responses to both B strains and the immune responses for all of the four strains in the vaccine were comparable to the immune responses induced by the trivalent vaccines. Additionally, Q/LAIV had a comparable safety profile to the trivalent FluMist formulations in the indicated FluMist population (eligible individuals 2-49 years of age).

"We believe that the inclusion of an additional B strain in an annual influenza vaccine could provide a direct health benefit to individual vaccine recipients in the event that the correct B lineage either is not selected for inclusion in a trivalent vaccine, or if both lineages co-circulate," said Filip Dubovsky, M.D., MedImmune's vice president of Clinical Development.