Sanofi Pasteur Announces Final Results of U.S. Clinical Trials of Influenza A (H1N1) Vaccine in Adults and Children

Sanofi Pasteur Announces Final Results of U.S. Clinical Trials of Influenza A (H1N1) Vaccine in Adults and Children
- Final data confirm immunogenicity, safety profile -
- Single dose provides robust immune response in adults; two doses provide robust immune response in children 6 months through 9 years -

Swiftwater, Pa (United States) - November 11, 2009 /PRNewswire/ - Sanofi Pasteur, the vaccines division of the sanofi-aventis Group (EURONEXT: SAN and NYSE: SNY), announced today the final analyses of data from clinical trials of the U.S. licensed Influenza A (H1N1) 2009 Monovalent Vaccine in adults and children.

The data confirm the immunogenicity and safety profile of the vaccine, with no serious vaccine-related adverse events reported during the 42 days of follow-up in the two trials.

"These are extremely important data," said Wayne Pisano, President and Chief Executive Officer of Sanofi Pasteur, "because they once again make clear not only the immunogenicity of the Influenza A (H1N1) 2009 Monovalent Vaccine manufactured by Sanofi Pasteur, but also the fact that this vaccine has a safety profile similar to that typically observed with seasonal influenza vaccine in all age groups studied."

The trials confirm that one dose of Influenza A (H1N1) 2009 Monovalent Vaccine induces a robust antibody response in adults - but two doses of vaccine are needed to assure a robust antibody response in children 9 years of age and younger. The two-dose regimen for these younger children is similar to the recommendations for seasonal influenza immunization in this age group.

About the Trial
The randomized, placebo-controlled, multicenter trials were conducted by Sanofi Pasteur to determine the immunogenicity and safety of the vaccine, given in two doses, with the second dose administered 21 days following the first dose. Immunogenicity was measured at day 21, just prior to administration of the second dose, and again at day 42.

The adult trial was conducted in 849 individuals divided into two age cohorts: 18 through 64 years of age; and 65 years of age and older. Study participants in each age cohort were randomized to four treatment groups. Three groups received a 0.5 mL injection of non-adjuvanted vaccine formulated to contain 7.5, 15 or 30 mcg of hemagglutinin (HA) antigen. The fourth group received a placebo control (ClinicalTrials.gov registration number NCT00953524).

In the pediatric trial, 474 children were enrolled in two age cohorts: 6 months through 35 months of age; and 3 years through 9 years of age. The trial evaluated two vaccine formulations, 7.5 mcg and 15 mcg of HA antigen in each of two cohorts, with a third group receiving a placebo (ClinicalTrials.gov registration number NCT00952419).

At Day 42, 21 days following a second 7.5 mcg dose of Influenza A (H1N1) 2009 Monovalent Vaccine, seroprotection (defined as an antibody titer of 1:40 or greater) was achieved in 92 percent of children 6 months through 35 months of age; and following a second 15 mcg dose of the vaccine, seroprotection was achieved in 99 percent of children 3 through 9 years of age, 99 percent of adults 18 through 64 years of age and in 95 percent of adults age 65 and older.

Sanofi Pasteur previously reported interim data showing that an immune response considered seroprotective was achieved following one 15 mcg dose of the vaccine in 50 percent of children 6 months through 35 months of age, 76 percent of children 3 through 9 years of age, 98 percent of adults 18 through 64 years of age and 92 percent of adults age 65 and older.

A rise in antibody titers lower than 1:40 following vaccination may minimize the occurrence of disease and its consequences but is not considered seroprotective.

The data from these clinical trials provide additional information to guide recommendations on the optimal dosage, number of doses and schedule.

No serious vaccine-related adverse events were reported during the trial. Adverse event monitoring will continue for six months after administration of the second vaccine dose. Solicited systemic and local reactions reported were similar to those observed in other studies of seasonal trivalent inactivated influenza vaccine administered to persons in comparable age groups.

About Influenza A (H1N1) 2009 Monovalent Vaccine
The U.S. licensed Influenza A (H1N1) 2009 Monovalent Vaccine manufactured by Sanofi Pasteur is an inactivated influenza virus vaccine indicated for active immunization of persons 6 months of age and older against influenza disease caused by pandemic (H1N1) 2009 virus. Influenza A (H1N1) 2009 Monovalent Vaccine was licensed by the U.S. Food and Drug Administration on September 15 as a monovalent strain change to Sanofi Pasteur's licensed seasonal influenza vaccine.

The Influenza A (H1N1) 2009 Monovalent Vaccine is manufactured by the same process as Sanofi Pasteur's seasonal trivalent influenza virus vaccine licensed in the U.S. Influenza A (H1N1) 2009 Monovalent Vaccine is formulated to contain 15 mcg hemagglutinin (HA) of influenza A/California/07/2009 (H1N1) v-like virus. Influenza A (H1N1) 2009 Monovalent Vaccine is licensed for single-dose presentations in syringes and vials and in multi-dose vials. There is no preservative used in the single-dose presentations. Multi-dose vials contain a preservative.

Safety Information for Influenza A (H1N1) 2009 Monovalent Vaccine
Influenza vaccine should not be administered to anyone with a known severe hypersensitivity to egg proteins, any vaccine component or life-threatening reactions after previous administration of any influenza vaccine. Recurrence of Guillain-Barré syndrome (GBS) has been temporally associated with the administration of influenza vaccine. The decision to give Influenza A (H1N1) 2009 Monovalent Vaccine to individuals who have a prior history of GBS should be based on careful consideration of the potential benefits and risks. Vaccination with Influenza A (H1N1) 2009 Monovalent Vaccine may not protect all individuals.

Before administering Influenza A (H1N1) 2009 Monovalent Vaccine, please see full U.S. Prescribing Information at www.vaccineplace.com/products.

About Influenza Vaccine Production at Sanofi Pasteur
Sanofi Pasteur operates influenza vaccine production facilities in Val de Reuil, France and in Swiftwater, Pa. (U.S.). All Sanofi Pasteur influenza vaccine facilities have been designed and built to be able to switch from seasonal influenza vaccine production to pandemic influenza vaccine production.

Sanofi Pasteur produces approximately 40 percent of the influenza vaccines distributed worldwide and more than 45 percent of the influenza vaccines distributed in the U.S. for the 2008-2009 influenza season. More information about Sanofi Pasteur's pandemic preparedness efforts can be found at www.pandemic.influenza.com.