FDA licenses Sanofi pasteur vaccine for protection against meningococcal disease

Sanofi pasteur, the vaccines business of the sanofi-aventis Group, announced today that the U.S. Food and Drug Administration (FDA) has licensed Menactra (Meningococcal [Groups A, C, Y and W-135] Polysaccharide Diphtheria Toxoid Conjugate Vaccine) for protection against meningococcal disease in adolescents and adults aged 11-55 years.

Menactra vaccine is the first quadrivalent conjugate vaccine licensed in the U.S. for the prevention of meningococcal disease and is designed to offer protection against four serogroups of Neisseria meningitidis (A, C, Y, W-135), the bacterium that causes meningococcal infection.

The U.S. Centers for Disease Control and Prevention's (CDC) Advisory Committee on Immunization Practices (ACIP) has formed a working group that is updating the recommendations for the prevention and control of meningococcal disease, including routine meningococcal vaccination of one or more birth cohorts (e.g., 11-12 year olds) and of selected college students. The ACIP is expected to approve any changes in recommendations during the February 2005 committee meeting.

"Adolescents and young adults are at increased risk for contracting meningococcal disease. I'm very pleased that pediatricians and family physicians in the United States now have a new tool to reduce the number of cases among this age group," said Michael Pichichero, MD, professor of microbiology/immunology, pediatrics and medicine, University of Rochester Medical Center. "The FDA licensure of Menactra vaccine, if it is coupled with wide-spread meningococcal immunization, represents a significant step toward eradicating this devastating disease."

Although meningococcal disease rates are highest in infants, rates begin to rise again in early adolescence and peak between the ages of 15 and 24. During the 1990s, one study reported substantially increased incidence among 15- to 24-year-olds. In addition to the increased incidence, the fatality rate was over 22 percent in this age group, over five times that seen in younger persons. Up to 83 percent of the cases reported in this study were caused by the potentially vaccine-preventable serogroups that are included in Menactra vaccine.

"In 2001, members of the CDC's Active Bacterial Core Surveillance Team called upon the pharmaceutical industry to create a conjugate vaccine for protection against multiple serogroups of Neisseria meningitidis to combat the increased risk for disease in the adolescent population," said Michael Decker, MD, MPH, vice president, scientific and medical affairs at sanofi pasteur, the human vaccines business of sanofi-aventis Group. "We are pleased to respond to their challenge with the licensure of Menactra vaccine. All evidence indicates that widespread use of Menactra vaccine will help to reduce invasive meningococcal disease in the United States, thereby preventing many deaths and anguish for thousands of families."

The FDA's decision to license Menactra vaccine was based on safety and immunogenicity data from six pivotal studies, which included more than 7,500 adolescents and adults receiving Menactra vaccine. Menactra vaccine induced the production of functional antibodies specific to the capsular polysaccharides of the four serogroups (A, C, Y and W-135) found in the vaccine. All vaccine immunogenicity measurements demonstrated strong immune responses to a single dose of Menactra vaccine that were equivalent to a single dose of sanofi pasteur's Menomune-A/C/Y/W-135 (Meningococcal Polysaccharide Vaccine, Groups A, C, Y and W-135 Combined).

Additional findings demonstrated 98 to 100 percent of seronegative adolescents were found to elicit four-fold increases in antibody titers to all four meningococcal serogroups. In seronegative adults, this range was 91 to 100 percent.

There are risks associated with all vaccines. The most common adverse reactions to Menactra vaccine may include pain, redness, and induration at the site of injection, headache, fatigue and malaise. Menactra vaccine is contraindicated in persons with known hypersensitivity to any component of the vaccine or to latex, which is used in the vial stopper.

Sanofi pasteur will work closely with the CDC in an effort to ensure production schedules that will support an orderly implementation of the anticipated new immunization recommendations. Additionally, the company is building a state-of-the-art production facility at its U.S. site in Swiftwater, Pennsylvania, to increase the production of Menactra vaccine to meet anticipated demand.

A supplemental licensure application in the U.S. for use of Menactra vaccine in children younger than 11 years is planned for early 2005. Additional submissions for licensures are planned for Canada in 2005 and at a future date for Europe.

In general, the benefits of a successful conjugate vaccine include improved duration of protection, induction of immunologic memory, booster responses and reduction in nasopharyngeal bacterial carriage. These characteristics have been recognized with Haemophilus influenzae type b (Hib) and Streptococcus pneumonaie conjugate vaccines. In 1987, sanofi pasteur licensed in the U.S. the first conjugate vaccine for protection against Hib -- ProHIBiT (Haemophilus influenza type b and diphtheria conjugate vaccine [diphtheria toxoid-conjugate]). Since the introduction of Hib conjugate vaccines, such as ProHIBit, the incidence of Hib invasive disease among children aged 4 years or younger has declined by 98 percent.

Meningococcal disease is a rare but serious bacterial infection that strikes between 1,500 and 3,400 Americans every year, causing meningitis or sepsis in the majority of cases. Approximately 10 percent of individuals who contract meningococcal disease will die. Of those who survive, up to one in five suffer permanent disabilities such as hearing loss, neurological damage and limb amputations. Meningococcal disease often begins with symptoms that can be mistaken for common viral illnesses, such as the flu. But unlike more common infections, meningococcal disease can progress very rapidly and kill an otherwise healthy young person in 48 hours or less.