Novartis announced that the new clinical data for the its development vaccine Menveo (MenACWY-CRM) shows an excellent and broad immune response in infants as young as six months of age against four common serogroups (or types) of meningococcal meningitis, a potentially fatal bacterial disease involving inflammation of membranes around the brain and spinal cord.
Menveo is currently the only vaccine to generate protective immune responses in infants, expanding beyond the coverage of currently available vaccines for teenagers and adults. This response was seen in all four of the common serogroups - A, C, W-135 and Y - associated with meningococcal meningitis, which is caused by the bacteria Neisseria meningitidis.
The infant clinical trial data for this conjugated meningococcal vaccine, which utilizes technology that offers improved immunization responses compared to older bacterial polysaccharide vaccines, were presented at the 5th World Congress of The World Society for Paediatric Infectious Diseases (WSPID) in Bangkok.
Using a flexible administration schedule, results from the Phase II study of 175 infants who received either two doses of Menveo at ages six and 12 months or one dose of Menveo at age 12 months showed a robust immune response against serogroups A, C, W-135, and Y after one month.
The data reinforce earlier findings showing that Menveo - which is currently on track for regulatory submissions in 2008 - was well-tolerated and immunogenic in the first year of life and has the potential to protect against the A, C, W-135 and Y serogroups from early infancy.
"These data are encouraging given the unmet need for an effective meningococcal meningitis vaccine with broad serogroup coverage that can be given to infants," said Scott Halperin, MD, the lead study investigator and Director of the Canadian Center for Vaccinology as well as Professor of Paediatrics and Microbiology and Immunology at Dalhousie University in Halifax, Canada.
Meningococcal meningitis primarily affects young children, with the highest attack rate seen in infants during the first 3 to 12 months of life.
However, currently available polysaccharide vaccines covering these serogroups (called "quadrivalent vaccines") are only approved in certain countries for use in children age two and older due mainly to poor efficacy, while a conjugated vaccine approved for use in infants is only available against the C serogroup.
Approximately 500,000 cases of meningococcal meningitis are estimated to occur each year around the world, with 50,000 deaths blamed on the disease annually. Up to 20 per cent of those who survive are left with permanent disability such as deafness, neurological damage or limb loss.
"Menveo has shown in clinical trials that it is well-tolerated and generates high immune responses across all age groups, including infants," said Joerg Reinhardt, CEO, Novartis Vaccines and Diagnostics. "Novartis is rapidly developing this vaccine in a broad range of ages as an effective new option against meningitis and expects to make regulatory submissions in 2008."
Menveo is currently in multiple phase III clinical trials involving infants, young children, adolescents and adults. It is based on the same technical expertise used to produce Menjugate, a meningococcal serogroup C conjugate vaccine of Novartis approved outside the US since 2000 for use in individuals from two months old through adulthood. More than 25 million doses of Menjugate have been distributed around the world.
In addition to Menveo, Novartis is developing a recombinant vaccine aiming to provide coverage against the B serogroup, for which no vaccine has been achieved.
Menveo has high protective antibody levels with two different dosing schedules.
The phase II multi-centre trial randomised 175 infants to receive either two doses of Menveo at both six and 12 months of age, one dose of Menveo at age 12 months or a currently approved meningococcal meningitis serogroup C vaccine also at age 12 months and then followed by Menveo at age 18 months.
One month after vaccination, infants receiving Menveo achieved protective antibody levels as measured by hSBA titer >1:4 for all four meningococcal serogroups. hSBA is the human serum bactericidal antibody assay, which measures the body's immune response to antigens. After two doses of Menveo, the percentage of subjects achieving hSBA titer >1:4 was 100 per cent for the serogroups C, W-135 and Y35 and 86 per cent for serogroup A. After a single dose of Menveo at age 12 months, the percentages were > 93 per cent for serogroups C and W-135 as well as > 75 per cent for serogroups A and Y. Of the subjects who received the Menveo booster at age 18 months following a single dose at age 12 months, 100 per cent achieved hSBA titers > 1:4 for serogroup C, 62 per cent for A, 84 per cent for W-135 and 81 per cent for Y. Menveo was well-tolerated in this population.
Two doses of Menveo led to markedly greater amounts of antibody levels, while one dose at age 12 months led to comparable titers for serogroup C compared to the existing meningitis C vaccine.
Novartis Vaccines and Diagnostics is a division of Novartis focused on the development of preventive treatments. The division has two businesses: Novartis Vaccines and Chiron. Novartis Vaccines is the world's fifth-largest vaccines manufacturer and second-largest supplier of flu vaccines in the US.