Regulators in the USA have asked Novartis to provide more data to support its bid to get expanded approval for the meningococcal vaccine Menveo.

The Swiss major says it has received a complete response letter from the US Food and Drug Administration for the expanded use of Menveo in infants and toddlers from two months months of age. The product, which was approved in the USA in February 2010, is used in individuals aged two to 55 to help protect against meningitis and sepsis caused by four common vaccine-preventable serogroups (A, C, Y and W-135).

Novartis did not give many details about the FDA's letter and simply said the agency "requests answers to additional questions" prior to proceeding with further review of the supplemental Biologics License Application submitted in April last year. The firm added that it "will work with the FDA to address these questions".

Since launch, more than three million doses of Menveo have been distributed worldwide and studies are ongoing in infants, toddlers, adolescents and adults.

The CRL is a blow and the Wall Street Journal quoted Karl-Heinz Koch, an analyst at Helvea. as saying that "this additional delay further postpones approval in this all-important age group, and puts it at a further disadvantage" to Sanofi's Menactra vaccine. The latter is also approved for the A, C, W-135 and Y serogroups.