Wyeth has received some mixed news from US regulators who will not extend use at the moment of its antibiotic Tygacil but will fast-track a new version of its Prevnar jab.

Firstly, the US Food and Drug Administration issued an approvable letter for Tygacil (tigecycline) for the treatment of adults with community-acquired pneumonia. The agency has told Wyeth it wants to see additional analyses to support the safety and efficacy of the antibiotic for CAP patients with illness severe enough to require hospitalisation, including those who are at higher risk of mortality.

In addition, the FDA requested information regarding the benefit/risk of Tygacil for any potential of liver toxicity. However Wyeth says that it recently provided that information to the agency and believes that its response “adequately addresses the issues raised”. Indeed, the agency acknowledged in its letter that it had not yet reviewed that information.

Tygacil, which had sales of $138 million last year, was approved by the FDA in June 2005 for the treatment of adults with complicated intra-abdominal infections and complicated skin and skin structure infections.

Better news came with the FDA’s decision to granted fast-track designation to the company's investigational 13-valent pneumococcal conjugate vaccine Prevnar for infants and toddlers. Wyeth is seeking a paediatric indication for active immunisation against invasive pneumococcal disease and otitis media caused by serotypes included in the vaccine.

The new version would protect against 13 strains of the bacteria, compared with seven at the moment. Wyeth plans to complete its filing for the new use of the jab, which had first-quarter sales of $706 million (+14%), in the first quarter of 2009.