Sanofi To Buy Acambis

In a deal that underscores big pharma's growing interest in vaccines, the French drug giant Sanofi-Aventis has agreed to pay roughly $550 million for the Cambridge, England-based vaccine company Acambis.

The planned acquisition does not come as a surprise, given the decade-long relationship between Sanofi and Acambis. The companies are currently partnered in the development of three vaccines; one is in Phase III trials for preventing Japanese encephalitis and the others are in Phase II studies against West Nile virus and Dengue fever.

With the purchase, Sanofi will also gain ACAM2000, a smallpox vaccine approved in the U.S. to immunize those at highest risk of infection. In April, Acambis won a 10-year, $425 million contract from the Centers for Disease Control & Prevention to establish U.S.-based manufacturing of the smallpox vaccine and supply at least 9 million doses per year starting in 2010.

The company also has two promising products in Phase I trials: a flu vaccine that targets all strains and a vaccine against Clostridium difficile, a bacterium that is the source of an increasing number of hospital-acquired infections.

Hedwig Kresse, senior analyst for infectious diseases at the health care consulting firm Datamonitor, says the deal between Sanofi and Acambis is more evidence of the drug industry's renewed interest in vaccines after years of ignoring them as mature and barely profitable.

"Vaccines are starting to become commercially attractive again," Kresse says, pointing to the success of newer products such as Merck & Co.'s human papillomavirus vaccine Gardasil and Wyeth's pneumonia vaccine Prevnar. Further, she notes, vaccines typically don't face patent challenges and thus are less susceptible to competition from generics than small-molecule pharmaceuticals.