Paris, April 11, 2005 - Mutabilis, a biopharmaceutical company focused on new therapies against infectious diseases, announces today a license agreement with Chiron Vaccines, one of the world leaders in infectious disease vaccines. Under the terms of the agreement, Chiron Vaccines aims to use Mutabilis' research to develop a new prophylactic vaccine. The agreement provides for the payment of license fees, milestone fees and royalties to Mutabilis. Further financial details and the exact vaccine target were not disclosed.

 "Signing this agreement with such an important player in the vaccines industry is highly encouraging," said Sonia Escaich, chairman and chief scientific officer of Mutabilis. "It validates our approach to controlling infections more specifically and will help the development of our drug discovery programs."

About Mutabilis

Mutabilis, Paris, France, is a biopharmaceutical company specialized in antibacterial drug discovery. The company's focus is to create a new class of anti-infectious drugs by developing molecules, which are not antibiotics. These drugs selectively aim at pathogenic bacteria without preventing the proliferation of bacteria of the normal flora. This approach opens the way to new treatments for severe infections, especially in the field of nosocomial infections. Mutabilis also has discovered antigens that are specific to pathogenic strains of bacteria to develop preventive vaccine. Since it was established in 2001, Mutabilis has raised more than EUR10 million (USD13M) from investors including Auriga, AXA Private Equity, BioAm, Crédit Agricole Private Equity and Inserm-Transfert. Mutabilis is based in the Biocitech technology park at Romainville, near Paris.