SAFC/VIVALIS REACH FIRST MILESTONE IN R&D COLLABORATION.

SAFC Biosciences, a member of the Sigma-Aldrich Group (NASDAQ: SIAL), and Vivalis, have announced the successful completion of the first stage of their on-going collaboration with the launch of their EX-CELL(TM) EBx(TM) platform, which includes EX-CELL(TM) EBx(TM) viral growth and production media. This media is designed exclusively to support EBx cells, a chicken embryonic derived stem cell line, for growth and production of viral vaccines for therapeutic use.

Under the R&D agreement, which commenced in 2004, SAFC Biosciences has developed and optimized media specifically for use with Vivalis' widely licensed EBx cells, in the commercial development of viral vaccines for clinical trials and recombinant protein production. This serum-free media is designed exclusively to support high growth of EBx cells and high productivity of viruses and viral constructs for production of vaccines for both therapeutic and prophylactic use.

As a result of the collaboration, EBx licensees' development work and success will be enhanced when sourcing medium through SAFC Biosciences. The EX-CELLTM EBx medium will also be used at Vivalis' contract manufacturing facility in Nantes, France, for cGMP production of vaccine lots for phase I/II clinical trials.

"The launch of the EX-CELL EBx technology platform marks a major breakthrough in the commercial production of viral vaccines and recombinant proteins," said Rod Kelley, president of SAFC Biosciences. "We are pleased to have developed a serum-free media specifically for Vivalis EBx cells, which have been viewed as an exciting new vaccine and human therapeutic production platform for the growing pipelines of today's biopharmaceutical companies."

Franck Grimaud, CEO of Vivalis, added, "We have been very pleased with our collaboration with SAFC Biosciences and the motivation of their research and development team. Today, Vivalis clients have access to highly performing EX-CELL EBx media, which further strengthens the performance and the robustness of Vivalis EBx cell lines."

About SAFC Biosciences:

SAFC Biosciences provides an integrated services package in mammalian cell culture media development to support customer programs from pre-clinical and clinical development to commercialization. Analytical and regulatory support is also part of the package to directly benefit speed-to-market times.

Headquartered in Lenexa, Kansas, SAFC Biosciences has six production facilities in the U.S., Europe and Australia, and employs 600 people. Main product lines are EX-CELL(TM)[1] serum-free media; serum-based products; LONG(TM)[2] growth factors and BIOEAZE(TM)[1] disposable bioprocessing systems.

As the basis for its biopharmaceutical expansion program, Sigma-Aldrich acquired JRH Biosciences from Australia's CSL Limited in February 2005 for a consideration of US$370 million.

About Sigma-Aldrich:

Sigma-Aldrich is a leading Life Science and High Technology company. Our biochemical and organic chemical products and kits are used in scientific and genomic research, biotechnology, pharmaceutical development, the diagnosis of disease and as key components in pharmaceutical and other high technology manufacturing. We have customers in life science companies, university and government institutions, hospitals, and in industry. Over one million scientists and technologists use our products. Sigma-Aldrich operates in 35 countries and has over 6,800 employees providing excellent service worldwide. We are committed to the success of our Customers, Employees and Shareholders through leadership in Life Science, High Technology and Service.

For more information, visit http://www.sigma-aldrich.com or call 913/469-5580.

About VIVALIS:

Vivalis is a biopharmaceutical company that manufactures vaccines and proteins, and discovers drugs to prevent and treat viral diseases. Vivalis know-how and proprietary technology are focused in three main areas: licensing the proprietary ebx(TM) chicken embryonic stem cell lines to the pharma and biotech industry, in particular for vaccine and proteins production; contract manufacturing of pre-clinical and clinical batches of viral vaccines and recombinant proteins; and discovery of new anti-viral allosteric modulators through its proprietary 3D-Screen(TM)[3] platform.

Based in Nantes, France, Vivalis has the backing of its main industrial shareholder, the Group GRIMAUD (1500 employees worldwide) and its financial investors, and has established several partnerships including SAFC Biosciences for media development and Clean Cells for quality controls.

For more information. visit http://www.vivalis.com.