St. Louis, MO: 20th July 2005 - SAFC, a leading custom chemical manufacturer and a member of the Sigma-Aldrich Group (NASDAQ: SIAL), today announced that MNLpharma Ltd (MNL) has appointed the company to provide chemical development and GMP manufacturing services for its drug discovery and development program. The services will target MNL's lead candidate from its small molecule immunomodulator program, MNLP462a, a cancer immunotherapeutic.

MNL is developing next generation glycotherapeutics, including imino sugars for use as immunomodulators. Imino sugars are naturally occurring analogues or mimics of sugars and MNL has demonstrated that these molecules and synthetic analogues can stimulate dendritic cells to produce IL-12; a key cytokine for efficacious cancer immunotherapy.

SAFC chemists will initially carry out process development on the synthesis of MNL's imino sugars to determine a suitable process for producing sufficient quantities of material to enable MNL to begin clinical trials. This will be followed by the GMP manufacture by SAFC of material for use in clinical trials, which are expected to start in 2006.

Neil Robinson, Development Director at MNL commented: "SAFC impressed us with their abilities and experience in small molecule chemical development and GMP manufacture. Thus, we are very pleased to announce that they will assist us with this critical part of the immunomodulator program. With the material provided by SAFC, we expect to undertake clinical trials in 2006."

Frank Wicks, SAFC President, added: "SAFC is delighted to act as the chemical development partner for MNL's immunomodulator. This compound has the potential to treat a wide range of cancers. The launch of 'SAFC' in October 2004 has been extremely well received by the fine chemical market. This appointment demonstrates SAFC's outstanding ability to meet the chemistry support needs of emerging pharma companies."

About SAFC:

SAFC is the custom manufacturing group within Sigma-Aldrich that focuses on both biochemical production and the manufacturing of complex, multi-step organic synthesis of APIs and key intermediates. SAFC has manufacturing facilities around the world dedicated to providing manufacturing services for companies requiring a reliable partner to produce their custom manufactured materials.

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 34 countries and has over 6,000 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.

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