AB Science — Net Asset Value 2011

Jan 5, 2011

Paris, January 5th, 2010 - 5.45 pm

Half-year report on AB Science's liquidity contract

Under the liquidity contract entrusted by AB Science to SG Securities (Paris), the following assets appeared on the liquidity account at 31 December 2010:

• 7 506 shares
• 17.419,35€

For information, the following assets appeared on the liquidity account at 23 June 2010:

• 150 shares
• 98.267,50 €

About AB Science

Founded in 2001, AB Science is a pharmaceutical company specializing in the research, development and commercialization of protein kinase inhibitors (PKIs), a new class of targeted molecules whose action is to modify signalling pathways within cells. Through these PKIs, the Company targets diseases with high unmet medical needs (cancer, inflammatory diseases and central nervous system diseases), in both human and veterinary medicines. Thanks to its extensive research and development capabilities, AB Science has its own portfolio of molecules. Masitinib, a lead compound, has already been registered in veterinary medicine in Europe and is pursuing three on-going phases 3 in human medicine in pancreatic cancer, GIST and mastocytosis.

AB Science is listed on NYSE Euronext Paris (Compartment B) - ISIN: FR0010557264 – Ticker: AB

Further information is available on AB Science's website: www.ab-science.com

Financial Communication & Press Relations

Contacts Citigate Dewe Rogerson : Agnès Villeret - Tel: +33 1 53 32 78 95 - agnes.villeret@citigate.fr