GALAPAGOS ENTERS INTO DISCOVERY COLLABORATION WITH IDENIX FOR INFECTIOUS DISEASE PROGRAMS

Galapagos’ services division BioFocus to provide SoftFocus® compound collections and medicinal chemistry activities for hepatitis and HIV programs of Idenix Pharmaceuticals

Mechelen, Belgium; 24 November, 2005 - Galapagos NV (Euronext & LSE: GLPG) announced today that it has entered into a collaboration with Idenix Pharmaceuticals, Inc. (NASDAQ: IDIX) on selected hepatitis and HIV infectious disease programs. Pursuant to the collaboration, Galapagos’ service division BioFocus will supply its proprietary SoftFocus® chemical compound collections to Idenix and provide expertise in the design and synthesis of biologically-directed compound collections. In addition, BioFocus will provide hit-to-lead and lead optimisation services. The entire discovery contract collaboration is worth up to $2.5 million over two years.

This arrangement represents Galapagos’ first collaboration with Idenix. Under the terms of the agreement, Galapagos will receive undisclosed technology access fees for SoftFocus® collections, as well as a fee component for medicinal chemistry services plus success payments upon realization of certain objectives relating to the identification of pre-clinical candidates.

Onno van de Stolpe, CEO of Galapagos, commented: “This agreement with Idenix is highly significant for our company and is further testament to the medicinal chemistry capabilities of our services division BioFocus. We are confident that this partnership will be fruitful and we are proud to be associated with this drug discovery program, which seeks to combat health issues associated with hepatitis and HIV.”

About Galapagos
Galapagos is a publicly traded, genomics-based drug discovery company (Euronext Brussels, GLPG; Euronext Amsterdam, GLPGA, London AiM: GLPG) that has drug discovery programs based on proprietary, novel targets in the bone and joint diseases - osteoarthritis, osteoporosis and rheumatoid arthritis. Galapagos offers a full suite of target-to-drug discovery products and services to pharmaceutical and biotech companies through its division BioFocus, encompassing target discovery and validation, and drug discovery services through to delivery of pre-clinical candidates. In addition, BioFocus provides adenoviral reagents for rapid identification and validation of novel drug targets and compound libraries for screening. Galapagos currently employs 193 people, including 74 PhDs, and occupies facilities in Mechelen, Belgium, Saffron Walden, UK and Leiden, The Netherlands. The partners of Galapagos include Amgen, AstraZeneca, Bayer, Boehringer Ingelheim, Celgene, GlaxoSmithKline, Novartis, Organon, Serono, Vertex, and Wyeth. More information about Galapagos and BioFocus can be found at www.glpg.com.

CONTACT
Galapagos NV
Onno van de Stolpe, CEO
Tel: +31 6 2909 8028
ir@galapagos.be