Mechelen, Belgium and Oxford, UK; 30 December, 2005 - Galapagos NV (Euronext & LSE: GLPG) and Prolysis Ltd announced today an extension of the research collaboration started earlier this year. BioFocus, the service division of Galapagos, is progressing a lead optimisation program for Prolysis to identify dual enzyme inhibitors that can overcome the problem of antibiotic resistance. Under the terms of the collaboration, Prolysis will fund BioFocus research for medicinal chemistry work throughout 2006. Prolysis also has the option to access in vitro ADMET and computational chemistry services from BioFocus during that period.

“Progress made in the collaboration with Prolysis indicates how BioFocus’ drug discovery services can accelerate a development program,” said Onno van de Stolpe, Chief Executive Officer of Galapagos. “We are pleased that Prolysis, a leader in anti-bacterial agent discovery and development, chooses BioFocus to move this key project through lead optimisation to development candidate nomination.”

Steve Ruston, Chief Executive Officer of Prolysis, added, “We have been very pleased with the quality of the collaboration with BioFocus to date and look forward to it making a substantial contribution to achieving our business objectives in the coming year.”

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 203 people, including 76 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, Idenix, Novartis, Organon, Serono, Vertex, and Wyeth. More information about Galapagos and BioFocus can be found at www.glpg.com.

About Prolysis
Prolysis, based in Oxfordshire, UK, is a research and development company focused on the creation of medicines to address the growing crisis of antibiotic resistance. The Company is exploiting unique insights into bacterial cell biology to create the new antibiotics that are urgently needed to treat resistant hospital and community-acquired infections. Prolysis’ expertise in bacterial cell biology combined with structural biology and medicinal chemistry from technology partners has created a multi-project preclinical portfolio. Prolysis will commercialise its new antibiotics by out-licensing after demonstrating proof-of-concept in human Phase IIa studies. For further information visit the Prolysis website at www.prolysis.com.

CONTACTS

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

Prolysis Ltd
Dr. Steven Ruston, CEO
steve.ruston@prolysis.com