Shares in Galapagos have risen after the Belgian biotech revealed that GlaxoSmithKline has exercised its option to exclusively license two investigational arthritis drugs.

The deal involves GLPG0778 and its back-up compound GLPG0555, both discovered and developed within GSKs immuno-inflammatory alliance with Galapagos. GSK now has the right to continue the clinical development of these candidate compounds.

Galapagos will receive an option fee payment of "single-digit million euros" and is eligible to receive more than 34 million euros in future milestones plus royalties on the two compounds. The Mechelen-based group says that GSK's decision to take up the option further highlights its "rapid progression of early discovery programmes into clinical results".

In the alliance with GSK, GLPG0778 was identified and progressed to a successful option exercise within 30 months, Galapagos notes. This means that "making the transition from committing to the target to clinical proof of mechanism in five years".

Chief executive Onno van de Stolpe said that "GLPG0778 and GLPG0555 are the first Galapagos alliance compounds to be in-licensed into a large pharma portfolio". He added that "we are excited to follow the future development and potential commercialisation" of the drugs.