Ligand Pharmaceuticals Incorporated's research collaboration with Pfizer for JAK3 has been extended by one year. The Research and License Agreement entered into in December 2006 with Wyeth provided for an initial three year research term. Under this extension, Ligand will receive US$ 3.1 million in research payments to continue conducting drug discovery and lead candidate optimization. Under the original agreement, Ligand is entitled to receive up to US$ 175 million in milestone payments for the successful development and commercialization of multiple products. In addition, Ligand will receive royalties on product sales.

"We are very pleased to learn that Pfizer has elected to extend the JAK3 research collaboration with Ligand," said John L Higgins, president and chief executive officer of Ligand. "We view JAK3 inhibitors as a very promising market opportunity, and given Pfizer's clinical success with its own internal programme we are convinced that they are highly committed to this category. Ligand has an exceptional record of drug discovery while serving major pharmaceutical companies in a number of research collaborations. We are pleased with the team's progress and look forward to continued success as we drive the programme forward for Pfizer."

JAK3 is a tyrosine kinase that belongs to the Janus family of enzymes, and it is an important target for therapeutic interventions in the treatment of autoimmune disorders, inflammation, and organ transplant rejections.

Ligand discovers and develops new drugs that address critical unmet medical needs of patients with muscle wasting, frailty, hormone-related diseases, osteoporosis, inflammatory diseases, anaemia, asthma, rheumatoid arthritis and psoriasis.