Ligand Partner GlaxoSmithKline Receives FDA Acceptance and Granted Priority Review for PROMACTA NDA

Ligand Pharmaceuticals Incorporated (NASDAQ:LGND) today announced that the U.S. Food and Drug Administration (FDA) has accepted for filing and review GlaxoSmithKline’s new drug application (NDA) and has granted a priority review status for PROMACTA (eltrombopag) for treatment of chronic short-term idiopathic thrombocytopenic purpura (ITP). Priority review is granted by the FDA for a treatment that addresses significant unmet medical needs or has the potential to provide a significant improvement compared to marketed products, and results in a review period of six months from the date of NDA submission.

If approved, PROMACTA would be the first oral thrombopoietin receptor agonist therapy for the short-term treatment of previously treated patients with chronic ITP to increase platelet counts and reduce or prevent bleeding. Chronic ITP is a disorder marked by increased platelet destruction and/or inadequate platelet production in the blood, which causes an increased risk of bruising and bleeding. PROMACTA is an investigational, once-daily oral treatment that induces the proliferation and differentiation of cells in the bone marrow to produce platelets.

“Priority FDA review for PROMACTA clearly reflects the need for an effective therapy for patients suffering from ITP," said John L. Higgins, President and Chief Executive Officer of Ligand Pharmaceuticals. “We are extremely pleased and commend GlaxoSmithKline’s team for their progress and dedication in taking PROMACTA a step closer toward commercialization. This is a critical milestone and we look forward to the completion of the FDA’s review.”

Ligand and GlaxoSmithKline Collaboration

The GSK-Ligand collaboration began in 1997 to utilize Ligand's expertise and technology to discover small-molecule drugs to control hematopoieses and treat patients with cancer, anemia or platelet deficiencies. The research phase of the collaboration ended in 2001. GSK is responsible for the registration and worldwide marketing of PROMACTA.

About Ligand Pharmaceuticals

Ligand discovers and develops new drugs that address critical unmet medical needs of patients in the areas of thrombocytopenia, cancer, hepatitis C, hormone-related diseases, osteoporosis and inflammatory diseases. Ligand's proprietary drug discovery and development programs are based on its leadership position in gene transcription technology, primarily related to intracellular receptors.