GSK's Promacta granted full US approval

The US Food and Drug Administration (FDA) has granted full marketing approval to GlaxoSmithKline's (GSK) Promacta (eltrombopag), an oral tablet that is used to raise platelet counts in patients with a rare blood disorder.

Promacta, which was granted provisional clearance under the agency' accelerated approval programme in late 2008, is approved for patients with chronic immune (idiopathic) thrombocytopenic purpura (ITP) who have had an insufficient response to corticosteroids, immunoglobulins or splenectomy. Chronic ITP is a serious disease marked by increased platelet destruction and/or inadequate platelet production in the blood, leading to an increased risk of bruising and bleeding.

"Promacta is a testament to how the FDA Accelerated Approval Programme supports development of therapies that meet unmet patient needs," said Steven Stein, vice president of Medicines Development at GSK. "Patients with limited treatment options gained access to Promacta while GSK conducted clinical studies that yielded additional efficacy and safety data."

Promacta's labelling is being updated to include efficacy and safety data from a six- month study showing that patients treated with the drug were significantly more likely to achieve the study's targeted platelet count during the entire six-month period than were the patients on placebo.

Promacta was discovered as a result of a research collaboration between GSK and Ligand Pharmaceuticals. GSK developed the product and has exclusive worldwide rights, with Ligand standing to receive milestone payments and royalties.

In May 2010, GSK halted a study of the drug in patients with thrombocytopaenia related to chronic liver disease after the treatment was linked to an increased risk for portal venous thrombosis in that population.