FDA rejects Ligand/GSK's Promacta, claims insufficient efficacy evidence in NDA

UK drug major GlaxoSmithKline and the USA's Ligand Pharmaceuticals' Promacta (eltrombopag) has been rejected for the short-term treatment of patients with chronic idiopathic thrombocytopenic purpura. The US Food and Drug Administration said that the companies did not "provide robust evidence" to support the efficacy of the investigational, once-daily oral treatment which would have been the first oral thrombopoeitin receptor agonist for increasing platelet counts and reducing bleeding in these patients. On the day of the news, May 28, shares in Ligand fell 35.9% to $2.30, while GSK shares dipped 1% to L11.16 the next morning. An FDA meeting scheduled for May 30 will discuss whether to recommend the agent for the condition.