SAN DIEGO (AP) — Ligand Pharmaceuticals Inc. said Friday a European advisory committee recommended approval of the blood disorder treatment Revolade. The drug, which was discovered by Ligand, is already approved in the U.S. as Promacta. Ligand's licensing partner GlaxoSmithKline is handling the European application. The Committee for Medicinal Products for Human Use of the European Medicines Agency recommended approval of the oral drug as a treatment for the blood disorder thrombocytopenia purpura. European regulators, much like the FDA, often follow the advice of their advisory committees. Thrombocytopenia purpura is rare blood condition that involves low platelet counts, making it more difficult for blood to clot.