GSK drops enrasentan after ENCORE results

GlaxoSmithKline has decided to stop development of its non-selectiveendothelin receptor antagonist enrasentan after clinical data from the Phase II ENCORE study of the drug in chronic heart failure, presented at the American College of Cardiology meeting, failed to show any benefit when added to standard therapy for CHF.

The finding is in marked contrast to the positive results achieved by Actelion and partner Genentech with their dual endothelin antagonist for acute heart failure, Veletri (tezosentan; see page 20). However, the trial's co-ordinator, William Abraham of the University of Kentucky, USA, noted that the results were consistent with research on Genentech and Actelion's non-selective endothelin-receptor antagonist Tracleer (bosentan) in a similar patient group. Tracleer remains in development as a treatment for patients with more severe stages of CHF. Dr Abraham said that, while the ENCORE results "raise a cautionary flag regarding the use of nonselective endothelin antagonists," they reinforce the need for further investigation into the role of selective antagonists in CHF.