Encysive Announces Topline Data From Stride-2 Pivotal Trial in PAH

Encysive Pharmaceuticals has announced topline results from the company's multicenter, pivotal Phase III STRIDE-2 (Sitaxsentan To Relieve ImpaireD Exercise) trial to evaluate the safety and efficacy of Thelin in patients with pulmonary arterial hypertension (PAH).

The trial met its primary endpoint of improved six-minute walk (6MW) distance in patients receiving a 100-mg dose of Thelin (sitaxsentan), with a placebo-subtracted improvement of 31.4 meters. A 50-mg dose of Thelin improved 6MW by 24.2 meters, and bosentan (Tracleer), currently the only approved oral agent for treating PAH, improved 6MW by 29.5 meters. As expected, placebo patients worsened in 6MW over the 18-week period of the trial.

World Health Organization functional class also improved significantly at the 100-mg dose of Thelin versus placebo. There were five clinical worsening events in the 100-mg patient group, seven events in the 50-mg group, 15 events in the bosentan group, and 13 for placebo. The 100 mg dose of Thelin continued to demonstrate an encouraging safety profile. Liver function abnormalities occurred in 3 percent of patients in the 100-mg Thelin group, compared to 5 percent in the 50-mg Thelin group, 11 percent in the bosentan group and 6 percent in the placebo group. Premature discontinuations due to safety or efficacy occurred in four patients at the 100-mg Thelin dose, eight at the 50-mg Thelin dose, nine in the bosentan group and 11 in the placebo group.