Encysive Pharmaceuticals announced that the first patient has been enrolled into its phase II dose-ranging study of oral TBC3711, the company's next-generation, highly selective endothelin receptor antagonist, in resistant hypertension. The 12-week, multi-centre, randomized, double-blind, placebo-controlled study will evaluate four once-daily oral doses of TBC3711 in approximately 150 patients with diagnosed resistant hypertension.

"With the commercialization of our lead product Thelin well underway in the European Union, we're able to focus on advancing our product pipeline," commented Bruce D. Given, MD, president and CEO of Encysive Pharmaceuticals. "This study is the crucial next step for TBC3711 development and we eagerly await the results."

Resistant hypertension patients enrolled in the phase II study will be randomized to one of four double-blind TBC3711 treatment arms or a placebo arm. Each arm will consist of approximately 30 patients. All study arms will receive once-daily doses of either TBC3711 or placebo. TBC3711 or placebo will be given concomitantly with each patient's current anti-hypertensive regimen. Primary outcome data will consist of blood pressure measurements taken pre-dose and two hours post-dose.

"A selective endothelin receptor antagonist may prove effective in improving persistent vasoconstriction, a hallmark finding of resistant hypertension," said Domenic Sica, Professor of Internal Medicine and Nephrology, Virginia Commonwealth University, Richmond, Virginia. "I look forward to the study of TBC3711 in the resistant hypertension population, a group of patients who, despite three drug therapy, are still presenting with poorly controlled high blood pressure."

TBC3711 is a small molecule that blocks the action of endothelin, a potent mediator of blood vessel constriction and growth of smooth muscle in vascular walls. TBC3711 is a next-generation endothelin.