The primary objective of the first phase III trial, named DORADO, is to determine if darusentan is effective in reducing systolic blood pressure in resistant hypertension patients currently treated with full doses of four or more antihypertensive medications, one of which is a diuretic.
Approximately 352 patients will be randomized to one of three doses of darusentan (50, 100, or 300mg qd) versus placebo in a ratio of 7:7:7:11. The treatment period for the trial is 14 weeks and the primary endpoint is change from baseline to week 14 in trough sitting systolic blood pressure as compared to placebo.
Upon completion of the 14-week assessment period, patients will be eligible to enroll in a long-term safety study. Patients will be treated and followed for safety for at least six months with a mean exposure expected to be in excess of one year.
Myogen also plans to initiate a second international phase III clinical trial, named DAR-312, for the same indication in the fourth quarter of 2006.