( tained for at least 48 weeks (+36.4 met...)Gilead Announces Presentation of Long-Term Data for Ambrisentan, a,Potential Treatment for Patients With Pulmonary Arterial,Hypertension,Health

Ambrisentan adverse events were similar in nature to those reported in the previous 12-week placebo-controlled studies. The most common adverse event was peripheral edema which was generally reported to be mild or moderate and did not lead to discontinuation of ambrisentan.

As of October 2006 (mean exposure = 1.4 years; maximum exposure = 2.8 years), 2.1 percent of patients developed liver enzyme (aminotransferase) elevations greater than three times the upper limit of normal, which was similar to the incidence observed for the placebo groups (2.3 percent) in the 12-week ARIES-1 and ARIES-2 studies. One patient required discontinuation of ambrisentan due to liver enzyme abnormalities.

Long-term results from the AMB-222 study (Abstract #2171) were presented by Michael McGoon, MD, Professor of Medicine, Mayo Clinic, Rochester, Minnesota. This open-label study evaluated 36 patients who had previously discontinued the ERAs bosentan (86 percent), sitaxsentan (6 percent), or both (8 percent) due to the development of liver function abnormalities. In this study, patients with idiopathic PAH or PAH associated with connective tissue disease, congenital heart defects, HIV infection, or anorexigen use received once-daily doses of ambrisentan -- 2.5 mg/day for four weeks, 5 mg/day for 20 weeks, and 2.5, 5 or 10 mg/day thereafter -- for up to 18 months. Twenty-five of the 36 patients enrolled were also receiving concomitant sildenafil and/or prostanoid treatment. The primary endpoint of the study was the incidence of liver function abnormalities during 12 weeks of therapy that resulted in discontinuation of drug.

No patients had liver function abnormalities that required discontinuation of a
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