Delaying ambrisentan has lasting effect on walk test.
A total of 100 ARIES-E participants who received ambrisentan (Letairis) after completing 12 weeks of double-blind placebo responded with a less robust improvement in exercise capacity during 2 years of follow-up than did 197 patients on ambrisentan from the start. The group on placebo before ambrisentan never caught up in terms of 6-minute walk distance, Dr. Aaron B. Waxman reported at the annual meeting of the American College of Chest Physicians.
At the 12-week mark in the double-blind ARIES-1 (Ambrisentan in Pulmonary Arterial Hypertension, Randomized, Double-Blind, Placebo-Controlled, Multicenter, Efficacy Study) and ARIES-2 trials, patients on ambrisentan from the outset had a mean 42-m gain in 6-minute walk distance over their baseline of 345 m. Patients who received placebo before ambrisentan averaged a 1-m decline from baseline.
When assessed after 2 years of follow-up in ARIES-E (the extension study) patients who had been on ambrisentan from the start had a mean 30-m improvement in 6-minute walk distance, compared with baseline. Patients on placebo for 12 weeks before receiving ambrisentan had a mean 10-m improvement, according to Dr. Waxman of Massachusetts General Hospital, Boston.
The rate of clinical worsening at 1 year was 16% in the group on ambrisentan from the outset, compared with 24% in those who got placebo first.
By 2 years, however, the clinical worsening rate was similar in both groups, at about 30%.
Ambrisentan was well tolerated in ARIES-E, with mild to moderate peripheral edema the most common adverse event. Liver enzymes were elevated during 2 years of follow-up in seven patients on ambrisentan from the start and six patients on placebo followed by the endothelin receptor antagonist.
Disclosures: The ARIES trials were funded by Gilead Sciences, which manufactures Letairis. Dr. Waxman disclosed serving on advisory boards for Gilead and United Therapeutics.
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|Title Annotation:||CARDIOVASCULAR MEDICINE|
|Publication:||Internal Medicine News|
|Date:||Mar 15, 2010|
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