Conference: 2014 International PHA Conference and Scientific Sessions
Release Date: 06.22.2014
Presentation Type: Abstracts
File Download: 2014 Conference Abstract - Torres F
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Purpose: Ambrisentan (ABS) is an ETA−selective endothelin receptor antagonist (ERA) that is approved (5mg and 10mg) for the treatment of pulmonary arterial hypertension (PAH) in patients with WHO class II or III symptoms to improve exercise capacity and delay clinical worsening.
Methods: This is an integrated analysis of 287 patients with WHO functional class I/II (n=123) or III/IV (n=164) symptoms at baseline who received 5mg or 10mg ABS in the ARIES−1, ARIES−2, or ARIES−E studies. Data are presented through 2 years of treatment, including all patients with post−baseline data and using last observation carried forward for missing data.
Results: Most patients had 6−minute walk (6MWD) data at 2 years: WHO I/II (range: 69%−82%) and WHO III/IV (range: 61%−71%). The change from baseline in 6WMD at 2 years for WHO class I/II patients was +35m (95% CI: 14 to 55) for the 5mg group and +29m (95% CI: 5 to 53) for the 10mg group. For WHO class III/IV patients, the change from baseline in 6WMD at 2 years was +14m (95% CI: −6 to 35) for 5mg and +27m (95% CI: 3 to 52) for 10mg. Kaplan−Meier(KM) estimates of long−term survival for the 5mg and 10mg groups combined at 1 year were 98% (95% CI: 93% to 100%) for WHO class I/II and 90% (95% CI: 84% to 94%) for class III/IV. KM estimates of long−term survival at 2 years were 95% (95% CI: 89% to 98%) for class I/II and 83% (95% CI: 76% to 88%) for class III/IV. Long term ABS treatment was generally well tolerated. A total of 4 adverse events of peripheral edema were considered severe by the investigator, with 3 of these in the class III/IV group. Twelve (4.2%) patients (5 class I/II and 7 class III/IV) reported aminotransferase abnormalities (ALT/AST>3xULN) during the 2 years.
Conclusions: Two years of treatment with ABS 5mg or 10mg once daily was associated with sustained clinical improvements and a low risk of death in patients with WHO class I/II or III/IV symptoms.