Ambrisentan (ABS) is an ETA-selective endothelin receptor antagonist (ERA) approved for the treatment of pulmonary arterial hypertension (PAH). Sustained clinical improvements have previously been reported in a 2-year analysis of a long-term ABS study (ARIES-E). This post-hoc analysis compares the 2-year ARIES-E data for patients who received ABS monotherapy (ABS-M; n = 302) to patients who added other PAH therapies to ABS (ABS-C; n = 81).
Analysis of 383 patients who received long-term ABS therapy (2.5, 5, or 10 mg qd). Categorical analysis of 6MWD, Borg dyspnea index (BDI) and WHO class were based on observed data for all patients at 2-years, including separate categories for death, discontinuation, and missing data. Kaplan-Meier analysis was used to estimate survival.
At 2-years, an improvement from baseline in 6MWD was observed in 47% of the ABS M subgroup and 41% of the ABS-C subgroup; a greater than 50m improvement was observed in 33% and 20%, respectively. An improvement from baseline in BDI was observed at 2-years in 29% of the ABS-M subgroup and 32% of the ABS-C subgroup. WHO functional class was maintained or improved at 2-years for 67% of the ABS-M subgroup compared to 56% of the ABS-C subgroup. Two-year survival was greater for ABS-M subgroup (91%; 95% CI: 87% to 94%) compared to ABS-C subgroup (76%; 95% CI: 63% to 84%). Adverse events were similar between the two subgroups, except the ABS-C subgroup had more adverse events consistent with worsening PAH.
The 2-year clinical response for patients receiving ABS monotherapy was similar to that observed for patients receiving ABS in combination with other PAH therapy. Therefore, the improvements in clinical outcome for the overall 2-year ARIES-E data were not due to the addition of other PAH therapy.
These data support the long-term use of ambrisentan, as monotherapy or in combination with other therapies, for the treatment of PAH.
Fernando Torres, University grant monies N/A; Grant monies (from sources other than industry) N/A; Grant monies (from industry related sources) I participate on clinical trials sponsored by Gilead.; Shareholder N/A; Employee N/A; Fiduciary position (of any organization, association, society, etc, other than ACCP N/A; Consultant fee, speaker bureau, advisory committee, etc. I participate in advisory committee and speaker bureau for Gilead.; No Product/Research Disclosure Information