Combo Therapy Helps in Pulmonary Arterial Hypertension

People with pulmonary arterial hypertension may benefit from initial combination therapy with ambrisentan and tadalafil, according to a recent study published in the New England Journal of Medicine. Nazzareno Galié, MD, and colleagues completed the study at the Department of Experimental, Diagnostic, and Specialty Medicine, University of Bologna, in Bologna, Italy.

The researchers performed an event-driven, double-blind study. The 500 participants had not received previous treatment and had class II or III functional symptoms of pulmonary arterial hypertension, according the World Health Organization classification system.

They were assigned to one of three groups: combination therapy, ambrisentan-monotherapy, or tadalafil-monotherapy. They received therapy until they were either hospitalized for worsening pulmonary arterial hypertension, the disease progressed, they died, or there was unsatisfactory long-term clinical response. Any of those events was classified as a “primary end point” for the purposes of the analysis.

The group that received ambrisentan-monotherapy consisted of 126 participants, and the tadalafil-monotherapy group was made up of 121 people. Of those 247 people in the two groups combined, 31% reached a primary end point.

The combination-therapy group included 253 participants, and of them only 18% experienced a primary end point. These participants also saw an improvement in the 6-minute walk distance and reductions in “N-terminal pro-brain natriuretic peptide levels.” However, there were some negative effects in the combination-therapy group that occurred more frequently than in either monotherapy group. Those included “peripheral edema, headache, nasal congestion, and anemia.

The researchers concluded that patients with pulmonary arterial hypertension who have not received previous treatment have a lower risk of experiencing a clinical failure event when they receive ambrisentan and tadalafil in combination than those who are given either therapy alone. This study was supported by Gilead Sciences and GlaxoSmithKline.