GSK and Gilead release AMBITION study results of ambrisentan and tadalafil

UK drugmaker GlaxoSmithKline (LSE: GSK) and US company Gilead Sciences (Nasdaq: GILD) have published data from the AMBITION study of a Volibris (ambrisentan) and Adcirca (tadalafil) combination in pulmonary arterial hypertension.

The randomized, double-blind Phase IIIb/IV was designed to compare the efficacy and safety of ambrisentan and tadalafil to monotherapy in treatment-naive patient with WHO/NYHA functional class II and III pulmonary arterial hypertension. The study comprised 500 patients: 253 were assigned to the combination-therapy group, 126 to the ambrisentan-monotherapy group, and 121 to the tadalafil-monotherapy group. A primary end-point event occurred in 18%, 34% and 28% of the participants in these groups, respectively, and in 31% of the pooled-monotherapy group (the two monotherapy groups combined).

The primary endpoint was time to first clinical failure event, which was defined as time from randomization to the first occurrence of death, hospitalization or worsening pulmonary arterial hypertension, disease progression or unsatisfactory long-term clinical response.