The FINANCIAL — GSK on August 26 announced publication of the AMBITION study, the first outcomes study to compare the safety and efficacy of investigational first-line combination therapy of Volibris (ambrisentan) and Adcirca (tadalafil) to first-line monotherapy of either treatment alone in treatment-naïve patients with pulmonary arterial hypertension (PAH).
The AMBITION study was a randomised, double-blind Phase 3b/4 study designed to compare the efficacy and safety of ambrisentan in combination with tadalafil to monotherapy in treatment-naïve patients with WHO/NYHA functional class II and III PAH. In the study, 500 patients were randomised (2:1:1) to receive ambrisentan and tadalafil combination (n=253) or monotherapy with ambrisentan (n=126) or tadalafil (n=121) (titrated from 5 mg to 10 mg once-daily and from 20 mg to 40 mg once-daily for ambrisentan and tadalafil, respectively). The AMBITION study was co-sponsored by GSK and Gilead. Eli Lilly and Company also provided funding and tadalafil drug supply for the study.
The primary endpoint was time to first clinical failure event, defined as time from randomisation to the first occurrence of death (all-cause), hospitalisation for worsening PAH, disease progression or unsatisfactory long-term clinical response (events adjudicated by an independent, blinded committee). Results of the AMBITION study were first presented at the European Respiratory Society congress in September 2014, according to GSK.
Dr Murray Stewart, Chief Medical Officer, GSK, said: “Combination therapy is commonly used by physicians to treat patients with pulmonary arterial hypertension, but prospective trials of combination therapy have been few in number and limited to sequential add-on therapy, resulting in a lack of evidence about when and how combination treatment could and should be used. Despite existing treatments, the median survival for a PAH patient is just 5-6 years after diagnosis, so the AMBITION study was designed to answer the important question of whether the upfront initiation of treatments with different modes of action could improve patient outcomes in this rare condition. The results of the study significantly advance the body of evidence and understanding in this important area.”