The trial, named STEP, was a double-blind, placebo-controlled trial, in which pulmonary arterial hypertension (PAH) patients treated with Tracleer, an oral endothelin receptor antagonist, were randomized to receive either Ventavis (inhaled iloprost) or inhaled placebo in combination with Tracleer (bosentan) for 12 weeks.
Common adverse events that occurred more frequently in the Ventavis arm were those known to be associated with inhaled prostacyclin administration and included flushing, headache, cough and jaw pain. Syncope occurred less frequently when compared to placebo (one Ventavis and two placebo), and no serious syncope adverse events were reported in either treatment group.
Clinical benefits of adding Ventavis to Tracleer were observed in a number of secondary endpoints. Combination-treated patients (Ventavis plus Tracleer) in the six-minute walk test walked a mean difference of 26 meters farther than patients treated only with Tracleer. Other important clinical endpoints, including change in NYHA functional class, reduction in mean pulmonary artery pressure and delay in clinical deterioration were also statistically significant.
“Like many other areas of medicine, we believe that the field of PAH is moving toward combination therapy,” said Dr Lewis Rubin, professor of medicine and director of the Pulmonary Hypertension Program at the University of California, San Diego. “This trial brings us one step closer in understanding how combination therapies may be used to effectively treat PAH.”