A comprehensive clinical trial program has been conducted to evaluate the efficacy and safety of Tracleer® across a broad range of PAH patient populations.
For a detailed analysis of the study results please refer to the scientific publications - reference information is given on the key scientific literature page.
The results of clinical studies including two pivotal randomized controlled studies, Study 351 and BREATHE-1, demonstrate the efficacy of Tracleer® in the treatment of patients with idiopathic PAH (where no specific cause can be identified), or PAH secondary to connective tissue diseases such as scleroderma.
The combination of Tracleer® with the initiation of intravenous therapy with epoprostenol in adult patients suffering from PAH is well tolerated, as shown in the randomized controlled BREATHE-2 study.
The BREATHE-3 open-label study provided safety and efficacy data in children with PAH treated with Tracleer® with or without concomitant prostanoid therapy. It also provided important information on the dose required in the pediatric formulation.
Results of the open-label BREATHE-4 study in patients whose PAH is related to their infection with the human immuno deficiency virus (HIV) showed improvement in exercise capacity, WHO functional class, and quality of life, as well as cardiopulmonary hemodynamics, compared to baseline after 16 weeks of treatment with Tracleer®.
The first ever randomized placebo-controlled study in patients with Eisenmenger’s syndrome (PAH associated with a congenital heart defect) BREATHE-5 showed that Tracleer® decreases pulmonary vascular resistance and improves exercise capacity in these patients.
The EARLY (Endothelin Antagonist tRial in miLdlY symptomatic PAH patients) study was a randomized, double-blind, placebo-controlled trial, and the only randomized controlled trial to study a dedicated early-stage, or WHO Functional Class II, PAH population. Patients were followed for at least six months, and results showed a significant reduction in pulmonary vascular resistance and a delay in time to clinical worsening. A trend towards improvement in exercise capacity was observed.
FUTURE-1 (Pediatric FormUlation of bosenTan in pUlmonary arterial hypeRtEnsion) an open-label study, evaluated the safety and pharmacokinetics of a new dispersible tablet formulation of Tracleer®. This study provided important pharmacokinetic and dosing information using the new pediatric formulation of Tracleer®. In FUTURE-1, the observed exposure to Tracleer® was similar to that in children who participated in BREATHE-3.
FUTURE-2, an open-label safety extension study, is ongoing to assess long-term safety and outcome data.
The multi-center, randomized placebo-controlled study BENEFiT evaluated BosEntan in iNopErable Forms of chronIc Thromboembolic pulmonary hypertension (CTEPH). The BENEFiT study met its primary objective with a significant reduction in pulmonary vascular resistance PVR (p < 0.0001). In addition, patients on bosentan showed a significant improvement in breathlessness (Borg dyspnea score) with exercise, and there was a trend in favor of bosentan towards prevention of worsening WHO functional class.
The RAPIDS (RAndomized Placebo-controlled Investigation of Digital ulcers in Scleroderma) program, consisting of two Phase III clinical trials (RAPIDS-1 and RAPIDS-2), tested the benefits of Tracleer® in ischemic digital ulcers secondary to systemic sclerosis. In both studies, Tracleer® reduced the number of new digital ulcers.
