Scleroderma

Actelion Ltd today announced the initial results of BUILD-3, a clinical study evaluating the safety and efficacy of Bosentan in patients suffering from idiopathic pulmonary fibrosis. While there was a consistent trend in favour of Bosentan, the primary endpoint, reduction in morbidity/mortality, was not met (p=0.21). The well characterized safety profile of Bosentan was confirmed.

Bosentan is an orally available dual Endothelin receptor antagonist, already approved worldwide for the treatment of pulmonary arterial hypertension under the brand name Tracleer. In the European Union and in other territories, Tracleer is also approved for the reduction of new digital ulcers in patients with Systemic Scleroderma.

Jean-Paul Clozel, M.D. and Chief Executive Officer of Actelion commented: "We are naturally disappointed with this outcome. While in BUILD-3 there is a consistent trend in favour of Bosentan, these findings do not support initiating regulatory proceedings."

Jean-Paul  Clozel continued: "We remain  convinced that Endothelin receptors are important  targets for potential future treatments in this poorly understood and rapidly  progressing form of pulmonary fibrosis.  The results of BUILD-3 suggest that a more complete blockade of both endothelin receptors - as potentially achieved with macitentan - might be needed."

The 150 patient exploratory studies with Actelion's highly potent, tissue-targeting Endothelin receptor antagonist, macitentan, is currently enrolling patients with idiopathic pulmonary fibrosis. The study is expected to be fully enrolled later this year and report data in second half of 2011.

Sources: PR Inside, MarketWatch