Actelion has posted its first quarter results which show that revenues and earnings took a tumble, hit by competition to its pulmonary arterial hypertension blockbuster Tracleer.

Net income was 45.1 million Swiss francs, about $49 million, down 69% on the like, year-earlier period, while revenues fell 21% to 417.5 million francs. Sales of Tracleer (bosentan) were down 6% to 363.7 million francs, reflecting its fight for market share with a rival PAH product, Gilead Sciences' Letairis (ambrisentan), which is selling well in the USA.

As for the Allschwil-based group’s other products, sales of Ventavis (iloprost), an inhaled therapy for the treatment of PAH, inched up 1% to 27.7 million francs. Turnover of Zavesca (miglustat), for patients with Gaucher disease for whom enzyme replacement therapy is not a therapeutic option, rose 19% to 18.6 million francs.

Chief executive Jean-Paul Clozel said that "as expected, the market place remains very challenging, mostly due to changes in the competitive landscape in the USA and strong pricing pressures in certain markets". In that context, he added "our product sales performance is acceptable".

Most interest in Actelion now will focus on soon-to-be published results from a Phase III trial of macitentan, its successor to Tracleer, the top-line results for which are due in the second quarter. Analysts at Deutsche Bank issued a research note saying "we continue to have high conviction in a positive outcome and expect a macitentan launch in around 2013".

They added that this will allow Actelion to "at least partially defend" its PAH franchise "from both competition from Gilead and from potential Tracleer generics over 2015-2017".