- Swiss biotech Actelion, currently in talks with Johnson & Johnson over a potential takeover, on Monday hit a modest roadblock in the clinical development of its pulmonary arterial hypertension (PAH) drug Opsumit (macitentan).
- A late-stage study of Opsumit in patients with PAH due to a congenital heart defect fell short of meeting its primary goal, failing to separate from placebo, Actelion reported.
- Analysts do not expect the trial setback to materially impact or otherwise derail discussions with J&J. The two companies entered exclusive negotiations over a potential acquisition late last month, and recent reports have indicated J&J could strike a deal for just Actelion's portfolio of marketed drugs.
Opsumit, currently Actelion's second best-selling drug, is a successor to the company's older PAH drug Tacleer (bosentan). Both drugs are oral endothelin receptor antagonists designed to lower blood pressure in the lungs. In PAH, abnormally high blood pressure in the arteries between the heart and lungs can lead to reduced exercise capacity and, in more severe cases, lowered life expectancy.
Tracleer has been Actelion's top seller but is now off-patent in the U.S. and in Europe. As Tracleer sales decline, Actelion has counted on growing sales from Opsumit, which was approved in the U.S. just over three years ago, to cushion the impact.
The two drugs, coupled with the more recently launched PAH drug Uptravi (selexipag), have given Actelion a leading portfolio of treatments for the disease. This portfolio is what has attracted interest from J&J and others.
J&J had pulled out of initial talks in early December, giving French drugmaker Sanofi a window of opportunity. But J&J and Actelion quickly picked negotiations back up, leaving Sanofi to again play second fiddle after losing out to Pfizer in a bid for the U.S. cancer company Medivation last year.
Although the trial setback will likely hurt potential sales growth for Opsumit, analysts from Jefferies described the impact on talks as "likely minor." Value from Opsumit's and Uptravi's approved indications as well as other extension studies for the drugs should underpin a takeover price of at least 250 Swiss francs per share, the analysts said.
The failed study for Opsumit had been aimed at patients with PAH due to Eisenmenger Syndrome, a condition where a heart defect leads to increased blood flow to the lungs. That higher-than-normal blood flow leads to stiffer and narrower blood vessels in the lung, eventually causing pulmonary hypertension.
Actelion had hoped to show treatment with Opsumit would improve exercise capacity in those patients, as measured by change from baseline in a 6-minute walk test. Yet the average change from baseline in those treated with Opsumit was only 18.3 meters, slightly less than the 19.7 meters seen in the placebo arm.