Actelion drug setback unlikely to derail J&J talks: analysts

A blow to Actelion's (ATLN.S) Opsumit drug in a test is unlikely to have an impact on talks over a strategic deal with Johnson & Johnson J&J.N, analysts said, as the Swiss drug maker's shares shook off the news.

Shares in Actelion were up 2.4 percent at 1040 GMT after the company said Opsumit had missed the main target in a late-stage study on patients with a deadly heart-lung ailment.

Actelion had been conducting the Phase III trial on 226 patients, part of its push to expand clinical use of Opsumit for patients suffering from pulmonary arterial hypertension due to Eisenmenger Syndrome.

Patients with Eisenmenger Syndrome have untreated congenital heart defects that lead to pulmonary hypertension, where blood vessels in the lung arteries become stiff and narrow.

Opsumit is a follow-on medicine to blockbuster PAH drug Tracleer, which has lost patent protection.

Missing the primary endpoint exercise capacity as measured in a six-minute walk test weakens Opsumit's revenue potential by as much as 200 million Swiss francs ($200 million) per year, analysts estimated.

Analysts said this would be insignificant to U.S. healthcare giant J&J's (JNJ.N) interest in Europe's biggest biotech group.

The two companies have held exclusive talks for weeks, although no deal has been announced.

"The failure is a modest disappointment to the company's efforts to differentiate Opsumit and protect it from price pressure," Deutsche Bank analyst Richard Parkes said.

Initially approved for PAH in 2013, Opsumit was Actelion's second-biggest selling drug behind Tracleer in the third quarter, with sales of 218 million Swiss francs.

Analysts at Jefferies also called the adverse impact "likely minor", in part because Actelion's older drug Tracleer is already approved in Europe to treat Eisenmenger-related PAH.

While conceding Opsumit failed to reach the study's primary objective, Actelion called its results "difficult to interpret".

"Although the results point toward a benefit of treatment with macitentan (Opsumit), we do not see a significant treatment effect on the primary endpoint of exercise capacity as measured in the 6 minute walk test," said Nazzareno Galie, head of the Pulmonary Hypertension Center at the University of Bologna's Institute of Cardiology.

The result may have been influenced by an "unexpected improvement" in the study's placebo arm that had not shown up in previous PAH studies, Galie said, adding that researchers must "fully analyze the data to understand what could have caused this phenomenon".