ALLSCHWIL, Switzerland—The U.S. Food and Drug Administration (FDA) recently announced that it had approved Opsumit (macitentan) from Actelion Pharmaceuticals Ltd., a new drug to treat adults with pulmonary arterial hypertension (PAH), a chronic, progressive and debilitating disease that can lead to death or the need for lung transplantation. The disease affects from one in 100,000 people to one in one million people, according to the American Lung Association.
“[The] approval of Opsumit by the FDA is providing the PAH community with a unique treatment option, the only oral PAH medicine that has proven to delay disease progression,” said Dr. Jean-Paul Clozel, the CEO of Actelion commented. “Over the last 14 years, Actelion has worked tirelessly to first discover and then develop Opsumit in the largest, longest and first-ever outcome study in PAH. I would like to express my gratitude to all the members of the PAH community. Without their contribution, Opsumit would not have become a reality. We will now leverage our existing PAH expertise and infrastructure to bring Opsumit to patients within the coming weeks."
PAH is high blood pressure that occurs in the arteries that connect the heart to the lungs. It causes the right side of the heart to work harder than normal, which can lead to limitations on exercise ability and shortness of breath. Opsumit belongs to a class of drugs called endothelin receptor blockers, which act to relax the pulmonary arteries, decreasing blood pressure in the lungs.
Opsumit’s safety and effectiveness were established in a long-term clinical trial where 742 participants were randomly assigned to take Opsumit or placebo. The average treatment duration was about two years. In the study, Opsumit was effective in delaying disease progression, a finding that included a decline in exercise ability, worsening symptoms of PAH or need for additional PAH medication.
Similar to other members of its drug class, Opsumit carries a warning—short of a black box—alerting patients and healthcare professionals that the drug should not be used in pregnant women because it can harm the developing fetus. Female patients can receive the drug only through the Opsumit Risk Evaluation and Mitigation Strategy (REMS) Program. This restricted-distribution program requires prescribers to be certified by enrolling in the program; all female patients to be enrolled in the program and comply with applicable pregnancy testing and contraception requirements before initiating treatment; and pharmacies to be certified and to dispense Opsumit only to patients who are authorized to receive it.
After the FDA’s announcement, the Swiss company’s stock rose 5.9 percent to close at 68.40 Swiss francs in Zurich, the biggest advance since April 30, 2012. Actelion returned 51 percent this year through Oct. 18, compared with a 20 percent return for the Bloomberg Europe Pharmaceutical Index. Sales of the drug are expected to reach about 996 million Swiss francs ($1.1 billion) in 2017, according to the average of six analysts. The new therapeutic gave Actelion a successor to a best-selling medicine that loses patent protection in late 2015.
Although Opsumit placed on the drug a warning that it shouldn’t be used by women who are pregnant, despite the FDA not requiring a black-box warning, that doesn’t seem to have adversely affected market interest in the approval. And certainly the lack of an official black-box warning is beneficial, say some market-watchers.
“The absence of a black box warning on Opsumit’s label for liver toxicity and no mandated liver function tests should drive the shares to outperform today,” Peter Welford, an analyst at Jefferies International Ltd., wrote in a report shortly after the approval was announced.
The approval may revive interest in Actelion as a takeover target, Andrew Weiss, an analyst at Bank Vontobel AG, said in a report. Clozel bet the future of the company that he co-founded on Opsumit, including fighting off a hedge fund that sought seats on the board and wanted the company to consider selling itself in 2011.
Actelion’s current top seller, Tracleer, had sales of 1.5 billion Swiss francs last year, accounting for 87 percent of revenue. The drug has been losing market share to Gilead’s Letairis, after the FDA allowed the Foster City, Calif.-based company to remove a reference to the risk of liver damage from the drug’s label in 2011. GlaxoSmithKline Plc (GSK) sells Letairis outside the U.S. under the brand name Volibris. Tracleer’s U.S. patent expires in November 2015, and in Europe it may face generic competition by the first half of 2017.