LAVAL, QC, Nov. 12, 2013 /CNW/ - Actelion Pharmaceuticals Canada Inc. announced today that Health Canada has approved the oral endothelin receptor antagonist OPSUMIT (macitentan) 10mg once daily for the long term treatment of pulmonary arterial hypertension (PAH) to reduce morbidity.
OPSUMIT is indicated for the long-term treatment of pulmonary arterial hypertension (PAH, WHO Group1) to reduce morbidity in patients in WHO Functional Class II or III whose PAH is either idiopathic or heritable, or associated with connective tissue disease or congenital heart disease. OPSUMIT is effective when used as monotherapy or in combination with phosphodiesterase-5 inhibitors.
The safety and efficacy of OPSUMIT were evaluated in the largest and longest randomized, placebo-controlled study in PAH patients, called SERAPHIN (Study with Endothelin Receptor Antagonist in Pulmonary Arterial Hypertension to Improve Clinical Outcome). 
Approval by Health Canada was based in part on data from this landmark phase III study published in the New England Journal of Medicine in August 2013. It was the first long-term study to include a clearly defined, clinically-important morbidity/mortality primary endpoint. Effectiveness was established in PAH patients with predominantly WHO Functional Class II-III symptoms treated for an average of 2 years with OPSUMIT monotherapy or in combination with phosphodiesterase-5 inhibitors (61%). The primary study endpoint was the time to first occurrence of a morbidity or mortality event up to end of double-blind treatment (EOT). 
"This new study represents a critical milestone in the treatment of PAH patients. We now have a new standard of excellence for clinical trials in PAH, and the strongest evidence ever of hope for long-term improved quality of life and clinical stability for those affected by PAH in Canada," said Dr. Sanjay Mehta, MD, FRCPC, FCCP, Professor of Medicine at Western University, Director of the Southwest Ontario Pulmonary Hypertension Clinic at the London Health Sciences Center in London, Ontario and Chair of the Pulmonary Hypertension Association of Canada.
"Five years ago, global and Canadian experts in PAH proposed that future PAH clinical studies should assess the effects of treatment on long-term morbidity and mortality, a clinically more important primary endpoint compared to all previous studies which only looked at very short-term outcomes, such as the six minute walk test. Today, thanks to OPSUMIT, we now have an answer to this critical question of long-term benefits of PAH treatment on clinical outcomes important to patients," continued Dr. Mehta who was also a SERAPHIN investigator and co-author of the published article in the New England Journal of Medicine.
"This approval marks a significant turning point in the management of PAH in Canada," said Jacques Archambault, President of Actelion Pharmaceuticals Canada Inc. "We look forward to continuing our work to improve the standard of care for Canadians living with PAH."
The SERAPHIN study showed that the risk of the first occurrence of a morbidity or mortality event, the primary endpoint of the study, was reduced by 45% (p<0.0001) with macitentan 10 mg daily compared to placebo. This effect was observed irrespective of whether or not patients were already treated with other therapies for PAH. SERAPHIN also showed a risk reduction in PAH related hospitalization and death of 50% (p<0.0001) compared to placebo. 
"Canadians living with PAH are not only in a constant battle with devastating symptoms that can drastically impact their daily life, they also face the very real possibility of a shortened lifespan - and even death," said Ruth Dolan, director of the Pulmonary Hypertension Association of Canada, and mother of a PAH patient. "Patients need better PAH treatment options proven to reduce hospitalizations and death due to their disease."
OPSUMIT is a novel dual endothelin receptor antagonist (ERA) that resulted from a tailored drug discovery process that focused on developing an ERA that was optimized for efficacy and safety.  The clinical pharmacology program also indicated a low propensity of OPSUMIT for drug-drug interactions. [3,4,5]
OPSUMIT is contraindicated in patients who are hypersensitive to this drug or to any ingredient in the formulation or component of the container; women who are or may become pregnant and nursing women (see Warnings and Precautions, Special Populations, Pregnant and Nursing Women sections of the product monograph).
The most common adverse reactions (more frequent than placebo by 3% or more) observed in patients treated with OPSUMIT were anemia, nasopharyngitis/pharyngitis, bronchitis, headache, influenza, and urinary tract infection.
Physicians are advised to measure hemoglobin prior to initiation of treatment, again after one month, and periodically thereafter as clinically indicated. Liver enzyme blood tests should be obtained prior to initiation of OPSUMIT, and monthly testing during the first year of treatment is recommended and then less frequently thereafter as clinically indicated.
PAH is a chronic, life-threatening disorder characterized by abnormally high blood pressure in the arteries between the heart and lungs of an affected individual. The symptoms of PAH are non-specific and can range from mild breathlessness and fatigue during normal daily activity to symptoms of right heart failure and severe restrictions on exercise capacity and ultimately reduced life expectancy.
About Actelion Ltd
Actelion Ltd is a biopharmaceutical company with its corporate headquarters in Allschwil/Basel, Switzerland. Actelion's first drug Tracleer® (bosentan), an orally available dual endothelin receptor antagonist, has been approved as a therapy for pulmonary arterial hypertension. Actelion markets Tracleer through its own subsidiaries in key markets worldwide, including the United States (based in South San Francisco), the European Union, Japan, Canada, Australia and Switzerland. Actelion, founded in late 1997, is a leading player in innovative science related to the endothelium - the single layer of cells separating every blood vessel from the blood stream. Actelion's over 2,300 employees focus on the discovery, development and marketing of innovative drugs for significant unmet medical needs. Actelion shares are traded on the SIX Swiss Exchange (ticker symbol: ATLN) as part of the Swiss blue-chip index SMI (Swiss Market Index SMI®).
To learn more about Actelion Pharmaceuticals, visit www.actelion.com.
About OPSUMIT® (macitentan) submissions to healthcare authorities
OPSUMIT® was recently approved in the United States. Actelion expects OPSUMIT to become available to patients in early 2014 in Canada. Outside of Canada, Actelion continues to work with health authorities to obtain regulatory approval for OPSUMIT.
OPSUMIT® is a registered trademark in the US and other countries.
- Pulido T, Adzerikho I, Channick RN, Delcroix M, Galiè N, Ghofrani H-A, et al. Macitentan and Morbidity and Mortality in Pulmonary Arterial Hypertension. N Engl J Med. 2013;369(9):809-818.
- Bolli MH et al. The Discovery of N-[5-(4-Bromophenyl)-6-[2-[(5-bromo-2-pyrimidinyl)oxy]ethoxy]-4-pyrimidinyl]-N'-propylsulfamide (Macitentan), an Orally Active, Potent Dual Endothelin Receptor Antagonist. J Med Chem. 2012; 55:7849-61.
- Sidharta PN et al. Macitentan: Entry-into-humans study with a new endothelin receptor antagonist. Eur J Clin Pharmacol. 2011;67(10):977-84
- Bruderer S et al. Absorption, distribution, metabolism, and excretion of macitentan, a dual endothelin receptor antagonist, in humans. Xenobiotica. 2012 Sep;42(9):901-10
- Bruderer S et al. Effect of cyclosporine A and rifampin on the pharmacokinetics of macitentan, a tissue-targeting dual endothelin receptor antagonist. AAPS J. 2012;14(1):68-78.
The above information contains certain "forward-looking statements", relating to the company's business, which can be identified by the use of forward-looking terminology such as "estimates", "believes", "expects", "may", "are expected to", "will", "will continue", "should", "would be", "seeks", "pending" or "anticipates" or similar expressions, or by discussions of strategy, plans or intentions. Such statements include descriptions of the company's investment and research and development programs and anticipated expenditures in connection therewith, descriptions of new products expected to be introduced by the company and anticipated customer demand for such products and products in the company's existing portfolio. Such statements reflect the current views of the company with respect to future events and are subject to certain risks, uncertainties and assumptions. Many factors could cause the actual results, performance or achievements of the company to be materially different from any future results, performances or achievements that may be expressed or implied by such forward-looking statements. Should one or more of these risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those described herein as anticipated, believed, estimated or expected.
SOURCE: Actelion Pharmaceuticals Canada Inc.
For further information:
Cohn & Wolfe
Director, Medical Affairs
Actelion Pharmaceuticals Canada Inc.
Laval, QC, Canada