Bellerophon Therapeutics, a clinical stage biotherapeutics company has completed enrollment of its 80-patient phase II clinical trial of INOpulse for the treatment of pulmonary arterial hypertension (PAH). PAH is a life-threatening, progressive disorder characterized by abnormal constriction of the arteries of the lung, leading to increased blood pressure in the lungs and abnormal strain on the heart's right ventricle, eventually leading to heart failure.

Bellerophon's INOpulse device delivers brief, controlled pulses of nitric oxide, which is a selective, short-acting pulmonary vasodilator, that are inhaled by the patient. INOpulse is portable, allowing for treatment of ambulatory patients on daily basis outside the hospital.

This phase II study, being conducted at 52 sites in the U.S. and Canada, is a randomized, placebo-controlled trial of INOpulse as an add-on therapy for use in patients whose disease is progressing despite treatment with other PAH medications. The trial will determine the safety, tolerability and efficacy in this population of two different doses of INOpulse for PAH. The primary endpoint is a change in pulmonary vascular resistance at 16 weeks from baseline. Secondary endpoints include change in mean pulmonary arterial pressure and cardiac index as well as change in six-minute walk distance. The trial is expected to be completed by the end of 2014.

"The FDA has granted orphan drug designation for nitric oxide for the treatment of PAH, which will give us seven years of exclusivity in the U.S. if INOpulse is the first inhaled nitric oxide therapy approved in this indication," said Daniel Tasse, interim chief executive officer of Bellerophon. "There is presently no cure for PAH and, despite several approved therapies, the mortality rate remains high. The completion of enrollment in this important phase II trial is therefore a key milestone for Bellerophon, and we look forward to the continued development of this potential new first-in-class therapy."

Prior to the availability of current treatments, primary PAH patients had an average survival of less than three years. There are a number of drugs approved for the treatment of PAH that work by reducing vascular resistance. However, despite the availability of multiple therapies for this indication, the mortality rate for PAH patients remains high, with estimates of median survival ranging from three to five years.

Patients with PAH also report severe impairment of health-related quality of life, including poor general and emotional health and impaired physical functioning. The most common symptoms of PAH are shortness of breath during exertion and fainting spells. Additional symptoms can include dizziness, swelling of the ankles or legs, chest pain and a racing pulse. PAH is classified as an orphan disease by the FDA, indicating that there are fewer than 200,000 patients who have been diagnosed with the condition in the U.S.