July 10 (Reuters) - U.S. drug developer Arena Pharmaceuticals Inc said on Monday its experimental drug for pulmonary arterial hypertension (PAH), a rare but deadly lung disease, met the main goal in a mid-stage study.
PAH occurs when the arteries of the lungs constrict, forcing the heart to work harder and potentially leading to heart failure. Its symptoms include shortness of breath and fatigue.
The disease has no cure, but there is an arsenal of U.S. Food and Drug Administration-approved drugs used to manage the condition. However, experts believe those drugs merely reflect the tip of the iceberg, raising the need for improved therapeutic options.
Arena's drug, ralinepag, was tested against a placebo in a 61-patient study in which patients were already on standard therapy, the company said.
Arena said the oral, long-acting drug induced a statistically significant improvement in pulmonary vascular resistance of nearly 30 percent when compared to the placebo.
Study data also showed improvements from the drug in patients' exercise capacity as measured by a six-minute walk test.
The results show ralinepag may bring about a consistent therapeutic effect similar to that of intravenous therapy, San Diego-based Arena's Chief Medical Officer Preston Klassen said in an interview.
Analysts at Leerink Partners had in May forecast peak ralinepag sales of $1.1 billion.
Johnson & Johnson last month bought Europe's biggest biotech group Actelion for $30 billion, to gain access to Opsumit and Uptravi, which treat PAH.
Ralinepag has the same underlying mechanism of action as Uptravi and is important for Arena as it seeks to revamp itself under new management, having undergone a reorganization.
Arena was originally betting on an obesity pill called Belviq as its main drug but tepid sales and poor adoption led it to renegotiate an agreement with partner Eisai Co Ltd, which acquired the rights to Belviq earlier this year. (Reporting by Natalie Grover in Bengaluru; Editing by Sai Sachin Ravikumar)