The US FDA has granted fast track designation to Myogen's ambrisentan, the company's type-A selective endothelin receptor antagonist (ERA), currently in Phase 3 clinical evaluation for the treatment of patients with pulmonary arterial hypertension (PAH).

Ambrisentan is intended to treat PAH, a life-threatening, progressive, and incurable disease of the pulmonary vasculature.

"We are pleased to receive Fast Track designation for ambrisentan," Michael J. Gerber, Senior Vice President of Clinical Development and Regulatory Affairs for Myogen said adding, "Based on clinical trial results to date and the properties of ambrisentan, Myogen believes that, if ambrisentan is ultimately approved, it may offer significant clinical benefit to PAH patients."

Ambrisentan is an investigational drug being developed as a once-daily oral therapy for patients with PAH and has been granted orphan drug designation for the treatment of PAH in both the United States and the European Union.
Ambrisentan is a non-sulfonamide, propanoic acid-class, type-A selective endothelin receptor antagonist. Endothelin is a small peptide hormone that plays a critical role in the control of blood flow and cell growth.

PAH is a highly debilitating disease characterized by severe constriction of the blood vessels in the lungs leading to very high pulmonary arterial pressures. These high pressures make it difficult for the heart to pump blood through the lungs to be oxygenated. Patients with PAH suffer from extreme shortness of breath as the heart struggles to pump against these high pressures causing such patients to ultimately die of heart failure. PAH afflicts approximately 200,000 patients worldwide.

Myogen has licensed ambrisentan ex-US rights to GlaxoSmithKline.