Researchers have documented an improved quality of life in patients with pulmonary arterial hypertension (PAH) who are treated with the investigational agent sitaxsentan.

Sitaxsentan is an oral, once-daily selective endothelin A receptor antagonist that is 6,500 times more selective for endothelin A than endothelin B receptors.

The new findings, based on a series of adult patients with either idiopathic PAH or PAH associated with collagen vascular diseases, were reported at the American Thoracic Society (ATS) 2006 International Conference.

R. Souza, MD, and associates at the University of Sao Paolo in Sao Paolo, Brazil, assessed 23 subjects at baseline and after 16 weeks of treatment with sitaxsentan 100 mg po qd.

"There has been limited information in the literature about quality of life in PAH patients," Dr. Souza pointed out.

"Sixtaxsentan has demonstrated a favorable impact on functional capacity and hemodynamics in PAH patients," he said. "While currently approved PAH therapies may improve patients' pulmonary hemodynamics and exercise capacity, they may or may not have a positive impact on functional status and quality of life."

The six-minute walk test (6MWT) and quality of life questionnaire (Short Form-36) were obtained at baseline and at week 16.

Results showed a significant increase in functional capacity evaluated by 6MWT (472 vs 490 m, p=0.03) and also in the physical domain component of the quality of life questionnaire (QOLQ), p