Idiopathic pulmonary fibrosis - pirfenidone

Pulmonary fibrosis is a scarring of the lungs in which the air sacs gradually become replaced by thick fibrotic tissue, causing an irreversible loss of the tissue's ability to transfer oxygen into the bloodstream.

Symptoms include a shortage of breath, cough, fatigue, weakness, loss of appetite and weight, and discomfort in the chest. There are currently no effective treatments, and idiopathic pulmonary fibrosis is a fatal disorder.

InterMune is investigating pirfenidone as a potential treatment for pulmonary fibroses. Eight patients with advanced idiopathic pulmonary fibrosis, and two with interstitial pneumonia associated with diffuse systemic sclerosis, were given 40mg/kg oral pirfenidone in an open-label one year compassionate use trial.1 The patients' radiographic scores, pulmonary functions and arterial blood oxygen pressures were compared one year before treatment, when treatment began, and one year after its conclusion.

Although it did not show a definite therapeutic effect on overall survival two years before treatment, there was no significant deterioration in chest radiographic scores or arterial oxygen pressure, and it was well tolerated.

As a result, a double-blind randomised placebo-controlled trial2 was carried out in 107 patients. The subjects given the active showed a positive treatment effect in secondary end points, and episodes of acute exacerbations of the disease occurred only in those given placebo. However, significant adverse events were seen with pirfenidone.