The National Institute for Health and Clinical Excellence has rejected the use of InterMune's Esbriet (pirfenidone) on the National Health Service to treat patients with idiopathic pulmonary fibrosis.

In draft guidelines published this morning (Thursday), the cost watchdog said that based on current clinical evidence it could not conclude that the drug would be a cost-effective use of NHS resources in this setting.

"Pirfenidone seemed to have a modest but measurable effect on slowing the decline in lung function, but that it was uncertain whether this benefit persisted over time because the clinical trials were short in duration," said Professor Carole Longson, Director of the Centre for Health Technology Evaluation at NICE, explaining the decision.

"Also, it was unclear whether the drug could improve overall survival for people with the disease because of uncertainty about the correct classification of deaths in the clinical trials as being related to idiopathic pulmonary fibrosis or not, a low number of deaths in both treatment and placebo arms and short follow-up," she said.

The Institute has now opened a consultation and said it encourages healthcare professionals, patients with the condition and other relevant parties to comment on the draft recommendations to help shape final guidance.

Idiopathic pulmonary fibrosis - a progressive disease associated with scarring of the lungs - affects around 4000 new adults in the UK every year.  

Esbriet was approved in Europe in March last year.