The NHS could be wasting millions of pounds by off-label use of an ineffective treatment for idiopathic pulmonary fibrosis when a licensed alternative exists, according to data presented at the British Thoracic Society meeting in London.

Study co-author Nazia Chaudhuri of the University Hospital of South Manchester, said that between 30% and 45% of patients with moderate IPF are currently treated using  monotherapy with n-acetyl cysteine (NAC), despite recent data from the US PANTHER-IPF study showing lack of efficacy. The latter, conducted by the National Institutes of Health, found NAC to be no better than placebo for preserving lung function.

Dr Chaudhuri noted that the use of NAC in adults with IPF “is commonplace in the UK, despite weak clinical evidence and limited support from clinical guidelines”. It is also pricey.

Her study of the cost burden of NAC prescribing in England based on the actual acquisition cost to the NHS found the current average annual cost to be 425% greater than NICE cost assumptions, ranging from £144–£1078 per annum. This equates to an estimated annual cost of NAC in England of more than £2 million.

Dr Chaudhuri said that “in light of the current financial position of the NHS, more should be done to reduce the use of ineffective treatments that offer poor value for money”. She added that doctors should “re-evaluate the use of NAC in the management of IPF – it should be discontinued if it is not benefitting patients”.

Esbriet (pirfenidone), developed by InterMune (which is now owned by Roche), has been available in Europe for IPF since 2011, while Boehringer Ingelheim’s Ofev (nintedanib) will soon hit the market, having been backed by advisors to the European Medicines Agency last month.