Introduction Pirfenidone is the only licensed drug in Europe for Idiopathic Pulmonary Fibrosis (IPF). Clinical trials (1) have demonstrated efficacy in reducing decline in forced vital capacity (FVC), improving progression free survival and reducing mortality. The translation of clinical trial results to clinical practice is a focus of interest.
Methods We describe our experiences in prescribing pirfenidone in a single centre observational study of 96 patients from September 2011 to April 2014.
Results This is an extension of our published work (2). Prior to NICE approval we recruited 49 patients in twenty months. NICE approval resulted in a 140% increase in pirfenidone prescribing. Patient demographics at baseline are shown in Table 1. 54 (56%) patients continued treatment, 19 (20%) discontinued treatments due to adverse effects (AEs), there were 17 (17%) deaths and 4 (4%) patients were transplanted. Patients that died had lower diffusing capacity (DLCO) at baseline compared to those that continued treatment (32.9 vs 47.7 p < 0.0001). Patients that discontinued treatment due to AEs did so within six months and had lower body mass index (25.1 vs 29 p = 0.002) and DLCO (38.8 vs 47.7 p = 0.007).
There were a total of 206 AEs in 77 (79%) patients. The majority were gastrointestinal in nature. Of these adverse effects the majority were self-limiting and resolved with simple measures. 44 (21%) resulted in a dose reduction, 23 (11%) resulted in a temporary discontinuation, in 101 (45%) AEs treatment was unchanged and 38 (19%) AEs resulted in drug discontinuation.
In selected patients we had one or more lung function results before (34%) and after (50%) pirfenidone treatment. Eighteen months prior to pirfenidone treatment there was an observed reduction in mean% predicted FVC over time. Accepting limitations of missing data, this decline appeared to stabilise over twelve months after commencement of pirfenidone.
Based on an annual unit cost of £22, 245.96 for pirfenidone (without undisclosed discount). To date 96 patients have been treated for a total of 876 months at a total cost of £1,623,955 in two and a half years.
Conclusion This study highlights both the health and economic impacts of pirfenidone over a two and a half year period of prescribing.
King TE Jr et al. A phase 3 trial of pirfenidone in patients with idiopathic pulmonary fibrosis. ASCEND Study Group. N Engl J Med. 2014 May 29;370(22):2083-92
Chaudhuri N et al. Real world experiences: pirfenidone is well tolerated in patients with idiopathic pulmonary fibrosis. Respir Med. 2014 Jan;108(1):224-6