Data suggest that pirfenidone has both antifibrotic and anti-inflammatory properties.1
Pirfenidone attenuates fibroblast proliferation, production of fibrosis-associated proteins and cytokines, and the increased biosynthesis and accumulation of extracellular matrix in response to cytokine growth factors.1
The efficacy of pirfenidone in IPF was evaluated in the 72-week randomised double-blind CAPACITY studies (n=435 and n=344) and a further study conducted in Japan (n=219).2
The two international CAPACITY trials compared pirfenidone 2403mg/day with placebo. The Japanese trial used a lower dose of pirfenidone (1.8g/day) which was considered comparable with the dose used in the international studies on a weight-normalised basis.2,3
Efficacy data from CAPACITY trials
The decline in per cent predicted forced vital capacity at week 72 was significantly lower with pirfenidone than placebo in one of the CAPACITY studies (p=0.001) but not the other (p=0.501); however, in the latter study, a significant benefit was observed at weeks 24, 36 and 48 (p=0.0001, p=0.011 and p=0.005, respectively). Fewer overall and IPF-related deaths occurred in the treatment arms than the placebo arms, although the studies were not powered to assess mortality.2
Similar results observed in Japan
In the Japanese study, pirfenidone was associated with a significantly reduced mean decline in vital capacity at week 52 compared with placebo (p=0.042).1
The most commonly reported adverse effects in the pirfenidone groups were nausea, diarrhoea, dyspepsia, fatigue, rash and photosensitivity reactions. To minimise the risk of rash and photosensitivity, patients should be advised to avoid exposure to direct sunlight (including UV lamps) and to apply sunscreen daily.1
- Esbriet Summary of Product Characteristics, April 2013.
- Noble PW et al. Lancet 2011; 377: 1760–9.
- Taniguchi H et al. Eur Respir J 2010; 35: 821–9.
Further information: Intermune