Lower dose of Pirfenidone as effective as full dose for reducing disease progression in IPF

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive disease. The prognosis of the disease is extremely poor, with a median survival duration of 3 years from diagnosis.

Pirfenidone is an antifibrotic drug. As shown in large trials, Pirfenidone reduces the rate of decline in FVC and prolongs progression-free survival. The important consideration here is that it has effectiveness, slows down the IPF progression, and has adverse events.

The study points include the following:

• The study included 338 patients treated with Pirfenidone (July 2012 - March 2018).
• The researchers investigated demographics, pulmonary function, mortality, and adverse events.
• Comparing Forced Vital Capacity (FVC) and DLCO, diffusing capacity of the lungs for carbon monoxide changes before and after treatment with Pirfenidone was + 2.45 % and + 3.79 %. With standard and lower doses, individual values were + 2.13 %, + 3.65 % and, + 3.17 %, + 4.57 %, respectively.
• The total adverse event reported was 81.7 %.
• Nearly 24.6 % discontinued the treatment due to adverse events.

In our study, there was no difference in the frequency of adverse events between the dose groups, contrary to our expectation that the non-standard dose group would have more adverse events, they said.

This study’s limitations include a retrospective cohort study small number of patients in the standard dose group.

Further reading:

Hwang H, Lee JK, Choi SM, Lee YJ, Cho YJ, Yoon HI, Lee JH, Lee CT, Kim YW, Park JS. Efficacy of lower dose pirfenidone for idiopathic pulmonary fibrosis in real practice: a retrospective cohort study. Korean J Intern Med. 2022 Mar;37(2):366-376. doi: 10.3904/kjim.2020.559