A real-world study of the dosing and tolerability of pirfenidone and its effect on survival in idiopathic pulmonary fibrosis.

BACKGROUND

Patients with idiopathic pulmonary fibrosis (IPF) often do not tolerate pirfenidone in the recommended dose of 2400 mg/day. The proportion of patients requiring dose reduction and its impact on survival in the real-world remain unclear.

METHODS

Consecutive subjects with IPF were enrolled between March 2017 and June 2019. The maximum tolerated dose of pirfenidone (primary outcome) and adverse drug reactions (ADRs) were recorded. A post hoc logistic regression analysis was performed to evaluate the predictors of drug discontinuation due to ADRs. We also compared survival between the full-dose (2400 mg/day), reduced-dose (< 2400 mg/day), and the no-pirfenidone groups, with age and percentage of the predicted forced vital capacity (%pred FVC) as covariates.

RESULTS

Of the 128 subjects (mean age, 67.4 years; 77.3% men) included, 115 were initiated on pirfenidone. Forty-nine (42.6%) and 51 (44.3%) subjects tolerated the full dose and reduced doses, respectively. Ninety-six (83.5%) subjects developed at least one ADR; anorexia dyspepsia, and nausea being the most common. Twenty-two subjects discontinued the drug; 15 of them due to ADRs. Body mass index < 20 kg/m2 was the only predictor of drug discontinuation due to ADRs. Among subjects newly initiated on treatment during the study period (n = 80), survival was longer (hazard ratio [interquartile range], 0.19 [0.04-0.96]; p = 0.045) in the full-dose but not the reduced-dose group (p = 0.08) compared with the no-pirfenidone group, after adjusting for covariates.

CONCLUSION

Pirfenidone was tolerated in the full dose in a minority of patients with IPF and appears to improve survival only with the full dose. (Sarcoidosis Vasc Diffuse Lung Dis 2020; 37 (2): 148-157).