Isshiki T, Sakamoto S, Yamasaki A, et al. - Researchers investigated the incidence of acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) among patients taking antifibrotic agents as well as compared AE-IPF frequency in patients undergoing treatment with pirfenidone and nintedanib. Clinical records of 199 patients with IPF who were initiated on pirfenidone or nintedanib from 2009 through 2018, were analyzed retrospectively. The 1-, 2-, and 3-year cumulative incidences of AE-IPF were estimated to be 9.3%, 22.1%, and 25.0%, respectively. For AE-IPF, 1-, 2-, and 3-year cumulative incidence rates in the pirfenidone group and nintedanib group were noted to be 5.1% vs 18.6%, 20.4% vs 25.2%, and 22.6% vs 29.6%, respectively. Patients who received pirfenidone had significantly lower AE-IPF incidence, vs those who received nintedanib. In the light of these findings, it was inferred that pirfenidone, in comparison to nintedanib, might afford a greater reduction in AE-IPF risk.