Switching Antifibrotic Agents May Improve Outcomes in Idiopathic Pulmonary Fibrosis

Because the 2 antifibrotics in use — pirfenidone and nintedanib — have differing mechanisms of action, when one is ineffective the other may provide benefit, thus improving survival.

Patients with idiopathic pulmonary fibrosis (IPF) may experience improved outcomes by switching antifibrotics, a recent study published in BMC Pulmonary Medicine suggested, though further validation is needed of the study’s findings.

The retrospective study evaluated 262 patients with IPF who received pirfenidone or nintedanib — 2 antifibrotic agents currently in use that have similar efficacy — at 3 Japanese hospitals. Approximately 14.1% (n=37) of patients switched antifibrotic agents during the treatment period of 2009 to 2020. The most common reason for switching was disease progression (45.9%; n=17), followed by gastrointestinal issues (32.4%; n=12).

A total of 29 patients switched from pirfenidone to nintedanib; the 8 remaining patients switched from nintedanib to pirfenidone. The researchers compared prognoses between patients who switched antifibrotics (switch-IPF; mean age, 70 years) and those who did not switch (nonswitch-IPF; n= 225; mean age, 73 years).

Although the causes of death were similar between the switch and nonswitch patients, the median survival time and 5-year survival rate were significantly higher in switch-IPF vs nonswitch IPF patients (median survival time 67.2 vs 27.1 months; 5-year survival rate 52.1% vs. 11.2, respectively).

The study participants switched antifibrotic agents after a median of 25.8 months. Notably, patients who switched because of disease progression had longer exposure to first-line antifibrotics and shorter periods from the end of first-line therapy to the start of second-line treatment compared with patients who switched for other reasons. Only 8 out of the 37 patients who switched antifibrotics discontinued second-line antifibrotics, highlighting the potential feasibility of switching therapies.

Limitations of this study included its retrospective design and overall small sample size, said researchers, adding that “The rationale for the longer survival times of the switch-IPF patients compared to the non-switch IPF patients is not entirely clear.”


Suzuki Y, Mori K, Aono Y, et al. Switching antifibrotics in patients with idiopathic pulmonary fibrosis: a multi-center retrospective cohort study. BMC Pulm Med. 2021;21(1):221. doi:10.1186/s12890-021-01587-3