Efficacy of Antifibrotic Therapy in Progressive Pulmonary Fibrosis

A meta-analysis published in BMC Pulmonary Medicine shows that 2 antifibrotic drugs, nintedanib and pirfenidone, protect against the decline in forced vital capacity (FVC) in progressive lung fibrosis. The analysis found no significant difference in efficacy of the agents, whether the underlying condition was idiopathic pulmonary fibrosis (IPF) or non-IPF with progressive fibrosis, thus reinforcing the theory of a common pathogenesis.

The investigators had 2 goals for their analysis: to assess the efficacy antifibrotic therapy using nintedanib and pirfenidone in the treatment of progressive pulmonary fibrosis (grouping together IPF and non-IPF); and to evaluate the efficacy of antifibrotic therapy for treating patients with IPF vs non-IPF. Both parts of the analysis used changes in FVC as the primary outcome and changes in mortality as the secondary outcome.

From a search of databases, the authors reviewed 97 papers, selecting 13 randomized controlled trials (RCTs) of pirfenidone or nintedanib in adults with IPF or non-IPF that had extractable data on mortality or the decline in FVC. When the IPF and non-IPF studies were combined, an overall reduction in both all-cause mortality (pooled risk ratio of 0.701, CI 0.539-0.911) and the rate of decline in FVC (pooled estimate of standardized difference from placebo − 0.306, SE 0.033) were seen. The non-IPF studies in isolation did not demonstrate a pooled effect on mortality from antifibrotics. However, both IPF and non-IPF studies showed that antifibrotics had a beneficial effect on decline in FVC, with the effect on both groups very close in value and statistically highly significant.

The investigators concluded that “Anti-fibrotic therapy offers protection against the rate of decline in FVC in progressive lung fibrosis, with similar efficacy shown between the two anti-fibrotic agents currently in clinical use. There was no significant difference in efficacy of antifibrotic therapy whether the underlying condition was IPF or non-IPF with progressive fibrosis, supporting the hypothesis of a common pathogenesis.” However, they added that their analysis did not conclusively show that antifibrotic therapy was associated with a reduction in mortality in non-IPF.  

Reference

Finnerty JP, Ponnuswamy A, Dutta P, Abdelaziz A, Kamil H. Efficacy of antifibrotic drugs, nintedanib and pirfenidone, in treatment of progressive pulmonary fibrosis in both idiopathic pulmonary fibrosis (IPF) and non-IPF: a systematic review and meta-analysis. BMC Pulm Med. 2021;21(1):411. doi:10.1186/s12890-021-01783-1