Rate of FVC decline within each ILD diagnostic subgroup
Result
Of 663 participants, 173 (26%) had chronic hypersensitivity pneumonitis, 170 (26%) an autoimmune ILD, 125 (19%) idiopathic non-specific interstitial pneumonia, 114 (17%) unclassifiable idiopathic interstitial pneumonia and 81 (12%) other ILDs. The effect on FVC decline was consistent in direction across all five: 73.1 mL/year (95% CI -8.6 to 154.8) in hypersensitivity pneumonitis, 104.0 (21.1 to 186.9) in autoimmune ILD and 141.6 (46.0 to 237.2) in idiopathic NSIP. The trial was not powered for any individual subgroup.
Secondary endpoints
Adverse events by subgroup
The INBUILD trial was not designed or powered to provide evidence for a benefit of nintedanib in specific diagnostic subgroups. However, its results suggest that nintedanib reduces the rate of ILD progression, as measured by FVC decline, in patients who have a chronic fibrosing ILD and progressive phenotype.
The trial authors, in the published abstract
How it has aged
Exemplary caution from the authors: they state in the abstract that the trial cannot prove subgroup benefit, and the finding is consistency of direction rather than significance within any diagnosis. That is precisely the right way to read it, and it is why guidelines treat progressive fibrosing ILD as one entity. See INBUILD.
Publications
Nintedanib in patients with progressive fibrosing interstitial lung diseases-subgroup analyses by interstitial lung disease diagnosis in the INBUILD trial: a randomised, double-blind, placebo-controlled, parallel-group trial
Wells AU, Flaherty KR, Brown KK, et al. Nintedanib in patients with progressive fibrosing interstitial lung diseases-subgroup analyses by interstitial lung disease diagnosis in the INBUILD trial: a randomised, double-blind, placebo-controlled, parallel-group trial. Lancet Respir Med 2020 May;8(5):453-460.
Consistent direction of effect across hypersensitivity pneumonitis, autoimmune ILD and idiopathic NSIP
No individual subgroup was powered to demonstrate benefit