When do you begin antifibrotic therapy for a patient with newly diagnosed ILD that is not IPF?

The evidence behind starting anti-fibrotic therapy for non-IPF ILD is largely based on the results of the INBUILD trial where patients who have non-IPF ILD who demonstrate progression (based on at least a 10% decline in FVC or a 5% decline in FVC with worsening symptoms or radiologic progression) have been shown to benefit from Nintedanib by reducing the rate of decline in the FVC.

In general, it is reasonable to address the underlying pathophysiology behind the ILD before considering antifibrotics. For example - in patients with hypersensitivity pneumonitis, antigen avoidance and environmental remediation are essential components of therapy. These patients may also still benefit from a trial of immunosuppression for a defined period of ti...

I appreciate and agree with Dr. @Dr. First Last's excellent answer and treatment approach.

It is important to recognize the INBUILD study had several restrictions which impact how its findings translate into routine clinical care, even though the study has provided notable information on the use of Nintedanib (Ofev) for non-IPF fibrotic lung disease.

(1) First and foremost, the underlying diagnoses for patients in the INBUILD study were markedly heterogeneous: the inclusion criteria centered on patients with progressive decline in PFTs and radiographic findings of fibrosing lung disease, and did not distinguish amongst underlying ILD etiology. The study group included very mixed patients: about 25% had hypersensitivity pneumonitis; about 25...

When I consider treatment for a patient with ILD, I am considering whether the patient has a predominantly inflammatory phenotype, fibrotic phenotype or both. In the absence of other reliable biomarkers, I use findings on the HRCT (consolidation, ground glass, organizing pneumonia), surgical lung biopsy (NSIP, OP, inflammatory infiltration, germinal centers) and whether the ILD is believed to be the consequence of a systemic disease to inform my recommendation for immunomodulator.

I consider using nintedanib for two non-IPF indications. The first is SSc-ILD (based on the SENSCIS paper) and the second is ILD with a progressive fibrotic phenotype (described in the INBUILD paper). Both of these indications are approved by the FDA, making prescr...

Typically I start antifibrotic therapy in a few situations:

1. The most common reason is ILD progression despite adequate immune suppression, defined as no extra-pulmonary disease activity (usually joint disease, but can tailor according to the patient's disease/situation, such as by presence of rash, inflammatory markers, etc).
   How do you define ILD progression? INBUILD used PFT parameters, CT findings, and symptoms as metrics. Practically, I uncommonly use symptoms because these patients are messy and have more reasons than just ILD to develop dyspnea (e.g. pulmonary hypertension, aspiration, deconditioning, airways disease). I tend to add antifibrotic therapy based on CT and/or PFT progression.
2. If patients have a usual interstitial pneumoni...

I use the same principles in my approach to autoimmune disease-related ILD, namely, identifying and treating patients with progressive disease. The INBUILD study inclusion criteria provided this useful guidance in patients meeting one of these three parameters within two years prior to receiving nintedanib:

1. Relative decline in FVC equal to or greater than 10% of predicted
2. Relative decline in FVC > - < 10% of predicted combined with worsened respiratory symptoms and/or increased extent of fibrosis on HRCT
3. Worsened respiratory symptoms and increased extent of Fibrosis on HRCT only.

I also assess for risk factors for progression. For example, in a new patient who has RA-ILD, with fibrosis extension of >10% on HRCT, and has active RA disease, i...

This has been a very interesting and informative discussion on the use of antifibrotic therapy (essentially the FDA-approved Nintedanib) in patients with non-IPF ILD by rheumatologists and pulmonologists. I will restrict my comments to scleroderma patients with ILD (although I suspect there is to a degree broader applicability to other autoimmune diseases that may result in ILD).
As pointed out by Dr. @Dr. First Last, and without going into the details that have been previously discussed, there are two trials that are particularly pertinent to scleroderma patients with ILD, the INBUILD trial and the SENSCIS trial. The INBUILD trial required all participants (some of whom had scleroderma) to have objective evidence of PROGRESSIVE fibrosing in...