Inclusion Criteria:

• - Written Informed Consent consistent with International Council on Harmonisation-Good Clinical Practice (ICH-GCP) and local laws signed prior to entry into the study (and prior to any study procedure including shipment of High-Resolution Computed Tomography (HRCT) to reviewer.

• - Male or female patients aged ≥ 18 years at Visit 1.

• - Patients with physician diagnosed Interstitial Lung Disease (ILD) who fulfil at least one of the following criteria for Progressive Phenotype within 24 months of screening visit (Visit 1) despite treatment with unapproved medications used in clinical practice to treat ILD, as assessed by the investigator: - Clinically significant decline in Forced Vital Capacity (FVC) % predicted based on a relative decline of ≥10% - Marginal decline in FVC % predicted based on a relative decline of ≥5-<10% combined with worsening of respiratory symptoms.

• - Marginal decline in FVC % predicted based on a relative decline of ≥5-<10% combined with increasing extent of fibrotic changes on chest imaging.

• - Worsening of respiratory symptoms as well as increasing extent of fibrotic changes on chest imaging [Note: Changes attributable to comorbidities e.g. infection, heart failure must be excluded.

Unapproved medications used in the clinical practice to treat ILD include but are not limited to corticosteroid, azathioprine, mycophenolate mofetil (MMF), n-Acetylcysteine (NAC), rituximab, cyclophosphamide, cyclosporine, tacrolimus].

• - Fibrosing lung disease on HRCT, defined as reticular abnormality with traction bronchiectasis with or without honeycombing, with disease extent of >10%, performed within 12 months of Visit 1 as confirmed by central readers.

• - For patients with underlying Connective Tissue Disease (CTD): stable CTD as defined by no initiation of new therapy or withdrawal of therapy for CTD within 6 weeks prior to Visit 1.

• - FVC ≥ 45% predicted at Visit 2.

Exclusion Criteria:

• - Aspartate Aminotransferase (AST) and / or Alanine Aminotransferase (ALT) > 1.5 x Upper Level of Normal (ULN) at Visit 1.

• - Bilirubin > 1.5 x ULN at Visit 1.

• - Creatinine clearance <30 milliliter (mL)/minute (min) calculated by Cockcroft-Gault formula at Visit 1.

[Note: Laboratory parameters from Visit 1 have to satisfy the laboratory threshold values as shown above. Visit 2 laboratory results will be available only after randomization. In case at Visit 2 the results do no longer satisfy the entry criteria, the Investigator has to decide whether it is justified that the patient remains on study drug. The justification for decision needs to be documented. Laboratory parameters that are found to be abnormal at Visit 1 are allowed to be re-tested (once) if it is thought to be a measurement error (i.e. there was no abnormal result of this test in the recent history of the patient and there is no related clinical sign) or the result of a temporary and reversible medical condition, once that condition is resolved].

• - Patients with underlying chronic liver disease (Child Pugh A, B or C hepatic impairment).

• - Previous treatment with nintedanib or pirfenidone.

• - Other investigational therapy received within 1 month or 6 half-lives (whichever was greater) prior to screening visit (Visit 1).

• - Use of any of the following medications for the treatment of Interstitial Lung Disease (ILD): azathioprine (AZA), cyclosporine, Mycophenolate Mofetil (MMF), tacrolimus, oral corticosteroids (OCS) >20mg/day and the combination of OCS+AZA+ n-Acetylcysteine (NAC) within 4 weeks of Visit 2, cyclophosphamide within 8 weeks of Visit 2, rituximab within 6 months of Visit 2.

Note: Patients whose Regulatory Authority (RA)/Connective Tissue Disease (CTD) is managed by these medications should not be considered for participation in the current study unless change in RA/CTD medication is medically indicated. Further exclusion criteria apply.

Arms

Experimental: nintedanib

Placebo Comparator: Placebo

Interventions

Drug: - nintedanib

nintedanib

Drug: - Placebo

Placebo