A Study to Test How Taking BI 1015550 for 12 Weeks Affects Lung Function in People With Idiopathic Pulmonary Fibrosis (IPF)

Inclusion criteria

• Patients aged ≥40 years when signing the informed consent.
• Diagnosis:

• IPF based on 2018 ATS/ERS/JRS/ALAT Guideline as confirmed by the investigator based on chest High Resolution Computed Tomography Scan (HRCT) scan taken within 12 months of Visit 1 and if available surgical lung biopsy.

and

• Usual interstitial pneumonia (UIP) or probable UIP HRCT pattern consistent with the clinical diagnosis of IPF, as confirmed by central review prior to Visit 2*

• if indeterminate HRCT finding IPF may be confirmed locally by (historical) biopsy
• Stable for at least 8 weeks prior to Visit 1. Patients have to be either :

• not on therapy with nintedanib or pirfenidone for at least 8 weeks prior to Visit 1 (combination of nintedanib plus pirfenidone not allowed), or
• on stable* therapy with nintedanib or pirfenidone for at least 8 weeks prior to Visit 1 and planning to stay stable on this background therapy after randomisation.

[*stable therapy is defined as the individually and general tolerated regimen of either pirfenidone or nintedanib]

• Forced Vital Capacity (FVC) ≥45% of predicted normal at Visit 1
• Diffusion capacity of the lung for carbon monoxide (DLCO) (corrected for haemoglobin [Hb] [Visit 1]) ≥ 25% to < 80% of predicted normal at Visit 1.
• Signed and dated written informed consent in accordance with ICH-GCP and local legislation prior to admission to the trial.

Exclusion criteria

• Relevant airways obstruction (pre-bronchodilator Forced Expiratory Volume in one second (FEV1)/Forced Vital Capacity (FVC) < 0.7) at Visit 1.
• In the opinion of the Investigator, other clinically significant pulmonary abnormalities.
• Acute IPF exacerbation within 4 months prior to screening and/or during the screening period (investigator-determined).
• Lower respiratory tract infection requiring antibiotics within 4 weeks prior to Visit 1 and/or during the screening period.
• Major surgery (major according to the investigator's assessment) performed within 3 months prior to Visit 1 or planned during the course of the trial. (Being on a transplant list is allowed).
• Any documented active or suspected malignancy or history of malignancy within 5 years prior to Visit 1, except appropriately treated basal cell carcinoma of the skin, "under surveillance" prostate cancer or in situ carcinoma of uterine cervix.
• Evidence of active infection (chronic or acute) based on clinical exam or laboratory findings at Visit 1 or at Visit 2.
• Any suicidal behaviour in the past 2 years (i.e. actual attempt, interrupted attempt, aborted attempt, or preparatory acts or behavior).
• The patient has a confirmed infection with SARS-CoV-2 within the 4 weeks prior to Visit 1 and/or during the screening period.

Further exclusion criteria apply.