A Study to Find an Efficacious and Safe Dose of CHF10067 (Zampilimab) in Participants With Idiopathic Pulmonary Fibrosis

The purpose of this study is to evaluate the efficacy, safety, and tolerability at Week 24 of 2 doses of CHF10067 (zampilimab) in participants with idiopathic pulmonary fibrosis (IPF). It is a phase IIb, multicentre, randomised, double-blind, placebo-controlled, three-arm parallel-group study. A total of 240 participants with IPF (Idiomatic Pulmonary Fibrosis) will be randomised in approximately 150 investigational sites in North and Latin America, Europe, Asia, and Oceania.

Inclusion Criteria: * Informed consent: Participant's written informed consent obtained prior to any study-related procedure. * Sex and age: Male or female, of any race and ethnicity, aged ≥40 years with a life expectancy of at least 1 year at screening in the opinion of the Investigator. * Body weight ≥45 kg. * Diagnosis of IPF: Diagnosis as defined by the 2018 and 2022 American Thoracic Society/European Respiratory Society/Japanese Respiratory Society/Latin American Thoracic Society Guidelines for a maximum 8 years before screening. The most recent High-resolution computed tomography (HRCT) ≤6 months prior to screening, reviewed by central reading, should be used to confirm the diagnosis. * Lung function: FVC ≥45% of predicted normal value and a ratio of forced expiratory volume in the first second (FEV1)/FVC ≥0.7 at screening. * Diffusing capacity of the lung for carbon monoxide (DLCO) corrected for haemoglobin ≥25% of predicted normal at screening. * Oxygen saturation measured by pulse oximetry (peripheral capillary oxygen saturation \[SpO2\]) \>90% at rest when the maximum oxygen flow is 4 L/min by standard nasal cannula or the equivalent oxygen delivery via reservoir nasal cannula (≤2 L/min). Exclusion Criteria: * Participant with a documented diagnosis of coeliac disease. * Low respiratory tract infection: Documented low respiratory tract infection in the last 4 weeks prior to screening or documented acute exacerbation of IPF (defined as acute worsening or development of dyspnoea typically \