To Evaluate the Effect of Different Doses of SAR156597 Given to Patients With Idiopathic Pulmonary Fibrosis (IPF)

The study consists of a screening period of up to 28 days, treatment period of up to 6 weeks
and a post-treatment follow-up period of up to 12 weeks. Total study duration is up to 22
weeks.

Inclusion criteria:

- Adult (aged >18 years) male or female patients,

- Documented diagnosis of IPF according to the current American Thoracic
Society/European Respiratory Society/Japanese Respiratory Society/American Latin
Thoracic Association (ATS/ERS/JRS/ALTA) guidelines

Exclusion criteria:

- Forced vital capacity (FVC) <50% of predicted value Carbon monoxide diffusing lung
capacity (DLCO) (corrected for hemoglobin) <35% predicted value

- Oxygen saturation <90% by pulse oximetry while breathing ambient air at rest (sitting
position for 10 min)

- Known diagnosis of significant respiratory disorders other than IPF

- Active vasculopathy or use of vasoactive drugs

- Known HIV or chronic viral hepatitis

- Patients with active tuberculosis or latent tuberculosis infection

- Evidence of any clinically significant, severe or unstable, acute or chronically
progressive medical (other than IPF) or surgical disorder, or any condition that may
affect patient safety in the judgment of the investigator

- Clinically significant abnormal ECG at screening

- Clinically significant laboratory tests at screening

- Current history of substance and/or alcohol abuse

- Females who are lactating or who are pregnant.

- Use of any registered therapy targeted to treat IPF within 4 weeks prior to screening

- Use of any cytotoxic/immunosuppressive agent including but not limited to
azathioprine, cyclophosphamide, methotrexate and cyclosporine within 4 weeks prior to
screening

The above information is not intended to contain all considerations relevant to a
patient's potential participation in a clinical trial.