Patient description: The patient is a 14-year-old boy complaining of scoliosis and back pain. He has no other medical condition. He used to be able to play routine activities such as basketball and soccer, however, he recently has problem doing them. The pain is in his leg and back and aggravated by physical activities. He prefer lying down most of the time. He is not happy with his body gesture and complaints of shoulder imbalance and shifting his head to right. Patient is a well-dressed and well-nourished adolescent who is alert and cooperative. The left shoulder is slightly higher than the right shoulder. The scoliotic curve is measured as 45 degree. The patients is candidate for scoliosis surgery according to perioperative MEP monitoring

Clinical trial eligibility criteria: eligible ages (years): 6.0-17.0,  Lung Diseases, Interstitial Children and adolescents 6 to 17 years old at Visit 2 Signed and dated written informed consent and assent, where applicable, in accordance with International Conference on Harmonisation-Good Clinical Practice (ICH-GCP) and local legislation prior to admission to the trial Male or female patients. Female of childbearing potential (WOCBP) must confirm that sexual abstinence is standard practice and will be continued until 3 months after last drug intake, or be ready and able to use a highly effective method of birth control per International Conference on Harmonisation (ICH) M3 (R2) that results in a low failure rate of less than 1% per year when used consistently and correctly, in combination with one barrier method, from 28 days prior to initiation of study treatment, during treatment and until 3 months after last drug intake. Sexual abstinence is defined as abstinence from any sexual act that may result in pregnancy. A list of contraception methods meeting these is provided in the parental information Patients with evidence of fibrosing Interstitial Lung Disease (ILD) on High-Resolution Computed Tomography (HRCT) within 12 months of Visit 1 as assessed by the investigator and confirmed by central review Patients with Forced Vital Capacity (FVC)% predicted ≥25% at Visit 2. [Note: Predicted normal values will be calculated according to GLI (Global Lung Initiative)] Patients with clinically significant disease at Visit 2, as assessed by the investigator based on any of the following Fan score ≥3, or Documented evidence of clinical progression over time based on either a 5-10% relative decline in FVC% predicted accompanied by worsening symptoms, or a ≥10% relative decline in FVC % predicted, or  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 mL/min calculated by Schwartz 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 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) at Visit 1 Previous treatment with nintedanib Other investigational therapy received within 1 month or 5 half-lives (whichever is shorter but ≥1 week) prior to Visit 2 Significant pulmonary arterial hypertension (PAH) defined by any of the following Previous clinical or echocardiographic evidence of significant right heart failure History of right heart catheterization showing a cardiac index ≤2 l/min/m² PAH requiring parenteral therapy with epoprostenol/treprostinil