European Trial of Pirfenidone in BOS, A European Multi-center Study

Inclusion Criteria: * Patients \>18 years of age * Azithromycin therapy for at least 4 weeks prior to study start, with an Azithromycin dose of minimum 250 mg/day at least 3 times per week as this is considered standard therapy for bronchiolitis obliterans syndrome. * Double lung transplantation is required. * Patients must be at least 6 months after transplantation and must have documented post-transplant baseline value of FEV1 (mean of the 2 highest values measured at least 3 weeks apart according to ISHLT criteria). * Patients must have BOS grade 1 to BOS grade 3. * Patients must have documented progressive disease as demonstrated by all of the following criteria: * Patients must have at least 3 FEV1-measurements in the last 6 months, each at least 3 weeks apart * a total decline of at least 200ml in FEV1 i * a decline of at least 50 ml in the last two measurements Exclusion Criteria * Patients with lung redo transplantation, combined transplantation (including heart and lung transplantation) or single lung recipients. * Patients with any severe comorbidity complicating BOS which might determine the prognosis and functional level of the patient (e.g. invasive aspergillosis, active malignant disease) within the last 12 months. * FEV1 decline related to other non BOS causes (eg pneumothorax, bronchial stenosis, effusion, etc.) * Patients who have developed BOS grade 3. * Patients who on Thorax CT at entry demonstrate new significant findings which are not compatible with …