A Phase II Trial on Treatment of Steroid-refractory Bronchiolitis Obliterans With Interferon Gamma 1b After Allogeneic SCT

Inclusion Criteria * Allogeneic SCT * Age ≥ 18 years * BO, firmed by 2 out of 3 examinations: * Lung function/ BGA * CT scan in in- and expiration or * Histological diagnosis * Therapy refractory BO, i.e. no improvement during at least three therapies, among: * Azithromycin + inhaled steroids/ bronchodilators * Systemic steroids 1 mg/kg BW * One of the following therapies: MMF, mTOR inhibitors or ECP * Effective contraception (before, during and for 8 weeks after the treatment) * Blood count: no severe neutropenia, defined as ANC \> 1000/ml, platelets \> 50/nl and haemoglobin \> 8 g/dl * Liver parameters (bilirubin, gammaGT, AP, ASAT, ALAT) lower than 3 x paramount normal range * Kreatinin lower than 3 x paramount normal range * Informed consent Exclusion Criteria: * Age \< 18 years * Pregnant or nursing woman * No appropriate contraception * Participation in any other study within 4 weeks before or during the study * Active acute GvHD of other organs than the lung \> grade II or severe active chronic GvHD * No appropriate antibiotic/ antimycotic therapy in documented infection * Severe bone marrow suppression (ANC \< 1000/ml) or graft failure * Liver parameters (bilirubin, gammaGT, AP, ASAT and ALAT) higher than 3 x paramount normal range * Kreatinin higher than 3 x paramount normal range * Participation in another study within 4 weeks before or during the study