P164 Cyclophosphamide for the treatment of refractory chronic hypersensitivity pneumonitis

Introduction Intravenous cyclophosphamide at a dose of 600 mg/m2 monthly for 6 months is an established treatment for various immune modulated interstitial lung diseases (ILDs). This practice has been extended to rapidly progressive chronic hypersensitivity pneumonitis (CHP), however, little is known about the therapeutic efficacy in this disease. Methods All patients receiving intravenous cyclophosphamide between 2007 and 2017 at the Royal Brompton Hospital were identified using pharmacy records. Those with a clinical diagnosis of CHP underwent MDT review to confirm the diagnosis. Clinical data, demographics and lung function at time of first treatment and 12 months pre- and post was captu…