A Trial to Compare Nebulized Amphotericin B and Nebulized Normal Saline as Maintenance in Patients With Chronic Pulmonary Aspergillosis

The treatment of CPA is with oral itraconazole for 6-12 months. Oral itraconazole results in better clinical outcomes in CPA compared to supportive care. A recent study comparing 6 months with 12 months of oral itraconazole for longer duration treatment found longer duration reduced CPA relapse and improved clinical outcomes. However, longer duration of itraconazole could cause emergence of drug resistant Aspergillus fumigatus and therapy related adverse event. A recent study found nebulized amphotericin B non-inferior to oral itraconazole for treating CPA as primary therapy. However, the study was small and included patients with simple aspergilloma and used nebulized amphotericin B for 7 days.To be effective, an inhaled drug should be delivered in sufficient quantity to achieve therapeutic levels.The minimum inhibitory concentration of amphotericin B for A.fumigatus is 0.5 mg/L. In one study, nebulization of 30 mg of amphotericin B deoxycholate achieved a mean concentration of 0.68 mg/L in the bronchoalveolar lavage fluid. Notably, the serum levels of amphotericin B after nebulization are 20 times less than after systemic administration and is safer. Further, there is a dose-response relation with nebulized amphotericin B, the higher the dose used for nebulization, the higher are the levels achieved in the lung tissue. Nebulized amphotericin B has been used in lung transplant recipients to prevent invasive aspergillosis. Also, two recent studies have demonstrated that use of nebulized amphotericin B as maintenance therapy led to a reduction in ABPA relapse rates and prolonged time to exacerbation. We believe that inhaled amphotericin B as a maintenance therapy could reduce CPA relapse and prolong time to relapse. In this study, we plan to evaluate nebulized amphotericin B as a maintenance therapy in clinically stable CPA patients treated with 12 months of oral antifungal therapy