Objective: Intestinal microsporidiosis caused by Enterocytozoon bieneusi is a cause of chronic diarrhoea in patients with HIV infection for which there is no current therapy. This study was designed to assess the safety and efficacy of oral fumagillin in this infection.
Design: A dose-escalation trial.
Methods: Twenty-nine HIV-infected patients with E. bieneusi infection were consecutively enrolled in the trial. Oral doses of fumagillin were given to four groups of patients for 14 days: 10 mg/day (group 1), 20 mg/day (group 2), 40 mg/day (group 3), and 60 mg/day (group 4). Patients were seen at weeks 1, 2, 4 and 6 to assess safety and efficacy. Efficacy was assessed primarily by the clearance of microsporidia from stools and follow-up duodenal biopsies.
Results: Thirteen patients complained of abdominal cramps, vomiting or diarrhoea during the study, and three patients had fumagillin withdrawn because of adverse events. Thrombocytopenia, neutropenia and hyperlipasaemia were the most frequent biological adverse events. Twenty-one out of 29 patients transiently cleared microsporidia from their stools during the study. By week 6, however, all patients in groups 1, 2 and 3 had parasitic relapse. Interestingly, eight out of 11 (72%) patients treated with 60 mg/day (group 4) apparently cleared microsporidia from their gastrointestinal tract and gained weight. No parasitic relapse was documented in these eight patients during a mean follow-up of 11.5 months.
Conclusion: Treatment with fumagillin at 60 mg/day for 14 days has promise as an effective oral treatment for E. bieneusi infections.