A Preliminary Evaluation of 566C80 for the Treatment of Pneumocystis Pneumonia in Patients with the Acquired Immunodeficiency Syndrome

Abstract

The drug 566C80 is an investigational hydroxynaphthoquinone that is active against Pneumocystis carinii in vitro and in animal models. Initial studies in humans indicate that 566C80 is safe and has adequate bioavailability after oral administration. We conducted an open-label trial of 566C80 in 34 adults with the acquired immunodeficiency syndrome (AIDS) and untreated pneumocystis pneumonia. All the patients had a partial pressure of arterial oxygen of at least 60 mm Hg while breathing room air. They were enrolled sequentially in three cohorts taking 566C80 at different dosages, all administered orally: 750 mg three times daily for 5 days, then twice daily for 16 days; 750 mg three times daily for 21 days; and 750 mg four times daily for 21 days. All 34 patients survived, and 27 (79 percent) were successfully treated with 566C80 alone. The mean partial pressure of oxygen in 33 patients was 78 mm Hg at entry and 93 mm Hg after the course of 566C80 (PP. carinii pneumonia of mild-to-moderate severity in patients with AIDS. (N Engl J Med 1991;325:1534–8.)