A Randomized, Controlled Trial of Foscarnet in the Treatment of Cytomegalovirus Retinitis in Patients with AIDS

Abstract

OBJECTIVE: To evaluate foscarnet sodium in treating cytomegalovirus retinitis in patients with AIDS. PATIENTS: Twenty-four previously untreated persons with AIDS and cytomegalovirus retinitis who were at low risk for loss of their visual acuity. INTERVENTION: PATIENTS were randomly assigned to receive either no therapy (delayed treatment, control group) or immediate treatment with intravenous foscarnet at a dose of 60 mg/kg body weight three times a day for 3 weeks (induction regimen) followed by a maintenance regimen of 90 mg/kg once a day. MEASUREMENTS: PATIENTS were examined weekly until they reached the primary clinical end point, defined as progression of their retinitis border by 750 microns or the development of a new retinal lesion due to cytomegalovirus. Progression was evaluated using retinal photographs by masked readers. Secondary evaluations included changes in visual acuity, cytomegalovirus shedding in the blood and urine, serum levels of human immunodeficiency virus type 1 (HIV-1) p24 antigen, and total CD4 T lymphocyte counts. RESULTS: The mean time to progression of retinitis was 3.2 weeks in the control group (n = 11) compared with 13.3 weeks in the treatment group (n = 13) (P less than 0.001). Nine of 13 patients in the treatment group had positive blood cultures for cytomegalovirus at entry and all nine cleared their blood of cytomegalovirus by the end of the induction period (P = 0.004) compared with one of six patients in the control group. No reductions in p24 levels were seen in the control patients compared with a reduction of more than 50% in p24 levels for all four patients on treatment for whom follow-up levels were available. The main adverse effects of foscarnet treatment were seizures (2 of 13 patients), hypomagnesemia (9 of 13), hypocalcemia (11 of 13), and elevations in serum creatinine above 176.8 mumol/L (2.0 mg/dL) (3 of 13). The control patients received an average of 0.2 units of blood per week compared with an average of 0.6 units of blood per week for the patients on treatment. CONCLUSIONS: The administration of foscarnet decreases the rate of progression of cytomegalovirus retinitis in persons with AIDS. Its judicious use is likely to prevent loss of vision in these patients. In this study, however, there was little change in visual acuity in patients in either the immediate or delayed treatment group because only patients with non-sight-threatening disease were selected.