Studies of the Ocular Complications of AIDS (SOCA)--Foscarnet-Ganciclovir CMV Retinitis Trial (FGCRT)

To evaluate the relative safety and efficacy of ganciclovir and foscarnet as initial treatment of patients with cytomegalovirus (CMV) retinitis.

CMV retinitis is the most common intraocular infection in patients with AIDS and is estimated to affect 35 to 40 percent of patients with AIDS. Untreated CMV retinitis is a progressive disorder, the end result of which is total retinal destruction and blindness. The first two drugs approved by the United States Food and Drug Administration (FDA) for the treatment of CMV retinitis were ganciclovir (Cytovene) and foscarnet (Foscavir). At the time of this trial, both ganciclovir and foscarnet were available only as intravenous formulations. Both drugs were given in a similar two-step fashion: an initial 2-week course of high-dose therapy (induction) to control the infection followed by long-term lower dose therapy to prevent relapse (maintenance). The FGCRT compared foscarnet and ganciclovir as initial therapy for CMV retinitis.

The FGCRT was a multicenter, randomized, controlled clinical trial comparing foscarnet and ganciclovir as initial therapy for CMV retinitis. Patients with previously untreated CMV retinitis were randomized to therapy with either intravenous ganciclovir or intravenous foscarnet. The outcome measures of this trial were survival, retinitis progression, loss of visual function (visual acuity and visual field), and morbidity.

Males and females eligible for the FGCRT must have been 13 years or older and have had AIDS (CDC definition) or laboratory confirmation of HIV infection and CMV retinitis. They could not have received previous treatment with an anti-CMV drug for their CMV retinitis. Furthermore, they must have had an absolute neutrophil count (ANC) greater than or equal to 1,000 cells/mL and a serum creatinine less than or equal to 2.0 mg/dL in order to tolerate either drug.

No longer recruiting. Comments: Completed. Recruitment began in March 1990 and was completed in October 1991.

Completed, with results published. Comments: Completed.

The FGCRT demonstrated that foscarnet and ganciclovir were equivalent for controlling CMV retinitis in patients with AIDS. Time to progression, loss of visual acuity, and loss of visual field were similar between the two groups. However, there was a 79 percent excess mortality in the ganciclovir-assigned group, presumably due to an anti-HIV effect of foscarnet. Ganciclovir therapy was associated with a greater rate of neutropenia, whereas foscarnet therapy was associated with greater rates of elevated serum creatinine and abnormalities of serum potassium, calcium, and magnesium. However, side effects were generally manageable and reversible with discontinuation of the appropriate drug.