The Safety and Effectiveness of FIAC in the Treatment of Cytomegalovirus (CMV) in Patients With AIDS

Overview

To find oral doses of FIAC (a pyrimidine nucleoside analog) that are effective in treating cytomegalovirus (CMV) viremia in HIV-infected immunocompromised patients; to determine tolerance and safety of FIAC in this patient population; and to determine pharmacokinetics following multiple doses of FIAC. (An example of another nucleoside analog effective against retroviruses such as HIV is zidovudine (AZT).) CMV infection is a medically significant opportunistic disease in patients with HIV-related infection. The purine nucleoside ganciclovir has been used to treat AIDS patients with CMV disease. Although ganciclovir is useful in treating CMV disease, such treatment is frequently complicated by hematologic (blood) toxicity. Also, treatment is difficult because it requires daily intravenous dosing. Test tube studies show that FIAC and its primary breakdown product FIAU are highly and specifically active against several viruses including CMV. A single-dose, pharmacokinetic (blood level) study showed that FIAC, when taken orally, is readily absorbed into the bloodstream, and most of it is converted to FIAU.

CMV infection is a medically significant opportunistic disease in patients with HIV-related infection. The purine nucleoside ganciclovir has been used to treat AIDS patients with CMV disease. Although ganciclovir is useful in treating CMV disease, such treatment is frequently complicated by hematologic (blood) toxicity. Also, treatment is difficult because it requires daily intravenous dosing. Test tube studies show that FIAC and its primary breakdown product FIAU are highly and specifically active against several viruses including CMV. A single-dose, pharmacokinetic (blood level) study showed that FIAC, when taken orally, is readily absorbed into the bloodstream, and most of it is converted to FIAU. Patients are treated as outpatients if general health permits. This is continued for up to 90 days or until failure on basis of efficacy, tolerance, or toxicity. The dose escalation between groups of patients uses the formula n + 0.7n. Entry of new patients at the next higher dose is based on results of antiviral, tolerance, and safety data for the prior cohort when they have received at least 14 days of therapy. Consecutively qualifying patients are enrolled for each dose group and not based on either disease severity or expected tolerance. Although not formally randomized due to the sequential nature of the study and serious medical condition of the patients, every attempt to avoid bias in assigning a patient to a dose is made. Patients are advised to avoid heavy exercise within 24 hours of any laboratory tests.