A Phase III, Randomized, Double-Blind, Placebo-Controlled Study of the Safety and Efficacy of Adefovir Dipivoxil (Bis-POM PMEA) in Prolonging Survival of HIV-Infected Individuals With a CD4+ Cell Count of <= 100/mm3 or With a CD4+ Cell Count Both > 100 and <= 200/mm3 and a Nadir CD4+ Cell Count of <= 50/mm3

Inclusion Criteria

Concurrent Medication:

Allowed:

• Chronically administered concomitant therapies for HIV and opportunistic diseases, including chemotherapy for cutaneous Kaposi's sarcoma, must be on these therapies for at least 30 days prior to study entry.
• Short courses of oral antibiotics or other therapies given for a limited period of 3 weeks.
• Episodic use of IV acyclovir or oral acyclovir > 1g/day for treatment of acute illness is permitted at the clinician's discretion.

Patients must have:

• A working diagnosis of HIV infection based on the patient's medical history, behavioral history, clinical signs and symptoms, or results of other laboratory tests.
• CD4+ cell count <= 100 cells/mm3 within 60 days prior to randomization (OR, AS PER AMENDMENT 8/7/97, a CD4+ cell count that is both > 100 and <= 200 cells/mm3 within 60 days prior to randomization and a documented nadir CD4+ cell count <= 50 cells/ mm3 at any time prior to randomization).
• Reasonably good health.
• Life expectancy of at least 6 months.
• Access to a refrigerator for the storage of adefovir dipivoxil.
• Signed informed consent from parent or legal guardian for patients less than 18 years of age.

AS PER AMENDMENT 8/7/97:

• CMV serology (IgG) positive (CMV bDNA cohort and CMV-virology cohort).

Exclusion Criteria

Co-existing Condition:

Patients with the following symptoms and conditions are excluded:

• Evidence of active CMV disease at screening.
• Conditions that would require use of medications listed in Exclusion Concurrent Medications.

Concurrent Medication:

Excluded:

• Any investigational anti-CMV agent.
• Adenine arabinoside (vidarabine).
• Amantadine hydrochloride (Symmetrel).
• Cidofovir (Vistide).
• CMV hyperimmune globulin.
• Cytosine arabinoside (cytarabine).
• Famciclovir.
• Foscarnet (phosphonoformic acid).
• Ganciclovir (Cytovene).
• GW 1263W94 (Benzamidazole).
• Idoxuridine.
• Intravenous acyclovir.
• ISIS 2922 (Anti-sense).
• Lobucavir.
• MSL109.
• Oral acyclovir > 1 g/day.
• Valacyclovir.

Patients with the following prior conditions are excluded:

• History of CMV end-organ disease.

Prior Medication:

Excluded within 2 weeks of randomization:

• Any investigational anti-CMV agent.
• Adenine arabinoside (vidarabine).
• Amantadine hydrochloride (Symmetrel).
• Cidofovir (Vistide).
• CMV hyperimmune globulin.
• Cytosine arabinoside (cytarabine).
• Famciclovir.
• Ganciclovir (Cytovene).
• GW 1263W94 (Benzamidazole).
• Idoxuridine.
• Intravenous acyclovir.
• ISIS 2922 (Anti-sense).
• Lobucavir.
• MSL109.
• Oral acyclovir > 1 g/day.
• Valacyclovir.

Excluded within 60 days prior to study entry:

• Foscarnet.

History of severe allergic reactions to study medication Currently pregnant or breastfeeding Recent participation in another clinical trial within the last 30 days Presence of uncontrolled medical conditions that could affect safety