To investigate the safety of thymic humoral factor (THF gamma 2), its effect on HIV load based on at least a 75 percent decrease in HIV quantitative PCR RNA copies/ml, and its persistence when administered in combination with an antiretroviral nucleoside derivative (zidovudine; AZT). To assess the effects of THF gamma 2 on T-cells, quality of life, and progression of disease.

All patients receive 12 weeks of AZT before being randomized to self-administer one of two doses of THF gamma 2 or placebo for 15 consecutive days and then twice weekly for an additional 50 weeks.

Inclusion Criteria

Concurrent Medication:

Allowed:

• AZT or another antiretroviral agent (marketed or investigational under a Treatment IND).
• Primary prophylaxis for Pneumocystis carinii pneumonia (PCP), toxoplasmosis, and Mycobacterium avium-intracellulare (MAI) if patient's CD4 count decreases to < 200 cells/mm3.
• Other marketed drugs as required.

Patients must have:

• HIV seropositivity and be either asymptomatic or have persistent generalized lymphadenopathy (PGL).
• No history of symptoms in Category B or C of 1993 Case Definition, other than oral candidiasis following previous broad-spectrum antibiotic therapy.
• Mean CD4 of 200-500 cells/mm3.
• HIV-1 positive PCR RNA.
• Ability to self-administer study drug by IM injection.
• Ability to tolerate AZT at 600 mg daily during first 8 weeks of run-in period (if AZT naive) OR tolerated AZT at >= 500 mg daily for at least 3 months but no more than 12 months prior to randomization.

Exclusion Criteria

Co-existing Condition:

Patients with the following symptoms or conditions are excluded:

• Malignancy.
• Hematuria.
• Proteinuria > 1+.

Concurrent Medication:

Excluded:

• Non-antiretroviral agents with known or suspected activity against HIV.
• Investigational new drugs that are not antiretroviral agents distributed under a Treatment IND.

Patients with the following prior conditions are excluded:

Myositis within the past 6 months.

Prior Medication:

Excluded:

• Experimental therapy, including interleukin-2, interferon, erythropoietin, or filgrastim nucleoside within 6 weeks prior to study entry.
• Prior antiretroviral therapy (AZT-naive patients only).

Prior Treatment:

Excluded within 6 weeks prior to study entry:

• Blood transfusion or blood products. Active alcoholism, drug abuse, or a mental or psychiatric problem sufficient to prevent adequate compliance with study.