A Phase II/III Study of Cysteamine (Mercaptoethylamine) and Zidovudine for the Treatment of HIV Disease

Inclusion Criteria Concurrent Medication: Allowed: * Chemoprophylaxis for Pneumocystis carinii pneumonia, candidiasis, Mycobacterium tuberculosis, and herpes as prescribed by the investigator. * Recombinant erythropoietin and G-CSF if clinically indicated. Patients must have: * Documented HIV infection. * CD4 count 300 - 500 cells/mm3. * Prior AZT therapy for at least 3 months but less than 12 months prior to study entry. * No past or current AIDS-defining opportunistic infection. Exclusion Criteria Co-existing Condition: Patients with the following symptoms or conditions are excluded: * Kaposi's sarcoma requiring systemic therapy. * Active malignancy other than basal cell carcinoma or in situ cervical carcinoma. Concurrent Medication: Excluded: * Antiretroviral therapy other than AZT. * Immunosuppressive drugs. * Investigational HIV drugs/therapies other than study drug. * Interferon. * Steroids. * Hematopoietins. * Cytotoxic chemotherapy including Adriamycin, bleomycin, and vincristine. Concurrent Treatment: Excluded: * Radiation therapy. Patients with the following prior condition are excluded: History of treatment-limiting intolerance to 500-600 mg AZT daily as manifested by the same recurrent grade 3 toxicity or any prior grade 4 toxicity. Prior Medication: Excluded: * Prior antiretroviral therapy other than AZT. Required: * AZT for at least 3 months but no more than 12 months prior to study entry.