Comparison of Ro 31-8959 Plus Zidovudine (AZT) Versus AZT Plus Zalcitabine (ddC) Versus Ro 31-8959 Plus AZT Plus ddC

Inclusion Criteria Prior Medication: Required: * At least 4 months total of AZT at some point in the past, alone or in combination with other antiretroviral therapy. Patients must have: * HIV seropositivity. * Diagnosis of AIDS, ARC, PGL, or asymptomatic infection. * CD4 count \> 50 to \<= 300 cells/mm3. * Life expectancy of at least 6 months. * Prior AZT therapy. Exclusion Criteria Co-existing Condition: Patients with the following symptoms or conditions are excluded: * Acute serious opportunistic infections requiring immediate treatment, including (but not limited to) tuberculosis, CMV, cryptococcal meningitis, disseminated MAC, cerebral toxoplasmosis, and Pneumocystis carinii pneumonia. * Known intolerance to Ro 31-8959, AZT, or ddC. * Symptoms suggestive of pancreatitis. * Moderate or severe peripheral neuropathy as evidenced by discomfort from numbness, tingling, burning or pain of the extremities or any related symptoms that are accompanied by an objective finding. * Visceral Kaposi's sarcoma. * Lymphoma that will require therapy within the next 6 months. * Transfusion dependence. Concurrent Medication: Excluded: * Investigational or antineoplastic agents. Concurrent Treatment: Excluded: * Radiotherapy (other than local skin radiotherapy). * Transfusions. Prior Medication: Excluded: * Any antiretroviral agent (other than AZT) or immunomodulatory therapy within 14 days prior to study entry. * Prior treatment with an HIV proteinase inhibitor.