A Randomized, Phase I/II Trial to Assess the Safety and Antiviral Effects of Escalating Doses of A Human Anti-Cytomegalovirus Monoclonal Antibody (SDZ MSL-109) in Patients With the Acquired Immunodeficiency Syndrome and CMV Viremia and/or Viruria

Inclusion Criteria Concurrent Medication: Allowed: * Zidovudine (AZT). * Acyclovir. * Experimental maintenance or prophylactic therapy with an approved therapeutic agent for a non-viral opportunistic infection. * Trimethoprim / sulfamethoxazole (TMP / SMX). * Pyrimethamine / sulfadoxine. * Inhaled pentamidine. * Amphotericin B. * Ketoconazole. * Flucytosine (5-FC). * Antituberculosis therapy. * Recombinant human erythropoietin. * Recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF). * Recombinant human interferon alfa 2 for AIDS-related Kaposi's sarcoma. Patients must have: * AIDS or be HIV positive with CD4 lymphocyte counts below 200 cells/mm3 and be receiving prophylaxis for Pneumocystis carinii pneumonia (PCP) (with or without prophylaxis for another opportunistic infection), but have no prior medical history of an opportunistic infection. * Expected survival of = or \> 6 months. * Willingness and ability to give written informed consent. * A copy of the signed and witnessed consent form must be maintained with the investigator's study files. * Positive culture results documenting the presence of cytomegalovirus (CMV) viremia and/or viruria. * Seropositive for the presence of circulating anti-CMV immunoglobulin. Exclusion Criteria Co-existing Condition: Patients with the following conditions or symptoms are excluded: * Significant pulmonary dysfunction. * Uncontrolled or unstable diabetes. * Significant cardiovascular disease including uncontrolled hypertension, congestive heart failure, cardiac arrhythmia, angina pectoris, or a history of myocardial infarction within one year of entry into the study. * Coagulation or hemorrhagic disorders. * Any active severe opportunistic infection. Concurrent Medication: Excluded: * Therapy with ganciclovir (DHPG) or phosphonoformate (PFA) or other experimental anti-cytomegalovirus therapy except as stipulated in this protocol. * Any other experimental antiviral therapy. * Biologicals including immunoglobulin therapy (except those patients randomized to receive Sandoglobulin as specified in this protocol). Patients with the following are excluded: * Any significant organ system dysfunction as described in Exclusion co-existing conditions. * Previous history of or evidence of idiopathic thrombocytopenia purpura, agammaglobulinemia, or hypogammaglobulinemia. * Any other severe concomitant clinical condition. * Documented, active cytomegalovirus (CMV) disease (tissue or organ invasion/dysfunction) at baseline. To this end, baseline indirect funduscopy (to detect and exclude patients with peripheral CMV retinitis) will be performed. Prior Medication: Excluded within 2 weeks of study entry: * Therapy with ganciclovir (DHPG) or phosphonoformate (PFA) or other experimental anti-cytomegalovirus therapy except as stipulated in this protocol. * Any other experimental antiviral therapy. * Biologicals including immunoglobulin therapy (except those patients randomized to receive Sandoglobulin as specified in this protocol). * Excluded: * Prior treatment with monoclonal antibodies derived from any animal species. Prior Treatment: Excluded within 2 weeks of study entry: * Major surgery.