Safety and Efficacy Study of MPC-4326 for Treatment of Patients With HIV-1 Infection.

Inclusion Criteria: * Be at least 18 years of age at the time of screening. * Have HIV-1-infection. * Have a CD4+-lymphocyte count≥100 cells/mm3 * Have a screening plasma HIV-1 RNA value, measured by the Roche Amplicor assay, of 2,000 - 500,000 copies/mL (inclusive). * Be free from any acute infection or serious medical illness within 14 days prior to study entry. Exclusion Criteria: * Current opportunistic infection characteristic of AIDS (Category C according to the CDC Classification System for HIV-1 Infection, 1993 Revised Version, Appendix A) that is diagnosed within 30 days or is poorly controlled. * Patients with systolic blood pressure \< 90 mmHg or \> 140 mmHg or diastolic blood pressure \< 60 mmHg or \> 90 mmHg. * A history of seizures (excluding pediatric febrile seizures) or current administration of prophylactic anti-seizure medications. * A history of cerebrovascular accident (CVA) or transient ischemic attacks (TIA). * Patients with the following laboratory parameters within 30 days prior to first dose of study drug: Hemoglobin \< 10.0 g/dL for men and \< 9.0 g/dL for women Neutrophil count \< 1000/mm3 Platelet count \< 50,000/mm3 AST or ALT \> 2.5 times the upper limit of normal (patients with a positive HBV surface antigen or HCV antibody test at screening must have AST and ALT no more than 1.5 times the upper limit of normal)