To Investigate the Efficacy and Safety of UB-421 Monotherapy in HIV-1 Infected Adults

A Phase III, Randomized, Open-label, Controlled Trial to Investigate the Efficacy and Safety of UB-421 Monotherapy as Substitution for Stable Antiretroviral Therapy in HIV-1 Infected Adults

The purpose of this phase III study is to evaluate the efficacy, safety and tolerability of UB-421 monotherapy in suppressing viral rebound in HIV-1 infected adults undergoing antiretroviral treatment interruption.

This is an open-label, Phase III study to evaluate the efficacy, safety and tolerability of UB-421 monotherapy in suppressing viral rebound while replace HAART in virally suppressed HIV-1 infected adults. In this study, approximately 375 subjects on stable HAART treatment will be randomized to receive either continuing HAART treatment alone (Cohort 1) or UB-421 as the monotherapy (Cohort 2) in 1:2 ratio. For Cohort 1, subjects will receive current standard HAART treatment as the active control group. For Cohort 2, UB-421 will be administered to enrolled subjects without HAART treatment in the Cohort 2 during the 26-week treatment period. After treatment period, both cohort 1 and cohort 2 enter 22-week follow-up period.

Inclusion Criteria:

• HIV-1 sero-positive
• Aged 20 years or older
• Were not breastfeeding for women
• Subjects with a negative serum pregnancy test result at screening visit for women of childbearing potential
• Subjects agree on using birth control barrier (female or male condom) during the entire study period
• Subjects sign the informed consent before undergoing any study procedures

Exclusion Criteria:

• Any active infection except for HIV, and required immediate therapy
• Any active AIDS-defining illness per Category B and Category C conditions according to the U.S. Centers for Disease Control and Prevention (CDC) Classification System for HIV Infection
• Any significant diseases (other than HIV-1 infection) or clinically significant findings, including psychiatric and behavioral problems, determined from screening, medical history, and/or physical examination that, in the investigator's opinion, would preclude the subject from participating in this study
• Life expectancy less than 12 months
• Any alcohol or illicit drug used, according to the investigator's opinion, will interfere with the subject's ability to comply with the dosing, visit schedules and protocol evaluations