Study to Evaluate Safety and Efficacy of UB-421 Antibody in HIV-1 Infected Adults

Safety evaluations include physical examination, measurement of vital signs, clinical chemistry and hematology tests at each visit (to assess changes from normal range), incidence of adverse event (AE) and serious AE (SAE) of two dose cohorts and are followed for 16 weeks (end of study).

Overall treatment tolerability of UB-421 for each cohort is defined as the percentage of the number of actual infusion doses divided by number of actual infusion doses plus number of missed doses of subject(s) who drops out due to drug-related AE(s); calculation follows specific formula.

Efficacy measurements include virologic responses and determination of the proportion of subjects with viral load <50 copies/mL or <200 copies/mL; viral load reduction >0.5 log10 copies/mL or >1.0 log10 copies/mL; viral rebound over 0.5 log10 increase in viral load from the nadir value during 8-week treatment period, suggesting presence of study drug resistance mutants. HIV-1 viral load is determined at each blood collection during 16-week study period.

Pharmacokinetic analyses are calculated at each visit during 8-week treatment period to determine the serum concentration before and after each infusion of UB-421 and during the 8-week follow-up period to determine the clearance of study drug in circulation.

Immunogenicity of the study drug is measured by analytical ELISA test at each visit to determine if the anti-UB-421 antibody concentration is increased above the pre-treatment baseline level.

Pharmacokinetic analyses are calculated at each visit during 8-week treatment period to determine the percentage of CD4+ T lymphocytes binding to the UB-421 study drug before each infusion and during the 8-week follow-up period to determine the duration of study drug bound to the CD4+ cells in circulation

Safety evaluations include evaluation of peripheral blood mononuclear cell proliferation and expression of Th1 and Th2 cytokines in the presence of study drug before the first and last UB-421 infusions during 8-week treatment period and at the end of follow-up period.

Efficacy measurements include virologic responses and determination of the proportion of subjects (if any) with viral load rebound during 8-week treatment period, suggesting emergence of study drug resistance mutants. Samples with viral load rebound will be characterized further to identify virus mutation(s).