The study, which has enrolled the target of 80 patients, is being conducted at 30 sites in the US, Canada and Puerto Rico. It will compare the effects of two different dosages of TNX-355 added to optimized background therapy (OBT) with the effect of OBT plus placebo in treatment-experienced, HIV-1 infected patients who have failed highly active antiretroviral therapy (HAART).
The primary endpoint for the phase II trial is a significant reduction in viral load levels between either of the active arms, versus the control OBT arm at 24 weeks. Secondary objectives of the study will include change in percentage and number of CD4 cell count from baseline, the proportion of patients who achieve an undetectable HIV-1 RNA, and time to loss of virologic response.
Tanox plans to present interim, 24-week data from the phase II trial in Q4 2005.