Comparison of TLOVR Algorithm Versus Snapshot Approach for HIV Studies

• Activity Number: 474
• Type: Contributed
• Date/Time: Wednesday, August 3, 2011 : 8:30 AM to 10:20 AM
• Sponsor: Biopharmaceutical Section
• Author(s): Wei Zhang and Michael Pannucci and Junhai Guo*+ and David Hall
• Companies: Boehringer Ingelheim and Boehringer Ingelheim and Boehringer Ingelheim and Boehringer Ingelheim
• Keywords: TLOVR algorithm ; SNAPSHOT approach ; HIV studies ; Phase III

Abstract

The time to loss of virologic response algorithm proposed in the FDA guidance for industry on antriretroviral drugs using plasma HIV RNA measurements (2002) has been used for sponsors traditionally for submission of clinical trials in the indication of HIV-1. This algorithm takes into account a patient's logitudinal viral load up to the pre-defined time point by considering patterns of suppression and rebounding. Recently, FDA is evaluating if this algorithm can be simplified using the SNAPSHOT approach, i.e., defining a patient's virologic response status using only the viral load at the pre-defined time point within an allowed window (Smith et al, 2009 JSM presentation). We compare the differences between the TLOVR algorithm and SNAPSHOT approach and apply both methods to two phase III pivotal trials: VERxVE and TRANxITION. The results suggest that the simple SNAPSHOT approach is a reasonable alternative to the complicated TLOVR algorithm.