Pitfalls in Assessing Relative Efficacy Across Trials

• Activity Number: 321
• Type: Contributed
• Date/Time: Tuesday, August 6, 2013 : 8:30 AM to 10:20 AM
• Sponsor: Biopharmaceutical Section
• Author(s): Xiao Sun*+
• Companies: Merck & Co., Inc.
• Keywords: relative efficacy ; cross-trial comparison

Abstract

Although it is well known that the gold standard for assessing relative efficacy of treatments A vs. B is by way of head-to-head comparison in a randomized controlled trial (RCT), there is a widespread use of cross-trial comparisons in HIV and oncology when the only available data are from two independent trials A vs. C and B vs. C. A synthesis method is used to assess the relative efficacy of treatment arms A vs. B through the common reference arm C. The synthesized across-trial is observational in nature and subject to pitfalls of various confounding factors. In this presentation, we will show even the two trials seemed very similar in terms of baseline prognostic factors; the missing data actually introduced bias and made the comparison invalid. Therefore, caution should be exercised when interpreting results from cross-trial comparisons. Cross-trial comparisons may have some role in hypothesis generating such as identifying promising treatments for further investigation, RCTs are still essential to make important clinical decisions.