The traditional regulatory requirement when assessing a new agent is often for two adequate and well controlled Phase III trials which control the type I error rate at 2.5% (one-sided) per trial. Such a requirement is a challenge for some antibacterial agents due to issues of feasibility, particularly for infections due to uncommon pathogens or treatments with a narrow spectrum of activity. As a result, there has been discussion regarding the use of differing amounts of clinical data to support approval in areas with large unmet medical need and limited feasibility.

This session will cover experiences working in this challenging area and will consider how to use the totality of evidence from a range of sources, the methodological considerations when interpreting such data, and the application of methods improving the precision of estimates of efficacy in the setting of uncommon pathogens along with design features to enable a more feasible development program while controlling the false-positive risk and ensuring there is sufficient evidence of drug effect.