The human immunodeficiency virus (HIV) disease has been a critical public health issue for decades. Pre-exposure prophylaxis (PrEP) has been recently recognized as a promising defense against HIV infection, particularly in high risk HIV-negative populations.
Designing PrEP trials is challenging from many perspectives. Previous studies have shown inconsistent effectiveness in different risk populations. Drug adherence could also largely impact the treatment effect. These and other related concerns should be addressed when designing a new trial.
In this round table session, we would like to discuss statistical challenges and considerations in PrEP trial design including sample size determination, choice between non-inferiority versus superiority, open label versus blinded study, the appropriate method to assess futility, and the framework of the interim analyses. We also would like to discuss innovative study designs for PrEP trials, for example, using of surrogate endpoint(s) for a smaller trial and incorporating Bayesian methods.