Donnell D, Gao F, Hughes JP, Hanscom B, Corey L, Cohen MS, Edupuganti S, Mgodi N, Rees H, Baeten JM, Gray G, Bekker LG, Hosseinipour M, Delany-Moretlwe S. Counterfactual estimation of efficacy against placebo for novel PrEP agents using external trial data: example of injectable cabotegravir and oral PrEP in women.. J Int AIDS Soc. 2023, 26 PMC10292682
Multiple antiretroviral agents have demonstrated efficacy for human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP). As a result, clinical trials of novel agents have transitioned from placebo- to active-controlled designs; however, active-controlled trials do not provide an estimate of efficacy versus no use of PrEP. Counterfactual placebo comparisons using other data sources could be employed to provide this information.