Bayesian Adaptive Clinical Trials for Anti-Infective Therapeutics during Epidemic Outbreaks

Qingyang Xu; Shomesh Chaudhuri; Danying Xiao; Andrew W Lo

We simulate an epidemic outbreak over a time period of weeks, where is the duration of the outbreak. For an epidemic with higher infectivity, its duration is shorter, which puts more pressure to reach a timely approval decision. To avoid numerical instability, we formally define as the first time when the number of cumulative infected patients reaches 99.9% of total infections predicted by the SEIR model. We assume an age-specific mortality rate at the level of COVID-19 (Onder et al. 2020; World Health Organization, 2020) , and incubation and recovery periods of 7 days each (Yang et al. 2020). These estimated parameters can all be challenged to varying degrees, depending on the specific drugindication pair under consideration and the particular circumstances of the epidemic, but they are meant to be representative for a typical anti-infective therapeutic during the midst of a growing epidemic.