Part III of the article that describes confirmatory adaptive platform trial (CAPT) design for COVID-19 treatment development. We continue with the section on statistical methods for CAPT design, covering topics on sequential p-value and monitoring, point estimate and confidence interval, multiplicity in hypothesis testing, missing data handling, and use of non-concurrent controls. We finish the article with discussion on controversy of stochastic curtailment, inappropriateness of adaptive Bayesian design, and free software for group sequential designs.