Dear Editor – We read with interest the recent article by Proschan and Evans [1] on the use of response-adaptive randomization (RAR) and its potential problems; however, these problems are neither new nor applicable in general to all RAR procedures. As discussed by Robertson et al. [2], there is a lingering debate around the value of RAR in clinical trials. While many of the points raised in [1] are valid for some RAR procedures, their broad brush diminishes their arguments. This caveat is important to prevent depreciating other existing procedures that do not have these problems.