This blog provides an overview of efficacy endpoints in oncology studies. We will focus on RECIST (Response Evaluation Criteria In Solid Tumours).This is a method of assessing how solid tumours change over the course of a study. We will cover the measurements taken for RECIST assessments (Target lesions, Non target lesions, New lesions) and the possible outcomes, (complete response, partial response, stable disease, progressive disease) and what they mean – for example; patient recovered, stayed the same or got worse. We will also cover how visit windows and censoring can be handled. How and why measurement methods are important. We will cover other endpoints relevant to oncology such as Overall survival, Objective Response Rate, Best overall response, Disease control at X weeks and quality of life.