Clinical Trials

❘❙❚■ Chapter 31 | Interim Monitoring and Stopping RulesWhat is interim monitoring?The interim monitoring of clinical trials has become increasingly importantand common for a variety of reasons. The reasons for monitoring might beethical, scientific, economic, or a combination of these.Interim monitoring is the process of collecting and reviewing trial informationover the course of a clinical trial. This information includes patient safety data,treatment efficacy data, logistics (such as patient accrual rates), and qualityassuranceinformation (such as the number of data-entry errors).What are the main reasons for interim monitoring?Potentially, the two main products of interim monitoring in clinical trials area decision to stop the trial early or a decision to change the study protocol.The primary ethical reason for interim monitoring is to ensure patient safety.Monitoring can help to:• ensure that adverse event frequency and toxicity levels are acceptable• ensure that patients are not recruited into a trial that is going to beunable to reach a definitive result• ensure that randomization of patients is stopped as soon as thereis sufficiently clear evidence either for or against the treatmentbeing evaluated• address unexpected problems with the study protocol such as exclusioncriteria delaying recruitmentThe scientific reasons for interim monitoring are to improve the integrity of thetrial and, in situations where intervention has a stronger effect than expected(either positively or negatively), reach conclusions early in the study.Interim monitoring is also beneficial economically because it can help trials to bemore efficient and prevent the use of resources on trials that either already havereached, or are unlikely to reach, an answer.Which trials should have interim monitoring?In the US, according to federal regulations (21 CFR 312.32 (c) [1]), all clinicaltrials need to be monitored for safety. However, there is no fixed rule fordetermining which trials should be monitored for efficacy endpoints or quality-354