The guideline titled "Guideline on Clinical Trials in Small Populations" (CHMP/EWP/83561/2005) was issued by the European Medicines Agency (EMA). This guideline provides recommendations and guidance for conducting clinical trials for medicines intended for rare diseases or conditions affecting small populations. Here's an elaboration of the key points covered in this guideline: 1. Background: The guideline recognizes that traditional clinical trial designs may not be suitable for rare diseases or conditions, where patient populations are limited. Therefore, it aims to provide a framework for conducting meaningful and scientifically sound clinical trials in such scenarios. 2. Definition of a Small Population: The guideline doesn't provide a specific numerical definition of a small population but rather focuses on diseases or conditions that are rare or have a low prevalence. It acknowledges that the definition may vary by region and disease. 3. Ethical Considerations:...