A comprehensive review of phase IV trials and post-marketing surveillance

Phase IV clinical trials, also known as post-marketing surveillance (PMS), represent a crucial stage in the drug development continuum where the safety and real-world effectiveness of approved therapies are evaluated. These trials bridge the gap between controlled clinical environments and heterogeneous, real-world patient populations. Phase IV efforts focus on identifying rare and long-term adverse events, studying safety and efficacy in diverse demographics, and generating real-world evidence (RWE) that informs clinical decision-making, regulatory actions, and healthcare policies. Recent advancements in artificial intelligence (AI), big data analytics, and wearable technologies are transforming surveillance methodologies, enabling near real-time safety monitoring and rapid signal detection. This review explores the methodologies, regulatory frameworks, case studies, clinical implications, and future directions of Phase IV and post-marketing surveillance to provide a robust understanding of their indispensable role in modern healthcare.