Regulatory harmonization: Evolution, globalization and future directions

Regulatory harmonization has become an increasingly important and accepted approach to streamline regulatory review processes and expedite access to safe, effective and high-quality medicines globally. This review explores the evolution and current status of regulatory harmonization, convergence and reliance initiatives. It traces progress from early European Economic Community efforts to the establishment and expansion of the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH). Global frameworks from the World Health Organization (WHO), the International Coalition of Medicines Regulatory Authorities (ICMRA) and the International Pharmaceutical Regulators Programme (IPRP) have further shaped this landscape. Regional initiatives illustrate diverse strategies for embedding harmonization principles into national systems, including the Association of Southeast Asian Nations (ASEAN) Joint Assessment procedure, the Pan American Network for Drug Regulatory Harmonization (PANDRH), the African Medicines Agency (AMA) and the EU's Joint Clinical Assessment. Collaborative models such as the Access Consortium and Project Orbis demonstrate how reliance and work-sharing can expedite approvals and strengthen regulatory capacity. New approaches, such as leveraging real-world evidence (RWE) and regulating advanced therapies like cell and gene therapies, highlight the need for adaptive, collaborative frameworks. Despite challenges including legal complexity, resource constraints and varying levels of regulatory maturity across jurisdictions, harmonization can enhance regulatory systems and support consistent benefit-risk assessments. Ongoing alignment and convergence remain essential to maintaining agile and responsive regulatory systems amid evolving global health priorities and increasing product complexity.