BIOSIMILARS AND INTERCHANGEABLE BIOLOGICS: GLOBAL REGULATORY HARMONIZATION AND CLINICAL UPTAKE FROM 2022 ONWARD

Biosimilars are biological products that are highly similar to an approved reference biologic, with no clinically meaningful differences in safety, purity, or potency. They offer the potential to reduce healthcare costs and expand patient access to biologic therapies. Regulatory frameworks for biosimilars have evolved significantly, with the European Medicines Agency and US Food and Drug Administration leading the way. A key development is the designation of interchangeability, which in the US allows a biosimilar to be substituted for the reference product without prescriber intervention, subject to state laws. Since 2022, multiple interchangeable biosimilars have been approved, including for adalimumab and insulin glargine. This review critically examines global regulatory harmonization efforts, clinical uptake, and real-world evidence for biosimilars from 2022 onward. Differences remain between regulatory requirements for interchangeability and substitution, and clinical acceptance varies by region and therapeutic area. Real-world studies have generally shown comparable effectiveness and safety for biosimilars, but concerns persist regarding immunogenicity, extrapolation, and nocebo effects. Future directions include harmonized interchangeability standards, increased physician and patient education, and expansion into emerging markets. Overall, biosimilars are a critical component of sustainable healthcare, but their full potential requires continued regulatory alignment and robust post-marketing surveillance.