Background: Biological medicines have transformed the management of several serious and chronic diseases, but their complex manufacturing processes and high development costs may create substantial barriers to treatment. Biosimilars offer an opportunity to increase therapeutic options and improve the affordability of biological therapies. Their adoption, however, raises ethical questions concerning patient safety, clinical evidence, informed consent, substitution, equitable access, commercial influence, and regulatory accountability.

Objective: This review critically examines the ethical governance of biosimilars in India and the United States, focusing on patient safety, accessibility, regulatory responsibility, interchangeability, pharmacovigilance, and the professional obligations of pharmacists and other healthcare stakeholders.

Methods: A comparative narrative review framework was adopted. Regulatory and scientific materials from the World Health Organization, the Central Drugs Standard Control Organization and Department of Biotechnology of India, and the United States Food and Drug Administration were considered alongside established literature on biosimilar development, immunogenicity, interchangeability, healthcare justice, and pharmaceutical ethics. The analysis uses the principles of beneficence, non-maleficence, autonomy, justice, transparency, and accountability to evaluate the ethical implications of biosimilar governance. This is a critical narrative review rather than a systematic review or meta-analysis.

Results and discussion: Biosimilar approval is based on a comprehensive comparability exercise demonstrating high similarity to an authorized reference biological product and the absence of clinically meaningful differences in relevant characteristics. Scientific similarity does not, by itself, resolve all ethical questions surrounding treatment switching, patient communication, medicine traceability, or equitable access. India and the United States have established regulatory pathways for biosimilars, but differences in regulatory terminology, substitution arrangements, healthcare financing, market structure, and institutional capacity create distinct ethical challenges. In the United States, the legal distinction between a biosimilar and an interchangeable biosimilar has important implications for pharmacy-level substitution. In India, the regulatory framework for similar biologics provides a pathway for authorization, while implementation of substitution, prescribing, pharmacovigilance, and patient communication requires careful consideration of clinical context and applicable rules. In both settings, affordability should not be pursued at the expense of safety, treatment continuity, or patient autonomy.

Conclusion: Ethical biosimilar governance requires an integrated approach combining scientific rigor, transparent regulation, responsible manufacturing, robust pharmacovigilance, informed clinical decision-making, and equitable access. Strengthening pharmacist participation, product traceability, patient education, conflict-of-interest safeguards, and public reporting of safety information may improve trust and responsible biosimilar adoption in India and the United States. Regulatory and health-policy reforms should remain sensitive to the different healthcare environments of the two countries...