Perceptions Still Play a Central Role in Biosimilar Insulin Switching

For people who rely on insulin every day, even small changes can carry outsized weight, a reality that has complicated efforts to expand use of lower-cost biosimilar insulins across health systems.¹ More than a decade after biosimilar insulins entered the market, uptake has grown slowly, shaped not only by regulatory frameworks and pricing policies but also by the perceptions and experiences of those most directly affected by switching.²

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A recent scoping review, published in Endocrinology, Diabetes, & Metabolism, sought to clarify how health care professionals, people treated with insulin, and health service administrators have viewed and experienced switches from reference insulin products to biosimilars, highlighting persistent gaps in evidence relevant to managed care decision-making.³

Biosimilar insulins have been available since 2014 and are approved on the basis of rigorous comparability exercises demonstrating similar quality, efficacy, and safety to reference products. Regulators in Europe, the UK, and the US have stated that biosimilars should be treated as interchangeable with their reference products, yet policies governing substitution and switching vary widely across jurisdictions.^4-6 Despite the potential for meaningful savings in publicly funded and private health care systems, concerns about safety, efficacy, delivery devices, and patient acceptance have continued to limit broader adoption.³ The authors undertook this scoping review to map existing literature on stakeholder perceptions and experiences of biosimilar insulin switching and to identify where evidence remains sparse.

Using a systematic search of PubMed, Web of Science, and CINAHL Ultimate, supplemented by grey literature searches and reference scanning, the authors identified 184 records, with 20 meeting inclusion criteria. Eligible sources included quantitative and qualitative research studies, reviews, guidance documents, and opinion pieces published in English since 2014. Stakeholders of interest were health care professionals (HCPs), health service administrators (HSAs), and people of any age treated with insulin. Findings were synthesized narratively using thematic analysis rather than pooled quantitative outcomes, reflecting the heterogeneity of the literature.

Across multiple studies, awareness of biosimilar principles among HCPs was generally high, particularly among pharmacists. However, practical experience with switching was limited; in one survey, 67% of HCPs reported no direct experience switching people to biosimilar insulins. Levels of concern varied by profession. Diabetologists and nurses expressed higher levels of concern than pharmacists, particularly regarding efficacy and safety when switching established patients. In some studies, up to 32% of physicians and more than half of nurses reported major concerns about efficacy when switching.

Insulin-specific issues distinguished biosimilars from other therapeutic classes. Differences in pen devices, availability of connected or half-unit pens, and varying injection forces were frequently cited as barriers. HCPs also raised concerns about workload associated with education and monitoring after a switch, as well as skepticism toward pharmacy-level substitution without prescriber involvement. Although most HCPs acknowledged regulatory assurances of comparability, questions about long-term safety data and multiple switches between biosimilars persisted.

Evidence on patient perspectives was notably limited, with only 3 primary research studies identified from the US, Canada, and Japan. In a US survey examining a hypothetical future switch, most respondents expressed neutral or positive views toward biosimilar insulin, with only a small minority stating they would definitely refuse a switch. People with type 1 diabetes were slightly more hesitant than those with type 2 diabetes. Concerns centered on perceived brand quality, satisfaction with current therapy, and fears of reduced efficacy or safety.

Real-world experience data were sparse but informative. A Japanese study of people with type 2 diabetes who switched from reference to biosimilar insulin glargine reported no meaningful changes in treatment satisfaction, glycemic control, or adverse events. Similarly, a Canadian analysis of a mandatory switching policy found that only 2.8% of people switched back to the reference product, suggesting general tolerability of the transition.

Guidance directed at HSAs emphasized the need for structured switching programs, including clear criteria, education plans, and processes for informed consent. Administrators expressed concerns about legal responsibility, potential nocebo effects, and the logistical challenges of selecting among multiple biosimilars. Importantly, one Canadian study found no increase in health care resource utilization following mandatory switching, addressing a common concern that switches might drive additional clinical visits or monitoring costs.

Cost considerations were central across stakeholder groups, particularly in publicly funded systems such as the UK, where modest price differences sometimes limited enthusiasm for switching. In contrast, in settings where people bore more out-of-pocket costs, lower prices were a stronger driver of acceptance, though some individuals associated lower cost with lower quality. Factors expected to facilitate switching included robust real-world evidence, consistent education for HCPs and patients, endorsement from professional bodies, and shared decision-making approaches that allowed for switching back if needed.

The analysis did not assess study quality or quantify effect sizes, and the included literature was heterogeneous in design and geography. The authors noted a striking lack of data on stakeholders who had direct experience with biosimilar insulin switching, particularly outside a few high-income countries. As they concluded, “almost no literature related to the experience of stakeholders who have already engaged in biosimilar insulin switching was identified,” underscoring the need for pragmatic, real-world research to inform managed care policies.

For payers and health systems considering broader biosimilar insulin adoption, the findings suggest that clinical equivalence alone is insufficient. Addressing education gaps, device-related concerns, and the lived experiences of people treated with insulin will be critical to translating theoretical savings into sustainable practice.

References

1. Switching or deprescribing insulins: when & how. Enclara Pharmacia. June 23, 2022. Accessed January 19, 2026. https://enclarapharmacia.com/palliative-pearls/switching-or-deprescribing-insulins-when-how

2. Jeremias S. From Amjevita to Zarxio: a decade of US biosimilar approvals. The Center for Biosimilars^®️. March 6, 2025. Accessed January 19, 2026. https://www.centerforbiosimilars.com/view/from-amjevita-to-zarxio-a-decade-of-us-biosimilar-approvals

3. Hindley B, Wright S, Ooi C, Da Costa R, Cope L. Exploring stakeholder perceptions and experience of biosimilar insulin switching: a scoping review. Endocrinol Diabetes Metab. 2026;9(1):e70142. doi:10.1002/edm2.70142

4. Biosimilar medicines can be interchanged. EMA. September 19, 2022. Accessed January 19, 2026. https://www.ema.europa.eu/en/news/biosimilar-medicines-can-be-interchanged

5. Guidance on the licensing of biosimilar products. UK MHRA. Accessed January 19, 2026. https://www.gov.uk/government/publications/guidance-on-the-licensing-of-biosimilar-products/guidance-on-the-licensing-of-biosimilar-products

6. Jeremias S. A closer look at new FDA guidance removing barriers to biosimilar development. The Center for Biosimilars. October 30, 2025. Accessed January 19, 2026. https://www.centerforbiosimilars.com/view/a-closer-look-at-new-fda-guidance-removing-barriers-to-biosimilar-development