Real-World Evidence Enters the Discussion for Biosimilar Switching

Biosimilars, molecules highly similar to their reference biologics, provide 2 key benefits: affordability and accessibility. Pressure on drug markets across the globe is rising as the established cost savings of biosimilars remains an opportunity with unmet potential. Despite clear, defined criteria that ensure biosimilars have comparable safety and efficacy as the reference biologic, skepticism persists among prescribers.

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To combat soaring pharmaceutical costs, Health Canada is completing a nationwide mandatory biosimilar switch policy. Most provinces have adopted the policy, deeming this a critical time for prescriber biosimilar literacy and patient advocacy.

The Journal of the Canadian Association of Gastroenterology recently published a systematic review that collated real-world safety and efficacy evidence for infliximab (IFX) and adalimumab (ADA) biosimilars. The primary outcome of interest was clinal effectiveness in patients with inflammatory bowel disease (IBD) within the first year of therapy and during long-term maintenance therapy. Secondary outcomes included loss of response, treatment cessation, or persistence and immunogenicity.

Results were mostly comparable between patients who switched from originator drug to biosimilars and patients who continued treatment with the originator. IFX’s clinical effectiveness, characterized as clinical remission at 12 months, was 78% for patients maintaining originator therapy and 75% for patients who switched to the biosimilar.

Previously, the Canadian Association of Gastroenterology and Crohn’s and Colitis Canada suggested IFX biosimilars should be recommended only in treatment-naïve patients. This was a weak recommendation based on low quality of evidence, but it’s not surprising that clinicians and patients report the most anxiety when switching from originator to biosimilar (compared to biosimilar induction in treatment-naïve patients). Some real-world evidence did show significant differences in frequency of injection site pain/reactions in patients receiving biosimilars with certain excipients.

The 2023 real-world evidence review opposes the original recommendation and demonstrates similar clinical effectiveness and safety in patients with IBD who switch from originator to biosimilar. Dedicated clinical trials in IBD cohorts that scrutinized biosimilar use in real-world clinical practice have direct implications on decision making. The original evidence, primarily based on data extrapolated from rheumatological cohorts, may not be as relevant. Also of note, the European Crohn’s and Colitis Organisation deems biosimilar switch acceptable.

However, the systematic review evidence is vulnerable to biases inherent to observational studies and poses additional considerations. Several included studies did not objectively report remission rates at baseline and when assessed, patients with active disease at baseline were more likely to lose response at follow up. All patients with IBD were grouped together, so distinguished outcomes by IBD type (ulcerative colitis or Crohn disease) and outcomes in patients with higher risk phenotypes were unavailable. Additionally, data for ADA were sparse, with significantly fewer patients and biosimilars investigated and a shorter duration of follow up.

Although real-world evidence and Canadian policies support biosimilar switching, it may not be right for every patient. Health care providers should leverage joint clinical decision making and consider individual patient needs. A comprehensive approach to biosimilar switching that includes appropriate counseling, disease activity monitoring, and careful follow up will help achieve financial benefits of a mandated switch policy and optimal patient care.

Reference

Meade S, Squirell E, Hoang TT, Chow J, Rosenfeld G. An Update on Anti-TNF Biosimilar Switching-Real-World Clinical Effectiveness and Safety. J Can Assoc Gastroenterol. 2023;7(1):30-45. Published 2023 Oct 25. doi:10.1093/jcag/gwad027