Infliximab Pricing in International Economic Evaluations in Inflammatory Bowel Disease to Inform Biologic and Biosimilar Access Policies: A Systematic Review

Abstract

Background. Policies mandating the use of lower cost biosimilars in patients with inflammatory bowel disease (IBD) have created concerns for patients who prefer their original biologic. Purpose. To inform the cost-effectiveness of biosimilar infliximab treatment in IBD by systematically reviewing the effect of infliximab price variation on cost-effectiveness for jurisdictional decision making. Data Sources. MEDLINE, Embase, Healthstar, Allied and Complementary Medicine, Joanna Briggs Institute EBP Database, International Pharmaceutical Abstracts, Health and Psychosocial Instruments, Mental Measurements Yearbook citation databases, PEDE, CEA registry, HTA agencies. Study Selection. Economic evaluations of infliximab for adult or pediatric Crohn’s disease and/or ulcerative colitis published from 1998 through 2019 in which drug price was varied in sensitivity analysis were included. Data Extraction. Study characteristics, main findings, and results of drug price sensitivity analyses were extracted. Studies were critically appraised. The cost-effective price of infliximab was determined based on the stated willingness-to-pay (WTP) thresholds for each jurisdiction. Data Synthesis. Infliximab price was examined in sensitivity analysis in 31 studies. Infliximab showed favorable cost-effectiveness at a price ranging from CAD $66 to $1,260 per vial, depending on jurisdiction. A total of 18 analyses (43%) demonstrated cost-effectiveness ratios above the jurisdictional WTP threshold. Limitations. Drug prices were not always reported separately, WTP thresholds varied, and funding sources were not consistently reported. Conclusion. Despite the high cost of infliximab, few economic evaluations examined price variation, limiting the ability to infer the effects of biosimilar introduction. Alternative pricing strategies and access to treatment could be considered to enable IBD patients to maintain access to their current medications. Highlights In an effort to reduce public drug expenditures, Canadian and other jurisdictional drug plans have mandated the use of lower cost, but similarly effective, biosimilars in patients with newly diagnosed inflammatory bowel disease or require a nonmedical switch for established patients. This switch has created concerns for patients and clinicians who want to maintain the ability to make treatment decisions and remain with the original biologic. It is customary for economic evaluations to assess the robustness of results to variations in high-cost items such as medications. In the absence of economic evaluations of biosimilars, examining biologic drug price in sensitivity analysis provides insight into the cost-effectiveness of biosimilar alternatives. A total of 31 economic evaluations of infliximab for the treatment of inflammatory bowel disease varied the infliximab price in sensitivity analysis. The infliximab price deemed to be cost-effective within each study ranged from CAD $66 to CAD $1,260 per 100-mg vial. A total of 18 analyses (43%) demonstrated an incremental cost-effectiveness ratio above the jurisdictional willingness-to-pay threshold. If policy decisions are based on price, then originator manufacturers could consider reducing the price or negotiating alternative pricing models to enable patients with inflammatory bowel disease to remain on their current medications.