Study: Biosimilar Infliximab Most Cost-Effective Biologic for Fistulizing CD

Randomized controlled trials have established the clinical efficacy and safety of infliximab in treating fistulizing Crohn disease (CD), and while evidence for adalimumab and vedolizumab in this indication is weaker, these drugs are also used in clinical practice, sometimes in treatment sequences of biologics, to treat fistulizing CD. In Europe, where access to biologic drugs is largely driven by budgetary considerations, biosimilars have the potential to improve access to treatment.

Authors of a study published in the United European Gastroenterology Journal developed a Markov model to compare the treatment sequences of 1, 2, and 3 biologic drugs, from the payer’s perspective, on a 5-year time horizon, with data on effectiveness and health state utilities obtained from the published literature. Country-specific costs (in Belgium, France, Germany, Hungary, Italy, the Netherlands, Spain, Sweden, and the United Kingdom), and both official list prices and estimated real prices for the drugs, were taken into consideration.

When considering the use of single biologics at list price versus standard (non-biologic) treatment:

• Reference infliximab and biosimilar infliximab, compared with standard care, produced quality adjusted life year (QALY) gains that varied between 0.244 to 0.252 across all 9 countries
• Lower QALY gains were observed for adalimumab (0.113-0.136) and vedolizumab (0.162-0.168) across all 9 countries
• In the 6 countries where biosimilar infliximab had a lower list price than did reference infliximab, additional costs compared with standard care were lowest for biosimilar infliximab (€8450-€17,854, or approximately $10,450-$22,080), and typically highest for vedolizumab (€14,117-€23295, or approximately $17,477-$28,839)
• At list price, incremental cost effectiveness ratios (ICERs) per QALY were between €38,420 and €95,540 (approximately $47,563-$118,277) for both infliximab products, €60,646 to €132,071 (approximately $60,6469-$163,501) for adalimumab, and €83,806 to €142,118 (approximately $83,806-$175,939) for vedolizumab

In treatment sequences involving 2 to 3 biologics, based on list price, adding a second biologic to the treatment sequence after biosimilar infliximab provided additional QALY gains (0.103—0.133) compared to the biosimilar infliximab alone, but at larger additional costs (€6129–€18,700, or approximately $7588-$23,150), with adalimumab being more cost-effective than vedolizumab as a second agent. Adding a third agent (vedolizumab) to biosimilar infliximab and adalimumab provided additional QALY gains (0.113-0.120) at larger additional costs (€10,444-€17,587, or approximately $12,929-$21,772) in most countries.

When considering a real price at a 30% discount to the list price of infliximab and biosimilar infliximab—and a 20% decrease for adalimumab—in each country, the researchers observed a 19% to 30% decrease in the ICERs for biosimilar infliximab (€24,364-€56,086, or approximately $30,162-$69,433) per QALY compared with standard care. The ICER of the biosimilar infliximab—adalimumab treatment sequence decreased by 20% to 22% (€45,513-€105,875, or approximately $56,344-$131,070) per QALY.

The authors conclude that the first choice of biologic treatment for fistulizing CD should be biosimilar infliximab. In the case of treatment failure, a switch to adalimumab or vedolizumab would provide meaningful health benefits, but at increased costs.

Reference

Baji P, Gulácsi L, Brodszky V, et al. Cost-effectiveness of biological treatment sequences for fistulising Crohn’s disease across Europe. United European Gastroenterol J. 2018;6(2):310-321. doi: 10.1177/2050640617708952.