Category: Federal Forum Posters
Purpose: Inflectra (infliximab-dyyb), an anti-tumor necrosis factor-alpha (anti-TNF-alpha), is a recently approved biosimilar to the biologic agent Remicade (infliximab). Both agents received FDA indication for moderate to severe irritable bowel disease (IBD). Of note, biosimilars are not considered interchangeable with biologics. To our knowledge, in the United States, there currently is no publication evaluating the interchangeability between infliximab biologic (Remicade) to infliximab-dyyb biosimilar (Inflectra). The primary objective of this study is to investigate the safety and efficacy of switching from Remicade to Inflectra. We also aim to calculate the potential cost savings when switching from biologics to its comparable biosimilar.
Methods: This is an institutional review board approved, retrospective chart review study. Patients with IBD cared for by the Veterans Affairs Long Beach Healthcare System gastroenterology clinic were converted from Remicade to Inflectra. Patients who did not receive continuous care by the aforementioned clinic, were newly initiated on Inflectra, or did not receive Remicade for at least 90 days prior to the conversion were excluded. Endpoints were evaluated at 6 months or longer after conversion. Safety endpoints were infusion reactions, steroid utilization, and hospital admissions related to IBD. Efficacy and clinically relevant endpoints were clinical remission (determined by GI attending), endoscopic remission (defined as Simple Endoscopic Score-Crohn’s Disease score 0 to 2; Mayo endoscopic score 0, 1), and biochemical remission (defined as stable or improving C-Reactive Protein results). As conversion dose was set at milligram to milligram, we also examined the need for dose escalation at 6-month evaluation. A subgroup analysis was conducted to examine safety and efficacy outcome differences between patients who were on concomitant immunosuppressive therapy versus those who were not. Finally, we calculated the cost-minimization associated with the conversion by estimating the yearly projected drug costs using the drug prices set for the Veterans Health Administration by its prime vendor. Descriptive analysis was conducted, t-test was performed for sub-analysis.
Results: Among the 61 patients identified with IBD, on long-term infliximab infusion, and followed by GI clinic, 17 met criteria and were included in analysis. Baseline characteristics revealed the average age was 47.6 years (standard deviation 14.3); 82.4 percent (14 patients) had Remicade as their first anti-TNF alpha therapy; 47.1 percent (8 patients) were on concomitant immunosuppressive therapy - either 6-mercaptopurine or methotrexate. At 6 months after conversion, 13 patients (76.5 percent) were in clinical remission; 15 patients (88.2 percent) achieved biochemical remission; and 12 patients (70.6 percent) were in endoscopic remission. Our data also showed 4 patients experienced infusion reactions; no patients required a new course of steroid therapy or increase in existing steroid doses; and there was no hospitalization. The sub-group analysis found only those who were not on concomitant therapy experienced infusion reactions (4 out of 9 patients without concomitant therapy). Overall, the yearly calculated cost savings was $68,629 for the study cohort.
Conclusion: We used multiple parameters to evaluate the safety and efficacy of Inflectra use in patients who switched from Remicade therapy for chronic IBD. Our findings suggest this conversion is safe and effective. Over 70 percent of patients achieved multiple desired outcomes. Infusion reactions only occurred in those who were not on concomitant immunosuppressive therapy. Furthermore, no converted patient experienced an increase in steroid utilization or hospitalization. Finally, the conversion yielded nearly $70,000 in yearly cost savings. Future studies with longer follow-up intervals and larger cohorts is warranted to further support the use of biosimilar therapies.
Ivy Tonnu-Mihara– Director, Program Development Analytics and Research, VA Long Beach Healthcare System, Long Beach, CA