Characterizing Real-world Safety and Tolerability of Infliximab and Infliximab-dyyb

From the 2022 HVPA National Conference

Calvin Hwang PharmD (UCSF Medical Center), Salem Kamalay PharmD, Candy Tsourounis PharmD

Background

Infliximab (Remicade®) is a monoclonal antibody that neutralizes the activity of TNFα and is used in a variety of disease states, including inflammatory bowel disease and several rheumatologic conditions. While new biologics continue to be marketed over time, the significant price tag associated with this therapeutic category is a difficult factor to ignore. Biosimilars were developed as a more affordable alternative to originator biologics. Although studies exist supporting a similar safety profile between the biologic and biosimilar, the studies were limited in scope and did not include a diverse patient population.

Objective

The purpose of this study was to evaluate the real-world safety and tolerability of infliximab and infliximab-dyyb among patients at a single academic medical center

Methods

This was a retrospective, cohort study comparing patients who received infliximab-dyyb to those receiving infliximab at affiliated infusion centers across the San Francisco Bay Area from April 1, 2018 to July 31, 2021. The primary endpoint was the incidence of infusion-related reactions (IRRs), which were classified as mild, moderate, or severe. Secondary endpoints included the occurrence and time to study drug discontinuation. This study included patients at least 6 years of age or older who were naïve to infliximab therapy at the time of initiation. Pregnant or breastfeeding women, prisoners, and patients who did not complete all infliximab infusions at affiliated infusion centers were excluded from this study. Fisher’s exact test and the χ² test were used to compare nominal data while the student’s t-test and Wilcoxon rank-sum test were used to analyze parametric and non-parametric continuous data, respectively.

Results

There was no statistically significant difference in incidence of at least one of infusion-related reaction among patients who received infliximab-dyyb compared to infliximab originator (6% vs. 12%, P = 0.15). Rates of infusion-related reactions cumulatively were also similar between the two groups (2.2% vs. 1.7%, P = 0.63). Patients in the originator group were found to be more likely to discontinue treatment (5% vs. 0%, P = 0.05). A cost comparison will be included comparing the drug purchasing costs between the reference product and the biosimilar.

Conclusion

Infliximab-dyyb was not associated with an increased rate of infusion-related reactions compared to originator infliximab.

Clinical Implications

Infliximab-dyyb is a safe and potentially more cost-effective alternative to infliximab, aligning with the results of the larger clinical trials.

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