Infliximab Monitoring Lowers Rate of IBD Surgeries in Real-World Study

Inflammatory bowel disease (IBD), which includes ulcerative colitis and Crohn’s disease, is characterized by chronic inflammation and flare-ups, which significantly contribute to permanent intestinal damage. Biologics, such as tumor necrosis factor (TNF) blockers, are now the standard of care for achieving remission and reducing the need for gastrointestinal surgery in patients with moderate to severe Crohn’s disease or ulcerative colitis.

Infliximab is a TNF blocker FDA-approved to induce and maintain remission in patients with moderate to severe ulcerative colitis or Crohn’s disease. It is marketed under the brand name Remicade and there are three biosimilars to Remicade on the market: Renflexis (infliximab-abda), Avsola (infliximab-axxq) and inflectra (infliximab-dyyb).

In a study presented at the Academy of Managed Care Pharmacy annual meeting in New Orleans last month, researchers from Prometheus Laboratories and Lynx.MD investigated the real-world impact of therapeutic drug monitoring of infliximab on IBD-related surgery rates and related expenses.

The study’s poster abstract was published in an April 2024 supplement issue of the Journal of Managed Care and Specialty Pharmacy.

Lead author Andrew Shim, Pharm.D., J.D., M.A.M., and his colleagues define therapeutic drug monitoring as the “measurement of drug and antibody levels” and suggest that it “may assist [infliximab] dose optimization to avoid loss of response”. They note that although experts and clinical guidelines recommend therapeutic drug monitoring, some payers consider the practice investigational and restrict its use.

Shim, who was at Promethus Laboratories when he conducted this research, and his colleagues used deidentified data from the charts of a community gastrointestinal clinic in the U.S. to compare IBD surgery rates and related expenditures of patients with optimized infliximab dosing via therapeutic drug monitoring to those without therapeutic drug monitoring.

The researchers analyzed data from patients with IBD ages 8 through 89 years treated with infliximab between 2016 and 2022. A control cohort group with no therapeutic drug monitoring was matched with the monitored group. The investigators viewed real-world outcomes at 12 and 24 months for the rate of IBD-related surgeries, mean IBD surgery expenditures, and mean biologic expenditures.

At 12 months, the rate of IBD-related surgeries for the monitored group was 1% versus 7% for the control group. Surgery-related expenditures were about $161,000 for the monitored group and $939,000 for the control group. Biologic expenditures were about $35,000 and $33,000 for the monitored and non-monitored cohorts, respectively.

At 24 months, the surgery rate for the monitored group was 4% versus 10% for the control group. Surgery-related expenditures were also significantly lower in the monitored group versus the control group ($583,000 versus $1,575,000). Biologic-related expenditures were about $71,000 for the monitored group and $77,000 for the control group.

Shim and his colleagues concluded that therapeutic drug monitoring of infliximab significantly reduced the rate ofIBD-related surgeries and related expenditures in a real-world setting, underscoring the value of therapeutic drug monitoring in IBD management.