IBD: Therapeutic Drug Monitoring Optimizes Outcomes

Optimizing the use of biologics through therapeutic drug concentration monitoring can, in turn, optimize the treatment of inflammatory bowel disease (IBD), said Adam Cheifetz, MD, at the Interdisciplinary Autoimmune Summit (IAS) 2018 this past weekend.

Dr Cheifetz, who is the director of the Center for Inflammatory Bowel Disease at Beth Israel Deaconess Medical Center and associate professor of medicine at Harvard Medical School in Boston, Massachusetts, presented “Optimizing the Treatment of IBD through Use of Therapeutic Drug Monitoring” at IAS 2018.
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In his presentation, Dr Cheifetz discussed the benefits associated with proactive vs reactive therapeutic drug monitoring, as well as the optimal timing for the use of proactive monitoring.

“Currently, the best data for use of proactive therapeutic drug monitoring is during the maintenance phase of treatment with anti-tumor necrosis factor [therapy],” Dr Cheifetz said.

“We recently showed that proactive therapeutic drug monitoring when compared with reactive therapeutic drug monitoring was associated with less treatment failure, fewer IBD-related hospitalizations and surgeries, and fewer antibodies to infliximab and serious infusion reactions,” he continued.

Dr Cheifetz added that it is likely even more important to perform proactive therapeutic drug monitoring during or after induction dosing, which is when a patient’s condition is the most active with the highest inflammatory burden and highest drug clearance. However, he noted, further studies are still needed to determine the optimal timing of therapeutic drug monitoring.

Despite these benefits, potential issues can arise with drug concentration monitoring, such as the timing of testing and accessibility to a test that is accurate and inexpensive, Dr Cheifetz noted.

Furthermore, the optimal trough concentration window for therapeutic drug monitoring remains unclear.

“There are many cohort studies and post-hoc analyses of large trials that show that higher drug concentrations correlate with better outcomes,” Dr Cheifetz explained. “And often the higher the concentration, the more stringent the outcome. For example, an infliximab concentration of 3 may be okay for clinical response, but 10 may be needed for endoscopic healing. Certain phenotypes, like perianal Crohn disease, may also require higher drug concentrations.”

Dr Cheifetz also noted that these association studies, which are population-based, do not account for individual patients who may have their own “therapeutic window.”

—Christina Vogt

Reference:

Cheifetz A. Optimizing the treatment of IBD through use of therapeutic drug monitoring. Presented at IAS 2018; April 27-29, 2018; Boston, MA.