What is the optimal approach to using therapeutic drug monitoring (TDM) for biologics?
This expert consensus recommends reactive TDM for all classes of biologic therapy in patients with inflammatory bowel disease, but controlled prospective data are still needed to prove that such strategies improve patient outcomes.
Papamichael K, Cheifetz AS, Melmed GY, et al. Appropriate Therapeutic Drug Monitoring of Biologic Agents for Patients with Inflammatory Bowel Diseases. Clin Gastroenterol Hepatol, Epub ahead of print March 27, 2019; https://doi.org/10.1016/j.cgh.2019.03.037
Therapeutic drug monitoring is used to guide dosing of biologics to individualize drug exposure and optimize outcomes. In this study, a panel of 13 international IBD experts conducted a comprehensive literature review and developed 24 consensus statements regarding when and how to use TDM during induction, post-induction and maintenance therapy with biologics.
For all anti-tumor necrosis factor (anti-TNF) treatments there was strong consensus that testing serum drug levels proactively at the end of the induction (including for primary non-response), and at least once during maintenance therapy is appropriate. Reactive testing in patients who lose response to anti-TNF treatment was also advised.
The experts also concluded it is appropriate to conduct reactive TDM for recipients of vedolizumab and ustekinumab who do not respond or who lose response to therapy but did not recommend proactive testing for these drugs in light of insufficient data regarding their optimal serum drug concentrations.
Other consensus statements detailed minimum post-induction drug concentrations for infliximab (3 μg/mL at week 14), adalimumab (5 μg /mL at week 4), certolizumab-pegol (32 μg/mL at week 6) and golimumab (2.5 μg/mL at week 6). The panel also identified minimum trough concentration recommendations for the same agents during their maintenance phase of treatment as 3 μg/ml, 5 μg/ml, 15 μg/ml and 1 μg/ml, respectively.
The authors called for more data, especially on non-anti-TNF biologics, to further define optimal drug concentration for specific therapeutic outcomes.
Study Design: Literature review
Funding: Unrestricted educational grants from Takeda, Pfizer and Abbvie
Allocation: Not applicable
Setting: International, multicenter
Level of Evidence: 4 (Oxford Levels of Evidence)
The summary and conclusion in this issue of E-mentoring in IBD pertains to the manuscript(s) being reviewed, and should be considered in the context of what is already known surrounding the topic and incorporated into practice as deemed appropriate by the individual learner.