Advances in IBD

Advances in IBD

December 17, 2019
2 min read

‘Outcomes will be better’: Therapeutic drug monitoring in IBD

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

We were unable to process your request. Please try again later. If you continue to have this issue please contact

Raymond Cross
Raymond Cross

ORLANDO — Whether reactive or proactive, therapeutic drug monitoring has become an important part of inflammatory bowel disease care, according to experts.

Raymond K. Cross Jr., MD, director of the IBD program at the University of Maryland School of Medicine, told Healio Gastroenterology and Liver Disease that therapies in IBD can be fickle, and for many patients who initially respond, that effect will be fleeting.

“Despite having more therapies ever to treat Crohn’s disease and ulcerative colitis, at least 30% to 40% of people are not going to respond to treatment, and with anti-TNF biologics, about 40% of patients are going to lose response over time,” Cross said. “We can’t just go from one therapy to another to another, or we will burn therapies out quite quickly and not have any therapeutic options left. So, we try to optimize our therapies as much as we can, before we change to something else.”

While using some form of TDM is critical to sustained treatment for patients, Cross said there is still plenty of debate on which method is best. In reactive TDM, clinicians wait until a patient begins experiencing symptoms or signs again before adjusting dosing. With the proactive technique, clinicians take measurements at set intervals to ensure the chosen drug is at the appropriate levels to sustain response.

Cross said that although he is solidly on the proactive TDM side, there is a place for both.

“Some people argue that drug levels are simply a marker of someone doing well,” Cross said. “Whereas the people in the proactive camp feel that there is a threshold that we need to get to for patients to get well. It’s probably a little of both. I think there are a significant number of patients if you just optimize their drug, they will do quite well.”

While dose escalation has a lower barrier, implementing proactive TDM can be more difficult. Obtaining the drug levels can be expensive, and there is even some controversy about which companies to use, Cross said. However, new research is showing that proactive monitoring could, in fact, reduce costs.

In a study submitted to Digestive Disease Week, Cross said they found that when looking at milligrams per kilogram per month for Remicade (infliximab, Janssen) and milligrams every week for Humira (adalimumab, AbbVie), patients in a proactive group used lower doses than patients in both dose escalation and reactive monitoring groups.

“We also looked at health care utilization, and almost every outcome we looked at, it was lower in the proactive arm,” Cross said. “If you have that data to show a payer, it potentially could be convincing that that's a good strategy.”

No matter the strategy, Cross said any kind of TDM has the potential to help struggling patients.

“If I convert some people to proactive, I think outcomes will be better,” Cross said. “At the very least, if I can at least get the attendees doing reactive and giving them some idea of what an optimal level is, that would be a win. Then, I think I have met my objective.” – by Alex Young


Cross R. How I do it in My Practice: Therapeutic Drug Monitoring. Presented at: Advances in Inflammatory Bowel Disease; Dec. 12-14, 2019; Orlando.

Disclosures: Cross reports consulting for AbbVie, Janssen, Pfizer, Samsung Bioepsis, Takeda and UCB.