Monitoring Trough Levels of VDZ Helps Accuracy in Patient Dosage

Researchers from the Lynda K. and David M. Underwood Center for Digestive Disorders recently found that monitoring trough levels in patients using the drug Vedolizumab (VDZ) to treat ulcerative colitis and Crohn’s Disease can inform dosage levels for better results. The study was published in the Journal of Digestive Diseases. “Higher levels (of the drug VDZ) were associated with better outcomes,” said Kerri Glassner, DO, Assistant Professor of Clinical Medicine, who conducted the study along with Malcolm Irani, MD, and other Underwood specialists. Irani added, “More and more therapies are coming out for both Crohn’s disease and ulcerative colitis. We have more effective therapies with less side effects and good safety profiles. We’re learning that if you get this disease in remission, people will live long healthy happy lives.” From 2015 to 2020, 89 Houston Methodist patients were studied. Patients’ blood was drawn at trough so that levels were lowest before more VDZ was administered. Blood also was drawn on follow-up visits (after at least eight weeks on VDZ therapy or after change in dose frequency). In some patients, levels were checked again after changes in dosing frequency. Among patients dosing every eight weeks, 81.5 percent had low troughs, and VDZ dosing frequency increased to four weeks. Higher VDZ levels during week-four dosing were associated with higher albumin, lower erythrocyte sedimentation rate and a higher likelihood of having a mild disease or endoscopic remission. Researchers concluded that patients who continue to have low VDZ troughs despite week-four dosing may require a change in therapy.

Glassner said more studies need to be conducted and that individual studies are necessary for ulcerative colitis patients and Crohn’s Disease patients. Both researchers agreed that the study data is not enough to confirm results. While the drug has been in use for 10 years, therapeutic drug level monitoring of Entyvio hasn’t been studied as frequently and the published data has been conflicting. They want to continue to study patients and see if there’s the same role for VDZ as other drugs used. Thanks to the availability of biologic and small molecule therapies, the specialists believe patients need less surgery and have lower rates of colon cancer than in the past. “We always see complicated cases at Methodist,” Irani said. “There quite a few instances when we have to go beyond the ‘standard therapies’ that we have in place. This study helped us qualify requests to accelerate dosing for some of these medications. It is important to have an adequate drug level and have the option of giving more frequent doses to achieve remission.” Glassner noted, “We need to continue to do larger studies to confirm our results. In our IBD Center, we conduct a lot of therapeutic drug monitoring, which means checking the drug levels and adjusting the dose to give our patients the best clinical outcome.”