Vedolizumab Level and Anti-Vedolizumab Antibodies
Label Mnemonic: VEDO
Epic Lab Code: LAB8523
Downtime Form: A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery
Commercial Mail-out Laboratory
5231 RCP
Specimen Instructions:
Note: Dose and interval are required
Collection Medium:
BD Gold SST 5 mL Vacutainer BD Gold SST 5 mL Vacutainer
Preferred Minimum: 7 mL serum in TWO Gold top SST tubes
Absolute Minimum: 5 mL serum in ONE Gold top SST tube
Rejection Criteria:
Grossly hemolyzed samples. Samples sent in red top tubes.
Turn Around Time:
5-7 days upon receipt at reference laboratory
Reference Range:
Vedolizumab: <40 ug/mL
Anti-Vedolizumab antibody: Not detected

Clinically Reportable Ranges:
Vedolizumab 2-60 ug/mL
Anti-Vedolizumab antibody 35-500 ng/mL
Interpretive Data:
Vedolizumab (VSZ)
-In the induction phase of the VDZ clinical trials (week 6), VDZ levels were higher in responders than non-responders.

-In a study of endoscopic outcomes in patients with ulcerative colitis UC treated with VDZ, at week 6 mucosal healing was more common and endoscopic scores were lower in patients with higher VDZ trough concentrations.

-Patients with sustained remission at induction week 6 had higher VDZ trough levels (41.7 ug/mL vs 21 ug/mL p = 0.07).

-A cutoff for VDZ at week 6 was predictive of sustained remission without need for optimization.

-Data on dose adjustment of VDZ are limited. However, in one study of patients with Irritable bowel disease (IBD) who had lost response to VDZ every 8 weeks, clinical remission and clinical response rates increased after VDZ dosing frequency was increased to every 4 weeks.

-Data on maintenance levels of VDZ are limited. However, in three studies in which patients were treated for approximately one year, higher drug levels were associated with higher rates of response.

Antibodies to Vedolizumab
Some patients on biologic therapy may develop antibodies that resolve over time. In clinical trials, approximately 4% of patients treated with VDZ had samples that were positive for ATV at any time and 1 % or less had samples that were persistently positive.

In patients with UC that lose response to VDZ but are receiving 300 mg every 4 weeks, clinical guidelines suggest a switch to another drug class.
Automated ELISA assay for simultaneous analysis of both drug and anti- drug antibody.
CPT Code:
83520 x2