26567 Vedolizumab Quantitation with Antibodies, Serum (VEDOZ)

VEDOZ; VEMAB; Vedolizumab; VEDO; Entyvio​

​Assessing for primary or secondary loss of response to therapy with vedolizumab

An aid to achieving desired serum concentration of vedolizumab

​Patient Preparation:
1. For 12 hours before specimen collection do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.
2. Nivolumab (Opdivo) must be discontinued at least 4 weeks prior to testing for vedolizumab quantitation in serum.​

Collection Instructions:
1. Draw blood immediately before next scheduled dose (trough specimen).
2. Centrifuge and aliquot serum into a plastic vial within 2 hours of collection.

​Patients actively undergoing therapy with both vedolizumab and nivolumab (rare scenario) should not have their therapeutic vedolizumab concentration assessed using this test. If the patient has taken nivolumab in the past, they should wait for 4 weeks after therapy with nivolumab has ended before being tested for vedolizumab quantitation using this method.

The presence of high concentrations of vedolizumab might inhibit the antibodies to vedolizumab (ATV) assay yielding false-negative results. In patients with concentrations of vedolizumab greater than 15.0 mcg/mL, the presence of an ATV is of little clinical significance.

Samples containing more than 100 ng/mL biotin (vitamin B7) may interfere with ATV (in the form of depressed signal) for VEMAB / Vedolizumab Antibodies, Serum.

Clinical management decisions for patients receiving vedolizumab treatment should not be based solely on quantitation of vedolizumab and assessment of ATV. Test results must be interpreted within the clinical context of the patient.

​Vedolizumab (Entyvio) is a humanized IgG1 kappa monoclonal antibody directed against integrin alpha-4 beta-7. Blocking the alpha-4 beta-7 integrin results in a gut-selective anti-inflammatory response. The drug is FDA-approved for the treatment of adult patients with moderately to severely active ulcerative colitis or Crohn disease. The main indication for therapeutic drug monitoring of vedolizumab is in the setting of primary nonresponse or loss-of-response to therapy, also called reactive monitoring. Vedolizumab trough concentrations greater than 12 mcg/mL to 15 mcg/mL have been associated with clinical or endoscopic remission. Proactive monitoring of vedolizumab concentrations has been proposed, but there is not sufficient data to support routine proactive testing at this time. Therapeutic drug monitoring of biologics is usually carried out by measuring the monoclonal antibody therapy concentration and assessing its immunogenicity or the appearance of anti-drug antibodies. Some patients on vedolizumab may develop antibodies to vedolizumab (ATV) over time. In clinical trials, approximately 4% of patients treated with vedolizumab were positive for ATV at any time and 1% or less were persistently positive. Clinically significant ATV impact drug clearance and a positive ATV is associated with lower trough concentrations of vedolizumab.​

​The limit of quantitation of the test is 2.0 mcg/mL. In a retrospective Mayo Clinic study with 171 patients (62% Crohn disease, 31% ulcerative colitis, and 7% indeterminate colitis), the median vedolizumab trough concentration was 15.3 mcg/mL. Trough (immediately before next infusion) therapeutic concentrations of vedolizumab are expected to be above 15 mcg/mL.

Vedolizumab concentration greater than 15 mcg/mL at trough is associated with clinical remission, endoscopic remission, or mucosal healing in inflammatory bowel disease.

Clinically significant antibodies-to-vedolizumab impact drug clearance and are associated with low (< or =15 mcg/mL at trough) or undetectable vedolizumab concentration.