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TEST ID VEDOL Vedolizumab Quantitation with Reflex to Antibodies, Serum

Reporting Name

Vedolizumab QN, S

Specimen Type

Serum


Ordering Guidance


If both quantitation and antibody testing are needed, regardless of the quantitation results, order VEDOZ / Vedolizumab Quantitation with Antibodies, Serum.



Specimen Required


Patient Preparation: For 12 hours before specimen collection, patient should not take multivitamins or dietary supplements (eg, hair, skin, and nail supplements) containing biotin (vitamin B7).

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 1.5 mL Serum

Collection Instructions:

1. Draw blood immediately before next scheduled dose (trough specimen).

2. Within 2 hours of collection, centrifuge and aliquot serum into a plastic vial.


Specimen Minimum Volume

Serum: 0.3 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 28 days
  Frozen  28 days

Testing Algorithm

Vedolizumab quantitation will be performed by liquid chromatography mass spectrometry on all samples. When this test is ordered and vedolizumab results are 15.0 mcg/mL or less, then testing for antibodies to vedolizumab will be performed at an additional charge.

 

This test includes vedolizumab drug quantitation and, if appropriate, antibody testing for antibodies-to-vedolizumab will be performed. Currently, the American Gastroenterology Association does not have a formal guideline on optimal thresholds for vedolizumab trough concentrations in the setting of loss of response to therapy, but trough concentrations greater than 15 mcg/mL have been associated with clinical or endoscopic remission and mucosal healing in inflammatory bowel disease.

 

For more information see Ulcerative Colitis and Crohn Disease Therapeutic Drug Monitoring Algorithm.

Method Name

VEDOL: Liquid Chromatography Mass Spectrometry (LC-MS/MS)

VEMAB: Electrochemiluminescent Bridging Immunoassay

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Reference Values

VEDOLIZUMAB QUANTITATION:

Vedolizumab lower limit of quantitation: 1.0 mcg/mL

 

VEDOLIZUMAB ANTIBODIES:

Antibodies to vedolizumab: <9.8 ng/mL

 

Absence of antibodies to vedolizumab is defined as <9.8 ng/mL

Presence of ATV is reported as positive when concentrations are ≥9.8 ng/mL

Day(s) Performed

Monday, Wednesday, Thursday

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
VEMAB Vedolizumab Ab, S No No

Report Available

5 to 7 days

Specimen Retention Time

14 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

80280

82397 (if appropriate)

Forms

If not ordering electronically, complete, print, and send 1 of the following with the specimen:

-Gastroenterology and Hepatology Test Request (T728)

-Therapeutics Test Request (T831)

Useful For

Evaluation of patients with loss of response to vedolizumab (VDZ) with recurrence of symptoms and/or low or undetectable serum VDZ measured at trough

 

Monitoring vedolizumab concentrations in patients undergoing therapy with this biologic for ulcerative colitis or Crohn disease

 

Assessing the loss of response to VDZ therapy

 

As an aid to achieving desired serum concentration of VDZ

Clinical Information

Drug and target:

Vedolizumab (VDZ, Entyvio) is a humanized IgG1 kappa monoclonal antibody directed against integrin alpha-4 beta-7 integrin expressed on lymphocytes. VDZ blocks the interaction between the alpha-4 beta-7 integrin and MAdCAM-1, preventing lymphocytes from migrating across the endothelium into inflamed gastrointestinal tissue, thereby reducing inflammation.

 

Indications:

Vedolizumab is US Food and Drug Administration-approved for the treatment of adult patients with moderately to severely active ulcerative colitis or Crohn disease.(1,2) The standard dosing is 300 mg intravenously (IV) at weeks 0, 2, and 6 (induction), and then every 8 weeks for maintenance. It may be given every 4 weeks in certain cases of partial response.

 

Pharmacokinetic highlights:

Steady-state trough concentrations are typically achieved after the first few maintenance doses (around 14-22 weeks into therapy). Another option is subcutaneous injection with 108 mg every 2 weeks for maintenance after initial IV induction at weeks 0 and 2. The reported median steady state trough serum concentrations range from 19 to 48 mcg/mL, with multiple studies demonstrating an increase of at least 10 mcg/mL after transition from IV to subcutaneous administration.(3-9)

 

Immunogenicity:

Patients on VDZ may develop antibodies to VDZ (ATV) over time. In clinical trials, approximately 4% of patients treated with VDZ were positive for ATV at any time and 1% or less had specimens that were persistently positive. ATV formation may increase drug clearance in treated patients and/or neutralize the drug effect, thereby potentially contributing to the loss of response. ATV could also cause adverse events such as serum sickness and hypersensitivity reactions. VDZ drug level quantitation is commonly performed in conjunction with immunogenicity assessment for ATV.

 

Evidence for therapeutic drug monitoring:

Optimal therapeutic concentrations of VDZ associated with clinical remission and mucosal healing range between 12 and 28 mcg/mL, depending on the stage of therapy (induction or maintenance).(10-13) Most often, testing is ordered for patients on therapy who are experiencing loss of response (reactive monitoring). In the setting of loss of response to therapy, testing for ATV may be performed as a reflex after the drug quantitation shows subtherapeutic levels of VDZ (this test) or as a panel where drug quantitation and ATV are performed simultaneously (VEDOZ / Vedolizumab Quantitation with Antibodies, Serum). Results from drug quantitation combined with ATV testing play an important role in patient management.(10,12,13)

 

Proactive monitoring of ATV in a patient who is responding to therapy with VDZ is not recommended by the American Gastroenterology Association.