INDIVIDUAL TEST 138, 139

Vedolizumab

Vedolizumab (trade name Entyvio) is a humanized monoclonal antibody that binds to α4β7 integrin and is prescribed to treat inflammatory bowel diseases (IBD) such as ulcerative colitis (UC) and Crohn's disease (CD).  Vedolizumab is a gut-selective immunosuppressive biologic that inhibits α4β7 integrin. The α4β7 integrin is expressed on a discrete subset of memory T helper lymphocytes which preferentially migrate into the gastrointestinal tract and cause inflammation that is characteristic of ulcerative colitis and Crohn’s disease. 

By binding to α4β7, vedolizumab inhibits adhesion of these lymphocytes to mucosal addressin cell adhesion molecule-1 (MAdCAM-1). MAdCAM-1 is mainly expressed on gut endothelial cells and plays a critical role in the homing of T lymphocytes to tissues within the gastrointestinal tract.  Vedolizumab has been shown to reduce gastrointestinal inflammation, and to improve clinical response, remission and mucosal healing in ulcerative colitis patients.  

Clinical Use

In Europe, vedolizumab is indicated for the treatment of:

• adult patients with moderately to severely active ulcerative colitis and Crohn's disease. 
• Vedolizumab is used when conventional therapy with TNF-α antagonists are ineffective, no longer effective, or cannot be tolerated by the patient.

Testing vedolizumab concentration:

The assay is performed using Enzyme Linked Immunosorbent Assay (ELISA). The limit of quantification (LOQ) for vedolizumab in serum is 0.01 µg/mL.

Testing vedolizumab anti-drug antibodies (ADA):

The assay is performed using radioimmunoassay (RIA). The limit of quantification (LOQ) for ADA is 10 AU/mL.

Clinical Relevance

No response or loss of response of treatment with vedolizumab. During treatment, some patients may develop antibodies against vedolizumab; anti-drug antibodies (ADA). With level testing of biologics, efficacy of therapy can be improved, as treatment decisions may need to be adapted depending on the test results in conjunction with clinical responses to treatment. Data and interpretation of vedolizumab ADA and its serum levels are still very limited.

Personalized Medicine

Monitoring biologic levels in individual patients allows optimization of treatment efficacy by adjusting therapy depending on the specific response of the patient. When drug levels are decreased in a non-responder, this may reflect formation of inactivating antibodies directed to the biologic treatment. Immunogenicity testing identifies presence or absence of inactivating antibodies, which guides the next treatment decision – switch to other biological treatment, lowering of dose or intensify dosing. Reducing drug dosage in well-responding patients with relatively high drug levels cuts down cost. A personalized approach can improve therapy efficacy and quality of life.

Suggested literature

1. Cherry LN and al., Vedolizumab: an alpha 4 beta 7 integrin antagonist for ulcerative colitis and Crohn’s disease, Therapeutic Advances in Chronic Disease, Vol.6(5), 224233, 2015.
2. Feagan BG and al., Induction and Maintenance Therapy with Vedolizumab, a novel biologic therapy for ulcerative colitis, Gastroenterology & Hepatology, 10, Issue 1, 2014.
3. Rosario M. and al., Population pharmacokinetics pharmacodynamics of vedolizumab in patients with ulcerative colitis and Crohn’s disease, Alimentary Pharmacology and Therapeutics, 2015.
4. Yu Jin and al., Meta-analysis of the effectiveness and safety of vedolizumab for ulcerative colitis, World Journal of Gastroenterology, 21, issue 20, 2015.