Enzyme-linked immunosorbent assay (ELISA) for the qualitative determination of specific antibodies to Vedolizumab (Entyvio®) in human serum and plasma. The Assay Genie Antibody to Vedolizumab (Entyvio®) ELISA Kit is intended for the qualitative determination of Vedolizumab anti-drug antibodies in serum and plasma. It is for research use only.

The Assay Genie Antibody to infliximab (Remicade®) ELISA is a sandwich assay for the determination of antibodies against infliximab in serum and plasma samples. During the first incubation period, antibodies to infliximab (ATI) in patient serum/ plasma samples are captured by the drug infliximab (Remicade®) coated on the wall of the microtiter wells. After washing away the unbound components from samples, a peroxidase labelled specific conjugate is added to each well and then incubated. After a second washing step, the bound enzymatic activity is detected by addition of tetramethylbenzidine (TMB) chromogen-substrate. Finally, the reaction is terminated with an acidic stop solution. The intensity of the reaction colour is directly proportional to the concentration of ATI in sample.

Vedolizumab is a recombinant humanized IgG1 monoclonal antibody directed against the human lymphocyte α4β7 integrin, a key mediator of gastrointestinal inflammation. Vedolizumab binds specifically to α4β7 integrin but does not bind to, or inhibit function of, α4β1 or αEβ7 integrins. Inhibition of the α4β7 integrin is a shared mechanism with natalizumab, however vedolizumab binds solely to the α4β7but not the α4β1 integrin, unlike natalizumab which binds to both.

As a result, natalizumab modulates the systemic immune system and is associated with other side effects such as progressive multifocal leukoencephalopathy (PML). Non-clinical studies have shown that the pharmacodynamic effects of vedolizumab are reversible upon removal of the antibody: pharmacologic activity of cells inhibited by vedolizumab could be partially restored within 24 hours after removal, with near complete restoration within 4 days. There are no known drug interactions as vedolizumab is a humanized antibody and does not modulate production of cytokines, which is known to affect drug metabolism

It is used in the treatment of moderate to severe active ulcerative colitis and Crohn's disease for patients who have had an inadequate response with, lost response to, or were intolerant to inhibitors of tumor necrosis factor alpha (TNF alpha) or other conventional therapies. By blocking its primary target, α4β7 integrin, vedolizumab reduces inflammation in the gut. Vedolizumab binds to α4β7 integrin, a key mediator of gastrointestinal inflammation expressed on the surfaces of T and B lymphocytes. By selectively inhibiting the α4β7 integrin, vedolizumab inhibits adhesion of lymphocytes to its natural ligand, mucosal addressin cell adhesion molecule-1 (MAdCAM-1), thereby preventing lymphocytic cells from entering the gut lamina propria and gut-associated lymphoid tissue (GALT). Specifically inhibiting this pathway alleviates GI inflammation without impairing systemic immune responses.

Vedolizumab is indicated for adult patients with moderately to severely active ulcerative colitis or Crohn's disease who have had an inadequate response with, lost response to, or were intolerant to a tumor necrosis factor (TNF) blocker or immunomodulator; or had an inadequate response with, were intolerant to, or demonstrated dependence on corticosteroids.

As with any biologic therapy, immunogenicity, in the form of anti-vedolizumab antibodies (AVAs), occurs with following administration. The demonstration of anti-vedolizumab antibodies during treatment with vedolizumab (Entyvio®) is a major concern. Monitoring for the presence and/or quantitation of specific antibodies during clinical trials is an important issue for treatment regimen follow-up. The Assay Genie Anti-Vedolizumab ADA Qualitative ELISA Kit can be efficiently used for monitoring vedolizumab anti-drug antibodies in biological samples and is for research use only.

Remicade® is a registered trademark of Janssen Biotech Inc.