Therapeutic drug monitoring (TDM)
• ELISA and rapid assay
• Quantification of drug concentrations and anti-drug antibodies
• Validated by KU Leuven, Belgium
• Ready to use reagents
• Validated on automated ELISA systems
Therapeutic monoclonal antibodies
Therapeutic monoclonal antibodies, such as infliximab, adalimumab and vedolizumab, are biologic agents used for the treatment of inflammatory diseases such as Crohn’s disease and ulcerative colitis. Infliximab and adalimumab (ADM) belong to the group of TNFα blockers. Vedolizumab instead is an α4β7-integrin antagonist.
How do therapeutic monoclonal antibodies function?
TNFα blockers
In healthy individuals, TNFα plays an essential role in the regulation of inflammation via binding to
specific receptors. In patients with Crohn’s disease and ulcerative colitis, the immune cells are continously triggered to produce TNFα, so that the inflammation does not cease and becomes chronic. TNFα blockers bind to TNFα (see Figure 1), hereby blocking the pro-inflammatory signaling pathway that inflicts damage to the gut tissue. As a result, gut inflammation and symptoms in patients with inflammatory bowel diseases resolve.
α4β7-integrin antagonists
The α4β7-integrin antagonist vedolizumab is a gutspecific, humanized monoclonal antibody targeting the α4β7-integrin protein. This protein is involved in the migration of lymphocytes to the gut.
By binding to the α4β7-integrin the lymphocytes are prevented from migrating into the gut lumen so that
they cannot exert their pro-inflammatory effect.
Individual dose adjustment by measuring drug levels and
immunogenicity
In order for biological drugs to work optimally, the drug concentration needs to be sufficiently high. Therefore, regular drug concentration monitoring is advised. The trough concentration (TC) is defined as the drug concentration in the blood measured right before the next infusion (see Figure 2).
Immunogenicity may have an impact on the efficacy of the drug. Anti-drug antibodies (ADA)
may bind to the drug and lead to a decrease in drug availability and allergy-like reactions.
Monitoring of drug- and anti-drug-antibodyconcentrations of biologic agents helps to
optimally adjust the therapy to the individual needs of the patient.
TDM of TNFα blockers and anti-integrins using RIDASCREEN®
and RIDA®QUICK assays
Key features of R-Biopharm’s TDM assays
• All TDM assays of R-Biopharm AG are validated by KU Leuven, Belgium
• ELISA assays and the rapid assays correlate very well due to identical monoclonal antibodies
• ELISA assays are validated on automated ELISA readers such as DSX®
• RIDASCREEN® IFX Monitoring and RIDA®QUICK IFX Monitoring quantify infliximab and its
biosimilars
• RIDA®QUICK IFX Monitoring is a rapid point-of care assay, which allows for the quantitative
determination of infliximab within 20 minutes.
Therapy adjustment based on therapeutic drug monitoring
The TAXIT-Algorithm (TAXIT = Trough Concentration Adapted Infliximab Treatment, Figure 3) is a recommendation for therapy adaptation based on the results of trough- and anti-drug-antibody-concentrations
of infliximab. It is a result of the study[1] by Niels Vande Casteele et al. (KU Leuven, Belgium) which investigated the effect of drug monitoring on the outcome of TNFα-treatment. The study shows the positive effect of TDM for therapy optimization and treatment cost reduction. Moreover, it indicates that testing for anti-drug-antibodies does not have to be performed on a standard basis but only in patients with undetectable trough concentrations of infliximab (see Figure 3). RIDASCREEN® IFX Monitoring and RIDASCREEN® Anti-IFX Antibodies are based on the assays used in this study.
TDM Products Click Here
- therapeutic_drug_monitoring
