P108 Development and evaluation of the i-Tracker Risankizumab and i-Tracker Anti-Risankizumab kits: rapid and innovative tests intended for monitoring patients treated with Risankizumab.

Khater, G.(1)*;Noguier, G.(2);Daviere, S.(1);Montaillier, C.(2);Guilbert, V.(2);

(1)Theradiag, Theranostic, Croissy Beaubourg, France;(2)Theradiag, Research & Development, Croissy Beaubourg, France;


Risankizumab is a human monoclonal antibody directed against the cytokine IL-23. This drug is commonly used for the treatment of patients with chronic inflammatory diseases such as psoriasis. Risankizumab is about to get an indication in Crohn's disease and Ulcerative Colitis. Theradiag has just developed new rapid (results in less than 40 minutes) and innovative assays allowing the quantification of Risankizumab: these tests are available on the new innovative i-Track10 chemiluminescence platform and allowing the rapid quantification of Risankizumab as well as anti-Risankizumab antibodies induced by the patient.


The analytical performance was studied using two types of samples: human serum samples spiked with Risankizumab or anti-Risankizumab antibodies, and human serum samples from patients with inflammatory diseases treated with Risankizumab. For drug assay, Risankizumab was captured using IL-23-coupled magnetic microparticles and detected using an acridinium ester-conjugated anti-Risankizumab polyclonal antibody. For the assay of anti-Risankizumab antibodies, microparticles coupled to Risankizumab were used. The anti-Risankizumab antibodies thus captured were detected by Risankizumab conjugated to the acridinium ester. Light emission from acridinium ester conjugates is directly related to the amount of Risankizumab or anti-Risankizumab antibodies present in the sample.


The quantification of Risankizumab by the i-Tracker Risankizumab kit shows very good accuracy (the percentages of recovery are between 84% and 108%). The intra-test and inter-test reproducibility is very good (CV <7.3% for the Risankizumab assay and CV <8.0% for the anti-Risankizumab antibody assay). No interference from biological agents (bilirubin, hemoglobin, triglycerides, rheumatoid factors) was detected. The assay measurement ranges are 1 µg/mL to 80 µg/mL for Risankizumab and 10 ng/mL to 2000 ng/mL for anti-Risankizumab antibodies.


The i-Tracker Risankizumab and anti-Risankizumab kits are rapid tests (results obtained in less than 40 minutes) and highly accurate. Monitoring Risankizumab plasma levels could provide clinicians with relevant information to improve treatment efficacy.