Biomarker Testing: Pushing the Limits of Ultrasensitivity

In drug development, there is a growing demand for ultrasensitive bioanalytical platforms and kits, especially in disciplines like neuroscience, where analytes are often present at very low concentrations in peripheral circulation. KCAS Bio addresses this demand by offering a spectrum of technologies, from dedicated platforms to ultra-sensitive kits on conventional systems.  Among these platforms, the NULISA™ / Argo™ HT represents the most recent cutting-edge new technology showing great potential not only in the ultra-sensitivity space but also in targeted proteomics. In this webinar, the speakers will present initial data from early-stage implementation, testing the platform’s ability to push the sensitivity limits for a target engagement biomarker. Viewers will gain valuable insights into developing, optimizing and applying this next-generation technology for challenging biomarker detection scenarios.

A sponsor transferred the Simoa® method, which proved insufficiently sensitive for monitoring a decrease of their target engagement biomarker in CSF (cerebrospinal fluid) and plasma from patients with a rare neurodegenerative disease. Leveraging the ultra-high sensitivity of the NULISA™ / Argo™ HT platform, the team tested the Custom Assay Development Kit for its ability to improve the method’s sensitivity.

Capture antibody (Ab) was conjugated to a partially double-stranded DNA fragment containing a poly-A tail and a target-specific molecular identifier (TMI), while detection Ab was conjugated to another partially double-stranded DNA fragment carrying a biotin group and a matching TMI. After controlling conjugation with SDS-PAGE, the Ab conjugates were tested in the same orientation as for the Simoa® method. In an initial experiment, calibrators prepared in buffer were tested in parallel with representative biological samples and kit controls. The default 1:1 ratio for capture and detection antibodies was tested for the calibration curve in buffer or in plasma. For test samples, different concentrations and ratios of Ab conjugates were compared.

Encouraging results were obtained from this initial experiment, validated with NULISA™ / Argo™ HT controls that fell within the expected Cq value range. Even when built with these default Ab conjugate concentrations, the calibration curve showed improved sensitivity compared to the one obtained with the Simoa® method. Results from test samples further indicated that optimizing assay conditions could further enhance assay sensitivity. A capture-to-detection ratio of 1:4 significantly improved the estimated LLOQ and the delta Cq signal-to-noise in biological samples.

Subsequent experiments will focus on evaluating the impact of Ab conjugate titration and assay buffer on the sensitivity of the method and its ability to quantify samples that were below the LLOQ of the Simoa® method. Additional preliminary data will be shared from plasma, CSF and extracellular-vesicle-derived biomarkers in ALS and Alzheimer’s disease compared with healthy controls using a 120-plex neurological panel.

Register for this webinar to learn how biomarker testing with NULISA™ / Argo™ HT can enhance assay sensitivity and expand discovery potential across neurodegenerative research.

Speakers

Christine Bain Wendlinger, PhD, Senior Scientific Advisor, KCAS Bio (Lyon)

Christine Bain Wendlinger is an Immunologist by training and has been working for years in the fields of immuno-oncology and persistent viral infections, such as Chronic Hepatitis C, at Biomérieux and Transgene. Before joining in 2011, the company that was acquired by KCAS Bio in 2022, she was coordinating biomarker programs supporting the development of immunotherapeutic products in cancer and infectious diseases at Transgene.

As a Senior Scientific Advisor at KCAS Bio, Christine supports the sales and operations team on scientific and technical aspects related to method development, validation and (pre)clinical sample analysis for pharmacokinetics, immunogenicity and biomarker assays for biologics in immuno-oncology, infectious diseases, inflammatory and autoimmune syndromes and neurological diseases.

She is currently a core member of the European Bioanalysis Forum (EBF) and EIP (European Immunogenicity Platform).

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Fabien Lavocat, MSc, Scientist, Bioanalytical Method Development, KCAS Bio (Lyon)

Fabien Lavocat is a Scientist at KCAS Bio in Lyon, specializing in ligand-binding assay (LBA) development for drug and biomarker analysis. With a Master’s degree and 15 years of experience, his career bridges academic research, clinical studies and pharmaceutical R&D, always focused on patient impact. He started in virology, then worked in immunology research on autoimmune diseases, and contributed to a clinical study identifying prognostic markers in ICU patients. At Sanofi, he supported vaccine and biomarker projects. Now at KCAS, he designs tailored bioanalytical methods, combining technical versatility with a collaborative approach to advance translational science.

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