Sapidyne Instruments Inc.

Investigations of Influence of Antibody Binding Kinetics on Tumor Distribution and Anti-Tumor Efficacy

"An important aspect of this area of research is the selection of an appropriate binding assay to accurately characterize the binding affinity and kinetics of the antibodies. Techniques commonly employed in binding assays, such as ELISA, flow cytometry, KinExA, and SPR, have their unique attributes and limitations. Among these, KinExA stands out for its applicability in quantifying high-affinity interactions. It works by measuring the concentration of free (i.e., unbound) ligand in a binding reaction that has reached equilibrium prior to the instrument analysis, effectively bypassing potential artifacts resulting from non-equilibrium conditions, ligand depletion, and mass transport effects. Such artifacts may lead to significant errors in other assays like ELISA or SPR (33, 34). Additionally, KinExA facilitates the direct measurement of binding kinetics on antigen-expressing cells, reflecting real and actual binding conditions (35, 36). Consequently, KinExA was chosen to characterize the binding affinity and kinetics of all the IgGs investigated in this study."

Investigations of Influence of Antibody Binding Kinetics on Tumor Distribution and Anti-Tumor Efficacy - The AAPS Journal The pharmacokinetics of antibodies with varied binding kinetics were simulated to assess the role of affinity and binding microconstants (kon, koff) on tumor exposure and intra-tumoral distribution. Anti-HER2 constructs (trastuzumab, pertuzumab, VK3VH6, and conjugates with DM1 and gelonin) were prod...

A recent 2024 publication in Cancer Immunology Research, scientists described a potent fully human antibody (COM503) that was developed to block binding of IL18BP to IL18.

A function of the IL18 cytokine is to induce inflammation in response to infectious microbes and molecules. That stimulates interferon gamma (IFNy) production which is important for adaptive immunity. When IFNy is upregulated, IL18BP is induced in the tumor microenviornment (TME) and binds to IL18 in a negative feedback mechanism. Antibody COM503 was designed to block IL18BP from binding to IL18 and restore activity to endogenous 1L18. The antibody proved to be a promising approach for the treatment of cancer.

KinExA was used to characterize the binding interaction of COM503 and Human IL18 to Human IL18BP. Both interactions exhibited very tight binding with Kds of 291 fM and 441 fM respectively. This study highlights the sensitivity of KinExA technology to measure precise, accurate Kd information at a level well below that of other technologies.

Unleashing Natural IL18 Activity Using an Anti-IL18BP Blocker Induces Potent Immune Stimulation and Antitumor Effects Therapeutic usage of cytokines in patients is limited by toxicity. The authors report that blocking a cytokine binding protein, IL18BP, to enhance the cytokine’s natural activity yields antitumor activity in preclinical models and shows promise for clinical translation.

https://www.chi-peptalk.com/

Thank you to everyone that attended our KinExA Seminar at Boise State last week! We had amazing speakers, interactive learning and of course, some fun! Can't wait for the next one!

Sapidyne presents a guided seminar into the world of Kinetic Exclusion Assays! Plan to join us on September 21 & 22, 2023 as we discuss the science of affinity & kinetic analysis for reversible binding interactions.
https://www.sapidyne.com/seminar.html

"In an effort to provide faster, economical and reliable PAH analyses, a variety of immunoassay methods have been examined for the detection and quantification of PAH in environmental samples (EPA, 1996a, EPA, 1996b, Spier et al., 2012, Behera et al., 2018). Our lab has developed a rapid, near-real-time method for PAH quantitation using the KinExA Inline Biosensor (Sapidyne Instruments, Boise, ID) and a mouse-derived anti-pyrene-butyric acid monoclonal antibody, 2G8, with previously demonstrated uniform selectivity for a range of 3–5 ring PAHs (Li et al., 2016). Additionally, the biosensor is a user-friendly instrument that can directly analyze environmental samples (i.e requires minimal sample preparation). It has been used to quantify PAH in porewater samples in the Chesapeake Bay and Houston ship channel and has demonstrated strong positive correlation with PAH measurements of sediment porewater when using passive sampling and GC–MS (Hartzell et al., 2017, Conder et al., 2021, Camargo et al., 2022)."

A novel antibody-based biosensor method for the rapid measurement of PAH contamination in oysters Conventional PAH analytical methods are time-consuming and expensive, limiting their utility in time sensitive events (i.e. oil spills and floods) or …

"Therefore, competition between the solution complex and the solid phase is “kinetically excluded” and the solution equilibrium is not altered during KinExA experiments. The signals generated from the captured CD40 and/or integrins, which are directly proportional to the concentration of free integrin in the equilibrated samples, are used to generate a binding curve, measured in a series. The KinExA method is a means to obtain true solution phase measurements."

Modulating CD40 and integrin signaling in the proinflammatory nexus using a 15-amino acid peptide, KGYY15. CD40-signaling has long been a target in autoimmunity. Attempts to block signaling between CD40 and CD154 during clinical trials using monoclonal anti…

"Interleukin (IL)-33 is a broad-acting alarmin cytokine that can drive inflammatory responses following tissue damage or infection and is a promising target for treatment of inflammatory disease. Here, we describe the identification of tozorakimab (MEDI3506), a potent, human anti-IL-33 monoclonal antibody, which can inhibit reduced IL-33 (IL-33red) and oxidized IL-33 (IL-33ox) activities through distinct serum-stimulated 2 (ST2) and receptor for advanced glycation end products - epidermal growth factor receptor (RAGE-EGFR complex) signalling pathways."..
"To gain an understanding of the binding kinetics and affinity required for a therapeutically effective anti-IL-33 antibody, we first determined the binding kinetics of IL-33 to sST2. The affinity of IL-33red for sST2 was 0.09 pM (95% confidence interval [CI], 0.05–0.15; Fig. 1a–c), which was determined using a highly sensitive kinetic exclusion assay (KinExA) [35]. "

Tozorakimab (MEDI3506): a dual-pharmacology anti-IL-33 antibody that inhibits IL-33 signalling via ST2 and RAGE/EGFR to reduce inflammation and epithelial dysfunction Interleukin (IL)-33 is a broad-acting alarmin cytokine that can drive inflammatory responses following tissue damage or infection and is a promising target for treatment of inflammatory disease. Here, we describe the identification of tozorakimab (MEDI3506), a potent, human anti-IL-33 monoclonal ant...

https://academic.oup.com/ecco-jcc/article/17/Supplement_1/i634/7009831

P504 Guselkumab, an IL-23p19 subunit–specific monoclonal antibody, binds CD64+ myeloid cells and potently neutralises IL-23 produced from the same cells AbstractBackground. Monoclonal antibodies targeting the interleukin (IL)-23p19 subunit are effective in the treatment of inflammatory bowel diseases (IBD), but

Winter has arrived at Sapidyne Instruments Inc. !

KinExA is a technique for measuring unmodified molecules with either both molecules in solution or with one in solution and the other expressed on a cell surface. This document describes the advantages KinExA has over other biosensor technologies.

The KinExA Advantage A comparison of biosensors for Kd analysis