A Novel B7-H6-Targeted IgG-Like T Cell-Engaging Antibody for the Treatment of Gastrointestinal Tumors.

Purpose: Advanced-stage gastrointestinal cancers represent a high unmet need requiring new effective therapies. We investigated the antitumor activity of a novel T cell-engaging antibody (B7-H6/CD3 ITE) targeting B7-H6, a tumor-associated antigen that is expressed in gastrointestinal tumors.

Experimental Design: Membrane proteomics and IHC analysis identified B7-H6 as a tumor-associated antigen in gastrointestinal tumor tissues with no to very little expression in normal tissues.

Allometric scaling of therapeutic monoclonal antibodies in preclinical and clinical settings.

Constant technological advancement enabled the production of therapeutic monoclonal antibodies (mAbs) and will continue to contribute to their rapid expansion. Compared to small-molecule drugs, mAbs have favorable characteristics, but also more complex pharmacokinetics (PK), e.g.

Analyze impact of tumor-associated kinetics on antibody delivery in solid tumors with a physiologically based pharmacokinetics/pharmacodynamics model.

Monoclonal antibody (mAb)-based drugs are critical anti-cancer therapies. Unfortunately, therapeutic efficacy can be compromised by spatially heterogeneous intratumoral Ab deposition. Binding-site barriers arising from Ab and tumor-associated kinetics often underlie this phenomenon.

Quantitative Systems Pharmacology Modeling of PBMC-Humanized Mouse to Facilitate Preclinical Immuno-oncology Drug Development.

Progress in immunotherapy has resulted in explosively increased new therapeutic interventions and they have shown promising results in the treatment of cancer. Animal testing is performed to provide preliminary efficacy and safety data for drugs under development prior to clinical trials. However, translational challenges remain for preclinical studies such as study design and the relevance of animal models to humans.

Selective Tumor Cell Apoptosis and Tumor Regression in CDH17-Positive Colorectal Cancer Models using BI 905711, a Novel Liver-Sparing TRAILR2 Agonist.

Activation of TRAILR2 has emerged as an important therapeutic concept in cancer treatment. TRAILR2 agonistic molecules have only had limited clinical success, to date, due either to lack of efficacy or hepatotoxicity. BI 905711 is a novel tetravalent bispecific antibody targeting both TRAILR2 and CDH17 and represents a novel liver-sparing TRAILR2 agonist specifically designed to overcome the disadvantages of previous strategies.

Combination therapy with T cell engager and PD-L1 blockade enhances the antitumor potency of T cells as predicted by a QSP model.

Background: T cells have been recognized as core effectors for cancer immunotherapy. How to restore the anti-tumor ability of suppressed T cells or improve the lethality of cytotoxic T cells has become the main focus in immunotherapy. Bispecific antibodies, especially bispecific T cell engagers (TCEs), have shown their unique ability to enhance the patient's immune response to tumors by stimulating T cell activation and cytokine production in an MHC-independent manner.

A Bispecific DLL3/CD3 IgG-Like T-Cell Engaging Antibody Induces Antitumor Responses in Small Cell Lung Cancer.

Purpose: Small cell lung cancer (SCLC) is the most lethal and aggressive subtype of lung carcinoma characterized by highly chemotherapy-resistant recurrence in the majority of patients. To effectively treat SCLC, we have developed a unique and novel IgG-like T-cell engaging bispecific antibody (ITE) that potently redirects T-cells to specifically lyse SCLC cells expressing Delta-like ligand 3 (DLL3), an antigen that is frequently expressed on the cell surface of SCLC cells, with no to very little detectable expression in normal tissues.

Experimental Design: The antitumor activity and mode of action of DLL3/CD3 ITE was evaluated using SCLC cell lines and primary human effector cells and in an SCLC xenograft model reconstituted with human CD3 T-cells.

A Quantitative Systems Pharmacology Model of T Cell Engager Applied to Solid Tumor.

Cancer immunotherapy has recently drawn remarkable attention as promising results in the clinic have shown its ability to improve the overall survival, and T cells are considered to be one of the primary effectors for cancer immunotherapy. Enhanced and restored T cell tumoricidal activity has shown great potential for killing cancer cells. Bispecific T cell engagers (TCEs) are a growing class of molecules that are designed to bind two different antigens on the surface of T cells and cancer cells to bring them in close proximity and selectively activate effector T cells to kill target cancer cells.

Retrospective analysis of model-based predictivity of human pharmacokinetics for anti-IL-36R monoclonal antibody MAB92 using a rat anti-mouse IL-36R monoclonal antibody and RNA expression data (FANTOM5).

Accurate prediction of the human pharmacokinetics (PK) of a candidate monoclonal antibody from nonclinical data is critical to maximize the success of clinical trials. However, for monoclonal antibodies exhibiting nonlinear clearance due to target-mediated drug disposition, PK predictions are particularly challenging. That challenge is further compounded for molecules lacking cross-reactivity in a nonhuman primate, in which case a surrogate antibody selective for the target in rodent may be required.

Maximizing in vivo target clearance by design of pH-dependent target binding antibodies with altered affinity to FcRn.

Antibodies with pH-dependent binding to both target antigens and neonatal Fc receptor (FcRn) provide an alternative tool to conventional neutralizing antibodies, particularly for therapies where reduction in antigen level is challenging due to high target burden. However, the requirements for optimal binding kinetic framework and extent of pH dependence for these antibodies to maximize target clearance from circulation are not well understood. We have identified a series of naturally-occurring high affinity antibodies with pH-dependent target binding properties.

Neonatal Fc receptor and its role in the absorption, distribution, metabolism and excretion of immunoglobulin G-based biotherapeutics.

The neonatal Fc receptor (FcRn) is a heterodimeric membrane associated protein expressed in a variety of endothelial, epithelial and hematopoietic cells. FcRn regulates pH dependent intracellular trafficking of immunoglobulin G (IgG) and albumin, resulting in enhanced serum persistence and transcellular permeability of these proteins compared to other proteins of similar size. FcRn confers passive immunity during the early stages of life by facilitating maternal transmission of antibodies during gestation, and in some species during the neonatal period.

Lack of appreciable species differences in nonspecific microsomal binding.

Species differences in microsomal binding were evaluated for 43 drug molecules in human, monkey, dog and rat liver microsomes, using a fixed concentration of microsomal protein. The dataset included 32 named drugs and 11 proprietary compounds encompassing a broad spectrum of physicochemical properties (11 acids, 24 bases, 8 neutral, c log D -1 to 7, MW 200 to 700 and free fraction <0.001 to 1).

Orally active and brain permeable proline amides as highly selective 5HT2c agonists for the treatment of obesity.

Brain-penetrable proline amides were developed as 5HT2c agonists with more than 1000-fold binding selectivity against 5HT2b receptor. After medicinal chemistry optimization and SAR studies, orally active proline amides with robust efficacy in a rodent food intake inhibition model were uncovered.

Impact of time-dependent inactivation on the estimation of enzyme kinetic parameters for midazolam.

Enzyme kinetic parameters for midazolam were time-dependent in human liver microsomes, under initial velocity conditions. V(max) and K(m) decreased up to 3.7 and 3.

Further evidence for a C-terminal structural motif in CCK2 receptor active peptide hormones.

A comparison of the conformational characteristics of the related hormones [Nle(15)] gastrin-17 and [Tyr(9)-SO(3)] cholecystokinin-15, in membrane-mimetic solutions of dodecylphosphocholine micelles and water, was undertaken using NMR spectroscopy to investigate the possibility of a structural motif responsible for the two hormones common ability to stimulate the CCK(2) receptor. Distance geometry calculations and NOE-restrained molecular dynamics simulations in biphasic solvent boxes of decane and water pointed to the two peptides adopting near identical helical C-terminal configurations, which extended one residue further than their shared pentapeptide sequence of Gly-Trp-Met-Asp-Phe-NH(2). The C-terminal conformation of [Nle(15)] gastrin-17 contained a short alpha-helix spanning the Ala(11)-Trp(14) sequence and an inverse gamma-turn centered on Nle(15) while that of [Tyr(9)-SO(3)] cholecystokinin-15 contained a short 3(10) helix spanning its Met(10) to Met(13) sequence and an inverse gamma-turn centered on Asp(14).

Conformational and molecular modeling studies of beta-cyclodextrin-heptagastrin and the third extracellular loop of the cholecystokinin 2 receptor.

The conformational features of a conjugate of the C-terminus of human gastrin (HG[11-17]), the shortest gastrin sequence retaining biological function, with beta-cyclodextrin ([Nle(15)]-HG[11-17]-betaCD) were determined by NMR spectroscopy in an aqueous solution of dodecylphosphocholine (DPC) micelles. The peptide-betaCD conjugate displays a binding affinity and activation profile comparable to those of HG[11-17] at the cholecysokinin 2 (CCK(2)) receptor, the G protein-coupled receptor responsible for the gastrointestinal function of gastrin. The structure of the peptide consisted of a well-defined beta-turn between Gly(13) and Asp(16) of gastrin.

Intermolecular interactions between peptidic and nonpeptidic agonists and the third extracellular loop of the cholecystokinin 1 receptor.

Intermolecular interactions were determined between a synthetic peptide corresponding to the third extracellular loop and several residues from the adjoining sixth and seventh transmembrane domains of the human cholecystokinin-1 receptor, CCK(1)-R(329-357), and the synthetic agonists Ace-Trp-Lys[NH(epsilon)CONH-o-(MePh)]-Asp-MePhe-NH(2) (GI5269) and the C1 N-isopropyl-N-(4-methoxyphenyl)acetamide derivative of 3-(1H-Indazol-3ylmethyl)-3-methyl-5-pyridin-3-yl-1,5-benzodiazepine (GI0122), using high-resolution nuclear magnetic resonance spectroscopy and computer simulations. Addition of the ligands to CCK(1)-R(329-357) in an aqueous solution of DPC micelles produced a number of intermolecular nuclear Overhauser enhancements (NOEs) to residues in TMs 6 and 7 of the receptor fragment. NOE-restrained molecular models of the GI5269 and GI0122/CCK(1)-R complexes provide evidence for overlapping ligand-binding sites for peptidic and nonpeptidic agonists.

Determination of ligand-receptor interactions of cholecystokinin by nuclear magnetic resonance.

To date high resolution structural studies of G protein coupled receptors, with the exception of rhodopsin, have not been feasible using conventional spectroscopic techniques. To overcome these difficulties, the structural features of partial or intact domains of GPCRs have been studied by nuclear magnetic resonance spectroscopy and X-ray crystallography. Here, we describe the structural characterization of receptor domains from the cholecystokinin 1 and 2 receptors and the elucidation of intermolecular interactions between the extracellular receptor domains and CCK-8 by solution state nmr.

Ni-to-Ni+ 3-ethylene-bridged partially modified retro-inverso tetrapeptide beta-turn mimetic: design, synthesis, and structural characterization.

A 10-membered heterocyclic ring system 1,3,8-trisubstituted 2,5,7-trioxo-1,4,8-triazadecane that represents a Ni-to-Ni+ 3-ethylene-bridged partially modified retro-inverso tetrapeptide beta-turn mimetic (EBRIT-BTM) has been designed, synthesized, and structurally analyzed. These compounds utilize an ethylene bridge to replace the COi..

NMR studies of CCK-8/CCK1 complex support membrane-associated pathway for ligand-receptor interaction.

The interaction of peptide ligands with their associated G-protein-coupled receptors has been examined by a number of different experimental approaches over the years. We have been developing an approach utilizing high-resolution NMR to determine the structural features of the peptide ligand, well-designed fragments of the receptor, and the ligand-receptor complexes formed upon titration of the peptide hormone. The results from these investigations provide evidence for a membrane-associated pathway for the initial interaction of peptide ligands with the receptor.

Conformational and molecular modeling studies of sulfated cholecystokinin-15.

Conformational features of the C-terminal carboxyamidated pentadecapeptide of CCK (S(19)HRISDRD[SO(4)]-YMGWMDF(33)-NH(2)) were determined by NMR spectroscopy in a zwitterionic membrane-mimetic solvent system, composed of DPC micelles. The C-terminal octapeptide consisted of a well-defined pseudohelix that was nearly identical to the structure previously reported for nonsulfated CCK-8 in the same solvent system. N-terminal amino acids of CCK-15 were highly disordered, with no clear conformational preference.

Intermolecular interactions between cholecystokinin-8 and the third extracellular loop of the cholecystokinin-2 receptor.

The structure of the third extracellular loop of the human cholecystokinin-2 receptor, CCK2-R(352-379), and its interactions with the C-terminal octapeptide of cholecystokinin (CCK-8) have been determined by high-resolution NMR and computer simulations. In the presence of dodecylphosphocholine micelles, the structure of the receptor fragment consisted of three helices, with the first and third corresponding to residues of the extracellular ends of transmembrane helices (TM) 6 and 7, respectively. The central, extracellular helix, consisting of residues 363-368, was found to be closely associated with the membrane mimetic used during the spectroscopic studies and molecular dynamics (MD) simulations.