Explore the vast range of titles available.

Heparin-binding EGF-like growth factor (HB-EGF) is a member of the EGF family and is an important therapeutic target in some types of human cancers. KHK2866 is a humanized anti-HB-EGF monoclonal antibody IgG that neutralizes HB-EGF activity by inhibiting the binding of HB-EGF to its receptors. The phase I study of KHK2866 was discontinued because of neuropsychiatric toxicity. In this study, the pharmacokinetics of KHK2866 was evaluated by super(89)Zr-immuno-PET study and the determination of drug concentrations in serum and cerebrospinal fluid using cynomolgus monkeys was performed in order to predict neurotoxicity in a reverse-translational manner. KHK2866 was radiolabeled with super(89)Zr for preclinical evaluations in normal cynomolgus monkeys and its distribution was analyzed. Furthermore, as a separate study, KHK2866 concentrations in serum and cerebrospinal fluid were determined after administration of a single dose. PET studies with monkeys revealed super(89)Zr-KHK2866 accumulation in the liver, spleen and joints of multiple parts, but not in brain. In addition, the pharmacokinetic analyses in serum and CSF demonstrated a low penetration of KHK2866 into the brain. These studies indicate the difficulty of prediction for neuropsychiatric toxicity of monoclonal antibodies in human by means of pharmacokinetic evaluations using cynomolgus monkeys.

Lecithin: cholesterol acyltransferase (LCAT) is a key liver-produced circulating enzyme responsible for high density lipoprotein (HDL) cholesterol esterification, HDL maturation, and potentially reverse cholesterol transport. To determine the feasibility of over-expressing cynomolgus LCAT above endogenous physiological levels in normal cynomolgus monkeys and to assess the effect of LCAT over-expression on modulating HDL cholesterol level, we generated an AAV8 vector expressing cynomolgus LCAT (AAV8-cyno LCAT) driven by a liver specific promoter. Prior to transducing cynomolgus monkeys, a proof-of-concept study in mice was conducted and the effectiveness of AAV8-cyno LCAT vector in raising HDL cholesterol was demonstrated. In summary, the data of AAV8-mediated cynomolgus LCAT overexpression and concomitant HDL cholesterol-raising in normal cynomolgus monkeys suggested the safety and efficacy of expressing a target gene above endogenous level to modulate physiological phenotype in non-human primates. These results in the non-human primate provide support for translation of LCAT raising modalities in humans.

Assessment of serotonin release in the living brain with positron emission tomography (PET) may have been hampered by the lack of suitable radioligands. We previously reported that fenfluramine caused a dose-dependent reduction in specific binding in monkeys using a classical displacement paradigm with bolus administration of [ super(11)C]AZ10419369. The aim of this study was to confirm our previous findings using an equilibrium approach in monkey. A total of 24 PET measurements were conducted using a bolus infusion protocol of [ super(11)C]AZ10419369 in three cynomolgus monkeys. Initial PET measurements were performed to assess suitable K sub(bol) values. The fenfluramine effect on [ super(11)C]AZ10419369 binding was evaluated in a displacement and pretreatment paradigm. The effect of fenfluramine on [ super(11)C]AZ10419369 binding potential (BP sub(ND)) was dose-dependent in the displacement paradigm and confirmed in the pretreatment paradigm. After pretreatment administration of fenfluramine (5.0 mg/kg), the mean BP sub(ND) of the occipital cortex decreased by 39%, from 1.38+/-0.04 to 0.84+/-0.09. This study confirms that the new 5-HT sub(1B) receptor radioligand [ super(11)C]AZ10419369 is sensitive to fenfluramine-induced changes in endogenous serotonin levels in vivo. The more advanced methodology is suitable for exploring the sensitivity limit to serotonin release as measured using [ super(11)C]AZ10419369 and PET.

VTX-2337 (USAN: motolimod) is a selective toll-like receptor 8 (TLR8) agonist, which is in clinical development as an immunotherapy for multiple oncology indications, including squamous cell carcinoma of the head and neck (SCCHN). Activation of TLR8 enhances natural killer cell activation, increases antibody-dependent cell-mediated cytotoxicity, and induces Th1 polarizing cytokines. Here, we show that VTX-2337 stimulates the release of mature IL-1[Beta] and IL-18 from monocytic cells through coordinated actions on both TLR8 and the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome complex. In vitro, VTX-2337 primed monocytic cells to produce pro-IL-1[Beta], pro-IL-18, and caspase-1, and also activated the NLRP3 inflammasome, thereby mediating the release of mature IL-1[Beta] family cytokines. Inhibition of caspase-1 blocked VTX-2337-mediated NLRP3 inflammasome activation, but had little impact on production of other TLR8-induced mediators such as TNF[alpha] . IL-18 activated natural killer cells and complemented other stimulatory pathways, including Fc[gamma]RIII and NKG2D, resulting in IFN[gamma] production and expression of CD107a. NLRP3 activation in vivo was confirmed by a dose-related increase in plasma IL-1[Beta] and IL-18 levels in cynomolgus monkeys administered VTX-2337. These results are highly relevant to clinical studies of combination VTX-2337/cetuximab treatment. Cetuximab, a clinically approved, epidermal growth factor receptor-specific monoclonal antibody, activates NK cells through interactions with Fc[gamma]RIII and facilitates ADCC of tumor cells. Our preliminary findings from a Phase I open-label, dose-escalation, trial that enrolled 13 patients with recurrent or metastatic SCCHN show that patient NK cells become more responsive to stimulation by NKG2D or Fc[gamma]RIII following VTX-2337 treatment. Together, these results indicate that TLR8 stimulation and inflammasome activation by VTX-2337 can complement Fc[gamma]RIII engagement and may augment clinical responses in SCCHN patients treated with cetuximab. Trial Registration: ClinicalTrials.gov NCT01334177

The design, synthesis and pharmacology of novel long-acting exenatide analogs for the treatment of metabolic diseases are described. These molecules display enhanced pharmacokinetic profile and potent glucoregulatory and weight lowering actions compared to native exenatide. [Leu14]exenatide-ABD is an 88 residue peptide amide incorporating an Albumin Binding Domain (ABD) scaffold. [Leu14]exenatide-ABP is a 53 residue peptide incorporating a short Albumin Binding Peptide (ABP). [Leu14]exenatide-ABD and [Leu14]exenatide-ABP exhibited nanomolar functional GLP-1 receptor potency and were metabolically stable in vitro in human plasma and in a pancreatic digestive enzyme mixture. Both molecules displayed picomolar and nanomolar binding association with albumin across multiple species and circulating half lives of 16 and 11 hours, respectively, post a single IV dose in rats. Unlike exenatide, both molecules elicited robust glucose lowering when injected 1 day prior to an oral glucose tolerance test, indicative of their extended duration of action. [Leu14]exenatide-ABD was compared to exenatide in a Lep ob/ob mouse model of diabetes. Twice-weekly subcutaneously dosed [Leu14]exenatide-ABD displayed superior glucose lowering and weight loss in diabetic mice when compared to continuously infused exenatide at the same total weekly dose. A single oral administration of each molecule via an enteric coated capsule to cynomolgus monkeys showed superior pharmacokinetics for [Leu14]exenatide-ABD as compared to [Leu14]exenatide-ABP with detectable exposure longer than 14 days. These studies support the potential use of these novel long acting exenatide analogs with different routes of administration for the treatment of type 2 diabetes.

The CD20-specific monoclonal antibody rituximab (MabThera registered , Rituxan registered ) is widely used as the backbone of treatment for patients with hematologic disorders. Intravenous administration of rituximab is associated with infusion times of 4-6 hours, and can be associated with infusion-related reactions. Subcutaneous administration of rituximab may reduce this and facilitate administration without infusion-related reactions. We sought to determine the feasibility of achieving equivalent efficacy (measured by endogenous B-cell depletion) and long-term durability of CD20 target coverage for subcutaneously administered rituximab compared with intravenous dosing. In these preclinical studies, male cynomolgus monkeys were treated with either intravenous rituximab or novel subcutaneous formulation of rituximab containing human recombinant DNA-derived hyaluronidase enzyme. Peripheral blood samples were analyzed for serum rituximab concentrations, peripheral B-cell depletion, and CD20 target coverage, including subset analysis according to CD21+ status. Distal lymph node B-cell depletion and CD20 target coverage were also measured. Initial peak serum concentrations of rituximab were significantly higher following intravenous administration than subcutaneous. However, the mean serum rituximab trough concentrations were comparable at 2 and 7 days post-first dose and 9 and 14 days post-second dose. Efficacy of B-cell depletion in both peripheral blood and distal lymph nodes was comparable for both methods. In lymph nodes, 9 days after the second dose with subcutaneous and intravenous rituximab, B-cell levels were decreased by 57% and 42% respectively. Similarly, levels of peripheral blood B cells were depleted by >94% for both subcutaneous and intravenous dosing at all time points. Long-term recovery of free unbound surface CD20 levels was similar, and the duration of B-cell depletion was equally sustained over 2 months for both methods. These results demonstrate that, despite initial peak serum drug level differences, subcutaneous rituximab has similar durability, pharmacodynamics, and efficacy compared with intravenous rituximab.

Background To date, experimental and preclinical studies on neuropsychiatric conditions have almost exclusively been performed in experimentally-induced animal models and have only rarely relied upon an ethological approach where animals have been observed in more naturalistic settings. The laboratory species of choice has been the rodent while the potential of more closely-related non-human primates have remained largely underexplored. Methods The present study, therefore, aimed at investigating the possible existence of spontaneous atypical/abnormal behaviours displayed by 40 cynomolgus macaques in captive conditions using an unbiased ethological scan-sampling analysis followed by multifactorial correspondence analysis and a hierarchical clustering. Results The study identified five distinct profiles (groups A to E) that significantly differed on several behaviours, body postures, body orientations, gaze directions and locations in the cage environment. We suggest that animals from the low n groups (D and E) present depressive-like and anxious-like symptoms, reminiscent of depressive and generalized anxiety disorders. Inter-individual differences were highlighted through unbiased ethological observations of spontaneous behaviours and associated parameters, although these were not associated with differences in plasma or cerebrospinal fluid levels of either stress-related hormones or monoamines, i.e. in accordance with the human situation. Conclusions No interventional behavioural testing was required to discriminate between 3 typical and 2 atypical ethologically-defined behavioural profiles, reminiscent of certain depressive-like and anxiety-like symptoms. The use of unbiased behavioural observations might, thus, allow the identification of animal models of human mental/behavioural disorders and their most appropriate control groups.

The identification of human broadly neutralizing antibodies (bnAbs) targeting the hemagglutinin (HA) stem revitalized hopes of developing a universal influenza vaccine. Using a rational design and library approach, we engineered stable HA stem antigens (\"mini-HAs\") based on an H1 subtype sequence. Our most advanced candidate exhibits structural and bnAb binding properties comparable to those of full-length HA, completely protects mice in lethal heterologous and heterosubtypic challenge models, and reduces fever after sublethal challenge in cynomolgus monkeys. Antibodies elicited by this mini-HA in mice and nonhuman primates bound a wide range of HAs, competed with human bnAbs for HA stem binding, neutralized H5N1 viruses, and mediated antibody-dependent effector activity. These results represent a proof of concept for the design of HA stem mimics that elicit bnAbs against influenza A group 1 viruses.

Animal models are an integral part of the drug development and evaluation process. However, they are unsurprisingly imperfect reflections of humans, and the extent and nature of many immunological differences are unknown. With the rise of targeted and biological therapeutics, it is increasingly important that we understand the molecular differences in the immunological behavior of humans and model organisms. However, very few antibodies are raised against non-human primate antigens, and databases of cross-reactivity between species are incomplete. Thus, we screened 332 antibodies in five immune cell populations in blood from humans and four non-human primate species generating a comprehensive cross-reactivity catalog that includes cell type-specificity. We used this catalog to create large mass cytometry universal cross-species phenotyping and signaling panels for humans, along with three of the model organisms most similar to humans: rhesus and cynomolgus macaques and African green monkeys; and one of the mammalian models most widely used in drug development: C57BL/6 mice. As a proof-of-principle, we measured immune cell signaling responses across all five species to an array of 15 stimuli using mass cytometry. We found numerous instances of different cellular phenotypes and immune signaling events occurring within and between species, and detailed three examples (double-positive T cell frequency and signaling; granulocyte response to Bacillus anthracis antigen; and B cell subsets). We also explore the correlation of herpes simian B virus serostatus on the immune profile. Antibody panels and the full dataset generated are available online as a resource to enable future studies comparing immune responses across species during the evaluation of therapeutics.

[carbonyl- super(11)C]N-(2-(1-(4-(2-methoxyphenyl)-piperazinyl)ethyl)- N-pyridinyl)cyclohexanecarboxamide ([carbonyl- super(11)C]WAY-1006 35) is an effective radioligand for imaging brain 5-HT sub(1A) receptors with positron emission tomography (PET). However, this radioligand has some drawbacks for deriving relative regional receptor densities, including rapid metabolism, which acts against accurate definition of an arterial input function for compartmental modeling, and very low nonspecific binding in brain, which detracts from the accuracy of modeling by a simplified reference tissue (cerebellum) approach. Here, in a search for a radioligand that overcomes these limitations, we investigated the effects of introducing a single methyl group at either of the carbon atoms alpha to the amide bond in [ super(11)C]WAY-100635. Ligands with a methyl group on the alpha carbon of the cyclohexyl group (SWAY) or the alpha carbon of the C sub(2)H sub(4) linker ((R,S)-JWAY) were synthesized and tested for binding affinity and intrinsic activity at 5-HT sub(1A) receptors. SWAY was labeled with carbon-11 (t sub(1/2) = 20.4 minutes; b super(+) = 99.8%) in its O-methyl group and (R,S)-JWAY in its carbonyl group. Each radioligand was evaluated by PET experiments in cynomolgus monkey. SWAY and (R,S)-JWAY were found to be high-affinity antagonists at 5-HT sub(1A) receptors. After injection of [ super(11)C]SWAY into monkey, radioactivity uptake in brain reached a maximum of 3% at 4.5 minutes and decreased to 0.7% at 72 minutes. However, over the time span of the experiment, radioactivity concentrations in 5-HT sub(1A) receptor-rich brain regions were only fractionally higher than in cerebellum. Radioactivity represented by parent radioligand in plasma was 39% at 45 minutes. After injection of [ super(11)C](R,S)-JWAY alone, radioactivity uptake in brain reached a maximum of 4.8% at 2.5 minutes and decreased to 1.2% at 90 minutes. At this time, radioactivity concentration in 5-HT sub(1A) receptor-rich brain regions was markedly greater than in cerebellum. In another PET experiment, the monkey was predosed with WAY-100635 before [ super(11)C](R,S)-JWAY injection. At 90 minutes after injection, the ratio of radioactivity in 5-HT sub(1A) receptor-rich regions to that in cerebellum was reduced to near unity. Radioactivity represented by parent radioligand in plasma was 12% at 45 minutes. [ super(11)C](R,S)- JWAY, but not [ super(11)C]SWAY, gives a sizeable 5-HT sub(1A) receptor-selective PET signal in monkey. The presence of a C-methyl group adjacent to the amide bond in SWAY or (R,S)-JWAY fails to counter metabolism.