Preclinical Profile Research Articles

Preclinical pharmacology characterization of HX009, a novel PD1 x CD47 Bi-specific antibody.

Certain immune-checkpoint inhibitors have a narrow therapeutic window (TW) as cancer therapeutics, and engineered dual-/multi-targeting agents could potentially widen the TW to bring true clinical benefits. We report a new rationally-designed bispecific-antibody (BsAb), HX009, simultaneously targeting PD1 and CD47 to improve both the efficacy and safety over the respective single-targeting agents by grafting the extracellular domain of SIRPα onto the parental anti-PD1-monoclonal antibody, HX008. This resulted in an IgG4-based "2 × 2" symmetric structure but with an intentionally-reduced CD47-binding affinity, suggesting a novel candidate cancer immunotherapy. Specifically, HX009 has binding affinity constant of 8.951 × 10-9M for human PD1 and 2.557 × 10-8M for human CD47, respectively, where the CD47 binding is significantly weaker as compared to the binding affinity of HX008 to PD1 as well as the binding affinity of SIRPα-Fc to CD47, leading to little binding to RBCs and platelets and is contrasting to many CD47-agents in development. However, HX009 effectively and simultaneously binds to the PD1 and CD47 on PD1+CD47+ T-cells via cis-binding and elicits enhanced T cell activation compared to the parental HX008. HX009 caused little cytokine-release in human peripheral blood mononuclear cells. HX009 cross-species binds to cynomolgus monkey PD1/CD47 but not to rodents, making cynomolgus monkeys the choice of species to investigate the pharmacokinetics (PK) and toxicology of HX009. HX009's anti-tumor activities were confirmed in several humanized preclinical mouse models by determining either its anti-PD1 (humanized hu-CD47-MC38 models) or anti-CD47 (HuT-102 lymphoma CDX and three PDX-AML models) functions, although limited available humanized models have hindered broadly demonstration of enhanced anti-tumor activities contributed from the dual targeting of the BsAb. The expanded DLBCL-PDX trial data suggested that both EBV-status and OX40 expression could potentially be two positive predictors for response to HX009. An intravenous (IV) infusion PK study in cynomolgus monkey revealed its largely vasculature distribution, terminal half-life (T1/2) of ~ 50h, and dose-proportional exposure without accumulation. The anti-drug antibody (ADA) was observed in all monkeys as expected, affecting the PK parameters of repeated administration. The IV single-dose toxicology study with a 14-day observation revealed a maximum tolerated dose of 150mg/kg, while the repeated-dose (once weekly for 4weeks, 5 doses in total) study showed a highest non-severely toxic dose (HNSTD) of 15mg/kg. The desired preclinical PK and safety profiles, along with its antitumor activity, support HX009's candidacy for its clinical development.

18F]NP3-627, a candidate PET imaging agent targeting the NLRP3 inflammasome in the central nervous system.

We describe the identification of a candidate positron emission tomography (PET) imaging agent for the NLRP3 protein. NLRP3 plays a critical role in the immune system and has proven a difficult target for the development of imaging agents due to its low and cell-specific expression profile. A recently described series of pyridazine-based inhibitors, with improved permeability and brain-penetration properties, was used as a starting point for the development of a suitable PET imaging agent. Optimization of affinity, non-specific binding and pharmacokinetic properties led to the identification of aminopyridazine (R)-2-(6-((1-cyclopropylpiperidin-3-yl)amino)pyridazin-3-yl)-5-fluoro-3-methylphenol (17b), which meets the preclinical profile of a successful imaging agent, and whose tritiated version demonstrated excellent specificity in a radioligand saturation binding assay, confirming its imaging potential.18F labeling led to [18F]NP3-627, the proposed PET imaging agent.

Preclinical thyroid hormone profile studies of an ayurvedic medicine Parthadyarishta after chronic administration to male Sprague-Dawley rats

Background: Parthadyarishta (PRTm) is an Ayurvedic preparation used as a traditional medicine to treat heart disease. This research was designed to study the thyroid hormone profile after chronic administration of this drug. Methods: Twenty healthy Sprague-Dawley male rats (90-110 g) were randomly divided into a control group and an experimental group. The experimental group was assigned to receive the drug at a dose of 40 ml/kg of body weight orally. After 28 days of treatment, blood samples were collected to carry out biochemical tests to determine the thyroid hormone safety profile. Serum circulating levels of total thyroxine (tT4), total triiodothyronine (tT3), free thyroxine (fT4), free triiodothyronine (fT3), thyroid stimulating hormone (TSH) were measured by Chemiluminescent Microparticle Immunoassay (CMIA) method. Results: This study showed statistically significant (p=0.008) [21.93%] decrease in tT3 level and statistically significant (p=0.047) [10.73%] increase in fT3 level in the rats. Also, statistically insignificant decrease in tT4 level and increase in fT4 level were observed. There is a [49.96 %] decrease in TSH level (p=0.371). The results suggested that Parthadyarishta have exerted an opposite effect on both the total and free form of T3 by increasing the free form (fT3) though causing decrease in the total form (tT3). Conclusions: As Parthadyarishta has significant impact on thyroid hormone levels so it is recommended to use it cautiously for chronic use specially in cardiac patients. Further studies are needed to determine the toxicological profile of Parthadyarishta and its effect on cardiovascular system through interference in thyroid function.

Rapid Hippocampal Synaptic Potentiation Induced by Ketamine Metabolite ( 2R , 6R )-Hydroxynorketamine Persistently Primes Synaptic Plasticity.

The pharmacologically active ( R , S )-ketamine (ketamine) metabolite ( 2R , 6R )-hydroxynorketamine (HNK) maintains ketamine's preclinical antidepressant profile without adverse effects. While hypotheses have been proposed to explain how ketamine and its metabolites initiate their antidepressant-relevant effects, it remains unclear how sustained therapeutic actions arise following drug elimination. To distinguish the physiological mechanisms involved in the rapid from sustained actions of HNK, we utilized extracellular electrophysiology combined with pharmacology to develop an in vitro hippocampal slice incubation model that exhibited pharmacological fidelity to the 1) rapid synaptic potentiation induced by HNK at the Schaffer collateral-CA1 (SC-CA1) synapse during bath-application to slices collected from mice, and 2) maintenance of metaplastic (priming) activity that lowered the threshold for N- methyl-D-aspartate receptor (NMDAR) activation-dependent long-term potentiation (LTP) hours after in vivo dosing. We then used this model to reveal novel druggable mechanisms engaged in HNK's temporally-sensitive antidepressant synaptic actions, finding that the induction of synaptic potentiation by HNK did not require NMDAR activity, but NMDAR activity was necessary to maintain synaptic priming. HNK required protein kinase A (PKA) activity to rapidly potentiate SC-CA1 neurotransmission to facilitate synaptic priming that persistently promoted LTP formation. HNK's rapid actions were blocked by inhibitors of adenylyl cyclase 1 (AC1), but not an AC5 inhibitor. We conclude that HNK rapidly potentiates SC-CA1 synaptic efficacy, which then stimulates priming mechanisms that persistently favor antidepressant-relevant plasticity. Targeting such priming mechanisms may be an effective antidepressant strategy, and using approaches such as our incubation model may aid in revealing novel pharmacological targets.

Desidustat: a novel PHD inhibitor for the treatment of CKD-induced anemia.

Desidustat is a small molecule inhibitor of hypoxia-inducible factor-prolyl hydroxylase (HIF-PH) discovered and developed by Zydus Lifesciences for the treatment of anemia associated with chronic kidney disease (CKD). This review summarizes the preclinical and clinical profile of desidustat which led to its approval and clinical use in India.

Role of Mandukparni (Centella asiatica Linn Urban) in neurological disorders: Evidence from ethnopharmacology and clinical studies to network enrichment analysis

Centella asiatica Linn Urban (C. asiatica), aka Mandukparni, is one of the flagship herbs used in traditional medicines to effectively manage neurological problems. Although this plant has a wealth of comprehensive preclinical pharmacological profiles, further clinical research and execution of its molecular mode of action are still required. We searched electronic databases (Google Scholar, SciFinder, MEDLINE, Scopus, EMBASE, Science Direct, and PubMed) using relevant key words to retrieve information pertaining to C. asiatica till June 2023 and performed network pharmacology to understand the mechanism related to their neurobiological roles. This study extensively analyses its pharmacological properties, nutritional profile, ethnomedical uses, safety, and mechanistic role in treating neurological and neurodegenerative disorders. Additionally, a network pharmacology study was performed which suggests that its phytomolecules are involved in different neuroactive ligand-receptor pathways, glial cell differentiation, gliogenesis, and astrocyte differentiation. Hopefully, this report will lead to a paradigm shift in medical practice, research, and the creation of phytopharmaceuticals derived from C. asiatica that target the central nervous system.

Abstract IA-04: Targeting the oncogenic state of RAS with tri-complex inhibitors

Abstract KRAS oncogenic driver mutations occur in approximately 30% of all human cancers, and in particular, in over 90% of patients with pancreatic ductal adenocarcinoma (PDAC). Small molecule inhibitors that selectively target the inactive, GDP-bound state of KRAS G12C mutant proteins have demonstrated clinical efficacy in non-small cell lung cancer (NSCLC) as monotherapies, and in the small subset of PDAC patients that harbor this mutation. However, there are no currently approved RAS-targeted therapy options for the majority of patients with non-G12C RAS mutant PDAC. We have designed a series of tri-complex inhibitors that specifically target the GTP-bound, active state of RAS (RAS(ON)). These small molecule inhibitors bind non-covalently to an abundant intracellular protein, cyclophilin A (CypA). The resulting binary complex selectively engages RAS(ON), forming a tri-complex that sterically inhibits RAS interaction with downstream effectors. We have generated mutant-selective inhibitors that covalently engage RAS(ON) G12C (RMC-6291) or RAS(ON) G12D (RMC-9805). In addition, RMC-6236 is a RAS(ON) multi-selective inhibitor that non-covalently inhibits the active, GTP-bound state of mutant and wild-type variants of the canonical RAS isoforms (KRAS, NRAS, and HRAS). Here we will describe the mechanism of action of these investigational agents and the preclinical profiles that support their clinical evaluation in patients with PDAC as monotherapies and in combination therapy regimens with standard-of-care agents or as novel RAS(ON) inhibitor doublets. Citation Format: Mallika Singh. Targeting the oncogenic state of RAS with tri-complex inhibitors [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr IA-04.

Discovery and Preclinical Profile of ALG-055009, a Potent and Selective Thyroid Hormone Receptor Beta (THR-β) Agonist for the Treatment of MASH.

Agonists of thyroid hormone receptor β (THR-β) decreased LDL cholesterol (LDL-C) and triglyceride (TG) levels in human clinical trials for patients with dyslipidemia. The authors present the highly potent and selective compound ALG-055009 (14) as a potential best in class THR-β agonist. The high metabolic stability and good permeability translated well in vivo to afford a long in vivo half-life pharmacokinetic profile with limited liability for DDI, and it overcomes certain drawbacks seen in recent clinical candidates.

CMG901, a Claudin18.2-specific antibody-drug conjugate, for the treatment of solid tumors

Claudin18.2 has been recently recognized as a potential therapeutic target for gastric/gastroesophageal junction or pancreatic cancer. Here, we develop a Claudin18.2-directed antibody-drug conjugate (ADC), CMG901, with a potent microtubule-targeting agent MMAE (monomethyl auristatin E) and evaluate its preclinical profiles. Invitro studies show that CMG901 binds specifically to Claudin18.2 on the cell surface and kills tumor cells through direct cytotoxicity, antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and bystander killing activity. Invivo pharmacological studies show significant antitumor activity in patient-derived xenograft (PDX) models. Toxicity studies show that the major adverse effects related to CMG901 are reversible hematopoietic changes attributed to MMAE. The highest non-severely toxic dose (HNSTD) is 6mg/kg in cynomolgus monkeys and 10mg/kg in rats once every 3weeks. CMG901's favorable preclinical profile supports its entry into the human clinical study. CMG901 is currently under phase 3 investigation in patients with advanced gastric/gastroesophageal junction adenocarcinoma expressing Claudin18.2 (NCT06346392).

Preclinical Development of SHR-1819, a Potent Humanized IL-4Rα Antibody for Treating Type 2 Inflammatory Diseases.

Interleukin (IL)-4 and IL-13 are critical pathogenic factors for type 2 inflammation-related allergic diseases, sharing the mutual receptor subunit IL-4Rα. However, it was ineffective for certain type 2 inflammation diseases by targeting IL-4, IL-13 ligand alone or both in clinical studies. The work presented herein aimed to evaluate the preclinical efficacy and pharmacokinetics profile of a novel monoclonal antibody against IL-4Rα, SHR-1819, as a promising therapy for type 2 inflammation diseases. SHR-1819 was generated through immunization by C57BL/6 mice with recombinant hIL-4Rα protein, followed by humanization and affinity maturation. Then, its binding properties with IL-4Rα were determined using surface plasmon resonance (SPR) and ELISA. In vitro inhibitory effects of SHR-1819 were assessed on hIL-4-/hIL-13-induced cell proliferation and signal transducer and activator of transcription 6 (STAT6) signaling activation. In vivo efficacy of SHR-1819 was evaluated in several type 2 inflammatory diseases models, including asthma, atopic dermatitis (AD), and allergic rhinitis (AR) by using hIL-4/hIL-4Rα transgenic mice. Furthermore, the pharmacokinetic (PK) profiles of SHR-1819 were characterized. SHR-1819 showed high binding affinity to human IL-4Rα and effectively blocked IL-4Rα at sub-nanomolar concentration. In vitro assays indicated that SHR-1819 significantly inhibited TF-1 cell proliferation and STAT6 activation induced by hIL-4/hIL-13. In the asthma model, SHR-1819 could reduce airway hyperresponsiveness, decrease serum IgE levels, and alleviated inflammatory lung cell infiltration. In the AD model, SHR-1819 could significantly alleviate inflammatory and skin symptoms. In the AR model, it could remarkably decrease the frequencies of nasal rubbing and sneezing, and inflammatory cell infiltration in nasal tissues. These in vivo efficacy studies demonstrated the therapeutic potential of SHR-1819 in preclinical disease models. Moreover, subcutaneous administration of SHR-1819 exhibited favorable bioavailability in mice. The results supported SHR-1819 as a promising preclinical candidate for the treatment of type 2 inflammatory diseases, including asthma, AD and AR.

Discovery of orally bioavailable phosphonate prodrugs of potent ENPP1 inhibitors for cancer treatment

Ectonucleotide pyrophosphatase phosphodiesterase 1 (ENPP1) is the dominant hydrolase of 2′,3′-cyclic GMP-AMP (cGAMP). Inhibition of ENPP1 contributes to increased cGAMP concentration and stimulator of interferon gene (STING) activation, with the potential to boost immune response against cancer. ENPP1 is a promising therapeutic target in tumor immunotherapy. To date, orally bioavailable ENPP1 inhibitors with highly potent activity under physiological conditions have been rarely reported. Herein, we report our effort in the design and synthesis of two different series of ENPP1 inhibitors, and in the identification of a highly potent ENPP1 inhibitor 27 (IC50 = 1.2 nM at pH 7.5), which significantly enhanced the cGAMP-mediated STING activity in THP-1 cells. Phosphonate compound 27 has good preclinical pharmacokinetic profiles with low plasma clearance rate in mouse, rat, and dog. It has been developed as bis-POM prodrug 36 which successfully improves the oral bioavailability of 27. In the Pan02 syngeneic mouse model of pancreatic cancer, orally administered 36 showed synergistic effect in combination with radiotherapy.

Discovery and preclinical profile of YK-2168, a differentiated selective CDK9 inhibitor in clinical development

Emerging clinical evidence indicates that selective CDK9 inhibition may provide clinical benefits in the management of certain cancers. Many CDK9 selective inhibitors have entered clinical developments, and are being investigated. No clear winner has emerged because of unforeseen toxicity often observed in clinic with these agents. Therefore, a novel agent with differentiated profiles is still desirable. Herein, we report our design, syntheses of a novel azaindole series of selective CDK9 inhibitors. SAR studies led to a preclinical candidate YK-2168. YK2168 exhibited improved CDK9 selectivity over AZD4573 and BAY1251152; also showed differentiated intravenous PK profile and remarkable solid tumor efficacy in a mouse gastric cancer SNU16 CDX model in preclinical studies. YK-2168 is currently in clinical development in China (CTR20212900).

Preclinical toxicological assessment of amido-bridged nucleic acid-modified antisense oligonucleotides targeting synaptotagmin XIII for intra-abdominal treatment of peritoneal metastasis of gastric cancer.

Peritoneal metastasis of gastric cancer is closely associated with dismal prognosis. In previous preclinical proof-of-concept studies, an amido-bridged nucleic acid (AmNA)-modified antisense oligonucleotide (ASO), designated ASO-4733 that targets the gene encoding synaptotagmin XIII (SYT13), inhibited cellular functions required for the formation of peritoneal metastasis of gastric cancer cells. ASO-4733 achieved therapeutic effects when intra-abdominally administered to mouse xenograft models. Here, we conducted an analysis of Syt13-deficient mice to determine the pharmacokinetics and toxicity of intra-abdominal administration of ASO-4733. The effects of Syt13-deficiency in mice were determined. Good Laboratory Practice toxicity tests and the toxicokinetics of intra-abdominal administration of ASO-4733 were conducted in cynomolgus monkeys and rats. The pharmacokinetics of ASO-4733 administered intravenously or intra-abdominally to rats were investigated. Syt13-deficient mice exhibited normal reproduction, organ functions, and motor functions. Weekly intra-abdominal administration of ASO-4733 (125mg/kg), corresponding to a 50-fold increase of the estimated clinical dose for 4weeks, was well tolerated by cynomolgus monkeys. In rats, off-target toxicity (not attributable to hybridization) was observed after weekly intra-abdominal administration of ASO-4733. Blood concentrations of ASO-4733 were lower and rose more slowly after intra-abdominal administration compared with intravenous administration. The preclinical profile of intra-abdominal administration of ASO-4733 demonstrated its suitability for entry into clinical trials of patients with peritoneal metastasis of gastric cancer.

Preclinical pharmacokinetic studies and prediction of human PK profiles for Deg-AZM, a clinical-stage new transgelin agonist.

Deglycosylated azithromycin (Deg-AZM), a newly developed Class I drug with good therapeutic effects on slow transit constipation, is a small-molecule transgelin agonist that has been approved for clinical trials in 2024. The preclinical pharmacokinetic profile of Deg-AZM was investigated to support further development. A LC-MS/MS method was established and validated to detected the concentration of Deg-AZM in various biological samples. In vivo tests such as pharmacokinetic studies in rats and dogs, tissue distribution studies in rats, and extraction studies in rats were conducted to investigated the preclinical pharmacokinetic behaviors of Deg-AZM comprehensively. The plasma protein rate of Deg-AZM was determined by rapid equilibrium dialysis method in vitro. The metabolic stability and metabolite profile of Deg-AZM was assessed using pooled mice, rats, dogs, monkeys and humans microsomes in vitro. The PK profiles of Deg-AZM in human was predicted based on physiologically based pharmacokinetic (PBPK) models. The plasma protein binding rates of Deg-AZM were lower in mice and rats, higher in dogs, and moderate in humans. The metabolic process of Deg-AZM was similar in rat and human liver microsomes. From Pharmacokinetic studies in rats and dogs, Deg-AZM was rapidly absorbed into the blood and then quickly eliminated. Plasma exposure of Deg-AZM was dose dependent with no accumulation after continuous gavage administration. In addition, there is no significant gender difference in the pharmacokinetic behavior of Deg-AZM. Deg-AZM was widely distributed in the tissues without obvious accumulation, and mainly excreted from the urinary excretion pathway. Furthermore, the pharmacokinetic profiles of Deg-AZM in humans showed dose dependency. The pharmacokinetic profiles of Deg-AZM was fully explored, these results could provide valuable information to support the first-in-human dosage prediction and phase I clinical design.

Pharmacological and pre-clinical safety profile of rSIV.F/HN, a hybrid lentiviral vector for cystic fibrosis gene therapy.

Cystic fibrosis (CF) is caused by mutations in the CF Transmembrane Conductance Regulator (CFTR) gene. CFTR modulators offer significant improvements, but approximately 10% of patients remain nonresponsive or are intolerant. This study provides an analysis of rSIV.F/HN, a lentiviral vector optimized for lung delivery, including CFTR protein expression, functional correction of CFTR defects and genomic integration site analysis in preparation for a first-in-human clinical trial. Air-liquid interface cultures of primary human bronchial epithelial cells (HBEC) from CF patients (F508del/F508del), as well as a CFTR-deficient immortalized human lung epithelial cell line mimicking Class I (CFTR-null) homozygous mutations, were used to assess transduction efficiency. Quantification methods included a novel proximity ligation assay (PLA) for CFTR protein expression. For assessment of CFTR channel activity, Ussing chamber studies were conducted. The safety profile was assessed using integration site analysis and in vitro insertional mutagenesis studies. rSIV.F/HN expressed CFTR and restored CFTR-mediated chloride currents to physiological levels in primary F508del/F508del HBECs as well as in a Class I cells. In contrast, the latter could not be achieved by small-molecule CFTR modulators, underscoring the potential of gene therapy for this mutation class. Combination of rSIV.F/HN-CFTR with the potentiator ivacaftor showed a greater than additive effect. The genomic integration pattern showed no site predominance (frequency of occurrence ≤10%), and a low risk of insertional mutagenesis was observed in an in vitro immortalization assay. The results underscore rSIV.F/HN as a promising gene therapy vector for CF, providing a mutation-agnostic treatment option.

Zinc for GNAO1 encephalopathy: Preclinical profiling and a clinical case

De novo pathogenic variants in GNAO1-the gene encoding the major neuronal G protein Gαo-cause pediatric encephalopathies and other neurological deficiencies largely refractory to available therapies. Zn2+ emerged to restore guanosine triphosphate hydrolysis and cellular interactions of pathogenic Gαo; dietary zinc salt supplementation improves lifespan and motoric function in a Drosophila disease model. Using biochemical, animal, and first-in-human studies, we provide support for the patient stratification and application of zinc acetate in GNAO1-associated disorders. We show that 16 different pathogenic missense variants cluster in three distinct groups in their responsiveness to Zn2+, and we provide the safety study in a mouse disease model. We further describe treatment of a 3-year-old patient with the common pathogenic GNAO1 variant c607G>A, p.Gly203Arg with oral 50mg zinc (in the form of zinc acetate) daily, as applied in Wilson's disease. During 11months of treatment, the patient shows cessation of daily dyskinetic crises, improved Burke-Fahn Marsden Dystonia Rating Scale movement score, reduction in epileptic seizures, and an excellent safety profile. Our findings warrant a large-scale clinical trial and might set the new standard of care for GNAO1-related disorders. This work was funded by the Russian Science Foundation (grant #21-15-00138) and GNAO1 España.

Discovery of Preclinical Candidate AD1058 as a Highly Potent, Selective, and Brain-Penetrant ATR Inhibitor for the Treatment of Advanced Malignancies.

The ataxia telangiectasia-mutated and Rad3-related protein (ATR) plays a crucial role in regulating the cellular DNA-damage response (DDR), making it a promising target for antitumor drug development through synthetic lethality. In this study, we present the discovery and detailed characterization of AD1058, a highly potent and selective ATR inhibitor, with good preclinical pharmacokinetic profiles. AD1058 exhibits superior efficacy in inhibiting cell proliferation, disrupting the cell cycle, and inducing apoptosis compared to AZD6738. AD1058 displays potent antitumor effects as a single agent or in combination with clinically approved tumor therapies such as PARP inhibitors, ionizing radiotherapy, or chemotherapy in vivo. Considering its enhanced ability to permeate the blood-brain barrier, AD1058 is a promising clinical candidate for the treatment of brain metastases and leptomeningeal metastases in solid tumors. Additionally, among reported ATR inhibitors, AD1058 features the shortest synthesis route and the highest efficiency to date.

Preclinical efficacy profiles of the sigma-1 modulator E1R and of fenfluramine in two chronic mouse epilepsy models.

Given its key homeostatic role affecting mitochondria, ionotropic and metabotropic receptors, and voltage-gated ion channels, sigma-1 receptor (Sig1R) represents an interesting target for epilepsy management. Antiseizure effects of the positive allosteric modulator E1R have already been reported in acute seizure models. Although modulation of serotonergic neurotransmission is considered the main mechanism of action of fenfluramine, its interaction with Sig1R may be of additional relevance. To further explore the potential of Sig1R as a target, we assessed the efficacy and tolerability of E1R and fenfluramine in two chronic mouse models, including an amygdala kindling paradigm and the intrahippocampal kainate model. The relative contribution of the interaction with Sig1R was analyzed using combination experiments with the Sig1R antagonist NE-100. Whereas E1R exerted pronounced dose-dependent antiseizure effects at well-tolerated doses in fully kindled mice, only limited effects were observed in response to fenfluramine, without a clear dose dependency. In the intrahippocampal kainate model, E1R failed to influence electrographic seizure activity. In contrast, fenfluramine significantly reduced the frequency of electrographic seizure events and their cumulative duration. Pretreatment with NE-100 reduced the effects of E1R and fenfluramine in the kindling model. Surprisingly, pre-exposure to NE-100 in the intrahippocampal kainate model rather enhanced and prolonged fenfluramine's antiseizure effects. In conclusion, the kindling data further support Sig1R as an interesting target for novel antiseizure medications. However, it is necessary to further explore the preclinical profile of E1R in chronic epilepsy models with spontaneous seizures. Despite the rather limited effects in the kindling paradigm, the findings from the intrahippocampal kainate model suggest that it is of interest to further assess a possible broad-spectrum potential of fenfluramine.

Harmine and exendin-4 combination therapy safely expands human β cell mass in vivo in a mouse xenograft system.

Five hundred thirty-seven million people globally suffer from diabetes. Insulin-producing β cells are reduced in number in most people with diabetes, but most individuals still have some residual β cells. However, none of the many diabetes drugs in common use increases human β cell numbers. Recently, small molecules that inhibit dual tyrosine-regulated kinase 1A (DYRK1A) have been shown to induce immunohistochemical markers of human β cell replication, and this is enhanced by drugs that stimulate the glucagon-like peptide 1 (GLP1) receptor (GLP1R) on β cells. However, it remains to be demonstrated whether these immunohistochemical findings translate into an actual increase in human β cell numbers in vivo. It is also unknown whether DYRK1A inhibitors together with GLP1R agonists (GLP1RAs) affect human β cell survival. Here, using an optimized immunolabeling-enabled three-dimensional imaging of solvent-cleared organs (iDISCO+) protocol in mouse kidneys bearing human islet grafts, we demonstrate that combination of a DYRK1A inhibitor with exendin-4 increases actual human β cell mass in vivo by a mean of four- to sevenfold in diabetic and nondiabetic mice over 3 months and reverses diabetes, without alteration in human α cell mass. The augmentation in human β cell mass occurred through mechanisms that included enhanced human β cell proliferation, function, and survival. The increase in human β cell survival was mediated, in part, by the islet prohormone VGF. Together, these findings demonstrate the therapeutic potential and favorable preclinical safety profile of the DYRK1A inhibitor-GLP1RA combination for diabetes treatment.

A drug-drug interaction study and physiologically based pharmacokinetic modelling to assess the effect of an oral 5-lipoxygenase activating protein inhibitor on the pharmacokinetics of oral midazolam.

Early clinical studies have indicated that the pharmacokinetics of Atuliflapon (AZD5718) are time and dose dependent. The reason(s) for these findings is(are) not fully understood, but pre-clinical profiling suggests that time-dependent CYP3A4 inhibition cannot be excluded. In clinical practice, Atuliflapon will be co-administered with CYP3A4 substrates; thus, it is important to determine the impact of Atuliflapon on the pharmacokinetics (PK) of CYP3A4 substrates. The aim of this study was to evaluate the effect of Atuliflapon on the pharmacokinetics of a sensitive CYP3A4 substrate, midazolam, and to explore if the time-/dose-dependent effect seen after repeated dosing could be an effect of change in CYP3A4 activity. Open-label, fixed-sequence study in healthy volunteers to assess the PK of midazolam alone and in combination with Atuliflapon. Fourteen healthy male subjects received single oral dose of midazolam 2mg on days 1 and 7 and single oral doses of Atuliflapon (125 mg) from days 2 to 7. A physiologically based pharmacokinetic (PBPK) model was developed to assess this drug-drug interaction. Mean midazolam values of maximum plasma concentration (Cmax) and area under the curve (AUC) to infinity were increased by 39% and 56%, respectively, when co-administered with Atuliflapon vs. midazolam alone. The PBPK model predicted a 27% and 44% increase in AUC and a 23% and 35% increase in Cmax of midazolam following its co-administrations with two predicted therapeutically relevant doses of Atuliflapon. Atuliflapon is a weak inhibitor of CYP3A4; this was confirmed by the validated PBPK model. This weak inhibition is predicted to have a minor PK effect on CYP3A4 metabolized drugs.