Src homology 2-containing protein tyrosine phosphatase 2 (SHP2) is the first reported nonreceptor oncogenic tyrosine phosphatase connecting multiple signal transduction cascades and exerting immunoinhibitory function through the PD-1 checkpoint receptor. As part of a drug discovery program aimed at obtaining novel allosteric SHP2 inhibitors, a series of pyrazopyrazine derivatives bearing an original bicyclo[3.1.0]hexane basic moiety on the left-hand side region of the molecule were identified. We report herein the discovery process, the in vitro pharmacological profile, and the early developability features of compound 25, one of the most potent members of the series.
An efficient synthetic route was set up to prepare in good scale M-108, a novel bicycle derivative recently identified as a potent and selective G9a inhibitor, potentially useful as anti-fibroadipogenic agent. In particular, a facile three-steps sequential transformation of a substituted cis-cinnamate ethyl ester intermediate allowed to obtain the corresponding cyclopropyl nitrile derivative in high yield, which was smoothly transformed into the title racemate and then resolved by chiral HPLC.
Chronic hepatitis B (CHB) is a major worldwide public health problem and novel anti-HBV therapies preventing liver disease progression to cirrhosis and hepatocellular carcinoma are urgently needed. Over the last several years, capsid assembly modulators (CAM) have emerged as clinically effective anti-HBV agents which can inhibit HBV replication in CHB patients. As part of a drug discovery program aimed at obtaining novel CAM endowed with high in vitro and in vivo antiviral activity, we identified a novel series of sulfamoylbenzamide (SBA) derivatives. Compound 10, one of the most in vitro potent SBA-derived CAM discovered to date, showed excellent pharmacokinetics in mice suitable for oral dosing. When studied in a transgenic mouse model of hepatic HBV replication, it was considerably more potent than NVR 3-778, the first sulfamoylbenzamide (SBA) CAM that entered clinical trials for CHB, at reducing viral replication in a dose-dependent fashion. We present herein the discovery process, the SAR analysis and the pre-clinical profile of this novel SBA CAM.
patients (88%) but sub-optimally dosed (<13 mg/kg/day) in 1732 (21.5%).Only 197 pts who were under-dosed were documented to have intolerance to higher dosing.Of individuals who were not taking UDCA, only 214 (23%) were referred for alternative/second-line therapy.Of pts taking UDCA for >12 months (n = 7007), 5475 (78%) and 1532 (22%) were classified as low-risk and high risk, respectively, by the contributing hospital.However, on applying the POISE criteria, 663 and 285 patients could be reclassified as 'low-risk and high risk' respectively.Among all who were deemed high-risk with regards disease progression (n = 2476; 29%), 1228 (49.5%) commenced second-line therapy (inc.551 obeticholic acid; 468 bezafibrate; 68 fenofibrate; 76 combination therapy) and 35 referred directly to a transplant centre.In all, 1831 pts were identified as having cirrhosis (22%), of which 1304 (71%) participated in hepatocellular carcinoma surveillance.Features of decompensated liver disease were identified in 272 pts, of which only 46% (n = 67) were discussed with a transplant centre.With regards symptoms/extrahepatic manifestations, n = 3237 and 3690 pts did not undergo any assessment of pruritus (38%) or fatigue (44%) in the 24 months prior to data collection.1803 pts reported ongoing pruritus at the time of assessment, of whom only 1205 (67%) were receiving anti-pruritus therapy. Conclusion:Our study of real-world practice identifies significant gaps in clinical care across the UK PBC population.Potential future strategies to maximise adherence to guideline standards include the implementation of an integrated care pathway, along with key performance indicators, and development of a centralised referral network, allowing equitable and virtual access to specialists for all those living with PBC.
A new series of in vitro potent and highly selective histone methyl transferase enzyme G9a inhibitors was obtained. In particular, compound 2a, one the most potent G9a inhibitor identified, was endowed with >130-fold selectivity over GLP and excellent ligand efficiency. Therefore, it may represent a valuable tool compound to validate the role of highly selective G9a inhibitors in different pathological conditions. When 2a was characterized in vitro in cellular models of skeletal muscle differentiation, a relevant increase of myofibers' size and reduction of the fibroadipogenic infiltration were observed, further confirming the therapeutic potential of selective G9a inhibitors for the treatment of Duchenne muscle dystrophy.
H3K9 methylation maintains cell identity orchestrating stable silencing and anchoring of alternate fate genes within the heterochromatic compartment underneath the nuclear lamina (NL). However, how cell type-specific genomic regions are specifically targeted to the NL is still elusive. Using fibro-adipogenic progenitors (FAPs) as a model, we identified Prdm16 as a nuclear envelope protein that anchors H3K9-methylated chromatin in a cell-specific manner. We show that Prdm16 mediates FAP developmental capacities by orchestrating lamina-associated domain organization and heterochromatin sequestration at the nuclear periphery. We found that Prdm16 localizes at the NL where it cooperates with the H3K9 methyltransferases G9a/GLP to mediate tethering and silencing of myogenic genes, thus repressing an alternative myogenic fate in FAPs. Genetic and pharmacological disruption of this repressive pathway confers to FAP myogenic competence, preventing fibro-adipogenic degeneration of dystrophic muscles. In summary, we reveal a druggable mechanism of heterochromatin perinuclear sequestration exploitable to reprogram FAPs in vivo.
The marine natural product Largazole is the most potent Class I HDAC inhibitor identified to date. Since its discovery, many research groups have been attracted by the structural complexity and the peculiar anticancer activity, due to its capability to discriminate between tumor cells and normal cells. Herein, we discuss the synthesis and the in vitro biological profile of hybrid analogues of Largazole, as dual HDAC inhibitor and nitric oxide (NO) donors, potentially useful as anticancer agents. In particular, the metabolic stability of the modified thioester moiety of Largazole, bearing the NO-donor function/s, the in vitro release of NO, and the antiproliferative activity in tumor cell lines are presented.
Acid-sensing ion channels (ASICs) are a family of ion channels permeable to cations and largely responsible for the onset of acid-evoked ion currents both in neurons and in different types of cancer cells, thus representing a potential target for drug discovery. Owing to the limited attention ASIC2 has received so far, an exploratory program was initiated to identify ASIC2 inhibitors using diminazene, a known pan-ASIC inhibitor, as a chemical starting point for structural elaboration. The performed exploration enabled the identification of a novel series of ASIC2 inhibitors. In particular, compound 2u is a brain penetrant ASIC2 inhibitor endowed with an optimal pharmacokinetic profile. This compound may represent a useful tool to validate in animal models in vivo the role of ASIC2 in different neurodegenerative central nervous system pathologies.
In this work, we investigated two strategies for the synthesis of the challenging ketones 2-acylbenzonitriles and we report their use as electrophiles in asymmetric organocatalytic cascade reactions with nitromethane. Promising results were obtained in the presence of chiral bifunctional ammonium salts under phase transfer conditions, which led to novel 3,3-disubstituted isoindolinones in quantitative yields and moderate enantioselectivity.
Since the time of its identification, the natural compound largazole rapidly caught the attention of the medicinal chemistry community for its impressive potency as an inhibitor of histone deacetylases (HDACs) and its strong antiproliferative activity against a broad panel of cancer cell lines. The design of largazole analogues is an expanding field of study, due to their remarkable potential as novel anticancer therapeutics. At present, a large ensemble of largazole analogues has been reported, allowing the identification of important structure-activity relationships (SAR) that can guide the design of novel compounds with improved HDAC inhibitory profiles, anticancer activity, and pharmacokinetic properties. The aim of this review is to concisely summarize the information obtained by biological evaluations of the various largazole analogues reported to date, with particular attention given to the latest analogues, as well as to analyze the various SAR obtained from this data, with the purpose of providing useful guidelines for the development of novel potent and selective HDAC inhibitors to be used as anticancer agents.
Several strategies aimed to "freeze" natural amino acids into more constrained analogues have been developed with the aim of enhancing in vitro potency/selectivity and, more in general, drugability properties. The case of L-glutamic acid (L-Glu, 1) is of particular importance since it is the primary excitatory neurotransmitter in the mammalian central nervous system (CNS) and plays a critical role in a wide range of disorders like schizophrenia, depression, neurodegenerative diseases such as Parkinson's and Alzheimer's and in the identification of new potent and selective ligands of ionotropic and metabotropic glutamate receptors (GluRs). To this aim, bicycle compound Ib was designed and synthesised from D-serine as novel [2.3]-spiro analogue of L-Glu. This frozen amino acid derivative was designed to further limit the rotation around the C3-C4 bond present in the azetidine derivative Ia by incorporating an appropriate spiro moiety. The cyclopropyl moiety was introduced by a diastereoselective rhodium catalyzed cyclopropanation reaction.
In this paper, a recently reported series of NPS antagonists is further expanded and biologically evaluated. The ligand efficiency and ADMET score concepts were then applied to the newly disclosed 5-phenyl-2-[2-(1-piperidinyl-carbonyl) phenyl]-2,3-dihydro-1H-pyrrolo[1,2-c]imidazol-1-ones, to limit the SAR exploration. Important pharmacophoric features were identified suggesting potential way forward for the identification of further developable templates.
In this work the pharmacology and the receptor kinetics of the following orexin receptor antagonists SB-649868, ACT-078573, JNJ-10397049, MK-6096 and Roche-Cp were evaluated at human OX1 and OX2 orexin receptors by using functional and receptor binding assays. Kinetic analysis of the unlabeled ligands was carried out by indirect measurement according to the Motulski and Mahan's method as opposed to the direct measure by using labeled test compounds. All compounds antagonized orexin-A-induced inositol 1 phosphate (IP1) accumulation with the following pKB values: SB-649868 (OX1=9.67; OX2=9.64), ACT-078573 (OX1=8.44; OX2=9.02), JNJ-10397049 (OX1=5.97; OX2=8.35), MK-6096 (OX1=9.13; OX2=9.79) and Roche-Cp (OX1=7.18; OX2=8.83). They displaced the [3H]ACT-078573 receptor binding with the following pKi values: SB-649868 (OX1=9.27; OX2=8.91), ACT-078573 (OX1=7.80; OX2=9.12), JNJ-10397049 (OX1=5.18; OX2=8.10), MK-6096 (OX1=8.39; OX2=8.90) and Roche-Cp (OX1=6.65; OX2=8.54). From dissociation kinetic studies using [3H]ACT-078573, the calculated long half-life, (t½) supported the non-surmountability profile of SB-649868 (t½=35.91 min) at OX1 orexin receptor. Similarly, the long or moderately long t½ values for ACT-078573 at OX2 orexin receptor (t½=69.71 min), MK-6096 (t½=17.70 min), SB-649868 (t½=8.09 min) and Roche-Cp (t½=5.79 min) sustained their non-surmountable profile. JNJ-10397049 showed short t½ values at both receptor subtypes (OX1 t½=0.19 min; OX2 t½=0.60 min) with surmountable antagonism.
Orexins (OX) and their receptors (OXR) modulate feeding, arousal, stress, and drug abuse. Neural systems that motivate and reinforce drug abuse may also underlie compulsive food seeking and intake. Therefore, the effects of GSK1059865 (5-bromo- N -[(2 S ,5 S )-1-(3-fluoro-2-methoxybenzoyl)-5-methylpiperidin-2-yl]methyl-pyridin-2-amine), a selective OX 1 R antagonist, JNJ-10397049 ( N -(2,4-dibromophenyl)- N ′-[(4 S ,5 S )-2,2-dimethyl-4-phenyl-1,3-dioxan-5-yl]urea), a selective OX 2 R antagonist, and SB-649868 ( N -[((2 S )-1-{[5-(4-fluorophenyl)-2-methyl-1,3-thiazol-4-yl]carbonyl}-2-piperidinyl)methyl]-1-benzofuran-4-carboxamide), a dual OX 1 /OX 2 R antagonist were evaluated in a binge eating (BE) model in female rats. BE of highly palatable food (HPF) was evoked by three cycles of food restriction followed by stress, elicited by exposing rats to HPF, but preventing them from having access to it for 15 min. Pharmacokinetic assessments of all compounds were obtained under the same experimental conditions used for the behavioral experiments. Topiramate was used as the reference compound as it selectively blocks BE in rats and humans. Dose-related thresholds for sleep-inducing effects of the OXR antagonists were measured using polysomnography in parallel experiments. SB-649868 and GSK1059865, but not JNJ-10397049, selectively reduced BE for HPF without affecting standard food pellet intake, at doses that did not induce sleep. These results indicate, for the first time, a major role of OX 1 R mechanisms in BE, suggesting that selective antagonism at OX 1 R could represent a novel pharmacological treatment for BE and possibly other eating disorders with a compulsive component.
A large body of compelling preclinical evidence supports the clinical use of neurokinin (NK) receptor antagonists in a plethora of CNS and non-CNS therapeutic areas. The significant investment made in this area over the past 2 decades culminated with the observation that NK1 receptor antagonists elicited clinical efficacy in major depression disorders. In addition, aprepitant (Merck) was launched as a new drug able to prevent chemotherapy-induced nausea and vomiting (CINV). After the discovery by GlaxoSmithKline of vestipitant, a wide drug discovery program was launched aimed at identifying additional clinical candidates. New compounds were designed to maximize affinity at the NK1 receptor binding site while retaining suitable physicochemical characteristics to ensure excellent pharmacokinetic and pharmacodynamic properties in vivo. Herein we describe the discovery process of a new NK1 receptor antagonist (casopitant) selected as clinical candidate and progressed into clinical studies to treat major depression disorders.
Further exploration around the recently disclosed potent triple re-uptake inhibitor 6-(3,4-dichlorophenyl)-1-[(methyloxy)methyl]-3-azabicyclo[4.1.0]heptane led to the identification of a new series of potent triple re-uptake inhibitors endowed with good developability characteristics. The insertion of a further aryl moiety into the template allowed the ‘titration’ of the SERT/NET/DAT ratio leading to the identification of further tools in this important area.