Discovery of Clinical Candidate NT-0796, a Brain-Penetrant and Highly Potent NLRP3 Inflammasome Inhibitor for Neuroinflammatory Disorders

The NLRP3 inflammasome is a component of the innate immune system involved in the production of proinflammatory cytokines. Neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, multiple sclerosis, and amyotrophic lateral sclerosis, have been shown to have a component driven by NLRP3 inflammasome activation. Diseases such as these with large unmet medical needs have resulted in an interest in inhibiting the NLRP3 inflammasome as a potential pharmacological treatment, but to date, no marketed drugs specifically targeting NLRP3 have been approved. Furthermore, the requirement for CNS-penetrant molecules adds additional complexity to the search for NLRP3 inflammasome inhibitors suitable for clinical investigation of neuroinflammatory disorders. We designed a series of ester-substituted carbamate compounds as selective NLRP3 inflammasome inhibitors, leading to NT-0796, an isopropyl ester that undergoes intracellular conversion to NDT-19795, the carboxylic acid active species. NT-0796 was shown to be a potent and selective NLRP3 inflammasome inhibitor with demonstrated in vivo brain penetration.

Discovery and Optimization of Triazolopyrimidinone Derivatives as Selective NLRP3 Inflammasome Inhibitors

The NLRP3 inflammasome is a multiprotein complex that facilitates activation and release of the proinflammatory cytokines interleukin-1β (IL-1β) and IL-18 in response to infection or endogenous stimuli. It can be inappropriately activated by a range of danger signals resulting in chronic, low-grade inflammation underlying a multitude of diseases, such as Alzheimer's disease, Parkinson's disease, osteoarthritis, and gout. The discovery of potent and specific NLRP3 inhibitors could reduce the burden of several common morbidities. In this study, we identified a weakly potent triazolopyrimidone hit (1) following an in silico modeling exercise. This was optimized to furnish potent and selective small molecule NLRP3 inflammasome inhibitors. Compounds such as NDT-30805 could be useful tool molecules for a scaffold-hopping or pharmacophore generation project or used as leads toward the development of clinical candidates.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Structure-guided evolution of potent and selective CHK1 inhibitors through scaffold morphing

Pyrazolopyridine inhibitors with low micromolar potency for CHK1 and good selectivity against CHK2 were previously identified by fragment-based screening. The optimization of the pyrazolopyridines to a series of potent and CHK1-selective isoquinolines demonstrates how fragment-growing and scaffold morphing strategies arising from a structure-based understanding of CHK1 inhibitor binding can be combined to successfully progress fragment-derived hit matter to compounds with activity in vivo. The challenges of improving CHK1 potency and selectivity, addressing synthetic tractability, and achieving novelty in the crowded kinase inhibitor chemical space were tackled by multiple scaffold morphing steps, which progressed through tricyclic pyrimido[2,3-b]azaindoles to N-(pyrazin-2-yl)pyrimidin-4-amines and ultimately to imidazo[4,5-c]pyridines and isoquinolines. A potent and highly selective isoquinoline CHK1 inhibitor (SAR-020106) was identified, which potentiated the efficacies of irinotecan and gemcitabine in SW620 human colon carcinoma xenografts in nude mice.

Abstract A235: Structure-guided evolution of potent and selective oral inhibitors of CHK1 through scaffold morphing

The DNA damage response network ensures the fidelity of DNA replication and controls the repair of damage arising during cellular replication or from exogenous agents such as genotoxic drugs. Checkpoint Kinase 1 (CHK1) is a serine/threonine kinase occupying a central position in this complex network of cell regulatory and DNA repair mechanisms. G1/S, S or G2/M cell cycle checkpoints are activated in response to genotoxic antitumor drugs to provide an opportunity for repair of damaged DNA or to activate apoptotic pathways. Unlike normal cells, human cancer cells frequently have functional defects in the tumor suppressor p53 with consequent loss of G1/S checkpoint control and greater reliance on S and G2/M checkpoints. Thus CHK1 inhibitors which abrogate the S and G2/M checkpoints will selectively sensitize p53 deficient cancer cells to DNA damaging agents. CHK1 inhibition by siRNA and several small molecule inhibitors have confirmed this in preclinical studies.

The challenges of improving the CHK1 potency and selectivity of our initial, fragment derived pyrazolopyridine inhibitors, addressing synthetic tractability, and achieving novelty in the crowded kinase inhibitor chemical space were tackled by multiple scaffold morphing steps. Initial hit compounds were optimised into potent inhibitors of CHK1 using iterative cycles of design, synthesis, assay and crystallography, progressing through tricyclic pyrimido[2,3-b]azaindoles to N-(pyrazin-2-yl)pyrimidin-4-amines and isoquinolines. The potent and highly selective isoquinoline CHK1 inhibitor (SAR-020106) was identified, and potentiated the efficacies of irinotecan and gemcitabine in SW620 human colon carcinoma xenografts when dosed i.p. in nude mice. Further lead optimisation led to orally bioavailable analogues with good in vitro ADME and in vivo pharmacokinetic properties, exemplified by CCT244747. CCT244747 has demonstrated both in vivo pharmacodynamic modulation of signaling through CHK1 and potentiation of cytotoxic drugs in human tumor xenografts.

In summary, we show how a fragment derived compound with weak, micromolar activity against CHK1 evolved through a scaffold hopping strategy to give the selective CHK1 isoquinoline inhibitor SAR-020106, from which optimisation of pharmacokinetic properties led to potent, selective and orally bioavailable CHK1 inhibitors such as CCT244747.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A235.

Parental reporting of smelly urine and urinary tract infection

BACKGROUND

Parents often report that young children have "smelly urine" or a particular urinary odour. There is little evidence that these observations are relevant to the diagnosis of urinary tract infection (UTI).

AIMS

To determine whether parental reporting of smelly urine is of any relevance to the diagnosis of UTI in children less than 6 years of age.

METHODS

Parents whose children were having urine collected as part of their admission to a large district hospital were given a simple questionnaire to complete regarding the current smell of their child's urine. Parents were asked whether their child's urine smelled different from usual or had a particular smell. Microscopy and culture results of the child's urine were compared to their parent's questionnaire answers to see if there was a association between parental reporting of a different or particular urine smell and a diagnosis of UTI.

RESULTS

One hundred and ten questionnaires and urine samples were obtained. Fifty two per cent of parents thought that their child's urine smelled different from usual or had a particular smell. Only 6.4% of children were diagnosed as having a UTI. There was no statistically significant association between parental reporting of abnormal urine smell and diagnosis of UTI.

CONCLUSION

In determining whether a young child has a UTI, asking parents about urine smell is unlikely to be of benefit.

Selection criteria among gastroenterologists and surgeons for laparoscopic antireflux surgery

BACKGROUND

Symptomatic gastroesophageal reflux disease (GERD) affects a substantial proportion of the American population. The diagnosis and treatment of GERD has advanced tremendously over the past 30 years. However, there remains a lack of understanding about the differences and advantages that laparoscopic antireflux surgery offers and a lack of agreement on the ideal surgical candidate. The purpose of this study was to determine whether a significant difference exists in the practice habits and selection criteria for surgery between gastroenterologists and laparoscopic surgeons.

METHODS

Surveys were sent to 1,000 randomly selected members of the American Gastroenterological Association (AGA) and to 1,000 randomly selected members of the Society of American Gastrointestinal Endoscopic Surgeons (SAGES). As a result, 20% of the AGA surveys and 33% of the SAGES surveys were completed and returned.

RESULTS

The AGA group considered patients whose symptoms are not well controlled, those who have complications of disease, and those who require significant lifestyle changes to control their symptoms as the best candidates for surgical evaluation. As a group, gastroenterologists remain somewhat hesitant to refer patients for laparoscopic antireflux surgery. Surgeons considered patients whose symptoms have been well controlled with medical therapy, those who have complications of disease, and those who require significant lifestyle changes to control their symptoms as ideal candidates for fundoplication.

CONCLUSION

A consensus should be reached between surgeons and gastroenterologists in establishing criteria for surgical intervention to manage GERD.

Increasingly intolerable boundaries: future control of environmental pollution

In recent years, there have been a number of toxic accidents on the sea and on land which have caused pollution down current, down wind and down stream. Four were dramatic and these four have led to substantial changes in the way we deal with risk to the environment. There have also been increasing concerns about a less spectacular but equally concerning problem, acid rain, though attempts to deal with this problem have been less successful. Perhaps the drama was lacking. In all these cases, unfortunately, the less developed countries can ill afford the costs of prevention and this means they are often the home of environmentally unfriendly development. While the current approaches to such problems will continue, it is likely that the countries on the receiving end of such pollution, especially if they have economic and military power, will seek more forceful solutions. One outcome may be a UN-sponsored environmental police force.

Relationship of the dimension of cardiac structures to body size: an echocardiographic study in normal infants and children

Normalization of the dimensions of cardiac structures to the size of the body, using so-called Z scores, is becoming increasingly common in the management of infants and children with congenital heart disease. Current published nomograms for the ascertainment of Z scores for cardiac structures in childhood are based largely on normal data obtained in formalin-fixed hearts. Since decisions concerning management are frequently based on the findings of cross-sectional echocardiograms, the dimensions of 15 cardiac structures were measured using cross-sectional echocardiography in 125 normal infants and children. Regression equations were derived relating cardiac dimensions to the size of the body. The expression of size with the highest correlation to cardiac dimensions was body surface area. Nomograms were then developed from which the Z score of a cardiac structure could be estimated from a knowledge of the body surface area and the echocardiographically derived measurement.

Pseudomeningocele/CSF fistula in a patient with lumbar spinal implants treated with epidural blood patch and a brief course of closed subarachnoid drainage. A case report

STUDY DESIGN

This case report illustrates the development of a cerebrospinal fluid fistula and pseudomeningocele in a patient after lumbar discectomy and fusion with instrumentation.

OBJECTIVE

The patient is treated successfully with a combined treatment protocol of epidural blood patch and brief course of spinal drainage.

SUMMARY OF BACKGROUND DATA

Many surgeons advocate a trial of cerebrospinal fluid diversion for postoperative cerebrospinal fluid fistula. This treatment may be problematic in patients with spinal implants because a trial of cerebrospinal fluid diversion may not obliterate the extradural anatomic dead space that is created by instrumentation procedures and increases the rist of infection. A few case reports indicate that epidural blood patch also may be an effective management technique. A combined treatment protocol that may offer some advantages to either treatment alone is described

METHODS

The patient was brought to the radiology department, and a lumbar spinal drain was placed at the L2-L3 interspace under fluoroscopic guidance with the patient in the prone position. A Tuohy needle was inserted into the pseudomeningocele, and the collection was drained. Thirty milliters of blood drawn from an antecubital vein was injected into the epidural space over the laminectomy site. Spinal drainage was continued for 4 days.

RESULTS

The treatment protocol resulted in resolution of cerebrospinal fluid leakage in the patient. This result was confirmed by myelogram.

CONCLUSIONS

Postoperative pseudomeningocele and cerebrospinal fluid fistula in patients with spinal instrumentation can be treated successfully with epidural blood patch and a brief course (4 days) of spinal drainage. This combined treatment protocol may have some advantages to treatment with 7 days of cerebrospinal fluid diversion or to percutaneous epidural blood patch alone.

Practical issues in developing and operating a halfway house program

During its six years of operation, the halfway house program of the Southern Arizona Mental Health Center has developed a well-defined set of program goals, referral procedures, staffing patterns, and procedures for operating the houses, many of which are described here. The program serves 25 residents in four adjacent houses. It is operated as a therapeutic community with a broad range of structured activities and treatment modalities and an emphasis on solving reality problems. The staff of director, therapist-counselors, residential (or nighttime) counselors, and volunteer counselors is supplemented by the services of consultants, the mental health center, and community agencies.

Regional obstetric anesthesia and newborn behavior: effect over the first ten days of life

This study examined the effects of carefully controlled amounts of analgesic premedications and anesthetics administered to mothers during delivery on the behavior of the newborn over the first ten days of life. The subjects were selected to minimize the synergistic effects of medication and other stress factors, such as abnormalities of pregnancy, labor, or delivery. The effects of these drugs on the behavior of these infants was small. The data provide a picture of the behavioral recovery of a group of minimally stressed newborns.

Intellectual development of youths as measured by a short form of the wechsler intelligence scale, United States

This report presents information on aspects of the intellectual development of youths 12 through 17 years of age in the noninstitutional population of the United States, as measured by two subtests of the Wechsler Intelligence Scale for Children (WISC) used in the Health Examination Survey of 1966-70. The two WISC subtests used, for reasons explained below, were the Vocabulary and Block Design subtests. Two reports describing WISC test results of a previous Health Examination Survey of children 6 through 11 years of age have been published. In this report on WISC findings from the survey of youths, analysis is limited to variations in test scores associated with age, sex, and grade placement. Construction of normalized scaled scores and of a short-form estimate of WISC Full Scale Scores for use in the analysis of other data collected in the survey is also described. Subsequent reports will explore the relationships between WISC scores and the behavioral, biomedical, socioeconomic, and other psychometric data gathered in the survey.

Early recognition of neonatal sepsis. The value of bacteriologic studies of gastric aspirate and external ear canal material

Cultures and gram stains of gastric and external ear canal contents can greatly assist the physician in the early diagno sis of newborn infections acquired in utero or during birth.