Exploring the Severity Strata of Disease Activity and Repigmentation in Vitiligo Based on Validated Physician Global Assessment (PGA) Scores.

Background/Objectives: There is currently no guidance on how to interpret the global degrees of activity (worsening) and repigmentation (improvement) in vitiligo. Stratification into global degrees can be completed for static evaluations (e.g., visible disease activity signs) and dynamic assessments (e.g., evolution over time). For the latter, the Vitiligo Disease Activity Score (VDAS15&60) and Vitiligo Disease Improvement Score (VDIS15&60) were recently validated. Methods: In the current study, a Physician Global Assessment (PGA) for disease activity (worsening) and repigmentation (improvement) was evaluated for validity (construct) and reliability (inter- and intrarater) based on a photo set of 66 patients. Subsequently, the PGA activity (worsening) and repigmentation (improvement) were used to stratify the Vitiligo Extent Score plus (VESplus), VDAS15&60 or VDIS15&60 into three global categories (slightly, moderately and much worse/improved), based on ROC analysis. Results: For the VESplus, cut-off values for the categories 'slightly, moderately and much worse' were >0.3%, >27.71% and >128.75% BSA (relative changes in the affected total BSA), respectively. For the categories 'slightly, moderately and much improved', they were >0%, >4.87% and >36.88% BSA (relative changes in the affected total BSA), respectively. The optimal cut-off values of the number of active (VDAS15) body areas were >0 areas for slightly worse, >2 areas for moderately worse and >7 for much worse. For VDIS15, the cut-off values for slightly improved and moderately improved were >0 and >1. For VDAS60 and VDIS60, the cut-off points were >0.5, >3, >9.5 and >0.5 and >1.5, respectively. The results should be interpreted with caution in patients with extensive vitiligo due to the rather limited disease extent of the included patient population (VESplus (median: 3.2%)). Conclusions: This research will aid in the development of more detailed international definitions.

Macrocyclic Carbon-Linked Pyrazoles As Novel Inhibitors of MCL-1.

Myeloid cell leukemia-1 (MCL-1) is a member of the antiapoptotic BCL-2 proteins family and a key regulator of mitochondrial homeostasis. Overexpression of MCL-1 is found in many cancer cells and contributes to tumor progression, which makes it an attractive therapeutic target. Pursuing our previous study of macrocyclic indoles for the inhibition of MCL-1, we report herein the impact of both pyrazole and indole isomerism on the potency and overall properties of this family of compounds. We demonstrated that the incorporation of a fluorine atom on the naphthalene moiety was a necessary step to improve cellular potency and that, combined with the introduction of various side chains on the pyrazole, it enhanced solubility significantly. This exploration culminated in the discovery of compounds (Ra)-10 and (Ra)-15, possessing remarkable cellular potency and properties.

Discovery of an Oral, Beyond-Rule-of-Five Mcl-1 Protein-Protein Interaction Modulator with the Potential of Treating Hematological Malignancies.

Avoidance of apoptosis is critical for the development and sustained growth of tumors. The pro-survival protein myeloid cell leukemia 1 (Mcl-1) is an anti-apoptotic member of the Bcl-2 family of proteins which is overexpressed in many cancers. Upregulation of Mcl-1 in human cancers is associated with high tumor grade, poor survival, and resistance to chemotherapy. Therefore, pharmacological inhibition of Mcl-1 is regarded as an attractive approach to treating relapsed or refractory malignancies. Herein, we disclose the design, synthesis, optimization, and early preclinical evaluation of a potent and selective small-molecule inhibitor of Mcl-1. Our exploratory design tactics focused on structural modifications which improve the potency and physicochemical properties of the inhibitor while minimizing the risk of functional cardiotoxicity. Despite being in the "non-Lipinski" beyond-Rule-of-Five property space, the developed compound benefits from exquisite oral bioavailability in vivo and induces potent pharmacodynamic inhibition of Mcl-1 in a mouse xenograft model.

Divide and Conquer. Pocket-Opening Mixed-Solvent Simulations in the Perspective of Docking Virtual Screening Applications for Drug Discovery.

The existence of a druggable binding pocket is a prerequisite for computational drug-target interaction studies including virtual screening. Retrospective studies have shown that extended sampling methods like Markov State Modeling and mixed-solvent simulations can identify cryptic pockets relevant for drug discovery. Here, we apply a combination of mixed-solvent molecular dynamics (MD) and time-structure independent component analysis (TICA) to four retrospective case studies: NPC2, the CECR2 bromodomain, TEM-1, and MCL-1. We compare previous experimental and computational findings to our results. It is shown that the successful identification of cryptic pockets depends on the system and the cosolvent probes. We used alternative TICA internal features such as the unbiased backbone coordinates or backbone dihedrals versus biased interatomic distances. We found that in the case of NPC2, TEM-1, and MCL-1, the use of unbiased features is able to identify cryptic pockets, although in the case of the CECR2 bromodomain, more specific features are required to properly capture a pocket opening. In the perspective of virtual screening applications, it is shown how docking studies with the parent ligands depend critically on the conformational state of the targets.

A Brain-Penetrant and Bioavailable Pyrazolopiperazine BACE1 Inhibitor Elicits Sustained Reduction of Amyloid ß In Vivo.

We recently disclosed a set of heteroaryl-fused piperazine inhibitors of BACE1 that combined nanomolar potency with good intrinsic permeability and low Pgp-mediated efflux. Herein we describe further work on two prototypes of this family of inhibitors aimed at modulating their basicity and reducing binding to the human ether-a-go-go-related gene (hERG) channel. This effort has led to the identification of compound 36, a highly potent (hAß42 cell IC50 = 1.3 nM), cardiovascularly safe, and orally bioavailable compound that elicited sustained Aß42 reduction in mouse and dog animal models.

Modulating physicochemical properties of tetrahydropyridine-2-amine BACE1 inhibitors with electron-withdrawing groups: A systematic study.

A common challenge for medicinal chemists is to reduce the pKa of strongly basic groups' conjugate acids into a range that preserves the desired effects, usually potency and/or solubility, but avoids undesired effects like high volume of distribution (Vd), limited membrane permeation, and off-target binding to, notably, the hERG channel and monoamine receptors. We faced this challenge with a 3,4,5,6-tetrahydropyridine-2-amine scaffold harboring an amidine, a key structural component of potential inhibitors of BACE1, the rate-limiting enzyme in the production of Aß species that make up amyloid plaques in Alzheimer's disease. In our endeavor to balance potency with desirable properties to achieve brain penetration, we introduced a diverse set of groups in beta position of the amidine that modulate logD, PSA and pKa. Given the synthetic challenge to prepare these highly functionalized warheads, we first developed a design flow including predicted physicochemical parameters which allowed us to select only the most promising candidates for synthesis. For this we evaluated a set of commercial packages to predict physicochemical properties, which can guide medicinal chemists in their endeavors to modulate pKa values of amidine and amine bases.

Development and implementation of an enterprise-wide predictive model for early absorption, distribution, metabolism and excretion properties.

Background: Accurate prediction of absorption, distribution, metabolism and excretion (ADME) properties can facilitate the identification of promising drug candidates. Methodology & Results: The authors present the Janssen generic Target Product Profile (gTPP) model, which predicts 18 early ADME properties, employs a graph convolutional neural network algorithm and was trained on between 1000-10,000 internal data points per predicted parameter. gTPP demonstrated stronger predictive power than pretrained commercial ADME models and automatic model builders. Through a novel logging method, the authors report gTPP usage for more than 200 Janssen drug discovery scientists. Conclusion: The investigators successfully enabled the rapid and systematic implementation of predictive ML tools across a drug discovery pipeline in all therapeutic areas. This experience provides useful guidance for other large-scale AI/ML deployment efforts.

JNJ-67569762, A 2-Aminotetrahydropyridine-Based Selective BACE1 Inhibitor Targeting the S3 Pocket: From Discovery to Clinical Candidate.

The discovery of a novel 2-aminotetrahydropyridine class of BACE1 inhibitors is described. Their pKa and lipophilicity were modulated by a pending sulfonyl group, while good permeability and brain penetration were achieved via intramolecular hydrogen bonding. BACE1 selectivity over BACE2 was achieved in the S3 pocket by a novel bicyclic ring system. An optimization addressing reactive metabolite formation, cardiovascular safety, and CNS toxicity is described, leading to the clinical candidate JNJ-67569762 (12), which gave robust dose-dependent BACE1-mediated amyloid ß lowering without showing BACE2-dependent hair depigmentation in preclinical models. We show that 12 has a favorable projected human dose and PK and hence presented us with an opportunity to test a highly selective BACE1 inhibitor in humans. However, 12 was found to have a QT effect upon repeat dosing in dogs and its development was halted in favor of other selective leads, which will be reported in the future.

Plasma ß-secretase1 concentrations correlate with basal forebrain atrophy and neurodegeneration in cognitively healthy individuals at risk for AD.

BACKGROUND: Increased ß-secretase 1 (BACE1) protein concentration, in body fluids, is a candidate biomarker of Alzheimer's disease (AD).We reported that plasma BACE1 protein concentrations are associated with the levels of brain amyloidß (Αß) accumulation in cognitively healthy individuals with subjective memory complaint (SMC). METHODS: In 302 individuals from the same cohort, we investigated the cross-sectional and longitudinal association between plasma BACE1 protein concentrations and AD biomarkers of neurodegeneration (plasma t-tau and Neurofilament light chain (NfL), fluorodeoxyglucose-positron emission tomography (FDG-PET), brain volumes in the basal forebrain [BF], hippocampus, and entorhinal cortex). RESULTS: We report a positive longitudinal correlation of BACE1 with both NfL and t-tau, as well as a correlation between annual BACE1 changes and bi-annual reduction of BF volume. We show a positive association between BACE1 and FDG-PET signal at baseline. CONCLUSIONS: The association between plasma BACE1 protein concentrations and BF atrophy we found in cognitively healthy individuals with SMC corroborates translational studies, suggesting a role of BACE1 in neurodegeneration.

The ß-Secretase BACE1 in Alzheimer's Disease.

BACE1 (beta-site amyloid precursor protein cleaving enzyme 1) was initially cloned and characterized in 1999. It is required for the generation of all monomeric forms of amyloid-ß (Aß), including Aß42, which aggregates into bioactive conformational species and likely initiates toxicity in Alzheimer's disease (AD). BACE1 concentrations and rates of activity are increased in AD brains and body fluids, thereby supporting the hypothesis that BACE1 plays a critical role in AD pathophysiology. Therefore, BACE1 is a prime drug target for slowing down Aß production in early AD. Besides the amyloidogenic pathway, BACE1 has other substrates that may be important for synaptic plasticity and synaptic homeostasis. Indeed, germline and adult conditional BACE1 knockout mice display complex neurological phenotypes. Despite BACE1 inhibitor clinical trials conducted so far being discontinued for futility or safety reasons, BACE1 remains a well-validated therapeutic target for AD. A safe and efficacious compound with high substrate selectivity as well as a more accurate dose regimen, patient population, and disease stage may yet be found. Further research should focus on the role of Aß and BACE1 in physiological processes and key pathophysiological mechanisms of AD. The functions of BACE1 and the homologue BACE2, as well as the biology of Aß in neurons and glia, deserve further investigation. Cellular and molecular studies of BACE1 and BACE2 knockout mice coupled with biomarker-based human research will help elucidate the biological functions of these important enzymes and identify their substrates and downstream effects. Such studies will have critical implications for BACE1 inhibition as a therapeutic approach for AD.

BACE1 and Other Alzheimer's-Related Biomarkers in Cerebrospinal Fluid and Plasma Distinguish Alzheimer's Disease Patients from Cognitively-Impaired Neurosyphilis Patients.

BACKGROUND: Patients with spirochetal infection, which causes neurosyphilis (NS) and at a later stage general paresis of the insane (GPI), present with brain pathology features of Alzheimer's disease (AD). However, the relationships among these illnesses regarding biomarker levels are still unclear. OBJECTIVE: To explore biomarker levels in NS and GPI compared with those in AD and the relationship between biomarker levels and cognitive function in NS and GPI. METHODS: Levels of neurogranin (NGRN) and ß-amyloid precursor protein cleaving enzyme (BACE1) in cerebrospinal fluid (CSF)/plasma, together with amyloid-ß 1-40 (Aß40), Aß42, and total tau in the CSF of 23 AD patients, 55 GPI patients, and 13 NS patients were measured. Patients were classified into none-to-mild, moderate, and severe stages of cognitive impairment. RESULTS: Levels of CSF NGRN, BACE1, and tau as well as plasma BACE1 levels were significantly different among groups. In the none-to-mild stage, plasma BACE1 levels correlated with the protein levels in CSF and were significantly increased in AD patients versus GPI patients. The CSF tau levels in AD patients were significantly increased versus GPI patients in the moderate and severe stages. Pooling data from GPI and NS patients, both CSF tau and plasma NGRN levels correlated with cognitive scale scores. CONCLUSION: GPI and NS patients might have different biomarker level patterns compared to AD patients. While plasma BACE1 could be a promising early biomarker for distinguishing AD from GPI, CSF tau and plasma NGRN levels might be valuable in indications of cognitive function in pooled NS populations.

Discovery of 3-({5-Chloro-1-[3-(methylsulfonyl)propyl]-1H-indol-2-yl}methyl)-1-(2,2,2-trifluoroethyl)-1,3-dihydro-2H-imidazo[4,5-c]pyridin-2-one (JNJ-53718678), a Potent and Orally Bioavailable Fusion Inhibitor of Respiratory Syncytial Virus.

Respiratory syncytial virus (RSV) is a seasonal virus that infects the lungs and airways of 64 million children and adults every year. It is a major cause of acute lower respiratory tract infection and is associated with significant morbidity and mortality. Despite the large medical and economic burden, treatment options for RSV-associated bronchiolitis and pneumonia are limited and mainly consist of supportive care. This publication covers the medicinal chemistry efforts resulting in the identification of JNJ-53718678, an orally bioavailable RSV inhibitor that was shown to be efficacious in a phase 2a challenge study in healthy adult subjects and that is currently being evaluated in hospitalized infants and adults. Cocrystal structures of several new derivatives helped in rationalizing some of the structure-activity relationship (SAR) trends observed.

Association of brain network dynamics with plasma biomarkers in subjective memory complainers.

Using a single integrated analysis, we examined the relationship between brain networks and molecular pathways in a cohort of elderly individuals at risk for Alzheimer's disease. In 205 subjective memory complainers (124 females, mean age: 75.7 ± 3.4), individual functional connectome was computed for a total of 3081 functional connections (set A) and 6 core plasma biomarkers of Alzheimer's disease (set B) were assessed. Partial least squares correlation analysis identified one dimension of population covariation between the 2 sets (p < 0.006), which we named bioneural mode. Five core plasma biomarkers and 190 functional connections presented bootstrap ratios greater than the critical value |1.96|. T-tau protein showed a trend toward significance (bootstrap resampling = 1.64). The salience, the language, the visuospatial, and the default mode networks were the strongest significant networks. We detected a strong association between network dynamics and core pathophysiological blood biomarkers. Innovative composite biomarkers, such as the bioneural mode, are promising to provide outcomes and better inform drug development and clinical practice for neurodegenerative diseases.

3,3-Difluoro-3,4,5,6-tetrahydropyridin-2-amines: Potent and permeable BACE-1 inhibitors.

Since its discovery in 1999, BACE-1, a membrane anchored aspartyl protease expressed primarily in the CNS, has been the target of numerous medicinal chemistry research programs. These efforts have produced highly potent inhibitors with nanomolar affinity and ever-increasing structural complexity. However, only a handful of these molecules have been able to combine in vitro potency with CNS permeability and progressed to the clinic. Herein, we describe a set of novel piperidine-based inhibitors. This investigation culminated with the identification of 43, a highly potent (IC50: 1.5 nM), permeable BACE-1 inhibitor with a low susceptibility to Pgp-mediatedefflux.

Brain Aß load association and sexual dimorphism of plasma BACE1 concentrations in cognitively normal individuals at risk for AD.

INTRODUCTION: Successful development of effective ß-site amyloid precursor protein cleaving enzyme 1 (BACE1)-targeted therapies for early stages of Alzheimer's disease requires biomarker-guided intervention strategies. METHODS: We investigated whether key biological factors such as sex, apolipoprotein E (APOE ε4) allele, and age affect longitudinal plasma BACE1 concentrations in a large monocenter cohort of individuals at risk for Alzheimer's disease. We explored the relationship between plasma BACE1 concentrations and levels of brain amyloid-ß (Aß) deposition, using positron emission tomography global standard uptake value ratios. RESULTS: Baseline and longitudinal mean concentrations of plasma BACE1 were significantly higher in women than men. We also found a positive significant impact of plasma BACE1 on baseline Aß-positron emission tomography global standard uptake value ratios. DISCUSSION: Our results suggest a sexual dimorphism in BACE1-related upstream mechanisms of brain Aß production and deposition. We argue that plasma BACE1 should be considered in further biomarker validation and qualification studies as well as in BACE1 clinical trials.

Preparation of 4'-Spirocyclobutyl Nucleoside Analogues as Novel and Versatile Adenosine Scaffolds.

Despite the large variety of modified nucleosides that have been reported, the preparation of constrained 4'-spirocyclic adenosine analogues has received very little attention. We discovered that the [2+2]-cycloaddition of dichloroketene on readily available 4'-exo-methylene furanose sugars efficiently results in the diastereoselective formation of novel 4'-spirocyclobutanones. The reaction mechanism was investigated via density functional theory (DFT) and found to proceed either via a non-synchronous or stepwise reaction sequence, controlled by the stereochemistry at the 3'-position of the sugar substrate. The obtained dichlorocyclobutanones were converted into nucleoside analogues, providing access to a novel class of chiral 4'-spirocyclobutyl adenosine mimetics in eight steps from commercially available sugars. Assessment of the biological activity of designed 4'-spirocyclic adenosine analogues identified potent inhibitors for protein methyltransferase target PRMT5.

Evaluation of a Series of ß-Secretase 1 Inhibitors Containing Novel Heteroaryl-Fused-Piperazine Amidine Warheads.

Despite several years of research, only a handful of ß-secretase (BACE) 1 inhibitors have entered clinical trials as potential therapeutics against Alzheimer's disease. The intrinsic basic nature of low molecular weight, amidine-containing BACE 1 inhibitors makes them far from optimal as central nervous system drugs. Herein we present a set of novel heteroaryl-fused piperazine amidine inhibitors designed to lower the basicity of the key, enzyme binding, amidine functionality. This study resulted in the identification of highly potent (IC50 ≤ 10 nM), permeable lead compounds with a reduced propensity to suffer from P-glycoprotein-mediated efflux.

Plasma amyloid ß 40/42 ratio predicts cerebral amyloidosis in cognitively normal individuals at risk for Alzheimer's disease.

INTRODUCTION: Blood-based biomarkers of pathophysiological brain amyloid ß (Aß) accumulation, particularly for preclinical target and large-scale interventions, are warranted to effectively enrich Alzheimer's disease clinical trials and management. METHODS: We investigated whether plasma concentrations of the Aß1-40/Aß1-42 ratio, assessed using the single-molecule array (Simoa) immunoassay, may predict brain Aß positron emission tomography status in a large-scale longitudinal monocentric cohort (N = 276) of older individuals with subjective memory complaints. We performed a hypothesis-driven investigation followed by a no-a-priori hypothesis study using machine learning. RESULTS: The receiver operating characteristic curve and machine learning showed a balanced accuracy of 76.5% and 81%, respectively, for the plasma Aß1-40/Aß1-42 ratio. The accuracy is not affected by the apolipoprotein E (APOE) ε4 allele, sex, or age. DISCUSSION: Our results encourage an independent validation cohort study to confirm the indication that the plasma Aß1-40/Aß1-42 ratio, assessed via Simoa, may improve future standard of care and clinical trial design.

Minisci-Photoredox-Mediated α-Heteroarylation of N-Protected Secondary Amines: Remarkable Selectivity of Azetidines.

The development of a general, mild, and functional-group-tolerant direct functionalization of N-heteroarenes by C-H functionalization with N-protected amines, including azetidines under Minisci-mediated photoredox conditions, is reported. A broad scope of substituted azetidines, including spirocyclic derivatives, and heterocycles were explored. This reaction enables the production of sp3-rich complex druglike structures in one step from unactivated feedstock amines and heterocycles.

Neurogranin and BACE1 in CSF as Potential Biomarkers Differentiating Depression with Cognitive Deficits from Early Alzheimer's Disease: A Pilot Study.

BACKGROUND/AIMS: Major depressive disorder (MDD) can cooccur with early Alzheimer's disease (AD) or may cause memory problems independently of AD. Previous studies have suggested that the AD-related cerebrospinal fluid (CSF) biomarkers tau and Aß(1-42) could help discriminate between early AD and depression unrelated to AD. Moreover, the postsynaptic protein neurogranin and presynaptic BACE1 have increasingly gained attention as potential new AD biomarkers, but they have not yet been investigated concerning depression. METHODS: Using ELISAs, we studied CSF neurogranin and BACE1 levels in patients with mild (n = 21) and moderate (n = 19) AD, as well as in MDD patients with (n = 20) and without (n = 20) cognitive deficits. The clinical examinations included analyses of t-tau, Aß(1-42), and Aß(1-40), besides neuropsychological tests and cranial magnetic resonance imaging. Depressive symptom severity was assessed using the Geriatric Depression Scale (GDS). RESULTS: Along with classic AD biomarkers, neurogranin and BACE1 CSF levels differed between moderate AD and MDD (p ≤ 0.01). MDD associated with cognitive deficits was distinguished from mild AD through the CSF neurogranin/BACE1 ratio (p < 0.05), which was strongly correlated with GDS scores (ρ = -0.656; p < 0.01). CONCLUSION: The neurogranin/BACE1 ratio in CSF can distinguish between depression and AD among patients with similar cognitive deficits, along with the classic AD biomarkers. Further longitudinal studies are ongoing to identify which biomarkers have prognostic value.