Novelty preference assessed by eye tracking: A sensitive measure of impaired recognition memory in epilepsy.

OBJECTIVE: Epilepsy patients often report memory deficits despite normal objective testing, suggesting that available measures are insensitive or that non-mnemonic factors are involved. The Visual Paired Comparison Task (VPCT) assesses novelty preference, the tendency to fixate on novel images rather than previously viewed items, requiring recognition memory for the "old" images. As novelty preference is a sensitive measure of hippocampal-dependent memory function, we predicted impaired VPCT performance in epilepsy patients compared to healthy controls. METHODS: We assessed 26 healthy adult controls and 31 epilepsy patients (16 focal-onset, 13 generalized-onset, 2 unknown-onset) with the VPCT using delays of 2 or 30 s between encoding and recognition. Fifteen healthy controls and 17 epilepsy patients (10 focal-onset, 5 generalized-onset, 2 unknown-onset) completed the task at 2-, 5-, and 30-minute delays. Subjects also performed standard memory measures, including the Medical College of Georgia (MCG) Paragraph Test, California Verbal Learning Test-Second Edition (CVLT-II), and Brief Visual Memory Test-Revised (BVMT-R). RESULTS: The epilepsy group was high functioning, with greater estimated IQ (p = 0.041), greater years of education (p = 0.034), and higher BVMT-R scores (p = 0.024) compared to controls. Both the control group and epilepsy cohort, as well as focal- and generalized-onset subgroups, had intact novelty preference at the 2- and 30-second delays (p-values ≤ 0.001) and declined at 30 min (p-values > 0.05). Only the epilepsy patients had early declines at 2- and 5-minute delays (controls with intact novelty preference at p = 0.003 and p ≤ 0.001, respectively; epilepsy groups' p-values > 0.05). CONCLUSIONS: Memory for the "old" items decayed more rapidly in overall, focal-onset, and generalized-onset epilepsy groups. The VPCT detected deficits while standard memory measures were largely intact, suggesting that the VPCT may be a more sensitive measure of temporal lobe memory function than standard neuropsychological batteries.

Characterization of a Novel Capsid Assembly Modulator for the Treatment of Chronic Hepatitis B Virus Infection.

The standard of care for the treatment of chronic hepatitis B (CHB) is typically lifelong treatment with nucleos(t)ide analogs (NAs), which suppress viral replication and provide long-term clinical benefits. However, infectious virus can still be detected in patients who are virally suppressed on NA therapy, which may contribute to the failure of these agents to cure most CHB patients. Accordingly, new antiviral treatment options are being developed to enhance the suppression of hepatitis B virus (HBV) replication in combination with NAs ("antiviral intensification"). Here, we describe GS-SBA-1, a capsid assembly modulator (CAM) belonging to class CAM-E, that demonstrates potent inhibition of extracellular HBV DNA in vitro (EC50 [50% effective concentration] = 19 nM) in HBV-infected primary human hepatocytes (PHHs) as well as in vivo in an HBV-infected immunodeficient mouse model. GS-SBA-1 has comparable activities across HBV genotypes and nucleos(t)ide-resistant mutants in HBV-infected PHHs. In addition, GS-SBA-1 demonstrated in vitro additivity in combination with tenofovir alafenamide (TAF). The administration of GS-SBA-1 to PHHs at the time of infection prevents covalently closed circular DNA (cccDNA) formation and, hence, decreases HBV RNA and antigen levels (EC50 = 80 to 200 nM). Furthermore, GS-SBA-1 prevents the production of extracellular HBV RNA-containing viral particles in vitro. Collectively, these data demonstrate that GS-SBA-1 is a potent CAM that has the potential to enhance viral suppression in combination with an NA.

Characterization of a KDM5 small molecule inhibitor with antiviral activity against hepatitis B virus.

Chronic hepatitis B (CHB) is a global health care challenge and a major cause of liver disease. To find new therapeutic avenues with a potential to functionally cure chronic Hepatitis B virus (HBV) infection, we performed a focused screen of epigenetic modifiers to identify potential inhibitors of replication or gene expression. From this work we identified isonicotinic acid inhibitors of the histone lysine demethylase 5 (KDM5) with potent anti-HBV activity. To enhance the cellular permeability and liver accumulation of the most potent KDM5 inhibitor identified (GS-080) an ester prodrug was developed (GS-5801) that resulted in improved bioavailability and liver exposure as well as an increased H3K4me3:H3 ratio on chromatin. GS-5801 treatment of HBV-infected primary human hepatocytes reduced the levels of HBV RNA, DNA and antigen. Evaluation of GS-5801 antiviral activity in a humanized mouse model of HBV infection, however, did not result in antiviral efficacy, despite achieving pharmacodynamic levels of H3K4me3:H3 predicted to be efficacious from the in vitro model. Here we discuss potential reasons for the disconnect between in vitro and in vivo efficacy, which highlight the translational difficulties of epigenetic targets for viral diseases.

Discovery of Reversible Covalent Bruton's Tyrosine Kinase Inhibitors PRN473 and PRN1008 (Rilzabrutinib).

Bruton's tyrosine kinase (BTK), a Tec family tyrosine kinase, is critical in immune pathways as an essential intracellular signaling element, participating in both adaptive and immune responses. Currently approved BTK inhibitors are irreversible covalent inhibitors and limited to oncology indications. Herein, we describe the design of covalent reversible BTK inhibitors and the discoveries of PRN473 (11) and rilzabrutinib (PRN1008, 12). These compounds have exhibited potent and durable inhibition of BTK, in vivo efficacy in rodent arthritis models, and clinical efficacy in canine pemphigus foliaceus. Compound 11 has completed phase 1 trials as a topical agent, and 12 is in phase 3 trials for pemphigus vulgaris and immune thrombocytopenia.

Diverse experiences and approaches to tele neuropsychology: Commentary and reflections over the past year of COVID-19.

Objectives: In response to the coronavirus disease 2019 (COVID-19) pandemic, neuropsychologists rapidly adopted teleneuropsychology (TeleNP) services to ensure continued clinical care. Prior to COVID-19, TeleNP was not widely used nor was it included in the majority of traditional practice or training models across graduate, internship, and postdoctoral programs. Out of necessity, the pandemic was a catalyst that promoted greater adoption of TeleNP services. In response, neuropsychological guidelines for modified assessments were developed and further empirical studies have been published. Numerous surveys in response to service delivery changes during COVID-19 now exist, but what follows is a commentary based on neuropsychologists' experiences with adapting clinical practice to TeleNP. Methods: Co-authors represent settings across academic medical centers, Veterans Affairs hospitals, and private practices that serve multiculturally diverse pediatric, adult, and geriatric populations in the United States. Results: The perspectives within this commentary aim to highlight the growth of TeleNP and highlight lessons learned from implementation across practice settings. Conclusions: Our goal is to help foster the development of further empirical studies through candid discussion of various TeleNP experiences and approaches. Through this reflective process, TeleNP presents both opportunities and challenges but it ultimately has potential to reduce healthcare disparities and enhance patient care.

Woolly Monkey-HBV Infection in Squirrel Monkeys as a Surrogate Nonhuman Primate Model of HBV Infection.

Development of curative therapies for chronic hepatitis B virus (HBV) infection will likely require new animal models. Here, we evaluate HBV infection in squirrel monkeys based on the high-sequence homology of the HBV receptor, Na+/taurocholate co-transporting peptide (NTCP), between humans and squirrel monkeys. HBV PreS1 peptide was examined for binding human and squirrel monkey NTCP. Immunodeficient Fah -/- , NOD, Rag1 -/- , Il2Rg null (FNRG) mice engrafted with human or squirrel monkey hepatocytes were challenged with HBV or Woolly Monkey HBV (WMHBV). In addition, adult squirrel monkeys were inoculated with HBV, WMHBV, adeno-associated virus containing an infectious genome of HBV (AAV-HBV), and AAV-WMHBV. Finally, neonate squirrel monkeys were assessed for the potential of chronic infection with WMHBV. PreS1 peptide efficiently bound to human and squirrel monkey NTCP but not to mouse or capuchin NTCP. FNRG mice engrafted with squirrel monkey hepatocytes were susceptible to infection by WMHBV but not human HBV. Similarly, adult squirrel monkeys could be infected with WMHBV but not human HBV, whereas chimeric mice engrafted with human hepatocytes were susceptible to HBV but not WMHBV. Infection of squirrel monkeys with AAV-WMHBV yielded maximum viremia of 108 genomes/mL with detectable virus for up to 8 months. Notably, covalently closed circular DNA was detected in the liver of these animals. Infection of neonates with WMHBV led to detectable viremia for up to 6 months. Conclusions: Adult and neonate squirrel monkeys exhibited prolonged WMHBV viremia lasting 6-8 months. This is greater than twice the duration of viremia achieved in other nonhuman primates and suggests that squirrel monkeys may be a suitable model for testing HBV therapeutics.

The Irreversible Covalent Fibroblast Growth Factor Receptor Inhibitor PRN1371 Exhibits Sustained Inhibition of FGFR after Drug Clearance.

An increasing number of cancers are known to harbor mutations, translocations, or amplifications in the fibroblast growth factor receptor (FGFR) family of kinases. The FGFR inhibitors evaluated in clinical trials to date have shown promise at treating these cancers. Here, we describe PRN1371, an irreversible covalent inhibitor of FGFR1-4 targeting a cysteine within the kinase active site. PRN1371 demonstrated strong FGFR potency and excellent kinome-wide selectivity in a number of biochemical and cellular assays, including in various cancer cell lines exhibiting FGFR alterations. Furthermore, PRN1371 maintained FGFR inhibition in vivo, not only when circulating drug levels were high but also after the drug had been cleared from circulation, indicating the possibility of sustained FGFR inhibition in the clinic without the need for continuous drug exposure. Durable tumor regression was also obtained in multiple tumor xenografts and patient-derived tumor xenograft models and was sustained even using an intermittent dosing strategy that provided drug holidays. PRN1371 is currently under clinical investigation for treatment of patients with solid tumors. Mol Cancer Ther; 16(12); 2668-76. ©2017 AACR.

Discovery of the Irreversible Covalent FGFR Inhibitor 8-(3-(4-Acryloylpiperazin-1-yl)propyl)-6-(2,6-dichloro-3,5-dimethoxyphenyl)-2-(methylamino)pyrido[2,3-d]pyrimidin-7(8H)-one (PRN1371) for the Treatment of Solid Tumors.

Aberrant signaling of the FGF/FGFR pathway occurs frequently in cancers and is an oncogenic driver in many solid tumors. Clinical validation of FGFR as a therapeutic target has been demonstrated in bladder, liver, lung, breast, and gastric cancers. Our goal was to develop an irreversible covalent inhibitor of FGFR1-4 for use in oncology indications. An irreversible covalent binding mechanism imparts many desirable pharmacological benefits including high potency, selectivity, and prolonged target inhibition. Herein we report the structure-based design, medicinal chemistry optimization, and unique ADME assays of our irreversible covalent drug discovery program which culminated in the discovery of compound 34 (PRN1371), a highly selective and potent FGFR1-4 inhibitor.

Assessment Trends Among Neuropsychologists Conducting Sport-Related Concussion Evaluations.

Neuropsychologists regularly conduct sport-related concussion (SRC) evaluations, although research has not tracked these assessment practices. As part of a survey of neuropsychological test usage, we analyzed data from 215 neuropsychologists who conduct SRC evaluations. Only 15% reported conducting baseline assessments of athletes as part of a sports program and 92% evaluate athletes' post-concussion without baseline data. The majority of respondents use a full battery, considered the most reliable approach for assessing concussion symptoms in athletes. Only 6% use computerized tests exclusively (>50% ImPACT). We discuss the implications of these results and address challenges faced by neuropsychologists who perform SRC evaluations.

Management of Cognitive Impairment in Heart Failure.

OPINION STATEMENT: Cognitive impairment (CI) is an inclusive term to describe trouble with memory, learning, concentration, or decision-making. CI is highly prevalent in patients with heart failure (HF) and is known to be associated with a variety of poor outcomes. While published HF guidelines recommend screening for CI, they do not indicate how, due to a lack of consensus in the literature about which instrument to use. Our recommendation is to use the Mini-Cog for this purpose because of its brevity and utility in identifying patients with HF at high risk for hospitalization or mortality. At this time, there is minimal published clinical trial evidence about how to manage CI in patients with HF. Reasonable approaches to management may include following guideline-directed medical therapy for HF, treatment of hypertension and atrial fibrillation, management of depression, proactive diagnosis and treatment of sleep apnea, and encouragement of aerobic exercise and weight loss. Left ventricular assist device (LVAD) therapy in patients with Stage D HF may improve CI in the short term after implantation, though there is a risk of worsening CI in the intermediate and long term. Clinicians who care for patients with HF should routinely screen for CI and when identified should encourage interventions to support self-care, increase family involvement, and arrange for more frequent follow-up.

Prolonged and tunable residence time using reversible covalent kinase inhibitors.

Drugs with prolonged on-target residence times often show superior efficacy, yet general strategies for optimizing drug-target residence time are lacking. Here we made progress toward this elusive goal by targeting a noncatalytic cysteine in Bruton's tyrosine kinase (BTK) with reversible covalent inhibitors. Using an inverted orientation of the cysteine-reactive cyanoacrylamide electrophile, we identified potent and selective BTK inhibitors that demonstrated biochemical residence times spanning from minutes to 7 d. An inverted cyanoacrylamide with prolonged residence time in vivo remained bound to BTK for more than 18 h after clearance from the circulation. The inverted cyanoacrylamide strategy was further used to discover fibroblast growth factor receptor (FGFR) kinase inhibitors with residence times of several days, demonstrating the generalizability of the approach. Targeting of noncatalytic cysteines with inverted cyanoacrylamides may serve as a broadly applicable platform that facilitates 'residence time by design', the ability to modulate and improve the duration of target engagement in vivo.

Dominance of orientation over frequency in the perception of 3-D slant and shape.

In images of textured three-dimensional surfaces, pattern changes can be characterized as changes in orientation and spatial frequency, features for which neurons in primary visual cortex are classically selective. Previously, we have demonstrated that correct 3-D shape perception is contingent on the visibility of orientation flows that run parallel to the surface curvature. We sought to determine the relative contributions of orientation modulations (OMs) and frequency modulations (FMs) for the detection of slant and shape from 3-D surfaces. Results show that 1) when OM and FM indicate inconsistent degrees of surface slant or curvature, observer responses were consistent with the slant or curvature specified by OM even if the FM indicated a slant or curvature in the opposite direction to the same degree. 2) For slanted surfaces, OM information dictates slant perception at both shallow and steep slants while FM information is effective only for steep slants. Together these results point to a dominant role of OM information in the perception of 3-D slant and shape.

Selective and brain-permeable polo-like kinase-2 (Plk-2) inhibitors that reduce α-synuclein phosphorylation in rat brain.

Polo-like kinase-2 (Plk-2) has been implicated as the dominant kinase involved in the phosphorylation of α-synuclein in Lewy bodies, which are one of the hallmarks of Parkinson's disease neuropathology. Potent, selective, brain-penetrant inhibitors of Plk-2 were obtained from a structure-guided drug discovery approach driven by the first reported Plk-2-inhibitor complexes. The best of these compounds showed excellent isoform and kinome-wide selectivity, with physicochemical properties sufficient to interrogate the role of Plk-2 inhibition in vivo. One such compound significantly decreased phosphorylation of α-synuclein in rat brain upon oral administration and represents a useful probe for future studies of this therapeutic avenue toward the potential treatment of Parkinson's disease.

Development of a novel ß-secretase binding assay using the AlphaScreen platform.

Alzheimer's disease (AD) is a devastating neurodegenerative disease affecting millions of people. ß-secretase-1 (BACE1), an enzyme involved in the processing of the amyloid precursor protein (APP) to form Aß is a validated target for AD. Herein, the authors develop and validate a novel binding assay for BACE1 using the AlphaScreen platform that is amenable for high-throughput screening (HTS). Small-molecule BACE1 inhibitors of the hydroxyethylamine, hydantoin, and sulfamide classes were functionalized by biotin PEG linkers of varying lengths forming probes that were bound to streptavidin donor beads. BACE1 was coupled to nickel-chelate acceptor beads. Upon mixing, probes designed from all three classes registered high signal-to-background values in the AlphaScreen binding assay, where the interaction between probe and BACE1 was completely blocked by free parent compound. A probe from the hydantoin class was chosen for further optimization, where the final assay conditions of 50 nM BACE and 250 nM probe were used and Z(') values >0.75 were commonly observed. IC50 values determined by the AlphaScreen assay format exhibited ~10-fold greater sensitivity when compared with a fluorescence polarization-based activity assay. The assay was miniaturized to a 1536-well format for HTS, in which 525 000 compounds were screened.

Design and synthesis of thiophene dihydroisoquinolines as novel BACE1 inhibitors.

Utilizing a structure based design approach, combined with extensive medicinal chemistry execution, highly selective, potent and novel BACE1 inhibitor 8 (BACE1 Alpha assay IC50=8nM) was made from a weak µM potency hit in an extremely efficient way. The detailed SAR and general design approaches will be discussed.

Design and synthesis of highly selective, orally active Polo-like kinase-2 (Plk-2) inhibitors.

Polo-like kinase-2 (Plk-2) is a potential therapeutic target for Parkinson's disease and this Letter describes the SAR of a series of dihydropteridinone based Plk-2 inhibitors. By optimizing both the N-8 substituent and the biaryl region of the inhibitors we obtained single digit nanomolar compounds such as 37 with excellent selectivity for Plk-2 over Plk-1. When dosed orally in rats, compound 37 demonstrated a 41-45% reduction of pS129-α-synuclein levels in the cerebral cortex.

Structure-based design of novel dihydroisoquinoline BACE-1 inhibitors that do not engage the catalytic aspartates.

The structure-activity relationship of a series of dihydroisoquinoline BACE-1 inhibitors is described. Application of structure-based design to screening hit 1 yielded sub-micromolar inhibitors. Replacement of the carboxylic acid of 1 was guided by X-ray crystallography, which allowed the replacement of a key water-mediated hydrogen bond. This work culminated in compounds such as 31, which possess good BACE-1 potency, excellent permeability and a low P-gp efflux ratio.

Discovery of 4-alkylamino-7-aryl-3-cyanoquinoline LRRK2 kinase inhibitors.

Mutations in leucine-rich repeat kinase 2 (LRRK2) are associated with familial Parkinson's disease (PD). The kinase activity of this complex protein is increased by pathogenic mutations. Inhibition of LRRK2 kinase activity has therefore emerged as a promising approach for the treatment of PD. Herein we report our findings on a series of 4-alkylamino-7-aryl-3-cyanoquinolines that exhibit kinase inhibitory activity against both wild type and G2019S mutant LRRK2. Activity was determined in both biochemical and cellular assays. Compound 14 was further evaluated in an in vivo pharmacodynamic study and found to significantly inhibit Ser935 phosphorylation after oral dosing.

Triazolopyridazine LRRK2 kinase inhibitors.

Leucine-rich repeat kinase 2 (LRRK2) has been implicated in the pathogenesis of Parkinson's disease (PD). Inhibition of LRRK2 kinase activity is a therapeutic approach that may lead to new treatments for PD. Herein we report the discovery of a series of [1,2,4]triazolo[4,3-b]pyridazines that are potent against both wild-type and mutant LRRK2 kinase activity in biochemical assays and show an unprecedented selectivity towards the G2019S mutant. A structural rational for the observed selectivity is proposed.

Novel cinnoline-based inhibitors of LRRK2 kinase activity.

Leucine rich repeat kinase 2 (LRRK2) has been implicated in the pathogenesis of Parkinson's disease (PD). Inhibition of LRRK2 kinase activity is a therapeutic approach that may lead to new treatments for PD. Herein we report the discovery of a series of cinnoline-3-carboxamides that are potent against both wild-type and mutant LRRK2 kinase activity in biochemical assays. These compounds are also shown to be potent inhibitors in a cellular assay and to have good to excellent CNS penetration.