Validity of remote live stream video evaluation of the North Star Ambulatory Assessment in patients with Duchenne muscular dystrophy.

Conducting functional assessments remotely can help alleviate the burden of in-person assessment on patients with Duchenne muscular dystrophy and their caregivers. The objective of this study was to evaluate whether scores from remote functional assessment of patients with Duchenne muscular dystrophy correspond to in-person scores on the same functional assessments. Remote live stream versus in-person scores on the North Star Ambulatory Assessment (including time [seconds] to complete the 10-meter walk/run and time to rise from the floor [supine to stand]) were assessed using statistical analyses, including intraclass correlation coefficient, and Pearson, Spearman, and Bland-Altman analyses. The remote and in-clinic assessments had to occur within 2 weeks of one another to be considered for this analysis. This analysis included patients with Duchenne muscular dystrophy, aged 4 to 7 years. Participants in this analysis received delandistrogene moxeparvovec (as part of SRP-9001-101 [Study 101; NCT03375164] or SRP-9001-102 [Study 102; NCT03769116]) or were randomized to receive placebo (in Part 1 of Study 102). This study evaluates score reproducibility between live stream remote scoring versus in-person functional assessments as determined by intraclass correlation coefficient, and Pearson, Spearman, and Bland-Altman analyses. The results showed that scores from remote functional assessment of patients with Duchenne muscular dystrophy strongly correlated with those obtained in person. These findings demonstrate congruence between live stream remote and in-person functional assessment and suggest that remote assessment has the potential to reduce the burden on a family by supplementing in-clinic visits.

Discovery, Optimization, and Biological Evaluation of Arylpyridones as Cbl-b Inhibitors.

Casitas B-lymphoma proto-oncogene-b (Cbl-b), a member of the Cbl family of RING finger E3 ubiquitin ligases, has been demonstrated to play a central role in regulating effector T-cell function. Multiple studies using gene-targeting approaches have provided direct evidence that Cbl-b negatively regulates T, B, and NK cell activation via a ubiquitin-mediated protein modulation. Thus, inhibition of Cbl-b ligase activity can lead to immune activation and has therapeutic potential in immuno-oncology. Herein, we describe the discovery and optimization of an arylpyridone series as Cbl-b inhibitors by structure-based drug discovery to afford compound 31. This compound binds to Cbl-b with an IC50 value of 30 nM and induces IL-2 production in T-cells with an EC50 value of 230 nM. Compound 31 also shows robust intracellular target engagement demonstrated through inhibition of Cbl-b autoubiquitination, inhibition of ubiquitin transfer to ZAP70, and the cellular modulation of phosphorylation of a downstream signal within the TCR axis.

Discovery of a Novel Benzodiazepine Series of Cbl-b Inhibitors for the Enhancement of Antitumor Immunity.

Casitas B-lineage lymphoma proto-oncogene-b (Cbl-b) is a RING finger E3 ligase that is responsible for repressing T-cell, natural killer (NK) cell, and B-cell activation. The robust antitumor activity observed in Cbl-b deficient mice arising from elevated T-cell and NK-cell activity justified our discovery effort toward Cbl-b inhibitors that might show therapeutic promise in immuno-oncology, where activation of the immune system can drive the recognition and killing of cancer cells. We undertook a high-throughput screening campaign followed by structure-enabled optimization to develop a novel benzodiazepine series of potent Cbl-b inhibitors. This series displayed nanomolar levels of biochemical potency, as well as potent T-cell activation. The functional activity of this class of Cbl-b inhibitors was further corroborated with ubiquitin-based cellular assays.

DockStream: a docking wrapper to enhance de novo molecular design.

Recently, we have released the de novo design platform REINVENT in version 2.0. This improved and extended iteration supports far more features and scoring function components, which allows bespoke and tailor-made protocols to maximize impact in small molecule drug discovery projects. A major obstacle of generative models is producing active compounds, in which predictive (QSAR) models have been applied to enrich target activity. However, QSAR models are inherently limited by their applicability domains. To overcome these limitations, we introduce a structure-based scoring component for REINVENT. DockStream is a flexible, stand-alone molecular docking wrapper that provides access to a collection of ligand embedders and docking backends. Using the benchmarking and analysis workflow provided in DockStream, execution and subsequent analysis of a variety of docking configurations can be automated. Docking algorithms vary greatly in performance depending on the target and the benchmarking and analysis workflow provides a streamlined solution to identifying productive docking configurations. We show that an informative docking configuration can inform the REINVENT agent to optimize towards improving docking scores using public data. With docking activated, REINVENT is able to retain key interactions in the binding site, discard molecules which do not fit the binding cavity, harness unused (sub-)pockets, and improve overall performance in the scaffold-hopping scenario. The code is freely available at https://github.com/MolecularAI/DockStream .

De novo design with deep generative models based on 3D similarity scoring.

We have demonstrated the utility of a 3D shape and pharmacophore similarity scoring component in molecular design with a deep generative model trained with reinforcement learning. Using Dopamine receptor type 2 (DRD2) as an example and its antagonist haloperidol 1 as a starting point in a ligand based design context, we have shown in a retrospective study that a 3D similarity enabled generative model can discover new leads in the absence of any other information. It can be efficiently used for scaffold hopping and generation of novel series. 3D similarity based models were compared against 2D QSAR based, indicating a significant degree of orthogonality of the generated outputs and with the former having a more diverse output. In addition, when the two scoring components are combined together for training of the generative model, it results in more efficient exploration of desirable chemical space compared to the individual components.

Research approaches for evaluating opioid sparing in clinical trials of acute and chronic pain treatments: Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials recommendations.

ABSTRACT: Randomized clinical trials have demonstrated the efficacy of opioid analgesics for the treatment of acute and chronic pain conditions, and for some patients, these medications may be the only effective treatment available. Unfortunately, opioid analgesics are also associated with major risks (eg, opioid use disorder) and adverse outcomes (eg, respiratory depression and falls). The risks and adverse outcomes associated with opioid analgesics have prompted efforts to reduce their use in the treatment of both acute and chronic pain. This article presents Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) consensus recommendations for the design of opioid-sparing clinical trials. The recommendations presented in this article are based on the following definition of an opioid-sparing intervention: any intervention that (1) prevents the initiation of treatment with opioid analgesics, (2) decreases the duration of such treatment, (3) reduces the total dosages of opioids that are prescribed for or used by patients, or (4) reduces opioid-related adverse outcomes (without increasing opioid dosages), all without causing an unacceptable increase in pain. These recommendations are based on the results of a background review, presentations and discussions at an IMMPACT consensus meeting, and iterative drafts of this article modified to accommodate input from the co-authors. We discuss opioid sparing definitions, study objectives, outcome measures, the assessment of opioid-related adverse events, incorporation of adequate pain control in trial design, interpretation of research findings, and future research priorities to inform opioid-sparing trial methods. The considerations and recommendations presented in this article are meant to help guide the design, conduct, analysis, and interpretation of future trials.

New Associations between Drug-Induced Adverse Events in Animal Models and Humans Reveal Novel Candidate Safety Targets.

To improve our ability to extrapolate preclinical toxicity to humans, there is a need to understand and quantify the concordance of adverse events (AEs) between animal models and clinical studies. In the present work, we discovered 3011 statistically significant associations between preclinical and clinical AEs caused by drugs reported in the PharmaPendium database of which 2952 were new associations between toxicities encoded by different Medical Dictionary for Regulatory Activities terms across species. To find plausible and testable candidate off-target drug activities for the derived associations, we investigated the genetic overlap between the genes linked to both a preclinical and a clinical AE and the protein targets found to interact with one or more drugs causing both AEs. We discuss three associations from the analysis in more detail for which novel candidate off-target drug activities could be identified, namely, the association of preclinical mutagenicity readouts with clinical teratospermia and ovarian failure, the association of preclinical reflexes abnormal with clinical poor-quality sleep, and the association of preclinical psychomotor hyperactivity with clinical drug withdrawal syndrome. Our analysis successfully identified a total of 77% of known safety targets currently tested in in vitro screening panels plus an additional 431 genes which were proposed for investigation as future safety targets for different clinical toxicities. This work provides new translational toxicity relationships beyond AE term-matching, the results of which can be used for risk profiling of future new chemical entities for clinical studies and for the development of future in vitro safety panels.

Uncertainty quantification in drug design.

Machine learning and artificial intelligence are increasingly being applied to the drug-design process as a result of the development of novel algorithms, growing access, the falling cost of computation and the development of novel technologies for generating chemically and biologically relevant data. There has been recent progress in fields such as molecular de novo generation, synthetic route prediction and, to some extent, property predictions. Despite this, most research in these fields has focused on improving the accuracy of the technologies, rather than on quantifying the uncertainty in the predictions. Uncertainty quantification will become a key component in autonomous decision making and will be crucial for integrating machine learning and chemistry automation to create an autonomous design-make-test-analyse cycle. This review covers the empirical, frequentist and Bayesian approaches to uncertainty quantification, and outlines how they can be used for drug design. We also outline the impact of uncertainty quantification on decision making.

Burden of illness of trigeminal neuralgia among patients managed in a specialist center in England.

BACKGROUND: Trigeminal neuralgia (TN) causes severe episodic, unilateral facial pain and is initially treated with antiepileptic medications. For patients not responding or intolerant to medications, surgery is an option. METHODS: In order to expand understanding of the pain-related burden of illness associated with TN, a cross-sectional survey was conducted of patients at a specialist center that utilizes a multidisciplinary care pathway. Participants provided information regarding their pain experience and treatment history, and completed several patient-reported outcome (PRO) measures. RESULTS: Of 129 respondents, 69/128 (54%; 1 missing) reported no pain in the past 4 weeks. However, 84 (65%) respondents were on medications, including 49 (38%) on monotherapy and 35 (27%) on polytherapy. A proportion of patients had discontinued at least one medication in the past, mostly due to lack of efficacy (n = 62, 48%) and side effects (n = 51, 40%). A total of 52 (40%) patients had undergone surgery, of whom 30 had microvascular decompression (MVD). Although surgery, especially MVD, provided satisfactory pain control in many patients, 29% of post-surgical patients reported complications, 19% had pain worsen or stay the same, 48% were still taking pain medications for TN, and 33% reported new and different facial pain. CONCLUSIONS: In most PRO measures, respondents with current pain interference had poorer scores than those without pain interference. In the Patient Global Impression of Change, 79% expressed improvement since beginning of treatment at this clinic. These results indicate that while the multidisciplinary approach can substantially alleviate the impact of TN, there remains an unmet medical need for additional treatment options.

Design of Phase 3 Studies Evaluating Vixotrigine for Treatment of Trigeminal Neuralgia.

PURPOSE: Vixotrigine (BIIB074) is a voltage- and use-dependent sodium channel blocker. These studies will evaluate the efficacy and safety of vixotrigine in treating pain experienced by patients with trigeminal neuralgia (TN) using enriched enrollment randomized withdrawal trial designs. PATIENTS AND METHODS: Two double-blind randomized withdrawal studies are planned to evaluate the efficacy and safety of vixotrigine compared with placebo in participants with TN (NCT03070132 and NCT03637387). Participant criteria include ≥18 years old who have classical, purely paroxysmal TN diagnosed ≥3 months prior to study entry, who experience ≥3 paroxysms of pain/day. The two studies will include a screening period, 7-day run-in period, a 4- or 6-week single-dose-blind dose-optimization period (Study 1) or 4-week open-label period (Study 2), and 14-week double-blind period. Participants will receive vixotrigine 150 mg orally three times daily in the dose-optimization and open-label periods. The primary endpoint of both studies is the proportion of participants classified as responders at Week 12 of the double-blind period. Secondary endpoints include safety measures, quality of life, and evaluation of vixotrigine population pharmacokinetics. CONCLUSION: There is a need for an effective, well-tolerated, noninvasive treatment for the neuropathic pain associated with TN. The proposed studies will evaluate the efficacy and safety of vixotrigine in treating pain experienced by patients with TN.

Historical trend toward improved long-term outcome in childhood absence epilepsy.

We retrospectively analyzed published studies to investigate historical trends in outcome of childhood absence epilepsy (CAE). We included patients based on onset of absence seizures in childhood, 3 Hz bilateral spike-wave discharges on EEG, and availability of seizure-free outcome data. The primary endpoint was seizure-freedom off medications by study publication year. We also analyzed relationships between seizure-freedom and 1. treatment medication, and 2. CAE diagnostic criteria. We included 29 studies published 1945-2013, encompassing 2416 patients. Seizure-freedom off medications was higher for studies after 1985 versus before 1975 (82% versus 35%; p < 0.001). Ethosuximide and valproate were used more commonly after 1985, and patients previously treated with ethosuximide or valproate had higher seizure-freedom off medications than those treated only with other medications (64% versus 32%; χ2>10; p < 0.001). Although differences in diagnostic criteria for early vs. later studies did not reach statistical significance, later studies tended to use normal EEG background (p = 0.09) and absence of comorbid disorders (p = 0.09) as criteria more commonly. These findings demonstrate that seizure-freedom off medications has improved in published CAE studies after 1985. Our results are limited due to retrospective analysis. Further work is needed with prospective, controlled trials to establish factors leading to improved long-term prognosis in CAE.

Information-Derived Mechanistic Hypotheses for Structural Cardiotoxicity.

Adverse events resulting from drug therapy can be a cause of drug withdrawal, reduced and or restricted clinical use, as well as a major economic burden for society. To increase the safety of new drugs, there is a need to better understand the mechanisms causing the adverse events. One way to derive new mechanistic hypotheses is by linking data on drug adverse events with the drugs' biological targets. In this study, we have used data mining techniques and mutual information statistical approaches to find associations between reported adverse events collected from the FDA Adverse Event Reporting System and assay outcomes from ToxCast, with the aim to generate mechanistic hypotheses related to structural cardiotoxicity (morphological damage to cardiomyocytes and/or loss of viability). Our workflow identified 22 adverse event-assay outcome associations. From these associations, 10 implicated targets could be substantiated with evidence from previous studies reported in the literature. For two of the identified targets, we also describe a more detailed mechanism, forming putative adverse outcome pathways associated with structural cardiotoxicity. Our study also highlights the difficulties deriving these type of associations from the very limited amount of data available.

Prospectively Validated Proteochemometric Models for the Prediction of Small-Molecule Binding to Bromodomain Proteins.

The bromodomain-containing proteins are a ligandable family of epigenetic readers, which play important roles in oncological, cardiovascular, and inflammatory diseases. Achieving selective inhibition of specific bromodomains is challenging, due to the limited understanding of compound and target selectivity features. In this study we build and benchmark proteochemometric (PCM) classification models on bioactivity data for 15,350 data points across 31 bromodomains, using both compound fingerprints and binding site protein descriptors as input variables, achieving a maximum performance as measured by the Matthew's Correlation Coefficient (MCC) of 0.83 on the external test set. We also find that histone peptide binding data can be used as a target descriptor to build a high performing PCM model (MCC 0.80), showing the transferability of peptide interaction information to modeling small-molecule bioactivity. 1,139 compounds were selected for prospective experimental testing by performing a virtual screen using model predictions and implementing conformal prediction, which resulted in 319 correctly predicted compound-target pair actives and the correct prediction for certain selectivity profile combinations of the four bromodomains tested against. We identify that conformal prediction can be used to fine-tune the balance between hit retrieval and hit structural diversity in a virtual screening setting. PCM can be applied to future virtual screening and compound design, including off-target prediction for bromodomains.

Headache plus: trigeminal and autonomic features in a case of cervicogenic headache responsive to third occipital nerve radiofrequency ablation.

OBJECTIVE: To describe a case of cervicogenic headache with associated autonomic features and pain in a trigeminal distribution, all of which responded to third occipital nerve radiofrequency ablation. DESIGN: Single case report. SETTING: Massachusetts General Hospital Center for Pain Medicine. PATIENTS: A 38-year-old woman with history of migraines and motor vehicle accident. INTERVENTIONS: Right third occipital nerve diagnostic blocks and radiofrequency lesioning. OUTCOME MEASURES: Pain reduction; physical findings, including periorbital and mandibular facial swelling, tearing, conjunctival injection, and allodynia; and use of opioid and non-opioid pain medicines. RESULTS: The patient had complete relief of her pain and autonomic symptoms, and was able to stop all pain medications following a dedicated third occipital nerve lesioning. CONCLUSIONS: This case illustrates the diagnostic and therapeutic complexity of cervicogenic headache and the overlap with other headache types, including trigeminal autonomic cephalgias and migraine. It represents a unique proof of principle in that not only trigeminal nerve pain but also presumed neurogenic inflammation can be relieved by blockade of cervical nociceptive inputs. Further investigation into shared mechanisms of headache pathogenesis is warranted.

Is epilepsy a preventable disorder? New evidence from animal models.

Epilepsy accounts for 0.5% of the global burden of disease, and primary prevention of epilepsy represents one of the three 2007 NINDS Epilepsy Research Benchmarks. In the past decade, efforts to understand and intervene in the process of epileptogenesis have yielded fruitful preventative strategies in animal models.This article reviews the current understanding of epileptogenesis, introduces the concept of a "critical period" for epileptogenesis, and examines strategies for epilepsy prevention in animal models of both acquired and genetic epilepsies. We discuss specific animal models, which may yield important insights into epilepsy prevention including kindling, poststatus epilepticus, prolonged febrile seizures, traumatic brain injury, hypoxia, the tuberous sclerosis mouse model, and the WAG/Rij rat model of primary generalized epilepsy. Hopefully, further investigation of antiepileptogenesis in animal models will soon enable human therapeutic trials to be initiated, leading to long-term epilepsy prevention and improved patient quality of life.

Development of spike-wave seizures in C3H/HeJ mice.

C3H/HeJ mice have been reported to have relatively early onset of spike-wave discharges (SWD), and a defective AMPA receptor subunit Gria4 as the genetic cause. We investigated the time course of SWD development through serial EEG recordings in C3H/HeJ mice to better characterize this model. We found that at immature postnatal ages of 5-15 days, rare SWD-like events were observed at an average rate of 3 per hour, and with relatively broad spikes, irregular rhythm, slow frequency (5-6 Hz), and short duration (mean 1.75 s). This was followed by a transitional period of increasing SWD incidence, which then stabilized in mature animals at age 26-62 days, with SWD at an average rate of 45 per hour, narrower spike morphology, regular rhythm, higher frequency (7-8 Hz), and longer duration (mean 3.40s). This sequence of maturational changes in SWD development suggests that effects of early intervention could be tested in C3H/HeJ mice over the course of a few weeks, rather than a few months as in rats, greatly facilitating future research on anti-epileptogenesis.

Early treatment suppresses the development of spike-wave epilepsy in a rat model.

PURPOSE: Current treatments for epilepsy may control seizures, but have no known effects on the underlying disease. We sought to determine whether early treatment in a model of genetic epilepsy would reduce the severity of the epilepsy phenotype in adulthood. METHODS: We used Wistar albino Glaxo rats of Rijswijk (WAG/Rij) rats, an established model of human absence epilepsy. Oral ethosuximide was given from age p21 to 5 months, covering the usual period in which seizures develop in this model (age approximately 3 months). Two experiments were performed: (1) cortical expression of ion channels Nav1.1, Nav1.6, and HCN1 (previously shown to be dysregulated in WAG/Rij) measured by immunocytochemistry in adult treated rats; and (2) electroencephalogram (EEG) recordings to measure seizure severity at serial time points after stopping the treatment. RESULTS: Early treatment with ethosuximide blocked changes in the expression of ion channels Nav1.1, Nav1.6, and HCN1 normally associated with epilepsy in this model. In addition, the treatment led to a persistent suppression of seizures, even after therapy was discontinued. Thus, animals treated with ethosuximide from age p21 to 5 months still had a marked suppression of seizures at age 8 months. DISCUSSION: These findings suggest that early treatment during development may provide a new strategy for preventing epilepsy in susceptible individuals. If confirmed with other drugs and epilepsy paradigms, the availability of a model in which epileptogenesis can be controlled has important implications both for future basic studies, and human therapeutic trials.