Allostery: Abl kinase and TruBind? Back-scattering Interferometry

When abnormally expressed or controlled, kinase activity can cause cellular dysregulation and contribute to the onset of several diseases, including cancer. Based on the understanding of kinase malfunction, the discovery of small organic molecules to alter kinase function has culminated in the development of targeted cancer therapy. However, limited selectivity and the emergence of drug resistance remain fundamental challenges.<br>Most known kinase inhibitors are Type I inhibitors, ATP-competitive compounds such as dasatinib that bind to the ATP binding site. Type II inhibitors are compounds which bind partially in the ATP binding site and extend into an adjacent allosteric site that is present only in the inactive kinase conformation. Compared to Type I inhibitors, Type II inhibitors have been shown to possess advantageous pharmacological properties. As such, many Type II inhibitors currently on the market, such as imatinib, are very effective anti-cancer drugs.<br>Mutations resistant to Type I/II inhibitors are emerging at a rapid pace and often limit the success of targeted cancer therapies. At present, there are more than 50 mutation sites conferring different levels of imatinib resistance. Recently, a number of Type III inhibitors that function via allosteric modulation have demonstrated promise towards addressing mutation dependent drug resistance. As such, the need to identify and develop reversible inhibitors that are resistant to such mutations and bind with a high affinity is the focus of many research projects.<br>The binding affinity of Type I, II and III Bcr-Abl kinase inhibitors with wild type and four mutant Bcr-Abl kinases (H396P, M351T, Q252H, and T315I) were measured using TruBind? Back-Scattering Interferometry (BSI). BSI successfully demonstrated facile determination of equilibrium dissociation constants (Kd) for all systems, with a high degree of concordance with competition assay derived IC50 results. These results indicate that BSI binding studies both class I, II, and III kinase inhibitors can easily be performed, allowing for confirmation of target engagement as well as direct binding assessment of type II and III kinase inhibitors against inactive Bcr-Abl kinase. The latter makes BSI an attractive biophysical technique for the study of second and third generation kinase inhibitors to address the challenges of kinase inhibitor drug resistance

Binding Studies of Type I, II, and IV Kinase Inhibitors against Abl Kinase using Back-Scattering Interferometry MOA for allosteric inhibitors that overcome drug resistance

<p>When abnormally expressed or controlled, kinase activity can cause cellular dysregulation and contribute to the onset of several diseases, including cancer. Based on the understanding of kinase malfunction, the discovery of small organic molecules to alter kinase function has culminated in the development of targeted cancer therapy. However, limited selectivity and the emergence of drug resistance remain fundamental challenges. Most known kinase inhibitors are Type I inhibitors, ATP-competitive compounds such as dasatinib that bind to the ATP binding site. Type II inhibitors are compounds which bind partially in the ATP binding site and extend into an adjacent allosteric site that is present only in the inactive kinase conformation. Compared to Type I inhibitors, Type II inhibitors have been shown to possess advantageous pharmacological properties. As such, many Type II inhibitors currently on the market, such as imatinib, are very effective anti-cancer drugs. Mutations resistant to Type I/II inhibitors are emerging at a rapid pace and often limit the success of targeted cancer therapies. At present, there are more than 50 mutation sites conferring different levels of imatinib resistance. Recently, a number of Type IV inhibitors that function via allosteric modulation have demonstrated promise towards addressing mutation dependent drug resistance. As such, the need to identify and develop reversible inhibitors that are resistant to such mutations and bind with a high affinity is the focus of many research projects. The binding affinity of Type I, II and IV Bcr-Abl kinase inhibitors with wild type and four mutant Bcr-Abl kinases (H396P, M351T, Q252H, and T315I) were measured using TruBind? Back-Scattering Interferometry (BSI). BSI successfully demonstrated facile determination of equilibrium dissociation constants (Kd) for all systems, with a high degree of concordance with competition assay derived IC50 results. These results indicate that BSI binding studies both class I, II, and IIV kinase inhibitors can easily be performed, allowing for confirmation of target engagement as well as direct binding assessment of type II and IV kinase inhibitors against inactive Bcr-Abl kinase. The latter makes BSI an attractive biophysical technique for the study of second and third generation kinase inhibitors to address the challenges of kinase inhibitor drug resistance.</p

Medication history-wide association studies for pharmacovigilance of pregnant patients

Background: Systematic exclusion of pregnant people from interventional clinical trials has created a public health emergency for millions of patients through a dearth of robust safety data for common drugs. Methods: We harnessed an enterprise collection of 2.8 M electronic health records (EHRs) from routine care, leveraging data linkages between mothers and their babies to detect drug safety signals in this population at full scale. Our mixed-methods signal detection approach stimulates new hypotheses for post-marketing surveillance agnostically of both drugs and diseases-by identifying 1,054 drugs historically prescribed to pregnant patients; developing a quantitative, medication history-wide association study; and integrating a qualitative evidence synthesis platform using expert clinician review for integration of biomedical specificity-to test the effects of maternal exposure to diverse drugs on the incidence of neurodevelopmental defects in their children. Results: We replicated known teratogenic risks and existing knowledge on drug structure-related teratogenicity; we also highlight 5 common drug classes for which we believe this work warrants updated assessment of their safety. Conclusion: Here, we present roots of an agile framework to guide enhanced medication regulations, as well as the ontological and analytical limitations that currently restrict the integration of real-world data into drug safety management during pregnancy. This research is not a replacement for inclusion of pregnant people in prospective clinical studies, but it presents a tractable team science approach to evaluating the utility of EHRs for new regulatory review programs-towards improving the delicate equipoise of accuracy and ethics in assessing drug safety in pregnancy

Augmenting Kalman Filter Machine Learning Models with Data from OCT to Predict Future Visual Field Loss: An Analysis Using Data from the African Descent and Glaucoma Evaluation Study and the Diagnostic Innovation in Glaucoma Study.

PurposeTo assess whether the predictive accuracy of machine learning algorithms using Kalman filtering for forecasting future values of global indices on perimetry can be enhanced by adding global retinal nerve fiber layer (RNFL) data and whether model performance is influenced by the racial composition of the training and testing sets.DesignRetrospective, longitudinal cohort study.ParticipantsPatients with open-angle glaucoma (OAG) or glaucoma suspects enrolled in the African Descent and Glaucoma Evaluation Study or Diagnostic Innovation in Glaucoma Study.MethodsWe developed a Kalman filter (KF) with tonometry and perimetry data (KF-TP) and another KF with tonometry, perimetry, and global RNFL data (KF-TPO), comparing these models with one another and with 2 linear regression (LR) models for predicting mean deviation (MD) and pattern standard deviation values 36 months into the future for patients with OAG and glaucoma suspects. We also compared KF model performance when trained on individuals of European and African descent and tested on patients of the same versus the other race.Main outcome measuresPredictive accuracy (percentage of MD values forecasted within the 95% repeatability interval) differences among the models.ResultsAmong 362 eligible patients, the mean ± standard deviation age at baseline was 71.3 ± 10.4 years; 196 patients (54.1%) were women; 202 patients (55.8%) were of European descent, and 139 (38.4%) were of African descent. Among patients with OAG (n&nbsp;= 296), the predictive accuracy for 36 months in the future was higher for the KF models (73.5% for KF-TP, 71.2% for KF-TPO) than for the LR models (57.5%, 58.0%). Predictive accuracy did not differ significantly between KF-TP and KF-TPO (P&nbsp;= 0.20). If the races of the training and testing set patients were aligned (versus nonaligned), the mean absolute prediction error of future MD improved 0.39 dB for KF-TP and 0.48 dB for KF-TPO.ConclusionsAdding global RNFL data to existing KFs minimally improved their predictive accuracy. Although KFs attained better predictive accuracy when the races of the training and testing sets were aligned, these improvements were modest. These findings will help to guide implementation of KFs in clinical practice

Walk before you run: feasibility challenges and lessons learned from the PROCLAIM Study, a multicenter randomized controlled trial of misoprostol for prevention of recurrent C. difficile during COVID-19

We analyzed our challenging experience with a randomized controlled trial of misoprostol for prevention of recurrent C. difficile. Despite careful prescreening and thoughtful protocol modifications to facilitate enrollment, we closed the study early after enrolling just 7 participants over 3 years. We share lessons learned, noting the importance of feasibility studies, inclusion of biomarker outcomes, and dissemination of such findings to inform future research design and implementation successes

0-6877 (Phase 1): Communications and Radar-Supported Transportation Operations and Planning (CAR-STOP) [Project Summary]

A recent NHTSA report indicates that more than 80% of all annual car crashes could be prevented by vehicular communications. To that end, the focus of this project was to develop a framework (conceptualizations, processes, procedures, and algorithms) to harness and mature wireless technology to improve transportation safety, with an emphasis on collision warning/collision avoidance (CW/CA) systems

Discovery of Desketoraloxifene Analogues as Inhibitors of Mammalian, <i>Pseudomonas aeruginosa</i>, and NAPE Phospholipase D Enzymes

Phospholipase D (PLD) hydrolyses cellular lipids to produce the important lipid second messenger phosphatidic acid. A PLD enzyme expressed by Pseudomonas aeruginosa (PldA) has been shown to be important in bacterial infection, and NAPE-PLD has emerged as being key in the synthesis of endocannabinoids. In order to better understand the biology and therapeutic potential of these less explored PLD enzymes, small molecule tools are required. Selective estrogen receptor modulators (SERMs) have been previously shown to inhibit mammalian PLD (PLD1 and PLD2). By targeted screening of a library of SERM analogues, additional parallel synthesis, and evaluation in multiple PLD assays, we discovered a novel desketoraloxifene-based scaffold that inhibited not only the two mammalian PLDs but also structurally divergent PldA and NAPE-PLD. This finding represents an important first step toward the development of small molecules possessing universal inhibition of divergent PLD enzymes to advance the field