Characterization of ascending dose canine telemetry model supports its use in E14/S7B QT integrated risk assessments.

INTRODUCTION: Nonclinical evaluation of the cardiovascular effects of novel chemical or biological entities (NCE, NBEs) is crucial for supporting first-in-human clinical trials. One important aspect of these evaluations is the assessment of potential QT/QTc prolongation risk, as drug-induced QT prolongation can have catastrophic effects. The recent publication of E14/S7B Q&As allows for the situational incorporation of nonclinical QTc data as part of an integrated risk assessment for a Thorough QT (TQT) waiver application provided certain best practice criteria are met. Recent publications provided detailed characterization of nonclinical QTc telemetry data collected from the commonly used Latin square study design. METHODS: To understand whether data from alternate telemetry study designs were sufficient to serve as part of the E14/S7B integrated risk assessment, we report the performance and translational sensitivity to identify clinical risk of QTc prolongation risk for an ascending dose telemetry design. RESULTS: The data demonstrated low variability in QTci interval within animals from day to day, indicating a well-controlled study environment and limited concern for uncontrolled effects across dosing days. Historical study variances of the ascending dose design with n = 4 subjects, measured by least significant difference (LSD) and root mean square error (RMSE) values, were low enough to detect a + 10 ms QTci interval change, and the median minimum detectable difference (MDD) for QTci interval changes was <10 ms. Furthermore, concentration-QTci (C-QTci) assessments to determine +10 ms QTci increases for known hERG inhibitors were comparable to clinical CC values listed in the E14/S7B training materials, supporting the use of the ascending dose design in an E14/S7B integrated risk assessment. DISCUSSION: These findings suggest that the ascending dose design can be a valuable tool in nonclinical evaluation of QT/QTc prolongation risk and the support of TQT waiver applications.

Clinician perspectives regarding CYP2C19 genotype testing in patients with critical limb ischemia: A Delphi approach.

OBJECTIVES: Antiplatelet therapy is an essential element in the management of patients with arterial vascular disease. In peripheral arterial disease (PAD), dual antiplatelet therapy (DAPT), primarily clopidogrel and aspirin, is routinely prescribed following intervention. There is sparse data regarding the need for DAPT, the appropriate duration, or the heterogeneity of treatment effects for antiplatelet regimens across patients, leading to potential uncertainty and heterogeneity around treatment practices. An example of heterogeneity of treatment effects is a patients' metabolizer status for the use of clopidogrel. The aim of the study was to (1) assess clinicians' knowledge of and attitudes toward managing patients with CYP2C19 mutations, (2) identify barriers to implementation of CYP2C19 testing and management policies, and (3) reach consensus for CYP2C19 testing and management strategies for patients with PAD who undergo peripheral vascular interventions (PVI). METHODS: A modified Delphi method was used to establish consensus amongst PAD interventionalists around CYP2C19 testing. All practicing Yale New Haven Hospital PAD interventionalists with backgrounds in interventional cardiology, vascular surgery, or interventional radiology were approached by email for participation. Round 1 included the collection of baseline demographic questions, knowledge questions, and three statements for consensus. Knowledge questions were rated on a 0-10 Likert scale with the following anchors: 0 ("Not at all"), 5 ("Neutral), and 10 ("Very Much"). Participants were asked to rate the importance of the three consensus statements on a 9-point Likert scale from 1 ("Strongly Disagree") to 10 ("Strongly Agree"). In Round 2, participants were shown the same consensus statements, the median response of the group from the previous round, and their previous answers. Participants were instructed to revise their rating using the results from the previous round. This process was repeated for Round 3. RESULTS: Of the 28 experts invited to participate, 13 agreed (46%). Participants were predominantly male (92.3%) and white (61.5%) with representation from interventional cardiology (46.2%) and vascular surgery (53.8%). Most participants reported more than 10+ years in practice (61.5%). PAD interventionalists felt they would benefit from more education regarding CYP2C19 mutations (median score 8.0, interquartile range 5.0-8.5). They indicated some familiarity with CYP2C19 mutations (7.0, 6.0-9.5) but did not feel strongly that CYP2C19 was important to their practice (6.0, 5.5-7.5). In each round, the median responses for the three consensus statements were 5, 6, and 9, respectively. With each successive round the interquartile range narrowed indicative of evolving consensus but did not reach the prespecified interquartile range for consensus of 1 for any of the statements. CONCLUSIONS: PAD interventionalists practicing at an academic health system recognize the heterogenous response of their patients to clopidogrel therapy but are unsure when to leverage genetic testing to improve outcomes for their patients. Our study identified gaps regarding PAD interventionalists' knowledge, perceived barriers, and attitudes toward CYP2C19 testing in PAD. This information highlights the need for randomized data on genetic testing for clopidogrel responsiveness in peripheral vascular disease following intervention to help guide antiplatelet management.

Structure Guided Discovery of Novel Pan Metallo-ß-Lactamase Inhibitors with Improved Gram-Negative Bacterial Cell Penetration.

The use of ß-lactam (BL) and ß-lactamase inhibitor combination to overcome BL antibiotic resistance has been validated through clinically approved drug products. However, unmet medical needs still exist for the treatment of infections caused by Gram-negative (GN) bacteria expressing metallo-ß-lactamases. Previously, we reported our effort to discover pan inhibitors of three main families in this class: IMP, VIM, and NDM. Herein, we describe our work to improve the GN coverage spectrum in combination with imipenem and relebactam. This was achieved through structure- and property-based optimization to tackle the GN cell penetration and efflux challenges. A significant discovery was made that inhibition of both VIM alleles, VIM-1 and VIM-2, is essential for broad GN coverage, especially against VIM-producing P. aeruginosa. In addition, pharmacokinetics and nonclinical safety profiles were investigated for select compounds. Key findings from this drug discovery campaign laid the foundation for further lead optimization toward identification of preclinical candidates.

Pharmacologic characterization of atogepant: A potent and selective calcitonin gene-related peptide receptor antagonist.

BACKGROUND: The trigeminal sensory neuropeptide calcitonin gene-related peptide (CGRP) is identified as an essential element in migraine pathogenesis. METHODS: In vitro and in vivo studies evaluated pharmacologic properties of the CGRP receptor antagonist atogepant. Radioligand binding using 125I-CGRP and cyclic adenosine monophosphate (cAMP) accumulation assays were conducted in human embryonic kidney 293 cells to assess affinity, functional potency and selectivity. Atogepant in vivo potency was assessed in the rat nitroglycerine model of facial allodynia and primate capsaicin-induced dermal vasodilation (CIDV) pharmacodynamic model. Cerebrospinal fluid/brain penetration and behavioral effects of chronic dosing and upon withdrawal were evaluated in rats. RESULTS: Atogepant exhibited high human CGRP receptor-binding affinity and potently inhibited human α-CGRP-stimulated cAMP responses. Atogepant exhibited significant affinity for the amylin1 receptor but lacked appreciable affinities for adrenomedullin, calcitonin and other known neurotransmitter receptor targets. Atogepant dose-dependently inhibited facial allodynia in the rat nitroglycerine model and produced significant CIDV inhibition in primates. Brain penetration and behavioral/physical signs during chronic dosing and abrupt withdrawal were minimal in rats. CONCLUSIONS: Atogepant is a competitive antagonist with high affinity, potency and selectivity for the human CGRP receptor. Atogepant demonstrated a potent, concentration-dependent exposure/efficacy relationship between atogepant plasma concentrations and inhibition of CGRP-dependent effects.