1 / 21

Cardiac Ion Channel Safety Profiling: hERG and beyond G Erdemli Novartis Institutes for Biomedical Research

Cardiac Ion Channel Safety Profiling: hERG and beyond G Erdemli Novartis Institutes for Biomedical Research. Summary. Introduction to preclinical cardiac ion channel safety profiling Overview of automated electrophysiology technologies used at Novartis QPatch 16, HT & HTX IonWorks Quattro

kelda
Télécharger la présentation

Cardiac Ion Channel Safety Profiling: hERG and beyond G Erdemli Novartis Institutes for Biomedical Research

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Cardiac Ion Channel Safety Profiling: hERG and beyondG ErdemliNovartis Institutes for Biomedical Research

  2. Summary • Introduction to preclinical cardiac ion channel safety profiling • Overview of automated electrophysiology technologies used at Novartis • QPatch 16, HT & HTX • IonWorks Quattro • IonFlux 16 microfluidics system • Cardiac ion channel in vitro assays and case studies • hERG, Nav1.5, Cav1.2 and KCNQ1/minK • Implementation of preclinical in vitro ion channel safety profiling in the integrated risk assessment for cardiac safety • Indirect ion channel modulation, potential mechanisms and implications in preclinical safety assessment G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  3. Ito (hKv 4.2 hKv 4.3) 1 IKs (hminK + hKvLQT1) IKr (KvHERG+hMiRP) QT interval 3 INa 0 2 R ICa T IK1 (hKIR) P RMP -80/90 mV Q S ECG and action potential repolarizationCardiac ion channel profiling cardiac risk assessment Repolarization reserve LQT +25 mV -0 mV G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  4. Genetic basis for LQTS (hERG) Kaufman. Heart rhythm 2009 vol. 6 (8 Suppl) pp. S51-5 Schwartz et al Circulation 2001 G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  5. Cardiac ion channel safety profiling hERG on Qpatch-HT • Routine hERG screening on QPatch-HT • 6 pnt CRC, n=3 • 70% success rate (completed experiments) G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  6. High quality and reproducible results on QPatch-HT G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  7. QPatch data analysis: Reaching equilibrium G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  8. hERG Openers During routine screening hERG channel enhancers from different chemical series are identified Incorporated into automated data analysis for alerts G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  9. Effects of temperature in drug-induced hERG inhibition 22°C 35°C G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  10. hERG current on IonFlux-16Automated patch clamp at physiological temperatures A. C D G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  11. Cardiac ion channel safety profiling Nav1.5 assay on IonWorks Quattro Raw traces pre-cpd Normalized current post-cpd QC Monitor for seals • 8 pnt CRC, n=4 • ~100% success rate • Use-dependency Multi-state IC50 determination Use-dependence Characterization G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  12. hNav1.5 Pharmacology on Quattro Manual patch clamp from literature G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  13. Compound 1 An example of translational value of hNav1.5 assay • Preclinical cardiosafety data • in vitro Nav1.5 IC50 = 15.4 mM • Dose dependent prolongation of P, PQ and QRS in dog telemetry, no/minimal QT interval prolongation • Sudden deaths in 13 week dog toxicity study & polymorphic ventricular tachycardia - consistent with an extreme sodium channel inhibition, with PR prolongation as the first sign • Clinical cardiosafety data • Compound 1 at 640 mg (single dose) caused PR interval prolongation that coincided with the Tmax of the drug’s plasma concentration. NOEL = 1.72 mM (320 mg/kg) • Clinical studiesstudies terminated due to risk of cardiac conduction abnormalities • Therapeutic margin < 0.8 for PR prolongation G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  14. Compound 1 Preclinical Cardiac Safety Data (Dog) • IV/IV Index50: In vitro/In vivo Index: Nav1.5 IC50/Free CMax • IV/IV Index20: In vitro/In vivo Index: Nav1.5 IC20/Free Cmax G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  15. Compound 1 Clinical Cardiac Safety Data NC: No change G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  16. Compound 1 – SAD 320mg, 640mg Maximum PR Interval Increase vs Maximum Plasma Concentration Pre-dose Baseline variability 3 measurements/patient (0.93 µM) (1.9 µM) (3.7 µM) (5.6 µM) (4.7 µM) G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  17. Cardiac Ion Channel Profiling on Automated SystemsA part of preclinical integrated risk assessment Structure G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  18. Indirect modulation of hERG channels • An indirect QTc mechanism is invoked if a drug produces: • An in vivo QTc prolongation despite no in vitro signal indicating direct effect on cardiac ion channels. • A clinical QTc prolongation despite no preclinical signal indicating direct effect on cardiac ion channels • Potential mechanisms • Channel trafficking, maturation and degradation • Hypokalemia - regulation of ventricular repolarization by plasma potassium levels • Furosemide has no effect on hERG current and APD in rabbit purkinje fiber but causes QT interval prolongation • Inverse relationship between the plasma potassium levels and QT and QTc interval durations • Changes in plasma glucose levels • Hypoglycemia-induced hERG channel inhibition - due to decrease in intracellular ATP • Hyperglycemia-induced hERG channel inhibition - due to production of reactive oxygen species • Changes in autonomic tonus • Adrenergic modulation of hERG channel - Functional coupling of α and β adrenoceptors to hERG channel • Adrenergic regulation of IKs channel - functional coupling of β adrenoceptors to IKs • Macromolecular Complexes can produce ↑QTc – Ankyrins, Caveolin-3, Syntrophin - No direct drug-induced examples, but candidates for off-target interactions G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  19. Indirect modulation of cardiac channels Definition & decision tree Negative in Nav1.5, Cav1.2, hERG, KCNQ1 but QTc prolongation in vivo PK/PD relationship Test metabolites Cmax/AUC driven Test on other cardiac ion channels PK/PD disconnect No effect • Delayed disposition (parent/metabolite) to heart tissue • Accumulation (parent/metabolite) in heart tissue • Modulation of ion channel trafficking/maturation/degradation • Modulation of ion channel gene expression • Hypokalemia • Autonomic nervous system • Glucose homeostasis • Structural macromolecular complexes G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  20. Summary • Automated electrophysiology has been implemented in routine cardiac ion channel safety screen in all stages of drug discovery • Allow thousands of compounds profiling with IC50 values and quick turnaround time • Assay validation, optimization and setting QC parameters for automated data analysis are key for successful implementation • Results show very good correlation with conventional electrophysiology in most cases • Common reasons for discrepancies between conventional and automated electrophysiology are differences in • compound application duration • recording temperature • Physicochemical properties of compounds should be taken into consideration for data analysis – solubility, permeability etc Overall in vitro preclinical cardiac ion channel profiling data provide high quality translational information for integrated risk assessment G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

  21. Acknowledgments • Chris Penland • Dan Meyers • TychoHeimbach • Albert Kim • Dmitri Mikhailov • Clayton Springer • Bob Pearlstein Novartis • Xueying Cao • Tony Lee • Mats Holmqvist • A Golden • Steven Whitebread • Karl Chin • Mark Deurinck • Berengere Dumotier • M Traebert • Laszlo Urban • Fluxion • Qin Chen • Nianzhen Li • Tanner Nevill • Juliette Johnson • CristianIonescu-Zanetti • Jeff Jensen • Sophion • Ali Yehia • Millipore • Duncan Jarman G Erdemli, Ion Channel Retreat, Vancouver, June 28-30 2010

More Related