PAGE 2013; Glasgow Towards the prediction of cardiovascular effects in human Nelleke Snelder, Bart Ploeger, Olivier Luttringer, Dean Rigel, Fumin Fu, Michael Beil, Donald Stanski and Meindert Danhof [email protected] 1 fingolimod • Fingolimod is effective in the treatment of multiple sclerosis • In 2010 fingolimod was approved at a dose of 0.5 mg Freedoms trial: patients with MS Event fingolimod 0.5 mg placebo • A dose of 0.5 mg resulted in: (N=425) (N=418) • A small increase in blood pressure Hypertension 26 (6.1 %) 16 (3.8 %) • 1-2 mm Hg after 2 months Bradycardia 9 (2.1 %) 3 (0.7 %) • A transient bradycardia • 8 bpm at 5 hours after the 1st dose (attenuation after 6 hours) • Are cardiovascular effects of relevance for fingolimod? • Is the effect reversible? • What are the long term effects? • Can early selection of follow-up compounds be improved? Introduction 2 Effect of fingolimod on the CVS Vasocontriction/dilation • Sphingosine-1-phosphate (S1P) Angiogenesis is a major regulator of vascular Airway resistance S1P1 S1P3 / and immune systems S1P1? Barrier Vascular Endothelium function S1P1/ Bronchial smooth S1P3 muscle S1P3 (S1P1, S1P2?) S1PS1P S1P3 (S1P1, S1P3 (S1P1 in S1P2?) humans?) • Fingolimod is a S1P agonist Vascular smooth Atrial myocytes • Subtypes S1P1, S1P3, muscle S1P4 and S1P5 Heart-rate Vascular tone AV Conduction • The mechanism of action needs further investigation Introduction 3 Hypothesis: a better understanding of the mechanism of action of compounds can result from a quantitative understanding of the system • Physiological principles of BP regulation Mean Arterial Total Peripheral Cardiac Output Pressure (MAP) = Resistance (TPR) x (CO) Cardiac Output (CO) = Heart Rate (HR) x Stroke Volume (SV) • Several feedback mechanism: • Baroreflex system • Renin-Angiotensin-Aldosterone System • Preclinical research may contribute to a quantitative understanding of the cardiovascular system (CVS) Introduction 4 Objectives 1) Development of a systems pharmacology model characterizing the effects of drugs on the interrelationship between BP, TPR, CO, HR and SV ⇒ Drug-independent CVS model 2) Characterization of the effect of fingolimod on the CVS using the developed systems pharmacology model ⇒ A better understanding of mechanisms leading to cardiovascular effects following administration of fingolimod Objectives 5 CVS model PAGE 2013 Glasgow 6 Collect preclinical data from different drugs acting on CVS to identify system specific parameters • Compounds: Effect on HR Effect on TPR Effect on SV atropine (M2 receptor antagonist) amlodipine (calcium channel blocker) amiloride (diuretic) propanolol (non-selectiveβ blocker) enalapril (ACE-inhibitor) enalapril (ACE-inhibitor) fasudil (rho-kinase inhibitor) HCTZ (diuretic) prazosin (selective α1 blocker) 2-3 rats per compound Electical swivel • Study design: Baseline measurements A different dose each day Washout arterial Ascending radiotransmitter aortic flow probe Day 1 Day 2-5 Days 6-7 BP,BP, COCO and HRTPR are measured measured CVS model 7 System-specific Model • Linked turnover model with SV = SVT * (1-HR_SV *LN(HR/BSL_HR)) differential equations for HR, HR CO = HR⋅SV SV and TPR linked by negative Kin_HR kout_HR MAP = CO ⋅TPR feedback through MAP FB - • Direct inverse relationship between HR and SV MAP FB - FB - • Circadian rhythm: two cosine SVT TPR functions, one influencing HR Kin_SV kout_SV Kin_TPR k and one influencing TPR out_TPR • Handling effect: exponentially decreasing functions influencing Kin_HR and Kin_TPR • Differences between hypertensive and normotensive rats: • Different baseline • The feedback was found to be dependent on the baseline blood pressure CVS model 8 TPR SV CO HR MAP mmHG/(mL/mi n) mL/beat mL/mi n beats/min mmHG 2.3 2.5 2.70.22 0.26 0.3400506070150 250 120 140 0122436 Negative effect on HR Time (h) 9 TPR SV CO HR MAP mmHG/(mL/mi n) mL/beat mL/mi n beats/min mmHG 1.2 1.8 0.22 0.24 70 80 90 320 360 400100 130 0122436 Negative effect on TPR Time (h) 10 Drug-specific Model EFF_HR SV = SVT * (1-HR_SV *LN(HR/BSL_HR)) HRC CO = HR⋅SV • PKPD modelling approach (NONMEM): Kin_HR kout_HR MAP = CO ⋅TPR PK models from literature FB - MAP FB - FB - • Drug effects on HR, SV or TPR SVC T TPR Kin_SV kout_SV Kin_TPR kout_TPR EFF_SV EFF_TPR • Best drug effect models: Compound Effect site Drug effect model amiloride SV Emax with Emax fixed to 1 amlodipine TPR Emax with Emax fixed to 1 atropine HR Linear enalapril TPR and SV Emax with Emax fixed to 1 fasudil TPR Emax with Emax fixed to 1 HCTZ SV Emax with Emax fixed to 1 prazosin TPR Power propranolol HR No effect • The effect of ACE inhibitors is delayed. This was described by an effect compartment model CVS model 11 CVS model TPR SV CO HR MAP Adequate descriptionoftheeffect amlodipine mmHG/(mL/mi n) mL/beat mL/mi n beats/min mmHG 1.0 2.0 3.0 0.20 0.30 50 70 90 250 400 100 140 180 Vehicle 0.3 mg/kg 1 mg/kg 3 mg/kg 10 mg/kg 10 mg/kg 3 mg/kg 1 mg/kg 0.3 Vehicle 0 12 24 36 48 60 72 84 96 108 132 156 Ti me (h) hypertensive rats Derived Measured drug effectonTPR asingle by described can be Effect onall • Observations (colored perrat) Observations (colored (n=38) prediction Population prediction Individual five endpoints 12 CVS model TPR SV CO HR MAP Adequate descriptionoftheeffect amlodipine mmHG/(mL/mi n) mL/beat mL/mi n beats/min mmHG 0.4 0.7 1.0 0.35 0.45 120 160 250 400 80 100 Vehicle 0.3 mg/kg 1 mg/kg 3 mg/kg 10 mg/kg 10 mg/kg 3 mg/kg 1 mg/kg 0.3 Vehicle 0 12 24 36 48 60 72 84 96 108 132 156 Ti me (h) normotensive rats Derived Measured • in normotensive rats described adequately Effect ofamlodipine Observations (colored perrat) Observations (colored (n=38) prediction Population prediction Individual 13 Conclusions and Future perspective CVS model •A systems pharmacology model was developed to describe the interrelationship between MAP, CO, HR, SV and TPR • The developed systems pharmacology model can be used to quantify cardiovascular drug effects of novel compounds • Can the CVS model be used to elucidate the mechanism of action of novel compounds? CVS model 14 Application of the developed drug- independent CVS model to fingolimod PAGE 2013 Glasgow 15 Prediction of the effect of fingolimod on the CVS Experimental design: MAP • Dose: 0, 0.1, 0.3, 1, 3 and 10 mg/kg 160 • MD administration (4 weeks) 150 • Hypertensive and normotensive rats 140 • 32 rats mmHg 130 • Measured: MAP, HR and CO 120 0 400 800 1200 Time (h) TPR HR 1.8 360 1.6 340 1.4 320 1.2 beats/min 300 mmHG/(mL/min) 1.0 280 0 400 800 1200 0 400 800 1200 Time (h) Time (h) CO SV 0.50 120 0.45 110 0.40 100 0.35 mL/min mL/beat 90 0.30 80 0.25 0 400 800 1200 0 400 800 1200 Time (h) Time (h) Example of a typical hyeprtensive rat (10 mg/kg) Effect of fingolimod on the CVS 16 Prediction of the effect of fingolimod on the CVS • The CVS model was used to Hypothesis 1: effect is on HR MAP predict the effect of fingolimod 160 • System-specific parameters were fixed 150 140 mmHg 130mmHg 120 0 400 800 1200 Time (h) TPR HR 1.8 EFF_HR 450360 1.6 1.5 400340 SV = SVT * (1-HR_SV *LN(HR/BSL_HR)) CO = HR⋅SV 1.4 HRC 350320 K k MAP = CO ⋅TPR 1.2 beats/min in_HR out_HR beats/min 1.2 300 mmHG/(mL/min) mmHG/(mL/min) 300 0.91.0 280 FB - 0 400 800 1200 0 400 800 1200 MAP Time (h) Time (h) FB FB CO SV - - 0.50 140120 0.45 125110 0.40 SVC T TPR 0.40 Kin_SV kout_SV Kin_TPR k 110100 out_TPR 0.35 mL/min mL/min mL/beat mL/beat 9590 0.30 80 0.25 0 400 800 1200 0 400 800 1200 Time (h) Time (h) The CVS model indicates that it is not likely that the primary effect of fingolimod is on HR Effect of fingolimod on the CVS 17 Prediction of the effect of fingolimod on the CVS • The CVS model was used to Hypothesis 2: effect is on TPR MAP predict the effect of fingolimod 160 • System-specific parameters were fixed 150 140 mmHg 130mmHg 120 0 400 800 1200 1200 Time (h) TPR HRHR 1.8 450 350 1.5 400 SV = SVT * (1-HR_SV *LN(HR/BSL_HR)) 1.5 330 CO = HR⋅SV 310 HRC 350 K k MAP = CO ⋅TPR 1.2 290 in_HR beats/min out_HR beats/min 270 mmHG/(mL/min) mmHG/(mL/min) 300 0.9 FB 0.9 250 - 0 400 800 1200 00 400 400 800 800 1200 1200 MAP Time (h) TimeTime (h)(h) FB FB CO SVSV - - 140 0.500.50 140 0.450.45 125 SVC TPR 0.400.40 K T k K k 110 in_SV out_SV in_TPR out_TPR 110 0.35 mL/min 0.35 mL/min mL/beat mL/beat 95 0.300.30 80 0.250.25 EFF_TPR 0 400 800 1200 00 400 400 800 800 1200 1200 Time (h) TimeTime (h)(h) The CVS model indicates that the primary effect of fingolimod is on TPR There may be a secondary effect on HR Effect of fingolimod on the CVS 18 Model to describe the effect of fingolimod Transient • PKPD modelling approach: negative • PK of the pro-drug fingolimod and its EFF_HR SV = SVT * (1-HR_SV *LN(HR/BSL_HR)) active metabolite were described HRC CO = HR⋅SV K k simultaneously by a compartmental model in_HR out_HR MAP = CO ⋅TPR FB - MAP FB - FB - SVC T TPR Kin_SV kout_SV Kin_TPR kout_TPR Fast positive SlowSlow positivepositive • The effect of fingolimod on the CVS was EFF_TPR diseaseEFF_TPR altering described by a combination of 3 effects: EFF_TPR • Fast positive effect on TPR: log-linear model • Slow positive effect on TPR: linear model K ·M Kin R out • Slow structural effect only in hypertensive rat at high doses • Transient negative effect on HR: power model • Tolerance was described by feedback model - type 1 K ·M Ktol·R M tol Effect of fingolimod on the CVS 19 Adequate description of the effect of fingolimod on the CVS in hypertensive rat MAP 200 Example: Dose 10 mg/kg 180 Individual prediction 160 mmHg • Observations (colored per rat) 140 120 0 600 1200 1800 2400 Time (h) CO HR 120 350 100 330