cardiac myosin activators
TRANSCRIPT
Acute Heart Failure
Cardiac Myosin Activators
Professor John ClelandNational Heart & Lung Institute
Harefield HospitalImperial College
London
Potential Conflicts of Interest:- I have received research support and/or speaker’s fees from Amgen, Medtronic, NI Medical, Novartis, Philips, Servier, Stealth BioTherapeutics, St Jude and Vifor.
Omecamtiv Mecarbil
Omecamtiv Mecarbil (OM) is a Novel Selective Cardiac Myosin Activator
Malik FI, et al. Science 2011; 331:1439-43.
Mechanochemical Cycle of Myosin
Force production
Omecamtiv mecarbil
Omecamtiv mecarbil increases the entry rate of myosin into the tightly-bound, force-producing
state with actin“More hands pulling on the rope”
Increases duration of systole
Increases stroke volume
No increase in myocyte calcium
No change in dP/dtmax
No increase in MVO2
3
Omecamtiv Mecarbil Does Not Alter the Ca2+ Transient
Rat Adult Cardiac MyocytesContractility Transient
-20
-16
-12
-8
-4
0
0 0.2 0.4 0.6 0.8 1Time (sec)
Cel
l Len
gth
∆ (m
m)
BasalOmecamtiv mecarbil200 nM
Contractility Transient
-10
-8
-6
-4
-2
0
0 0.2 0.4 0.6 0.8 1Time (sec)
Cel
l Len
gth
∆ (m
m)
BasalIsoproterenol
2 nM
Calcium Transient
Time (sec)
Fura
-2 R
atio
0.7
0.9
1.1
1.3
1.5
0 0.2 0.4 0.6 0.8 1
BasalOmecamtiv mecarbil200 nM
Calcium Transient
Time (sec)
Fura
-2 R
atio
0.7
0.9
1.1
1.3
1.5
0 0.2 0.4 0.6 0.8 1
BasalIsoproterenol
2 nM
Malik et al, 2011
Intravenous• Healthy Volunteer Study• Pharmacokinetic Study (2-72hours)• ATOMIC
Oral• Angina Treadmill Study• COSMIC
Clinical Trials of Omecamtiv Mecarbil
Cleland JGF, et al. Lancet 2011; 378: 676–83.
Teerlink JR, et al. Lancet 2011; 378: 667–75. Dose limiting chest discomfort and troponin release
Changes in Selected Echocardiographic Variables Over time in Patients with CHF
•Cleland JGF, et al. Lancet 2011.
Patients received 1.0 mg/kg per h for 1 h, then 0.5 mg/kg per h for 1 h, and then 0.1 mg/kg per h for 70 h.
Objective:• To evaluate the safety, pharmacokinetics/ pharmacodynamics, and
efficacy of IV omecamtiv mecarbil (OM) in patients with acute heart failure (AHF) – with HFrEF, raised NP and SysBP >90mmHg but excluding ACS
Hypothesis: • At least 1 dose level of IV OM will be well tolerated and will result in
improvement of dyspnoea (at 6, 24 & 48 hrs) in subjects with left ventricular systolic dysfunction hospitalised for AHF
ATOMIC-AHFAcute Treatment with Omecamtiv Mecarbil to Increase Contractility in Acute Heart Failure
Study Design: Sequential Dosing Cohort
Cohort 1 Cohort 2 Cohort 3Omecamtiv
Placebo1:1 Randomization (n≈200)
Omecamtiv
Placebo1:1 randomization (n≈200)
Placebo
Omecamtiv1:1 randomization (n≈200)
DMC DMC
Cohort 1 Cohort 2 Cohort 315 mg/hr @ 0-4 hr3 mg/hr @ 4-48 hrTarget: 230 ng/mLCmax: 75-500 ng/mLSET: ~8-55 msec
20 mg/hr @ 0-4 hr4 mg/hr @ 4-48 hrTarget: 310 ng/mLCmax: 125-700 ng/mLSET: ~14-78 msec
7.5 mg/hr @ 0-4 hr1.5 mg/hr @ 4-48 hrTarget: 115 ng/mLCmax: 30-250 ng/mL SET: ~3-28 msec
Pharmacokinetic simulations
Teerlink JR, et al. Lancet 2011; 378: 667–75; Cleland JGF, et al. Lancet 2011; 378: 676–83.
Characteristic
PooledPlacebo (N = 303)
Cohort 1 OM
(N = 103)
Cohort 2 OM
(N = 99)
Cohort 3 OM
(N = 101)
Age , mean (SD) 66 (11) 65 (12) 67 (10) 68 (10)Ischemic heart disease, % 62 62 59 66Systolic BP (mmHg), mean (SD) 119 (18)* 118 (18) 117 (17) 117 (15)Heart rate (beats/min), mean (SD) 78 (13) 78 (13) 79 (13) 78 (14)Dyspnea (NRS), Mean (SD) 6 (2) 6 (2) 6 (2) 6 (2)ACE inhibitors/ARBs, % 78 79 74 84Beta blocker, % 86* 90 87 90Digoxin, % 20 28 26 22Mineralocorticoid Receptor Antagonist, % 55 54 59 58Troponin-I, median (URL 0.04 ng/mL) 0.044* 0.060 0.044 0.056NT-proBNP (pg/mL), median 9026 7674 10488 10416eGFR (mL/min/1.73m2), mean (SD) 53 (18)* 52 (18) 53 (19) 50 (18)Time to randomisation, mean (SD) 15 (8)* 12 (8) 16 (10) 15 (9)
Baseline Characteristics
*p < 0.05 for a difference in cohorts 1-3 Placebo arms compared to each other; URL= upper reference limit
Primary Efficacy Endpoint:Dyspnea Response (Likert Scale)
Pooled Placebo
Response Rate Ratio* 1.03 1.15 1.23
95% CI (0.79, 1.35) (0.90, 1.47) (0.97, 1.55)
*Ratio of response rate to Pooled Placebop-value of a CMH test among all 3 Placebo arms = 0.32
Overall p-value = 0.33
PooledPlacebo
OMCohort 1
OMCohort 2
OMCohort 3
Dys
pnea
Res
pons
e R
ate
(% R
espo
nder
s)
05
10152025303540455055
42%47%
51%
41%
For Increases of…
Response Rate Ratio
Increases… 95% CI P-value
Dose* 50 mg total OM administered 5.5% 0.7% – 10.6% 0.025
Plasma concentration*
4000 hr*ng/mL AUC48h 6.4% 1.7% – 11.4% 0.007
Exploratory Analyses: Dose and ConcentrationRelationship to Dyspnea Response
* Adjusted for region, cohort, age, baseline NRS, presentation-randomization duration (continuous)
Change in Heart Rate and SBP
PK Concentration Bin Analysis Control OM Conc. Bin 1
OM Conc. Bin 2
OM Conc. Bin 3
OM concentration (ng/ml) ≥88-200 >200-300 >300-787
Heart Rate (beats/min) LS means -4.3 -4.4 -6.3 -6.5 Difference from control -0.1 -2.0 -2.3 95% CI (-1.4, 1.1) (-3.6, -0.4) (-3.9, -0.6) p-value 0.835 0.016 0.008Linear regression slope p < 0.0001SBP (mmHg) LS means -4.6 -4.4 -4.0 -2.2 Difference from control 0.3 0.6 2.4 95% CI (-1.2, 1.7) (-1.2, 2.4) (0.6, 4.2) p-value 0.719 0.521 0.009Linear regression slope p = 0.0017
N: number of patients in the bin, n: number of observations in the bin. Heart rate measured by ECG. Control = observations in Placebo + PK below quantification limit. PK bin concentration analysis: repeated measures analysis of covariance. Linear regression slope analysis: repeated measures multiple linear regression.
H
R 4 -0.05
-0.04
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
Troponin-I Change from Baseline (ng/mL) Compared with Pooled Placebo
Baseline TnI (ng/mL)PooledPlacebo Cohort 1 Cohort 2 Cohort 3
Median 0.044 0.060 0.044 0.056(Q1, Q3) 0.023, 0.080 0.028, 0.141 0.030, 0.084 0.026, 0.092
4 hours 15 hours 24 hours 48 hours Day 4 Day 6Time
Troponin Change from Baseline (ng/mL)
Q3
Median
Q1
0.03
0.02
0.01
0.00
–0.01
–0.02
–0.03
–0.04
–0.05
Patient Incidence, n (%)
PooledPlacebo (N = 303)
Pooled OM
(N = 303)
Cohort 1OM
(N = 103)
Cohort 2OM
(N = 99)
Cohort 3OM
(N = 101)
Death 10 (3.3) 8 (2.6) 1 (1.0) 4 (4.0) 3 (3.0) Cardiovascular 10 (3.3) 8 (2.6) 1 (1.0) 4 (4.0) 3 (3.0) ACS/MI (fatal) 0 1 (0.3) 0 0 1 (1.0)
All Rehospitalizations 37 (12.2) 29 (9.6) 11 (10.7) 11 (11.1) 7 (6.9) Acute MI 1 (0.3) 1 (0.3) 1 (1.0) 0 0 Unstable angina 0 0 0 0 0 Heart failure 19 (6.3) 22 (7.3) 6 (5.8) 11 (11.1) 5 (5.0) Other 18 (5.9) 7 (2.3) 4 (3.9) 0 3 (3.0)
All Index hospitalization NFMI 2 (0.7) 5 (1.7) 1 (1.0) 0 4 (4.0) Investigator reported 0 (0.0) 2 (0.7) 0 (0.0) 0 2 (2.0) Troponin triggered 2 (0.7) 3 (1.0) 1 (1.0) 0 2 (2.0)
Post-Randomization Adjudicated Events
ACS/MI = Acute Coronary Syndrome/Myocardial Infarction. 66 patients had 73 positively adjudicated rehospitalizations.
ConclusionsWhere Next for Cardiac Myosin Activators in Acute Heart Failure?
Breathlessness at RestProblem 0-3hrs
Peripheral OedemaProblem 48hrs onwards
Cachexia & FrailtyPeri-discharge
Characteristic
PooledPlacebo (N = 303)
Cohort 1 OM
(N = 103)
Cohort 2 OM
(N = 99)
Cohort 3 OM
(N = 101)
Age , mean (SD) 66 (11) 65 (12) 67 (10) 68 (10)
Gender – male, % 76 76 82 76
Region, % *
Eastern Europe 53 45 56 62
North America 25 37 24 18
Australia 2 0 1 0
Western Europe 21 18 19 20
Ischemic heart disease, % 62 62 59 66
Years from HF diagnosis, mean (SD) 6 (6) 6 (6) 6 (5) 6 (5)
Most recent LVEF (%), mean (SD) 26 (8) 26 (8) 25 (7) 28 (7)
Persistent Atrial Fibrillation or Flutter, % 33 29 32 36
Diabetes Mellitus, % 45 49 41 42
Hypertension, % 81 84 81 82
Baseline Characteristics (1)
*p < 0.05 for a difference in cohorts 1-3 Placebo arms compared to each other
Omecamtiv Mecarbil Concentrations vs. Troponin-I Maximal Change from Baseline
Red lines represent linear regression line and its +/- SE. Baseline troponin-I is adjusted.
Omecamtiv mecarbil Cmax Omecamtiv mecarbil AUC0-48
p=0.83p=0.95
Max
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poni
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asel
ine(
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OM Cmax (ng/mL)
OM AUC0-48 (ng*hr/mL)
OM AUC0-48 (ng*hr/mL)
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