Model-Based Meta-Analysis with NONMEM Jae Eun Ahn, Ph.D. College - - PowerPoint PPT Presentation
Model-Based Meta-Analysis with NONMEM Jae Eun Ahn, Ph.D. College - - PowerPoint PPT Presentation
Longitudinal Aggregate Data Model-Based Meta-Analysis with NONMEM Jae Eun Ahn, Ph.D. College of Pharmacy, Kangwon National University 7 Sep 2012 WCoP, Seoul, Korea Acknowledgments Department of Pharmacometrics, Pfizer, Inc. Jonathan
Acknowledgments
- Department of Pharmacometrics, Pfizer, Inc.
- Jonathan French, Sc.D., Metrum Research Group
Ahn and French, Longitudinal aggregate data model-based meta-analysis with NONMEM: approaches to handling within treatment arm correlation, JPKPD (2010) 37: 147-201
2
Negative study results from PoC study in acute schizophrenia
3
Better
PANSS Total (Change From Baseline) Ahn et al., ASCPT 2012 Visit (week) PANSS: Positive & Negative Syndrome Scale
How is the placebo response in the literature?
Mean Change from BS in PANSS Total Score at 6 Weeks for Acute Subjects
RE Model for All Studies
- 85
- 75
- 65
- 55
- 45
- 35
- 25
- 15
- 5
5 15 25 PANSS Total Change from BS at Week 6 Sunovion Study D1050006-39,2010 Sunovion Study D1050049-41,2010
- C. M. Canuso-3,2010
Sunovion Study D1050229-43,2010 Sunovion Study D1050196-42,2010 Sunovion Study D1050231-45,2010 Vanda Study ILPB202-50,2009 Canuso CM-4,2009 Organon Study 041022-31,2009 Organon Study 041023-33,2009 Organon Study 041004-29,2009 Vanda Study ILP3000ST-48,2009 Organon Study 041021-30,2009 Potkin SG study 2-4,2008 Potkin SG study 3-5,2008 Marder SR-3,2007 McEvoy et al.,2007 Cutler et al.,2006 NDA 20-825 study 1,2001
- 6.2
- 12.3
- 10.8
- 14.7
- 5.5
- 15.2
- 18.4
- 25.5
- 10.1
- 10.8
- 5.3
- 4.1
- 11.1
- 3.5
- 7.6
- 7.6
- 2.4
- 5.3
- 0.4
2.7 2.3 1.9 1.6 2.2 1.7 3.3 2.2 1.7 1.6 2.3 2.1 1.6 1.6 1.5 2.4 1.9 2.1 2.1 50 72 95 127 90 116 35 80 93 123 59 127 100 156 160 110 108 88 83
- 6.20 [ -11.57 , -0.83 ]
- 12.30 [ -16.85 , -7.75 ]
- 10.80 [ -14.52 , -7.08 ]
- 14.70 [ -17.84 , -11.56 ]
- 5.50 [ -9.75 , -1.25 ]
- 15.20 [ -18.53 , -11.87 ]
- 18.40 [ -24.84 , -11.96 ]
- 25.50 [ -29.76 , -21.24 ]
- 10.10 [ -13.43 , -6.77 ]
- 10.80 [ -13.94 , -7.66 ]
- 5.30 [ -9.81 , -0.79 ]
- 4.10 [ -8.29 , 0.09 ]
- 11.10 [ -14.24 , -7.96 ]
- 3.50 [ -6.55 , -0.45 ]
- 7.60 [ -10.61 , -4.59 ]
- 7.59 [ -12.20 , -2.98 ]
- 2.38 [ -6.04 , 1.28 ]
- 5.30 [ -9.36 , -1.24 ]
- 0.40 [ -4.58 , 3.78 ]
- 9.25 [ -11.96 , -6.55 ]
Delta PANSS Total SE N Study Author, Year Delta PANSS Total + 95%CI
PANSS Total change from baseline at week 6 in placebo group
Courtesy: Sima Ahadieh and Vikas Kumar, Pfizer, Inc.
Comparison of the Placebo Response
1 2 3 4
- 30
- 20
- 10
10
Placebo
Time (Weeks) Change from Baseline in PANSS Total Model Simulation (90% PI) with Overlaid Observed
Mean change from baseline PANSS Total in placebo group seems to be greater than model estimated mean from the literature meta-analysis but within 90% PI
Courtesy: Sima Ahadieh and Vikas Kumar Pfizer, Inc.
Meta-Analysis
- A quantitative review and synthesis of results from
related but independent studies (Normand, 1999) Meta-analysis estimate = weighted average
- More precise inferences (pooling data)
- Point of reference for in-licensing opportunities
- Relationship b/w early (Phase 1, 2) and later (Phase 3)
endpoints
- Quantitative predictions of the probability of a successful
phase 3 study
6
Model-Based Meta-Analysis
- Incorporates parametric model to describe dose-
response, time effects, etc.
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Lalonde RL et al., Clin Pharmacol Ther 2007;82:21-32
Model-Based Drug Development
Drug & Disease Models Competitor Info. & Meta-Analysis Design & Trial Execution Models Data Analysis Model Quantitative Decision Criteria Trial Performance Metrics
Benefits and Challenges
- Address uncertainty and
heterogeneity of studies
- Increase statistical power
- Improve estimates of
treatment effect
- Lead to new knowledge
- Formulate new questions
- Publication bias
- Incomplete description of
trial design and methods
- Combining aggregate
data (AD) and individual patient-level data (IPD)
- Appropriately accounting
for the correlation between time points within each study
8
Lalonde RL et al., Clin Pharmacol Ther 2007;82:21-32
Longitudinal Aggregate Data
9
Response variable = Mean outcome over time within an arm
- Observations within a study
are correlated
– Because the patients come from a common population – Use the study as ID (the grouping factor for the first level random effects)
- Mean observations over time
within a treatment arm are correlated
– Because they are based on the same set of patients
Need to account for more than two-level random effects
10
How to handle within-treatment arm correlation?
- 1. IOV
Random Effects Population PK Analysis with IOV Meta-Analysis* 1st Level (ID) Individual (Inter-Individual Variability, IIV) 2nd Level Occasions (Inter-Occasion Variability, IOV) RUV Usually assumed to be independent
* Modified from Laporte-Simitsidis et al. Inter-Study Variability in Population Pharmacokinetic Meta-Analysis: When and Howe to Estimate It? J of Pharm Sci 89: 155-167 (2000)
Study (Inter-Study Variability, ISV) Treatment arm (Inter-Arm Variability, IAV) Can be correlated
11
How to handle within-treatment arm correlation?
- 2. L2
- L1 (=ID): group together the data records of the same
realization of etas
- L2: group together the data records of the same
realization of epsilons
– Within a L1 observation, the L2 random effects can be made to be correlated between L2 observations
- A way to handle correlation of multivariate observations
within individual records
– PK and PD – Parent and metabolite – Replicates
- S. L. Beal, L. B. Sheiner, and A. J. Boeckmann (Eds.). NONMEM Users Guides, ICON Development Solutions, Ellicott City, MD,
1989-2006
What if ignoring the correlation?
- Simulation Experiments
12
Impact On
- Estimating the drug effect
- Predicting the outcome of interest in a
future study
– E.g., what is the probability that the observed mean difference from placebo is at least c2, for a given design?
2 ik i
P Y Y c
Simulation Model and Study Design
Parameters Correlation Low Med High E0 30 EMAX 10 ED50 250 K0 0.1 OMGS (inter-study variability) 1 1 1 OMGP (inter-patient variability) 3 9 27 SIG (residual unexplained variability) 9 9 9 Correlation = OMGP/(OMGP+SIG) 0.25 0.5 0.75 TV (total variance = OMGS+(OMGP+SIG)/n) 1.12 1.18 1.36 100 mg Effect 2.86 500 mg Effect 6.67 14
w = 1/sqrt(n)
500 simulations per design; NONMEM VI (level 1.2)
w Dose ED Dose E time k E Y
p s MAX
) ( ) exp(
50
ID Phase Sample Size (per dose) Doses Time Points 1 2 50 0, 50, 100, 200, 400 0, 1, 2, 4 2 2 50 0, 100, 300, 500, 1000 0, 1, 2, 4 3 2 50 0, 100, 200, 300, 400 0, 2, 4, 8, 12 4 2 50 0, 300, 400, 500, 600 0, 2, 4, 8, 12 5 3 100 0, 200, 400 0, 4, 8, 12 6 3 100 0, 400, 600 0, 4, 8, 12 7 3 100 0, 200, 600 0, 4, 8, 12 8 3 250 0, 200, 400 0, 4, 8, 12 9 3 250 0, 400, 600 0, 4, 8, 12 10 3 250 0, 200, 600 0, 4, 8, 12
15
Estimation Models
- A1: Inter-study on E0, Inter-arm on E0
(=simulation model)
- A2: Inter-study on E0 with correlated residual
errors (L2)
- A3: Inter-study on with uncorrelated residual
errors (ID=Study)
- A4: Inter-arm on E0 with uncorrelated residual
errors(ID=Arm)
Results - Parameter Estimates
Hardly any bias in the fixed effect parameter estimates
(mean estimation error: -1 ~ 7%)
When the within arm correlation was ignored (A3), residual variability was inflated When the study effects were ignored (A4), inter- patient variability is under- estimated (close to the true first level random effects)
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- 100
50 100 150 200 1 2 3 4 ISV
- 100
50 100 150 1 2 3 4 IAV 100 200 300 400 500 1 2 3 4 RUV
- 50
50 100 150 1 2 3 4 TOTVAR
- 100
50 100 150 200 1 2 3 4 ISV
- 100
50 100 150 1 2 3 4 IAV 100 200 300 400 500 1 2 3 4 RUV
- 50
50 100 150 1 2 3 4 TOTVAR
- 100
50 100 150 200 1 2 3 4 ISV
- 100
50 100 150 1 2 3 4 IAV 100 200 300 400 500 1 2 3 4 RUV
- 50
50 100 150 1 2 3 4 TOTVAR
Inter-Study Inter-Arm Residual Total Var
L
- w
M e d H i g h
A1 A2 A3 A4
Standard Error*: 95% CI for High Dose Effects
Width of 95% CI ↑ for A1-A3 as correlation ↑
Information from longitudinal measurements ↓ , as correlation ↑
Not A4
17
Low
simulation # A1 100 200 300 400 500 2.5 3.0 3.5 4.0 simulation # A3 100 200 300 400 500 2.5 3.0 3.5 4.0 simulation # A4 100 200 300 400 500 2.5 3.0 3.5 4.0
Medium
simulation # 100 200 300 400 500 2.5 3.0 3.5 4.0 simulation # 100 200 300 400 500 2.5 3.0 3.5 4.0 simulation # 100 200 300 400 500 2.5 3.0 3.5 4.0
High
simulation # 100 200 300 400 500 2.5 3.0 3.5 4.0 simulation # 100 200 300 400 500 2.5 3.0 3.5 4.0 simulation # 100 200 300 400 500 2.5 3.0 3.5 4.0
Low Medium High
A1 A3 A4
*Delta method to approximate the SE using variances and covariance
- f EMAX and ED50
White line = True value
Distribution:
18
0.0 0.1 0.2 0.3 20 40 60 80 120 A1, 100 mg 0.6 0.7 0.8 0.9 1.0 20 60 100 140 A1, 500 mg 0.0 0.1 0.2 0.3 20 40 60 80 120
Medium Correlation; Delta=2.5
A3, 100 mg 0.6 0.7 0.8 0.9 1.0 20 60 100 140 A3, 500 mg 0.0 0.1 0.2 0.3 20 40 60 80 120 A4, 100 mg 0.6 0.7 0.8 0.9 1.0 20 60 100 140 A4, 500 mg
Gray line = True probability
2 50 2 2
1 1 1
EMAX ik ED ik P i ik
D c D n n
A1 A3 A4
Low Dose High Dose
A1 A3 A4
Δ) Y Y P(
plcb i, drug i,
- Not distinguish the treatment arms in one study
from the other
- Arm-to-arm variability is overestimated
– Wider distribution of the observed difference
- Tends to overestimate the probability for low dose,
and underestimate for high dose
Potential Problem with A4 (Ignoring study effects)
19
low dose (100 mg)
delta P 5 10 0.0 0.2 0.4
high dose (500 mg)
delta P 5 10 0.0 0.2 0.4
VPC of the observed difference for each method*
20
B1
Dose (mg) Delta (treatment-placebo) 200 400 600 800 1000
- 6
- 5
- 4
- 3
- 2
- 1
- bs delta
sim median sim quartile
B2
Dose (mg) Delta (treatment-placebo) 200 400 600 800 1000
- 6
- 5
- 4
- 3
- 2
- 1
B3
Dose (mg) Delta (treatment-placebo) 200 400 600 800 1000
- 6
- 5
- 4
- 3
- 2
- 1
B4
Dose (mg) Delta (treatment-placebo) 200 400 600 800 1000
- 6
- 5
- 4
- 3
- 2
- 1
25th-75th
*Simulation and estimation strategies (Part B in Ahn and French, JPKPD 2010) are different from the previous example (Part A) but presented to make a point
Concluding Remark
- Multi-level random effects models for
longitudinal MBMA with NONMEM
Should expect correlation between longitudinally observed mean values Inclusion of treatment arm-level random effects only is not recommended
21
backup
22
Example Data Set
23 REFID=ID ARM NTRT DAY absolute SE SD BASELINE TRT2 L2 FLG 100 91 25.3 0.304003 2.9 25.3 8 1 1 100 91 42 17.7 9999 9999 25.3 8 1 2 100 1 95 24.8 0.307794 3 24.8 9 2 1 100 1 95 42 14.2 9999 9999 24.8 9 2 2 100 2 92 24.9 0.312772 3 24.9 9 3 1 100 2 92 42 15.1 9999 9999 24.9 9 3 2 100 3 91 25.7 0.335451 3.2 25.7 9 4 1 100 3 91 42 16.5 9999 9999 25.7 9 4 2 107 75 20.42 0.475737 4.12 20.42 8 5 1 107 75 56 13.65 0.815219 7.06 20.42 8 5 2 107 1 82 19.9 0.463812 4.2 19.9 3 6 1 107 1 82 56 13.1 0.958546 8.68 19.9 3 6 2 107 2 37 21.43 0.598412 3.64 21.43 5 7 1 107 2 37 56 14.4 1.232992 7.5 21.43 5 7 2 108 90 17.79 0.498586 4.73 17.79 8 8 1 108 90 7 15.85 9999 9999 17.79 8 8 2 108 90 14 14.77 9999 9999 17.79 8 8 3 108 90 28 13.92 9999 9999 17.79 8 8 4 108 90 42 12.6 9999 9999 17.79 8 8 5 108 90 56 12.8 9999 9999 17.79 8 8 6 108 90 56 13.51 0.712567 6.76 17.79 8 8 7 108 1 91 17.47 0.545108 5.2 17.47 3 9 1 108 1 91 7 16.13 9999 9999 17.47 3 9 2 108 1 91 14 14.27 9999 9999 17.47 3 9 3 108 1 91 28 12.9 9999 9999 17.47 3 9 4 108 1 91 42 11.48 9999 9999 17.47 3 9 5 108 1 91 56 11.41 9999 9999 17.47 3 9 6 108 1 81 56 12.04 0.701111 6.31 17.47 3 9 7
$INPUT ID ARM … L2 FLG $DATA $PRED FL1=0 FL2=0 FL3=0 FL4=0 FL5=0 IF (FLG.EQ.1) FL1=1 IF (FLG.EQ.2) FL2=1 IF (FLG.EQ.3) FL3=1 IF (FLG.EQ.4) FL4=1 IF (FLG.EQ.5) FL5=1 ERR1=FL1*ERR(2)+FL2*ERR(3)+FL3*ERR(4) ERR2=FL4*ERR(5)+FL5*ERR(6) ERRC=ERR1+ERR2 E0 = THETA(1) EMAX = THETA(2) LED50 = THETA(3) K0=THETA(4) W=1/SQRT(NTRT) MU = E0*EXP(-K0*TIME)-POST*EMAX*DOSE/(EXP(LED50)+DOSE) F = MU + ETA(1) Y = F + W*(ERR(1)+ERRC) $THETA (0, 30 ) ;E0 (0, 10) ;EMAX (5,) ;ED50 (0, 0.1) ;K0 $OMEGA 1 $SIGMA 3 $SIGMA BLOCK (1) 9 $SIGMA BLOCK (1) SAME $SIGMA BLOCK (1) SAME $SIGMA BLOCK (1) SAME $SIGMA BLOCK (1) SAME Allows for correlation between
- bservations
within an arm Study-to-study variability
How to Set up
24
Output Interpretation (compound symmetry correlation)
SIGMA - COV MATRIX FOR RANDOM EFFECTS - EPSILONS **** EPS1 EPS2 EPS3 EPS4 EPS5 EPS6 EPS1 + 3.64E+00 EPS2 + 0.00E+00 7.57E+00 EPS3 + 0.00E+00 0.00E+00 7.57E+00 EPS4 + 0.00E+00 0.00E+00 0.00E+00 7.57E+00 EPS5 + 0.00E+00 0.00E+00 0.00E+00 0.00E+00 7.57E+00 EPS6 + 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 7.57E+00
325 . 57 . 7 64 . 3 64 . 3 variation total component shared ρ
25
26
Compound Symmetry
2 2 2 1 2 1 2 2 2 1 2 2 2 1 2 1 2 1 2 1 2 2 2 1 2 1 2 1 2 1 2 2 2 1 2 1 2 1
1 ... ... ... ... ... ... 1 ... 1 ) ( ... ... ... ... ... ... ... I 1 where
ARM= L2
Example: Replicates*
ID TIME AMT DV FLG L2 1 200 . . 1 1 2 . 17.9 1 2 . 17.3 1 1 4 . 8.53 1 4 . 8.99 1
$ERROR Y = F + ERR(1) $SIGMA 1
; common errors
+ ERR(2)*(1-FLG) + ERR(3)*FLG $SIGMA BLOCK (1) 1 $SIGMA BLOCK (1) SAME ; cor = 0.5
; replicate-specific errors
1 1 2 2
* Karlsson MO, Beal SL, Sheiner LB. Three new residual error models for population PK/PD analyses. J Pharmacokinet Biopharm 23: 651-672 (1995)
27
28
Imagine data arise from this simple patient-level model …
2
3 1 4
( ) exp ( )
ij t study patient ij i ij ij ij
Dose Y t t Dose
Yij(t) is the response for patient j in the ith study at time t
2
~ (0, )
study i S
N
2
~ (0, )
patient ij P
N
2
( ) ~ (0, )
ij t
N
The study-level variability represents different patient populations across studies. The patient-level variability represents variability across patients within a study.
29
… but that we only observe the mean responses over time
{ }:
1 ( ) ( )
ij ik
ik ij ij Dose D ik
Y t Y t n
2
3 1 { } 4
1 ( ) exp ( )
t study patient ik ik i ij ij ij ik ik
D Y t t D n
( )
ik
Y t
is the mean response for dose Dk in the ith study at time t
( , , )
ik
f D t θ
30
We can view this model in two ways
2
3 1 { } 4
1 ( ) exp ( )
t study patient ik ik i ij ij ij ik ik
D Y t t D n
*
1 ( ) ( , , )
study ik ik i ik ik
Y t f D t t n θ 1 1 ( ) ( , , ) ( )
study arm ik ik i ik ik ik ik
Y t f D t t n n θ
* 2 2 { }
1 ( ) ~ 0,
patient ik ij ij P ij ik
t N n
where
2
( ), ( )
ik ik P
Cov t t
2 2 2
( ), ( )
P ik ik P
Corr t t
where
2
~ (0, )
arm ik P
N
2
( ) ~ (0, )
ik t
N
{ }
1
arm patient ik ij ij ik
n
{ }
1 ( ) ( )
ik ij ij ik
t t n
and
Doesn’t depend on time * * * *
STDY=ID ARM=L2 DOSE TIME NTRT DV FLG (ARM) (ARM, FLG) 1 11 50 30.08 1 η1 ε1(11) ε2(11,1) 1 11 1 50 27.06 2 η1 ε1(11) ε2(11,2) 1 11 2 50 24.75 3 η1 ε1(11) ε2(11,3) 1 11 4 50 20.87 4 η1 ε1(11) ε2(11,4) 1 12 50 50 31.18 1 η1 ε1(12) ε2(12,1) 1 12 50 1 50 25.67 2 η1 ε1(12) ε2(12,2) 1 12 50 2 50 22.89 3 η1 ε1(12) ε2(12,3) 1 12 50 4 50 19.08 4 η1 ε1(12) ε2(12,4) 1 13 100 50 29.41 1 η1 ε1(13) ε2(13,1) 1 13 100 1 50 24.50 2 η1 ε1(13) ε2(13,2) 1 13 100 2 50 22.54 3 η1 ε1(13) ε2(13,3) 1 13 100 4 50 17.93 4 η1 ε1(13) ε2(13,4) 1 14 200 50 30.19 1 η1 ε1(14) ε2(14,1) 1 14 200 1 50 23.50 2 η1 ε1(14) ε2(14,2) 1 14 200 2 50 20.46 3 η1 ε1(14) ε2(14,3) 1 14 200 4 50 16.83 4 η1 ε1(14) ε2(14,4) 1 15 400 50 29.83 1 η1 ε1(15) ε2(15,1) 1 15 400 1 50 21.34 2 η1 ε1(15) ε2(15,2) 1 15 400 2 50 19.02 3 η1 ε1(15) ε2(15,3) 1 15 400 4 50 14.55 4 η1 ε1(15) ε2(15,4) 2 16 50 29.01 1 η2 ε1(16) ε2(16,1) 2 16 1 50 26.16 2 η2 ε1(16) ε2(16,2) 2 16 2 50 23.16 3 η2 ε1(16) ε2(16,3) 2 16 4 50 18.78 4 η2 ε1(16) ε2(16,4) 2 17 100 50 28.74 1 η2 ε1(17) ε2(17,1) 2 17 100 1 50 22.43 2 η2 ε1(17) ε2(17,2) 2 17 100 2 50 20.48 3 η2 ε1(17) ε2(17,3) 2 17 100 4 50 14.47 4 η2 ε1(17) ε2(17,4)