Document 185391

How to Design Clinical Trials in Non
Non--small
C ll Lung Cancer
Cell
C
iin 2012 with
i h Omics
O i Data
D
J. Jack Lee, Ph.D.
Department of Biostatistics
Past – Life was simple
2012: Data Deluge
Help!!!
Big Data Challenge - How to Make Sense?
Miller, Big data analytics in biomedical research
Miller
research, Biomedical Computation Review
Review, Winter
2011/2012
Trelles et al. Big data, but are we ready? Nat Review Genetics, 2011
Shah and Tenenbaum, The coming age of data-driven medicine: Translational
bioinformatics' next frontier, Journal of the American Medical Informatics Assoc, 2012.
Big Data Initiative:http://www.whitehouse.gov/sites/default/files/microsites/ostp/
big_data_press_release_final_2.pdf
Premise
Biological knowledge advances in a lightning speed
There are many new targeted agents and many more
potential combination therapies
Only a small fraction of the drugs are tested
A small number of patients enrolled in clinical trials
Unfortunately, success rate for oncology drug
development is very low.
Targeted agents do not work for all patients.
Search for the predictive markers to guide the choice
of treatments
How do we find the answers to the above questions?
How to treat patients best in the trial?
Time is of the essence.
Questions
How to enroll more patients in clinical trials?
How to test more agents and their combinations
efficiently?
How to best identify markers, gauge treatment
efficacy, and treat patients in a clinical trial?
Adaptive Designs !
- Use accumulating data to guide study conduct
- We learn as we go.
1. Berry DA. A guide to drug discovery: Bayesian clinical trials. Nature Reviews Drug
Discovery, 2006.
2. Lee JJ, Gu X, Liu S. Bayesian adaptive randomization designs for targeted agent
development. Clinical Trials, 2010.
3. Berry DA. Adaptive clinical trials in oncology. Nature Reviews Clinical Oncology, 2012.
Bayesian Paradigm
What is the Bayesian
method?
y
– Prior + Data Æ Posterior (Bayesian 11-2-3)
Î New Prior + New Data Æ New Posterior
– We learn as we go!
– Models unknown parameters with statistical distributions
– Properly
P
l addresses
dd
various
i
llevels
l off uncertainty
t i t
– Allows more frequent monitoring and decision making
Adaptive in nature
– Since we don’t know the answers before the trial, we need to
continue to learn during
g the trial.
– Clinical trial is a learning process. It makes sense to adjust
the study conduct based on realreal-time learning during the
ti l
trial.
Ideal for clinical trials!
Lee and Chu, Bayesian Clinical Trials in Action. Statistics in Medicine, 2012
Traditional Drug Development
Phase I
I
Phase II
Phase III
II
I
III
II
I
II
R
II
R
III
Traditional Drug Development
One dose, Schedule
A few doses/schedules
Multiple doses/schedules
Traditional Drug Development
We Did It All Wrong !
How to Fix It?
D more Ph
i l tto d
t
i th
Do
Phase I ttrials
determine
the b
bestt d
dose,
schedule, and route of administration.
D more singleDo
single
i l -arm or randomized
d i d Ph
Phase IIA ttrials.
i l
Do more randomized Phase IIB trials to refine the
efficacy.
ffi
Identify prognostic and predictive markers.
Do smaller, more focused Phase III trials.
Conduct seamless Phase I/II or Phase II/III trials.
Do platform trials. Enroll all patients in trials.
Apply adaptive randomization & early stopping rules
Continue to learn and to adapt.
Evolution of Knowledge in NSCLC
Pao and Girard, Lancet Oncology 2010
Evolution of Knowledge in NSCLC
Pao and Girard, Lancet Oncology 2010
2011
Sequist et al, Annals of Oncology 2011
How to Choose Treatment Based on Biomarkers?
erlotinib
crizotinib
trastuzumab
vemurafenib
sorafenib?
PIK3 Inhibitors?
AKT Inhibitors?
MAPK inhibitors?
MET inhibitor ?
CTTNB1, NRAS, IDH1
???
Ti 1 evidence:
Tier
id
Assign
A i pts
t to
t corresponding
di treatments
t t
t
Tier 2 evidence: Randomized trials, Adaptive randomization
Tier 3 evidence: Single arm or randomized screening trials
Goals of Clinical Trials for Targeted Agents
Identify prognostic and predictive markers
– Prognostic markers
markers that associate with the disease outcome regardless of the
g , stage,
g , performance
p
treatment: e.g.,
status
– Predictive markers
markers which predict differential treatment efficacy in different
marker groups: e.g., In Marker (−
(−), tx does not work
b t in
but
i M
Marker
k ((+),
) tx
t works
k
Test treatment efficacy
– Control type I and II error rates
– Maximize study power for testing the effectiveness between treatments
– Collective ethics
Provide better treatment to patients enrolled in the trial
– Assign patients into the better treatment arms with higher probabilities
M i i ttotal
t l number
b off successes iin th
i l
– Maximize
the ttrial
– Individual ethics
Tool #1: Bayesian Outcome
Ad ti Randomization
Adaptive
R d
i ti
- Provide better treatments to patients in the
trials while testing the treatment efficacy
Bayesian Outcome Adaptive Randomization
Consider two treatments, binary outcome
A new patient is assigned to TX2 with probability
Pr( p2 > p1 )c / {Pr( p1 > p2 )c + Pr( p2 > p1 )c }
Note that the tuning parameter
– c = 0, ER
Less imbalance
– c = n / (2N)
– c = 0.5 or 1
0.1
– c = (n / N )
– c = ∞, “play the winner”
More imbalance
Continue until reaching early stopping criteria or Nmax
Demo 1: P1=0.2, P2=0.4
c = (n / N )0.1
A Simulation Study
vs H1: p1 < p2
H0: p1 = p2 vs.
Take the Bayesian framework, conclude Arm 2 is
better than Arm 1 if: Prob
Prob(p
(p2 > p1 | Data) > θT
Calibrate the design parameters (N and θT)
– α=0.1
0.1 for p1=p
p2=0.2
0.2 and 11- β = 0.9 for p1=0.2,
0.2, p2=0.4
0.4
For ER, N=134, θT=0.9.
0.1
c
=
(
n
/
N
)
For AR with the tuning parameter
N=184, θT=0.905.
Extend the study to reach equal sample size for all
designs s.t. the overall response rate can be directly
compared.
p
– At the end of the study, allocate all remaining pts to the
better arm, if any; or the control arm if not.
ER versus AR
Korn and Freidlin. Outcome-Adaptive Randomization: Is It Useful? JCO 2011
Berry DA. Adaptive Clinical Trials: The Promise and the Caution. JCO 2011
Lee, Chen, and Yin. Worth adapting? Revisiting the Usefulness of Outcome-Adaptive Randomization. CCR, 2012
c = (n / N )0.1
No. of NonNon-Responders and
Overall Response Rate for ER and AR
True
Response
Rate
Equal Randomization
Adaptive Randomization
[N=134]
[[N=184]]
Cntl
Exp
No. of
NonResp
0.2
0.2
107.2
20.0
Overall
Resp %
Expd to
Expd.
N=184
20.0
02
0.2
04
0.4
93 8
93.8
30 0
30.0
0.2
0.6
80.4
0.2
0.8
67.0
Overall
Resp %
c = (n / N )0.1
No. of
% on Exp.
Non-Resp
Arm
Overall
Resp %
147.2
50.0
20.0
32 2
32.2
117 5
117.5
80 6
80.6
36 1
36.1
40.0
45.4
84.0
85.9
54.4
50.0
58.2
51.1
87.1
72.2
AR: Randomization probability bounded at 0.9.
Compare AR vs ER w/o Early Stopping
ER
AR
ER stop the
trial earlier
P1 = 0.2
128.8
124.3
10
00
(184,117.5)
(134,93.8)
50
All pts
received
TX 2
0
50
100
P2 = 0.4
α = 0.10
1-β = 0.90
0
Cu
umulative Num
mber of Non-Re
esponders
150
AR stop
t th
the
trial later
150
Number of Patients Accrued
200
Compare AR vs ER w/o Early Stopping
P2 = 0.4
20
18.4
15
ER
AR
14.4
10
(134,13.4)
Gain
5
(184 7 1)
(184,7.1)
0
50
α = 0.10
1-β = 0.90
0
Add
ditional Non-Re
esponders Co
ompared to
All P
Patients Receiv
ved The Bette
er Treatment
25
2
P1 = 0.2
100
150
Number of Patients Accrued
200
Early Stopping
Based on the interim result, if the comparison between
the treatment arms and the control arm is highly
informative, we can stop the trial early.
– Early stopping for efficacy if Pr( pk > p1 | D) > θ H for any k
P ( pk > p1 | D) < θ L for
– Early
E l stopping
t
i ffor futility
f tilit if Pr(
f allll k’s
’s,, k ≠ 1
Compare AR vs ER with Early Stopping
27.4
P2 = 0.4
25
α = 0.10
ER
AR
15
20
0
1-β = 0.90
10
(190,8.7)
10.5
Gain
5
84
(274,5.9)
110
0
Additional Non-Re
esponders Com
mpared to
All Patients Receiv
ved The Bette
er Treatment
30
P1 = 0.2
0
50
100
150
200
Number of Patients Accrued
250
300
Compare AR versus ER
AR yields a higher overall success ( Ï response rate or
Ï survival) than ER at the cost of increasing N.
The differences between AR and ER are less pronounced
with early stopping for efficacy and futility.
AR enhances
h
iindividual
di id l ethics;
thi
whereas
h
ER emphasizes
h i
collective ethics.
AR has substantial benefit over ER when
– the efficacy difference between treatments is large
– Outside trial population is small, e.g., rare disease, and
there is an effective treatment
The choice of AR versus ER depends on the focus of the trial
and the utility function of the clinical trialists
trialists..
Lee, Chen, and Yin. Worth adapting? Revisiting the Usefulness of Outcome-Adaptive Randomization. CCR, 2012
Tool #2: Biomarker Stratified
Outcome Adaptive Randomization
- Stratify patients based on the biomarkers
- Assign
g more patients to better treatments
Biomarker Stratified AR: A Simulation
Total number patients N=240
Two or four treatments with a predictive marker for each treatment
treatment.
Outcome is binary – response or no response
True response
Arm 1 Arm 2 Arm 3 Arm 4
Arm 1
Arm 2
Marker Group 1
0.8
0.2
Marker Group 2
02
0.2
08
0.8
Marker Group 1
0.8
0.2
0.2
0.2
Marker Group 2
0.2
0.8
0.2
0.2
Marker Group 3
0.2
0.2
0.8
0.2
Marker Group 4
0.2
0.2
0.2
0.8
Equal randomization design (ER)
Physician guided design (PG)
– Randomization probability to the better arm: r0 = 0.7, 0.8.
– Randomization probability to other arms: r1 = (1(1-r0)/(K
r0)/(K--1)
Adaptive randomization design (AR)
– ER for the first 20% patients
– Randomization tuning parameter: (n/N)^0.1
– Beta prior for each treatment
Non-informative prior Beta(1,1)
NonInformative Prior Pr(Beta(f*0.7,f*0.3)>Beta(f*0.5, f*0.5))>0.95
– f is the equivalent number of patients, f=31.4
2-Arm: ER and PG
0.0
07
Distribution of Number of Responders
0.04
0.03
0.02
0.01
0.00
0
Density
0.05
5
0.06
ER
PG0.7
PG0.8
60
80
100
120
140
Number of Responders
160
180
200
2-Arm: ER, PG, and AR (non(non-informative prior)
0.0
07
Distribution of Number of Responders
0.04
0.03
0.02
0.01
0.00
0
Density
0.05
5
0.06
ER
PG0.7
PG0.8
AR-Noninformative
60
80
100
120
140
Number of Responders
160
180
200
2-Arm: ER, PG, and AR
(non--informative & informative p
((non
prior))
0.0
07
Distribution of Number of Responders
0.04
0.03
0.02
0.01
0.00
0
Density
0.05
5
0.06
ER
PG0.7
PG0.8
AR-Noninformative
AR Informative
AR-Informative
60
80
100
120
140
Number of Responders
160
180
200
4-Arm: ER and PG
0.0
07
Distribution of Number of Responders
0.04
0.03
0.02
0.01
0.00
0
Den
nsity
0.05
0.06
ER
PG0.7
PG0.8
60
80
100
120
140
Number of Responders
160
180
200
4-Arm: ER, PG, and AR (Non(Non-informative prior)
0.0
07
Distribution of Number of Responders
0.04
0.03
0.02
0.01
0.00
0
Den
nsity
0.05
0.06
ER
PG0.7
PG0.8
AR-Noninformative
60
80
100
120
140
Number of Responders
160
180
200
4-Arm: ER, PG,
PG, and AR
(Non--informative and Informative p
((Non
prior))
0.0
07
Distribution of Number of Responders
0.04
0.03
0.02
0.01
0.00
0
Den
nsity
0.05
0.06
ER
PG0.7
PG0.8
AR-Noninformative
AR-Informative
60
80
100
120
140
Number of Responders
160
180
200
Bayesian Adaptive Randomization Design
A: Standard
Therapy
Registration
Marker−
k
R d
Randm.
AR
1:1
AR
2
2:1
1
B: Targeted
AR
1:1
Therapy
C: Standard
Therapy
py
Testing Markers
Marker +
Randm.
AR
1:1
AR
1:3
D: Targeted
AR
1:4
Therapy
Lee JJ, Gu X, Liu S. Bayesian adaptive randomization designs for
targeted agent development. Clinical Trials, 2010;7:584-596
Tool #3: Platform Design
- for
f efficient
ffi i t drug
d
screening
i
- treat patients best in the trial
Goals:
Platform Design
– To efficiently screen as many drugs as possible
– To treat patients with the better treatments in the trial
Assumptions
– Binary endpoints with 88-week response rate p=0.2 for the
standard
t d d (CNTL) ttreatment.
t
t
– For experimental (E) arms, p=0.2 or p=0.4
– The study runs for 5 years with enrollment = 10/month
– Simultaneous compare 5 E
E--arms to the CNTL
– Maximum N=60/arm.
N 60/arm. When sufficient info accumulates,
Graduate effective arms; Fail the ineffective arms
Control type I error (10%) and type II error (20%)
– Compare
C
with
ith ttwo other
th d
designs:
i
Two-arm phase II trials with N=60/arm
TwoSequential twotwo-arm study with early stopping
Statistical Assumptions
Demo 2: Platform Design
Results for Number of Drugs Screened
Hobbs B. and Lee JJ (unpublished)
Tool #4: Seamless Phase II/III Design
- Start with a multi-arm
multi arm Phase II trial
- Eliminate inefficacious arms
- Roll into Phase III
Seamless Phase II/III Design
St t with
ith a randomized
d i d Ph
i l with
ith an active
ti control
t l
Start
Phase II ttrial
(standard treatment) and several experimental arms with
different treatments and/or dose or schedules
Use a shortshort-term endpoint in the Phase II part, e.g., ORR
Drop
p inefficacious arms
If at least one experimental arm is promising, roll into
Phase III with one standard treatment and one or more
selected experimental treatments. Use longerlonger-term
endpoint, e.g. OS.
I f
Information
ti collected
ll t d in
i th
the Ph
Phase II partt is
i used
d in
i th
the
Phase III. No “white space” in trial conduct.
Inoue et al, Biometrics 2002; Bretz et al, Biometrical J 2006; Stallard, SIM 2010
Seamless Phase IIII-III Design
Berry, Nature Review Clinical Oncology, 2012
Seamless Phase IIII-III Design
Berry, Nature Review Clinical Oncology, 2012
Seamless Phase IIII-III Design
Berry, Nature Review Clinical Oncology, 2012
STAMPEDE Trial: 6 Arms, 5 Stages
Trial Stages
Purpose
Primary Endpoint
2nd Endpoints
1
Pilot Phase
Safety
Feasibility
2
Activity Stage I
Failure-free Survival
OS, Toxicity,
3
Activity Stage II
Failure-free Survival
OS, Toxicity,
4
Activity Stage III
Failure free Survival
Failure-free
OS Toxicity,
OS,
Toxicity
5
Activity Stage IV
Overall Survival
FFS, Toxicity, QoL, Cost-Eff.
Sydes et al, Trials 2009
Tool #5: Multi-marker, Multi-arm
Bayesian Adaptive Randomization
Design
- Biopsy required
- Biomarker based
- AR
- Early stopping (suspend randomization)
BATTLE (Biomarker(Biomarker-based
Approaches of Targeted Therapy
for Lung Cancer Elimination)
Patient Population: Stage IV recurrent nonnon-small cell
lung cancer (NSCLC)
Primary Endpoint: 8
8--week disease control rate (DCR)
4 Targeted treatments, 11 Biomarkers
200 evaluable patients
Goal:
– Test treatment efficacy
– Test biomarker effect and their predictive roles to treatment
– Treat patients better in the trial based on their biomarkers
1. Zhou X, Liu S, Kim ES, Lee JJ. Bayesian adaptive design for targeted therapy
development in lung cancer - A step toward personalized medicine (Clin
(Clin Trials
Trials,, 2008).
2. Kim ES, Herbst RS, Wistuba II, Lee JJ, et al, Hong WK. The BATTLE Trial:
Personalizing Therapy for Lung Cancer. (Cancer
(Cancer Discovery,
Discovery, 2011)
BATTLE Schema
Umbrella Protocol
Core Biopsy
EGFR
VEGF
KRAS/BRAF
RXR/CyclinD1
Biomarker
Profile
Randomization:
Equal Æ Adaptive
Erlotinib
Vandetanib
Erlotinib + Bexarotene
Sorafenib
Primary end point: 8 week Disease Control (DC)
Demo 3: Adaptive Randomization –BATTLE
BATTLE Results: Disease Control in % (n)
Marker Groups
Treatm
ments
EGFR
KRAS
VEGF
RXR/
CycD1
None
Total
Erlotinib
35% ((17))
14% ((7))
40% ((25))
0% ((1))
38% ((8))
34% ((58))
Vandetanib
41% (27)
0% (3)
38% (16)
NA (0)
0% (6)
33% (52)
Erlotinib +
Bexarotene
55% (20)
33% (3)
0% (3)
100% (1)
56% (9)
50% (36)
Sorafenib
39% (23)
79% (14)
64% (39)
25% (4)
61% (18)
58% (98)
Total
43% (87)
48% (27)
49% (83)
33% (6)
46% (41)
46% (244)
AACR Presentation: http://app2.capitalreach.com/esp1204/servlet/tc?cn=aacr&c=10165&s=20435&e=12587&&m=1&br=80&audio=false
55
Individual Biomarkers for Response
and Resistance to Targeted Treatment:
Exploratory Analysis
Drug Treatment
Biomarker
P–value
DC
Erlotinib
EGFR mutation
0.04
Improved
Vandetanib
High VEGFR-2 expression
0.05
Improved
Erlotinib +
Bexarotene
High Cyclin D1 expression
0.001
Improved
EGFR FISH Amp
p
0.006
Improved
p
EGFR mutation
0.012
Worse
EGFR high polysomy
0.048
Worse
Sorafenib
Lessons Learned from BATTLE-1?
Biomarker-based adaptive design is doable! It is well
received by clinicians and patients.
Prospective tissues collection & biomarkers analysis
provide a wealth of information
Treatment effect & predictive markers are efficiently
assessed.
Pre-selecting markers is not a good idea. We don’t
know what are the best predictive markers at get-go.
Bundling markers into groups
groups, although reducing the
total number of marker patterns, is not the best way to
use the marker information either.
W t h for
Watch
f time
ti
drift
d ift and
d avoid
id it
it.
AR should kick in earlier & be monitored closely.
AR works well only when we have good drugs and
good predictive markers.
BATTLE-2 Schema
Principles
•
•
•
•
Better specific drugs
Better specific
targets
No biomarker
grouping
Selection, integration
and validation of
novel predictive
biomarkers
Open: June 2011
September 2012:
90 randomized
Erlotinib
Protocol enrollment
Biopsy performed
Stage 1 (N=200):
Adaptive Randomization
KRAS mutation
Stage 2 (N=200):
Refined Adaptive Randomization
“Best” discovery markers/signatures
Erlotinib+AKTi
MEKi+AKTi
Sorafenib
Primary endpoint: 8-week disease control
N = 400
Biomarker Selection
Clinical Trial Stage 1
Cli i l T
Clinical
Trial
i l St
Stage 2
Initial Adaptive Randomization with Group 1 markers
Refined Adaptive Randomization with Group 4 Markers
(200 Pts)
(Enrollment of 160 of 200 Pts)
Group 1
E t bli h d Known
Established
K
Markers
M k
(N=1)
(N 1)
Kras mutation
Group 2
High Potential, Candidate Markers (N~20)
EGFR copy number,
number IGF-1R copy number
number, EGFR
protein, IGF-1R protein, IGFBP-3 protein, pAKT
protein, PTEN protein, LKB1 protein, PIK3CA
mutation, BRAF mutation, mRNA RAS pathway
activation signature, mRNA EGFR pathway
activation signature, and miRNA EGFR signature
Bayesian Variable Selection
& Model Building
• Markers with highest posterior
probability as prognostic or
predictive markers are selected.
Choose 1 or 2 markers per
treatment.
• Identify models with best power
for predicting treatment
response
Group 3 Initial Discovery Markers
(N = Many)
Microarray, RPPA, SNP, other mutations,
proteins, IHC, FISH, miRNA markers, etc.
Group 3
Selected Discovery Markers
(N = ~20)
20)
Preprocessing for selecting putative
individual or composite markers
Group
p 4 Refined Adaptive
p
Randomization Markers
(N=6 to 10)
• Biomarker Steering
Committee:
• R01 Exec Comm; selected
IAB / EAB members
• Prespecified Guidelines
for Selection:
• Rank-ordering from Baysian
modeling
• Prevalence in Clinical
Specimens
• Biologic Plausibility
• CLIA-certifiable
Marker selection for
f adaptive randomization. Group
G
1 markers are used for
f initial adaptive randomization (AR)
( ) in Stage
S
1 as well
as the refined AR in Stage 2. Group 2 markers and the selected Group 3 markers are entered into the Bayesian variable selection
and model building process to identify best markers and corresponding models for predicting treatment response. Biomarker
Steering Committee evaluates markers/models based on preselected guidelines to make final decision on Group 4 markers to be
used for refined AR in Stage 2.
Discovery Platform versus
Confirmatory Platform
Early phase of drug developing is about discovery
and learning
learning..
Adaptive design provides an ideal platform for
learning – “We
We learn as we go.”
go
go...”
Due to the large number of tests, the overall false
positive rate may be large.
Results found in the discovery platform need to be
validated in the confirmatory platform
– Validation
V lid ti off ttreatment
t
t efficacy
ffi
– Validation of predictive markers
After narrowing down the biomarkers and treatments
combination(s), confirmatory trials can be more
focused with smaller sample size.
My Dream on Curing Cancer…
Enroll all patients into clinical trials
trials. Pts are followed
uniformly. Endpoints are recorded consistently.
Tissues are collected for biomarker analysis.
y
There is something for everyone
–
–
–
–
Pts with actionable mutations: Treat /w effective agents
g
Pts with putative predictive markers: marker
marker--based AR trials
Pts without informative markers: screening trials
Pts serve as their own controls; N
N--of
of--1 trials
All relevant information are collected timely and stored
i a searchable
in
h bl kknowledge
l d b
base.
Each center holds a database /w a compatible format.
Information is updated and aggregated regularly.
Updated info is used for designing trials & treating pts.
Summary
Life is complex
complex.
We know less than what we think we know.
Adaptive
about
Ad ti design
d i continues
ti
tto learn
l
b t the
th new
agents’ activities, identifying the predictive markers
in order to apply this knowledge to better treat
patients in real time.
– Ideal for discoveryy
– Need validation
Adaptive
p
design
g can increase study
y efficiency,
y allow
flexibility in study conduct, and provide better
treatment to study participants.
Need to conduct more innovative trials to learn and
to improve so we can turn promise into progress.