H. Lundbeck A/S Efficacy Data in regulatory settings, DSBS January, May 2013
Jan 07, 2016
H. Lundbeck A/S
Efficacy Data in regulatory settings, DSBS January, May 2013
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Outline
Part 1: Objectives and Endpoints in test strategies
Part 2:
– Integrated Data Analysis: Purpose, Requirements, Terminology
– Methodology for Pooled and Meta Analysis
– Applications to filing of Vortioxetine
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Part 1: Endpoints in RCTs
Secondary Endpoints are Increasingly importantfor differentiation of products
• highly competitive markets• demands from authorities• Publishing on clinicaltrials.gov
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Definitions of Endpoints in RCTs:
’Good old Days’: Primary, Secondary and Exploratory
Now:
Primary: More or less as before
Secondary: Key SecondariesOther Secondaries
Exploratory: perhaps bigger than before
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Regulatory view
Primary Endpoint: Multiplicity control in case of e.g. several doses
Key Secondary Endpoints should be under proper multiplicity control together with the primary and can potentially be included in labelling text and promotional material. Will normally require significant primary
Other Secondary Endpoints can (normally) not be included in labelling text but have to go on ’www.clinicaltrials.gov’
Exploratory endpoints can (normally) not be included in labelling text but does not have to go on ’www.clinicaltrials.gov’
- Unclear whether secondary analyses have to go on .gov
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Authority Requirements to protocols and SAPs (EMA+FDA)
• Clinical formulation of objectives
• Clear correspondence between objectives and endpoints
Testing Strategy• Primary and Key secondaries should be selected based
on ‘Objectives’• Only one endpoint per objective. No redundancy• Only one analysis method (population) per endpoint
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Objectives and Endpoints
Objective Endpoint Analysis Methodology
Similar for other objectives. Select one row within each objectiveOften a mix is seen in protocols
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Primary Analysis
Objective Endpoint Analysis Methodology
: Secondary analysis method of primary endpoint adressing primary objective Can not be used as key secondary
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Key Secondary Analysis I
Objective Endpoint Analysis Methodology
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Key Secondary Analysis II
Objective Endpoint Analysis Methodology
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Example: Depression Study
Primary Objective:
Evaluate the efficacy of LuAA21004 compared to Placebo on depressive symptoms (in patients with MDD).
Key Secondary Objectives:
Evaluate the efficacy of LuAA21004 compared to Placebo on1. Global Status2. Functioning3. Anxiety
Assessments/endpoints MADRS, HAM-D (Response,Remission)adressing objective CGI-S, CGI-I (Response, Remission) SDS, work/family/social/total HAM-A, HAM-D Subscale
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Hierarchical Testing
MADRS
HAM-A
SDS
CGI-I
Depression
Global Status
Functionalitywork/social/family
Anxiety
One endpoint per objectiveTwo doses: alfa=2.5% in each sequence
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Primary Objective
Objective Endpoint Analysis Methodology
Response/Remission considered redundant, not a separate objective.However, special interest in EU
Depression
MADRS
OC
Response
HAM-D
Remission
LOCF
Non-par
MMRM
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Response and Remission
EMA: Particular Clinical Relevance + Redundant
FDA: Arbitrary and Inadequate Definition
+ Redundant
Response and Remission:– attractive for profiling– attractive for pricing – difficult to formulate as separate objective
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EMA: Responders
MADRS
HAM-A
SDS
CGI-I
- proceed as long as p<0.05
MADRS 50% Response
MADRS Remission
”Branching”, overall α>5%
Confirming Clinical Relevance
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Number of Key Secondary Endpoints
– no formal requirement or limitations– limited through non-redundancy within and
between objectives– ’Rule of thumb’: 4-5 tests within each dose– chose hierarchi according importance and
’hit-likelihood’– status of non-tested endpoints can be unclear
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Testing Strategy
– How to report p-values outside testing strategy or after stop within sequence ?
– Phrasing ’Statistical Significance’ should be reserved for results from testing strategy
Tip: Phrasing ’seperated from placebo’ has been introducedin accepted Lundbeck publications and in filing documents.
Other possible phrasings: Nominal significanceNominal p<0.05Nominal evidencePotential significance
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Part II
Integrated Data Analyses in Regulatory Setting
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Integrated Data Analyses
When a clinical development program entersregistration phase a need for integrated analyses arises:
• Regulatory requirements• Questions during approval phase• Profiling after approval
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Terminology
Meta Analysis
Pooled Analysis
Integrated Data Analysis
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Terminology
Definitions of Meta-Analysis:
FDA: Meta-analysis refers to the analysis of analyses...the statistical analysis of a large collection of analysis results from individual studies for the purpose of integrating the findings. (Glass, 1976) Examples of related terms used in literature include: analysis of combined data, combined analysis, analysis of pooled data, and pooled analysis. No matter what term is used, the objective is to use appropriately sound methods when formulating an integrated analysis.
ICH E9 + EMA: The formal evaluation of the quantitative evidence from two or more trials bearing on the same question. This most commonly involves the statistical combination of summary statistics from the various trials, but the term is sometimes also used to refer to the combination of the raw data.
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Meta-analysis Definition (google)
• Statistical solutions Software: Meta-analysis is a statistical technique in which the results of two or more studies are mathematically combined in order to improve the reliability of the results. Studies chosen for inclusion in a meta-analysis must be sufficiently similar in a number of characteristics in order to accurately combine their results. When the treatment effect (or effect size) is consistent from one study to the next, meta-analysis can be used to identify this common effect. When the effect varies from one study to the next, meta-analysis may be used to identify the reason for the variation
• Wikipaedia: In statisitics, a meta-analysis refers to methods focused on contrasting and combining results from different studies, in the hope of identifying patterns among study results, sources of disagreement among those results, or other interesting relationships that may come to light in the context of multiple studies
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Terminology
Meta Analysis
Pooled Analysis
Integrated Data Analysis
Meta Analysis
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Terminology
Meta Analysis
Pooled Analysis
Integrated Data Analysis
Pooled Analysis
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Terminology in this presentation
Meta Analysis
Pooled Analysis
Integrated Data Analysis
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Terminology
Meta Analysis (AD):
A specific statistical methodology based on summary statistics or aggregate data from each trial (AD Meta Analysis)
Pooled Analysis (IPD):
Statistical analysis based on data pooling at individual patient data level, that is, combination of raw data. (IPD Meta Analysis)
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Pre-requisities for Integrated analyses
Similarity of Studies with respect to
• Clinical endpoints• Study designs• Populations
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FDA: ISE requirements
• Integrated summary demonstating substantial eveidence of effectivenes
• Evidence to support recommended dosing in labelling
• Analyses in subgroups: Sex, age, race• Dosing in specific subgroups
- So, actually no specific demand for integrated analysis, could just be side by side presentation
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EMA: Points to consider on Meta-Analysis
• Not a requirement
• Cannot normally serve a primary
• Cannot save individual negative studies
• Needs prespecification
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EMA: Pre-requisits for acceptance of results from Meta-analysis as pivotal evidence
Pre-specification
• Statistical Methodology• Arguments for Inclusion and exclusion of
studies• Plan for evaluation of robustness of
results: subgroup, subsets of studies etc..• Populations
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EMA: Accepted Purposes of Meta-Analysesfor supportive evidence
• Precise estimate of treatment effects
• Confirm effect in subgroups
• Secondary outcomes requiring more power
• Evaluate dose-response
• Evaluate conflicting study results
- similar to FDA ISE
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Pooled Analysis
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Properties of Pooled Analysis
Intuitively attractive using individual patient dataFlexibility in having original data (subgroups, outliers etc.)
Complex statistical modelling possible/necessaryAssumptions on variability, baseline dependence, sites etc. Heterogeneity not straightforward
Risk of getting meaningless comparisonsDesign and convergence issues when using MMRM
Not really recommended by FDA?: Correspondence in Relation to AA21004: ’pooling on patient level is in general not recommended’
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AA21004 Data Package for MDD
8 Studies for Major Depressive Disorder
Differences between Studies:
1. Duration, 6-week 8-week2. Doses: 1, 2.5, 5, 10, 15 ,20 3. Primary endpoint: MADRS, HAMD-244. Method for primary (ANCOVA LOCF, MMRM, nominal/window)5. Test Strategy (step-down/alfa-split)6. Differences in key secondaries: SDS, Response, CGI7. Region8. Results
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AA21004/Vortioxetine Studies for MDD
Short-Term Long-Term
HLu 11492,PoC
HLu 11984,DF
TAK305
HLu 13267
TAK315
TAK316
TAK303
TAK304
Hlu 12541, Elderly
HLu 11985, Relapse prevention
6 weeks 8 weeks 8 weeks 8 weeks 8 weeks 8 weeks 6 weeks 8 weeks 8 weeks OL: 12 weeksDB: 24-64 weeks
PBO
5 mg10 mg
225 mg VEN (AR)
PBO2.5 mg5 mg10 mg
60 mgDUL (AR)
PBO1 mg5 mg10 mg
PBO
15mg20mg
60 mg DUL (AR)
PBO
15mg20mg
60 mg DUL (AR)
PBO
10mg
20mg
PBO
5 mg
PBO2.5 mg5 mg
60 mg DUL (AR)
PBO
5 mg
60 mg DUL (AR)
PBO
5 mg10 mg
EU/Asia/CA
EU/Asia/CA
EU/ZA/Asia
EU/ZA US US US US EU/CA/US
EU/CA/Asia
Positive study
(MADRS, LOCF)
Failed study, but supportive
(MADRS, LOCF)
Positive study
(HAM-D24, MMRM)
Positive study
(MADRS, MMRM)
Positive study
(MADRS, MMRM)
Positive study
(MADRS, MMRM)
Failed/nega-tive study
(HAM-D24, LOCF)
Negative study
(HAM-D24, LOCF)
Positive study
(HAM-D24, LOCF)
Positive study
(Time to relapse)
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Methodology for Pooled Analysis
Example: Standard ANCOVA model
MADRS, LOCF, Week 8
Alternatives (SAS):
1. model MADRS_DL = MADRS_BL ARMCD; (Naive)
2. model MADRS_DL = MADRS_BL ARMCD STUDY;
3. model MADRS_DL = MADRS_BL ARMCD SITEID(STUDY);
4. model MADRS_DL = MADRS_BL*STUDY ARMCD SITEID(STUDY);
Further Modelling: Random STUDY*ARMCD; Random Treatment*Study Effect Repeated group=study; Heterogeneous Variability
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Example: Treatment versus Placebo
Estimate S.E P-value
Original StudyN: 112 versus 105
-6.42 1.36 <0.0001
Pooled Analysis N: 112 versus 1290
-4.60 1.11 <0.0001
- substantial difference in estimate
TTreatment Arm only in one Study
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Interpretation of Pooled Methodology
Misleading Estimates
MMRM design and convergence problems
Modelling does not seem to account for all study differences
A lot of effort can be done to make the pooled analysis do what the meta-analysis seems to do automatically
Seems not to be the best choice for AA21, but was used for small subgroups
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Meta Analysis
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Properties of Meta Analysis
Analysis of analyses
Original data not needed(survey setting not so relevant for AA21)
Only relevant comparisons are retained
Works on any treatment estimate (+/-SE)logistic regression, Cox, ANCOVA, SES
Well-established method for heterogeneity
Less powerfull ?
Pairwise Comparisons mainly
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Methodology for Meta Analysis
Trials: i=1,…,k
Fixed Effects Modelling:
ai = true treatment effect in trial iâi= estimated treatment effect in trial i
vi = variance of âi
wi = 1/vi, weights
Estimated effect: â = Σwiâi/Σwi
Variance of estimate: 1/Σwi
Test H0: ai=0: (Σwiâi)2/Σwi ~ ϰ2(1)
ref: Encyclopaedia of Biostats. page 2570-2578Der Simonian (1976)
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Methodology for Meta Analysis with heterogeneity: Random Effects
Test for heterogeneity of effects
Q = Σwi(âi – â)2 ~ ϰ2(k-1) I2=max(0,100*(Q-k)/Q)
I2 describes the percentage of total variation across studies that is due to heterogeneity rather than chance (ref: Higgins, 2007)>50% considered problematic
Random effects in case of Heterogeneity: ai ~ N(a*,σ2) , σ2 estimated using Q (ref: Der Simonian)
wi*= 1/(vi+σ2)
â*= Σwi*âi/Σwi
*
Variance of estimate: 1/Σwi*
Test: (Σwi
*âi)2/Σwi* ~ ϰ2(1)
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Meta Analyses in SAS
PROC MEANS;
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Plan for Meta Analyses on AA21004 for regulatory purposes
• ‘Prespecification’ in separate SAP
• To be shown in 2.7.3
• Applied for sub-groups: gender, baseline severity
• Pooled analyses for small subgroups
- not all studies finalised at planning stage
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Preliminary Meta Analysis without two non-finalised studies. Differences to Placebo
Dose Response ?
10 better than 5 ?
Fixed or Random ?
Removed for confidentiality reasons
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Meta Analysis with all studies
Dose Response ?
15 mg ?
Removed for confidentiality reasons
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Meta Analysis SummaryDifferences to Placebo
Removed for confidentiality reasons
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Pooled versus Meta Analysis of AA21004
• Severe heterogeneity complicates interpretations
• Confounding with Region US/Non-US
• For both analysis types it is mandatory that interpretations involving comparions across treament arms take the individual study results into account.
• The random effects model has less power in the presence of heterogeneity but estimated treament differences change only slightly. Does not solve all heterogeneity problems.
• Random effects not feasible in pooled MMRM, but gets close to Meta results for LOCF
• Neither method completely satisfactory
• Mixed treatment comparison (MTC) meta-analysis allows several treatments (doses) to be compared in a single analysis while utilising direct and indirect evidence
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Meta Analysis in the filing documents
• Need to downplay due to severe heterogeneity
• Demonstrate Region issue US/Non-US
• Results across subgroups: age, bmi, gender, severity
• Argumentation for dose
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Planned talk at 8 January 2013
…… 4 Months Later ……..
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Lu AA21004, Vortioxetine, Brintellix
August 2012: Filing EUSeptember 2012: Filing US
January 8: Planned Talk at DSBSJanuary 17: Day 120 Q’s received
April 15: Day 120 Q’s answered
June 7: Day 180 Q’s
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Day 120 Questions
•Focus on US versus non-US
•No focus on pool- versus meta- approach
•Some value of meta-analyses in terms of dosing and subgroup arguments
•Testing strategy issues only in relation to PROs
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Guidelines
EMA: Points to consider on applications with meta-analysis, (2001)
FDA: Guidance for industry. Integrated Summary of Effectivenesss ISE (2008)
ICH E9: Statistical Principles for Clinical Trials