This document discusses approaches for handling multiple time-to-event endpoints in group sequential clinical trial designs. It provides examples of hierarchical testing procedures where the secondary endpoint is only evaluated if the primary endpoint is significant. It also discusses approaches where trials are driven by both primary and secondary event types, with interim analyses planned for each endpoint. Maintaining control of the overall type I error rate across multiple analyses and endpoints is an important consideration.
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Chapter 11: Goodness-of-Fit and Contingency Tables
11.1: Goodness of Fit Notation
A Trial Master File (TMF) is a comprehensive collection of essential documents and records that are generated or collected during the conduct of a clinical trial. The TMF serves as the centralized repository of all study-related documentation and provides a complete and accurate account of the trial's planning, execution, and outcomes. It is an important component of Good Clinical Practice (GCP) and regulatory compliance.
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Chapter 11: Goodness-of-Fit and Contingency Tables
11.1: Goodness of Fit Notation
A Trial Master File (TMF) is a comprehensive collection of essential documents and records that are generated or collected during the conduct of a clinical trial. The TMF serves as the centralized repository of all study-related documentation and provides a complete and accurate account of the trial's planning, execution, and outcomes. It is an important component of Good Clinical Practice (GCP) and regulatory compliance.
5 essential steps for sample size determination in clinical trials slidesharenQuery
In this free webinar hosted by nQuery Researcher & Statistician Eimear Keyes, we map out the 5 essential steps for sample size determination in clinical trials. At each step, Eimear will highlight the important function it plays and how to avoid the errors that will negatively impact your sample size determination and therefore your study.
Watch the Video: https://www.statsols.com/webinar/the-5-essential-steps-for-sample-size-determination
5 essential steps for sample size determination in clinical trials slidesharenQuery
In this free webinar hosted by nQuery Researcher & Statistician Eimear Keyes, we map out the 5 essential steps for sample size determination in clinical trials. At each step, Eimear will highlight the important function it plays and how to avoid the errors that will negatively impact your sample size determination and therefore your study.
Watch the Video: https://www.statsols.com/webinar/the-5-essential-steps-for-sample-size-determination
An overview of the ICH E9 guidance. Easy to follow, and I can provide a live presentation of this to your team! Great for those who are not familiar with statistics.
In clinical trials and other scientific studies, an interim analysis is an analysis of data that is conducted before data collection has been completed. If a treatment is particularly beneficial or harmful compared to the concurrent placebo group while the study is on-going, the investigators are ethically obliged to assess that difference using the data at hand and to make a deliberate consideration of terminating the study earlier than planned.
In interim analysis, whenever a new drug shows adverse effect on human being while testing the effectiveness of several drugs, we immediately stop the trial by taking into account the fact that maximum number of patients receive most effective treatment at the earliest stage. Interim analysis is also used to possibly reduce the expected number of patients and to shorten the follow-up time needed to make a conclusion. One wouldn't have to spend extra money if he/she already have enough evidence about the outcome. In this presentation, the total sample size is divided into four equal parts to perform the analysis and decision is made based on each individual step.
The DNP must have a basic understanding of statistical measureme.docxtodd701
The DNP must have a basic understanding of statistical measurements and how they apply within the parameters of data management and analytics. In this assignment, you will demonstrate understanding of basic statistical tests and how to perform the appropriate test for the project using SPSS or other statistical programs.
General Requirements:
Use the following information to ensure successful completion of the assignment:
Refer to "Setting Up My SPSS," "SPSS Database," and "Comparison Table of the Variable's Level of Measurement," located in the DNP 830 folder of the DC Network Practice Immersion workspace.
Doctoral learners are required to use APA style for their writing assignments. The APA Style Guide is located in the Student Success Center.
This assignment uses a rubric. Review the rubric prior to beginning the assignment to become familiar with the expectations for successful completion.
You are required to submit this assignment to LopesWrite. Refer to the
LopesWrite Technical Support articles
for assistance.
Directions:
Set up your IBM SPSS account and run several statistical outputs based on the "SPSS Database" Use "Setting Up My SPSS" to set up your SPSS program on your computer or device. You may also use programs such as Laerd Statistics or Intellectus, if you subscribe to them.
The patient outcome or dependent variables and the level of measurement must be displayed in a comparison table which you will provide as an Appendix to the paper. Refer to the "Comparison Table of the Variable's Level of Measurement."
Submit a 1,000-1,250 word data analysis paper outlining the procedures used to analyze the parametric and non-parametric variables in the mock data, the statistics reported, and a conclusion of the results.
Provide a conclusive result of the data analyses based on the guidelines below for statistical significance.
PAIRED SAMPLE T-TEST:
Identify the variables
BaselineWeight
and
InterventionWeight
. Using the Analysis menu in SPSS, go to Compare Means, Go to the Paired Sample
t
-test. Add the
BaselineWeight
and
InterventionWeight
in the Pair 1 fields. Click OK. Report the mean weights, standard deviations,
t-statistic,
degrees of freedom, and p level. Report as
t(df)=value, p = value.
Report the
p
level out three digits.
INDEPENDENT SAMPLE T-TEST:
Identify the variables
InterventionGroups
and
PatientWeight
. Go to the Analysis Menu, go to Compare Means, Go to Independent Samples
t
T-test. Add
InterventionGroups
to the Grouping Factor. Define the groups according to codings in the variable view (1=Intervention, 2 =Baseline). Add
PatientWeight
to the test variable field. Click OK. Report the mean weights, standard deviations,
t-statistic,
degrees of freedom, and p level. Report
t(df)=value, p = value.
Report the
p
level out three digits
CHI-SQUARE (Independent):
Identify the variables
BaselineReadmission
and
InterventionReadmission
. Go to the Analysis Menu, go to Descripti.
Data Analysis Of An Analytical Method Transfer ToDwayne Neal
To provide the basis for a PDA task force discussion to arrive at a consensus of best industry practices for data analysis of method transfers. The discussion is also relevant to method validation activities.
Worked examples of sampling uncertainty evaluationGH Yeoh
ISO/IEC 17025:2017 laboratory accreditation standard has expanded its requirement for measurement uncertainty to include both sampling and analytical uncertainties.
Clinical trials are the gold standard of evidence-based medicine. Properly designed clinical trials can lead to chance findings and potentially lead to erroneous conclusions.
Importantly, clinical trials can also be badly designed on purpose to increase the risk of false or chance findings leading to support misleading claims. Such techniques are frequently used by bad researchers and charlatans to substantiate their claims with biased clinical trials. It is therefore important to be weary of the limitations of clinical trials and understand how causal inference should be approach. In that presentation, I discuss the situations under which the risk of erroneous conclusions from clinical trials is increased and I discuss ways to identify and prevent bad clinical research.
The views expressed and presented in that presentation are my own views and may not represent the views of the National Institute for Health and Care Excellence.
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
EUGM 2011 | JEHL | group sequential designs with 2 time to event endpoints
1. Group sequential designs with two
time-to-event endpoints
Valentine Jehl, Novartis Pharma AG, Switzerland
Paris, 14-Oct-2011
2. Objective
Give a few examples on how designs with two time-to-
event can be implemented
Provide the rational for chosen strategies
2 | Presentation Title | Presenter Name | Date | Subject | Business Use Only
3. 3 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
Motivations
In oncology, time-to-event type variables are the most
commonly used endpoints for phase III trials
Ex. Progression free survival, Overall survival
Objective of the phase III = proof of efficacy as soon as
possible
Condideration of group sequential design with interim looks
Consideration of surrogate endpoints, if applicable
Multiple tests performed
Multiplicity has to be taken into account
4. Definition
Primary endpoint
• should be the clinical measures that best characterize the
efficacy of the treatment, and used to judge the overall success
of the study.
• should be clinically meaningful, and, ideally, fully characterize
the treatment effect
Secondary endpoint
• may provide additional characterization of the treatment effect.
• if positive might be mentionned in the label
4 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
5. Handling multiplicity
How to deal with more than one endpoints in a group
sequential design (GSD)?
• Hierachical procedure
• Different spending functions
• Simultaneous testing
5 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
6. Stagewise hierarchical testing
• Two-arm, two-stage design to demonstrate superiority
• One primary endpoint P, one secondary endpoint S
- Example from the respiratory therapeutic area:
• Primary endpoint P: change in area under curve of the forced expiratory volume
from 1 second of exhalation (FEV1) after 12 weeks of treatment
• Secondary endpoint S: trough FEV1
• Overall significance level α = 0.025
• One interim analysis (IA) after n1 = n/2 patients per group
• Trial success = primary endpoint is significant:
- Trial stops at interim when P is significant at interim, otherwise continues to
final analysis
Hierarchical testing for primary and secondary endpoints in GSD
- the easier case of non time-to-event endpoints
6 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
7. Hierarchical testing for primary and secondary endpoints in GSD
- the easier case of non time-to-event endpoints
Stagewise hierarchical testing:
• HS is tested only if HP is rejected
Primary hypothesis tested with O Brien-Fleming boundaries
• Nominal rejection level for HP : α1 = 0.0026 , α2 = 0.0240 if α = 0.025
Secondary hypothesis is tested only once; at what level?
• At level α ? ..... or at same level as primary? ... or something else?
7 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
8. Naive idea:
Since S is tested only once and only when P was
significant, S can be tested at full level α
This is not true!
Naive strategy leads to type I error rate inflation
• (Hung, Wang and O‘Neill (2007))
Inflation of type I error rate for HS
8 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
9. Maximum type I error for conditional testing HS at level α is
• For n1/n = 0.5 and α = 0.025, maximum type I error is 0.041.
Significance level for HS must be adjusted to keep a given
significance level αS for the secondary variable
For conditional testing HS at levels α*1 = α*2 = 0.0147 > α/2,
the maximum type I error attained is αS = 0.025
• α*1 = α*2 are the „Pocock -boundaries
( )2 1 1 11 , ; /z z n nα α− −− Φ
Actually, it can be shown that …
9 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
10. Consequences for the stagewise hierarchical testing
problem:
• If FWER control is desired, a group-sequential approach
must be used for both HP and HS (each at level α)
• The two approaches do not have to be the same.
• Regarding design, it does not matter if the trial is stopped at
IA when both HP and HS are rejected or if just HP is rejected
Stagewise hierarchical testing
10 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
11. Is there a best choice of spending function for HS
given a spending function for HP?
Not real “best“ choice however :
• If correlation between P and S is 1 (i.e. expected values are the same),
using the same spending function for P and S is always better.
• In realistic scenarios, study powered for primary endpoint with 80-90%,
some correlation between primary and secondary
Pocock is a good choice for S.
Stagewise hierarchical testing
11 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
12. S tested only if and at the point in time when P is significant.
Testing S at full level α does not keep the FWER.
For FWER control, set up a group-sequential-approach each for P
and S.
Spending functions don‘t have to be the same.
If study stops when P is significant: Usually advantageous to plan
for more aggressive stopping rules for S than for P (e.g. OBF for P,
Pocock for S).
More than one interim: approach is equally valid
Do the same principles apply to time-to-events analysis ?
Summary: stagewise hierarchical testing
12 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
13. An important example for oncology:
Primary endpoint: disease related time-to-event endpoint
• ex: progression-free survival (PFS) could also be Time to progression (TTP)
• correlated with OS but exact correlation unknown.
Overall survival (OS) as the key secondary endpoint,
for which a control of the type I error rate is also required.
Hierarchical testing procedure for OS
consistent with seeking inclusion of OS results in the
drug label
Two endpoints: PFS and OS
13 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
14. Depending on context:
• OS primary endpoint and PFS secondary endpoint
• Both co-primary endpoints.
Event-driven interim looks: two cases
1. Either OS (or PFS) drives interim looks
e.g. interim after n1 of a total n OS events, PFS just „carried along“
→ requires estimation of PFS information fractions
2. Event-driven trials for PFS and OS
Two endpoints: PFS and OS
14 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
15. Example : OS only driver for the trial
• A total number of OS is fixed, # of PFS events is „left open“
• IA after 50% of planned OS events
• At design stage, rough estimate of # PFS events at interim and at
final (knowing that these are not precise)
• At interim, a certain α spend for PFS based on #(interim PFS
events)/#(planned finalPFS events)
• At the final, critical value u2 recalculated based on # PFS events
actually observed at the final analysis and at interim such as
1-PH0(t1<u1,t2<u2)=α.
• Could reveal that the fraction spend at interim was inappropriate
• u2 ↓ if more events than anticipated are observed at interim !
PFS and OS: OS event-driven trials
15 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
16. PFS: one final analysis only
OS: i) interim OS analysis at the time of the final PFS analysis
ii) final OS analysis after additional follow-up
Final # deaths not
expected to be
observed at this time
point
Required # deaths for
final OS analysis
observed after
additional follow-up
Trials driven by both event types - simple case
16 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
17. Trials driven by both event types - simple case
17 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
18. Example:
Study RAD001C2324 (RADIANT-3)
Phase III study of RAD001 & BSC vs. BSC & Placebo in patients with
advanced pancreatic neuroendocrine tumor (pNET)
Primary endpoint: PFS
• targeted number of PFS events = 282,
• total number of patients to be randomized = 392 (1:1 randomization)
OS as key secondary endpoint,
• a total of 250 deaths would allow for at least 80% power to demonstrate
a 30% risk reduction
Originally IA planned for PFS, but canceled (amendment) due to fast
recruitment (expected time between IA and final analysis 4 months
only)
⇒ one final PFS analysis only, IA for OS at final PFS analysis,
⇒ Final OS analysis planned with 250 OS events
18 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
19. First interim at s1
(Final analysis)
Final analysis at s2
(Final OS analysis)
Information fraction (%) 47.2 100
Number of events 118 250
Patients accrued 392 392
Boundaries
Efficacy ( reject H0)
Z-scale 3.0679 1.9661
p-scale 0.001078 0.024644
Cumulative Stopping probability (%)2
Under H0 for activity2 0.10% 2.39%
Under Ha for activity2 12.57% 80.09%
2 results obtained by simulations. Probabilities are reported as if OS was tested alone, regardless of the testing
strategy with . The true probabilities should take into account the probability of at each look.
At OS interim analysis, information fraction will be computed as the ratio of the number of events
actually observed relative to the number targeted for the final analysis. The critical value for the final
analysis will be calculated using the exact number of observed events at the final cut-off date, and
considering the α-levels spent at interim analysis (analyses), in order to achieve a cumulative type I
error smaller than 2.5% for one-sided test.
Example: RADIANT-3 (cont‘ed)
Statistical considerations in statistical analysis plan
estimated
101 OS observed (40.4% of targeted)
=> boundary z=3.33846, p=0.000421
19 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
20. PFS: interim and final analysis
OS: i) 2 interim OS analyses at interim/final PFS analysis
ii) final OS analysis after additional follow-up
s1 s2
* s3
Analysis determined before study start:
• IA 1 after s1 PFS events
• IA 2 after s2* PFS events
• IA 3 after s3 OS events
Trials driven by both event types - more
complex case
20 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
21. PFS as primary and OS as key secondary
Trials driven by both event types - more
complex case
21 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
22. Calculation of critical values / α spent:
• Interim 1: Critical value cOS,1 such that PH0 (tOS,1> cOS,1) = αOS,1,
αOS,1 from selected α-spending approach for the observed OS info
fraction (#OS events in stage 1)/(total # OS events planned)
• Interim 2:
Critical value cOS,2 such that PH0 (tOS,1≤ cOS,1, tOS,2> cOS,2) = αOS,2 -αOS,1,
αOS,2 from selected α-spending approach for the observed OS info
fraction (OS events in stage 2)/s3, using αOS,1 „already spent“ and
observed information fraction (OS events in stage 1)/(OS events in
stage 1 and 2)
• Final analysis:
Critical value cOS,3 such that
PH0 (tOS,1≤ cOS,1, tOS,2 ≤ cOS,2, tOS,3> cOS,3) = α-αOS,2
Easy to do with EAST
Trials driven by both event types - more
complex case
22 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
23. Adequate handling of multiplicity in group-sequential time-to-
event trials has many aspects:
• Importance of endpoints: (co-)primary, secondary? A mix of all?
• Study conduct:
- stop as soon as primary endpoint is significant?
- Event-driven by just one endpoint?
General strategy:
• Set up an appropriate GS-approach per endpoint.
• Select an appropriate multiplicity-adjustment method
• Merge the two.
• Investigate operation-characteristics.
Summary
23 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
24. Thank you
24 | Group sequential designs with two time-to-event endpoints| Jehl V| 14-Oct-2011 | Business Use Only
For providing this material
• Ekkehard Glimm
• Norbert Hollaender
25. Back up slides
25 | Presentation Title | Presenter Name | Date | Subject | Business Use Only
27. ... but we still know the correlation between stage 1 and 2
To each of the hypotheses Hj, j = 1,…,h, a significance level αj is
assigned such that
• and define group sequential testing strategies with spending functions ai(y)
separately for each of the hypotheses at level αj .
1
h
jj
α α=
=∑
t 0 1 2 3
H1
H2
Hh
α1
α2
αh
Bonferroni on endpoints, then GS.
Note: First calculating the GS boundaries for α, then „bonferronizing“ them
does not keep the multiple type I error rate in general.
Several primary endpoints: correlation
unknown