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Stage III NSCLC Phase 3 Time-to-Event Analysis NCT03521154

LAURA: Complete Statistical Analysis of Osimertinib in Stage III Unresectable Non-Small Cell Lung Cancer

An independent statistical review of the randomized phase 3 LAURA trial evaluating osimertinib following chemoradiation in patients with stage III unresectable non-small cell lung cancer, with progression-free survival as the registered primary endpoint.

Trial start: 19 Jul 2018  ·  Primary completion: 05 Jan 2024  ·  Enrollment: 216
Scope of this record

This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results and trial-specific facts on this page are limited to the ClinicalTrials.gov record.

1. Trial at a Glance

LAURA is a randomized, parallel-group, double-masked phase 3 study evaluating osimertinib 80mg/40mg versus placebo osimertinib 80mg/40mg following chemoradiation in patients with stage III unresectable non-small cell lung cancer.

216
Enrollment
Randomized trial
2
Arms
Osimertinib vs placebo
0.16
Primary PFS HR
95% CI 0.10–0.24
<0.001
Primary PFS P-value
Two-sided
FeatureLAURA
Trial nameLAURA
NCT IDNCT03521154
PhasePhase 3
ConditionNon Small Cell Lung Cancer (Stage III)
DesignRandomized, parallel
MaskingDouble
Primary purposeTreatment
Enrollment216.0
Arms2
Lead sponsorAstraZeneca
Sponsor typeIndustry
StatusActive, not recruiting
Start2018-07-19
Primary completion2024-01-05

2. Clinical Question

The central statistical question was whether patients randomized to osimertinib 80mg/40mg would experience a different progression-free survival distribution than patients randomized to placebo osimertinib 80mg/40mg.

Population

Patients with stage III unresectable non-small cell lung cancer participating in the LAURA study.

Intervention

Osimertinib 80mg/40mg.

Comparator

Placebo osimertinib 80mg/40mg.

Primary question

Does osimertinib improve progression-free survival compared with placebo in the randomized study population?

3. Trial Design

LAURA was a phase 3, randomized, parallel-group, double-masked trial with a treatment purpose. The registry reports an enrollment of 216.0 participants and two treatment arms.

01
Randomize216.0 enrolled
02
Two armsOsimertinib vs placebo
03
FollowProtocol-defined assessments
04
AssessPFS and secondary endpoints
05
AnalyzeTime-to-event and binary outcomes
ARM 1

Osimertinib

  • Osimertinib 80mg/40mg
  • Randomized treatment arm
  • Compared with placebo in the posted analyses
ARM 2

Placebo

  • Placebo osimertinib 80mg/40mg
  • Randomized comparator arm
  • Reference group for reported treatment-effect estimates
Design interpretation. Randomization creates the basis for comparing the two groups as assigned. Double masking is a design feature intended to reduce the influence of knowledge of treatment assignment on trial conduct and assessment. The ClinicalTrials.gov record does not report a randomization ratio, stratification factors, crossover rules, an interim-analysis plan, or a multiplicity strategy, so those features are not inferred here.

4. Registered Primary Endpoint

EndpointRegistry definitionTime frame
Progression-free Survival (PFS) by Blinded Independent Central Review (BICR) Time from randomisation until the date of objective disease progression or death (by any cause in the absence of progression) regardless of whether the patient withdraws from randomised therapy or receives another anti-cancer therapy prior to progression, based on BICR assessment according to RECIST v1.1 Every 8 weeks for first 48 weeks, then every 12 weeks until BICR-confirmed radiological disease progression. Assessed up to date of DCO (05Jan24) to a maximum of approximately 63 months

This is a classic time-to-event endpoint. The event is the earlier relevant occurrence defined by the registry: objective disease progression or death in the absence of progression. Importantly, the definition explicitly retains events regardless of withdrawal from randomized therapy or receipt of another anti-cancer therapy before progression.

5. Results: Primary Progression-Free Survival

The posted primary analysis compared progression-free survival between osimertinib and placebo in the full analysis set. The registry reports a log-rank analysis, a hazard ratio as the effect measure, a two-sided 95% confidence interval, and a superiority hypothesis.

Primary PFS hazard ratio

0.16

95% CI: 0.10–0.24   ·   P < 0.001

Analysis population: Full analysis set  ·  Method: Log-rank test

Clinical Biostats interpretation

A hazard ratio of 0.16 means that, under the time-to-event comparison represented by the reported analysis, the estimated instantaneous rate of progression or death was substantially lower in the osimertinib group than in the placebo group. Expressed as a simple relative interpretation, 0.16 corresponds to an estimated hazard that is 16% of the comparator hazard, or approximately an 84% lower estimated hazard under the model.

The hazard ratio does not mean that 84% of patients were cured, that 84% of patients avoided progression, or that every patient experienced exactly an 84% reduction in individual risk. A hazard ratio is a relative time-to-event measure, not an absolute probability.

The 95% confidence interval of 0.10–0.24 describes statistical uncertainty around the estimated hazard ratio. It does not describe the range of outcomes for individual patients. Its width also matters: the data support a substantially lower estimated hazard, while the interval quantifies uncertainty about the magnitude of that relative effect.

The P < 0.001 value addresses the evidence against the relevant null hypothesis under the reported statistical test. It is not a measure of effect size, clinical importance, or the probability that the treatment works. The size of the estimated effect is communicated by the HR, while its statistical uncertainty is communicated by the confidence interval.

Because this is a hazard-ratio analysis, interpretation also depends on the assumptions and censoring structure underlying time-to-event analysis. The ClinicalTrials.gov record does not report a proportional-hazards diagnostic, so the HR should not be treated as a literal constant risk reduction at every point in time.

The registry identifies PFS as a time-to-event endpoint and reports a log-rank test with a hazard ratio. A Kaplan-Meier curve is the standard graphical way to display the estimated event-free distribution over time, but the ClinicalTrials.gov record does not contain the underlying event and censoring times needed to reconstruct a valid curve independently.

6. Secondary Time-to-Event Results

The registry also reports several secondary time-to-event analyses. These analyses use the full analysis set and compare osimertinib with placebo. Most are reported using the log-rank test; the EGFR mutation-specific PFS analyses use a Cox proportional-hazards model.

Secondary endpointMethodEffect95% CIP-value
Number of Participants With PFS Events in Patients With EGFR Ex19del or L858R Mutation Cox proportional-hazards model HR 0.17 0.10–0.29 Not reported
Number of Participants With PFS Events in Patients With EGFR Ex19del or L858R Mutation Cox proportional-hazards model HR 0.32 0.19–0.56 Not reported
Number of Participants With PFS Events in Patients With EGFR Mutations Ex19del or L858R Detectable in Plasma-derived ctDNA Cox proportional-hazards model HR 0.22 0.15–0.34 Not reported
Central Nervous System (CNS) PFS by BICR Log-rank test HR 0.17 0.09–0.32 <0.001
Overall Survival (Duration) Log-rank test HR 0.81 0.42–1.56 0.530
Time to Death or Distant Metastases by BICR Log-rank test HR 0.21 0.11–0.38 <0.001
Time to Study Treatment Discontinuation Log-rank test HR 0.21 0.14–0.32 <0.001
Time to First Subsequent Treatment Log-rank test HR 0.13 0.08–0.21 <0.001
Time to Second Subsequent Treatment Log-rank test HR 0.51 0.28–0.91 0.022
Second Progression-free Survival (PFS2) Log-rank test HR 0.62 0.35–1.08 0.088

The registry uses the same broad superiority framework for these reported comparisons. The absence of a posted P-value for the three mutation-specific PFS analyses should not be filled in by calculation; the ClinicalTrials.gov record reports the hazard ratio and confidence interval but no P-value.

CNS Progression-Free Survival

CNS PFS hazard ratio

0.17

95% CI: 0.09–0.32   ·   P < 0.001

Method: Log-rank test  ·  Analysis population: Full analysis set

The CNS PFS estimate is another time-to-event comparison, but the endpoint specifically concerns central nervous system progression-free survival by BICR. The HR below 1 indicates a lower estimated event hazard in the osimertinib group under the reported analysis.

Overall Survival

Overall survival hazard ratio

0.81

95% CI: 0.42–1.56   ·   P = 0.530

Time frame: Date of randomisation to date of death by any cause. Assessed up to a maximum of approximately 63 months.

The reported OS estimate is less precise than the primary PFS estimate, as reflected by the 95% confidence interval extending from 0.42 to 1.56. The ClinicalTrials.gov record does not report a median OS or absolute survival probabilities, so those quantities are not used here to characterize the result.

Time to Death or Distant Metastases

Hazard ratio

0.21

95% CI: 0.11–0.38   ·   P < 0.001

Time frame: Time from randomisation to the date of distant metastases or death. Assessed up to date of DCO (05Jan24) to a maximum of approximately 63 months

Time to Study Treatment Discontinuation

Hazard ratio

0.21

95% CI: 0.14–0.32   ·   P < 0.001

Time frame: Time from randomisation to the earlier of the date of study treatment discontinuation or death. Assessed up to date of DCO (05Jan24) to a maximum of approximately 63 months

Time to First Subsequent Treatment

Hazard ratio

0.13

95% CI: 0.08–0.21   ·   P < 0.001

Time frame: Time from randomisation to the start of first subsequent anti-cancer therapy or death. Assessed up to date of DCO (05Jan24) to a maximum of approximately 63 months

Time to Second Subsequent Treatment

Hazard ratio

0.51

95% CI: 0.28–0.91   ·   P = 0.022

Second Progression-Free Survival

PFS2 hazard ratio

0.62

95% CI: 0.35–1.08   ·   P = 0.088

Time frame: Every 8 weeks for first 48 weeks, then every 12 weeks. Assessed up to date of DCO (05Jan24) to a maximum of approximately 63 months

7. Secondary Binary Endpoint Results

LAURA also reports binary response outcomes. These use logistic regression and odds ratios rather than time-to-event methods. This distinction matters: an odds ratio compares odds, not probabilities directly.

EndpointMethodEffect measure95% CIP-value
Objective Response Rate by BICR Logistic regression OR 2.77 1.54–5.08 <0.001
Disease Control Rate by BICR Logistic regression OR 2.06 0.94–4.47 0.069

Objective Response Rate

The reported odds ratio was 2.77, with a two-sided 95% CI of 1.54–5.08 and P < 0.001. The registry notes that an odds ratio > 1 favors osimertinib.

Disease Control Rate

The reported odds ratio was 2.06, with a two-sided 95% CI of 0.94–4.47 and P = 0.069. The registry notes that an odds ratio > 1 favors osimertinib.

8. Statistical Methodology

Log-rank test

The registry reports the log-rank test for the primary PFS analysis and several secondary time-to-event endpoints. The log-rank test compares survival or event-time distributions between groups while accounting for the timing of events and censoring.

Conceptual question
H0: the event-time distributions do not differ between randomized groups

The test uses information from observed event times and the numbers of participants at risk. It is therefore fundamentally different from a simple comparison of proportions at a single time point.

Cox proportional-hazards model

The registry reports a Cox proportional-hazards model for the three mutation-specific PFS analyses. The model produces a hazard ratio that summarizes the relative event hazard associated with treatment under the model.

Hazard-ratio interpretation
HR < 1  →  lower estimated instantaneous event hazard in the osimertinib group

For example, an HR of 0.22 indicates an estimated hazard that is 22% of the comparator hazard under the fitted model. It is not equivalent to a 78-percentage-point reduction in the probability of an event.

Logistic regression

The registry reports logistic regression for objective response rate and disease control rate. These are binary outcomes, so the analysis works with the odds of the specified response or disease-control state.

Intention-to-treat analysis

The registry's analysis text identifies intention-to-treat analysis as an associated concept for the posted efficacy analyses, while the analysis population is described as the full analysis set. The central principle is that randomized treatment assignment remains the basis of comparison rather than redefining groups according to subsequent treatment experience.

Confidence intervals

The reported effect estimates use two-sided 95% confidence intervals. A confidence interval describes statistical uncertainty around the estimated effect under the analysis framework; it is not a range containing 95% of individual patient outcomes.

Statistical significance and effect size

A small P-value and a large treatment effect are different pieces of information. In LAURA, the primary PFS analysis has both a hazard ratio of 0.16 and P < 0.001. The HR communicates the estimated relative effect, the confidence interval communicates precision, and the P-value addresses the evidence against the null hypothesis under the specified test.

9. Statistical Methods Explained

Why is PFS analyzed as a time-to-event endpoint?

PFS records not only whether progression or death occurs, but also when it occurs. Participants who have not experienced the event by their last evaluable assessment can contribute information up to that point through censoring. This makes ordinary binary comparisons inadequate as the sole analysis framework for the endpoint.

What does an HR of 0.16 mean?

An HR of 0.16 means the estimated instantaneous event hazard for progression or death was 16% of the comparator hazard under the reported time-to-event analysis. A useful relative interpretation is therefore an approximately 84% lower estimated hazard. This is not the same as saying that 84% of patients avoided progression.

Why is the confidence interval important?

The 95% CI of 0.10–0.24 places the estimated primary PFS HR in the context of sampling uncertainty. A point estimate alone can give a false impression of precision; the interval shows how much uncertainty surrounds that estimate within the statistical framework.

Why does the P-value not measure effect size?

The P-value is a measure of how incompatible the observed data are with a specified null hypothesis under the test procedure. It does not tell us how large the treatment effect is. The HR of 0.16 is the effect estimate; the 95% CI describes its uncertainty; P < 0.001 describes the hypothesis-test result.

Why use logistic regression for objective response rate?

Objective response is a binary outcome: a participant either meets the response definition or does not. Logistic regression models the probability through the odds scale, allowing an odds ratio to summarize the treatment comparison. An OR of 2.77 therefore means the estimated odds of the specified response were 2.77 times those in the comparator group under the reported model; it is not itself a 2.77-fold probability.

Why are the PFS and response analyses statistically different?

PFS incorporates the timing of progression or death and censoring, so survival-analysis methods are appropriate. Objective response rate is a binary outcome assessed over the specified response-assessment period, so logistic regression is appropriate for the reported comparison. Using different methods for different endpoint structures is a feature of the analysis rather than an inconsistency.

Why should subgroup or biomarker-specific estimates be read cautiously?

The ClinicalTrials.gov record includes mutation-specific and plasma-derived ctDNA-defined analyses. These are narrower analysis populations or endpoint definitions than the overall primary comparison. Their estimates should be interpreted in the context of the corresponding analysis population and confidence interval rather than assuming that every secondary estimate has the same evidentiary role as the primary endpoint.

10. Endpoint Time Frames

EndpointRegistry time frame
Primary PFS by BICREvery 8 weeks for first 48 weeks, then every 12 weeks until BICR-confirmed radiological disease progression. Assessed up to date of DCO (05Jan24) to a maximum of approximately 63 months
Mutation-specific PFS analysesEvery 8 weeks for first 48 weeks, then every 12 weeks until BICR-confirmed radiological disease progression. Assessed up to date of DCO (05Jan24) to a maximum of approximately 63 months
CNS PFS by BICREvery 8 weeks for first 48 weeks, then every 12 weeks until BICR-confirmed radiological disease progression. Assessed up to date of DCO (05Jan24) to a maximum of approximately 63 months
Overall SurvivalDate of randomisation to date of death by any cause. Assessed up to a maximum of approximately 63 months
Objective Response Rate by BICREvery 8 weeks for first 48 weeks, then every 12 weeks until radiological disease progression. Assessed up to date of DCO (05Jan24) to a maximum of approximately 63 months
Time to Death or Distant Metastases by BICRTime from randomisation to the date of distant metastases or death. Assessed up to date of DCO (05Jan24) to a maximum of approximately 63 months
Time to Study Treatment DiscontinuationTime from randomisation to the earlier of the date of study treatment discontinuation or death. Assessed up to date of DCO (05Jan24) to a maximum of approximately 63 months
Time to First Subsequent TreatmentTime from randomisation to the start of first subsequent anti-cancer therapy or death. Assessed up to date of DCO (05Jan24) to a maximum of approximately 63 months
Time to Second Subsequent TreatmentTime from randomisation to the start of second subsequent anti-cancer therapy or death. Assessed up to date of DCO (05Jan24) to a maximum of approximately 63 months
PFS2Every 8 weeks for first 48 weeks, then every 12 weeks. Assessed up to date of DCO (05Jan24) to a maximum of approximately 63 months

11. Analysis Population and Interpretation

FeatureReported information
Primary PFS analysis populationFull analysis set
Secondary time-to-event analysis populationFull analysis set
Binary endpoint analysis populationFull analysis set
Groups comparedOsimertinib vs Placebo
Hypothesis typeSuperiority
Confidence interval95%, two-sided

The use of the full analysis set means the posted efficacy estimates are not presented as a comparison restricted only to participants who completed treatment. This distinction is important in randomized trials because restricting analysis according to post-randomization behavior can alter the treatment comparison that randomization was designed to establish.

What is not reported in the ClinicalTrials.gov record: the registry extract does not specify the randomization ratio, stratification factors, an explicit missing-data or imputation strategy, a formal multiplicity-adjustment procedure, a non-inferiority margin, a crossover rule, or an interim-analysis plan. Those features are therefore not used to characterize the statistical design of this page.

12. Safety Results

The ClinicalTrials.gov record provides serious adverse-event counts by treatment arm as affected/at risk. These should be read as reported counts rather than converted into additional comparative estimates.

ArmSerious adverse eventsReported format
Osimertinib55/143Affected / at risk
Placebo11/73Affected / at risk

The registry caveat states that, as per CSP Section 7.2, patient monitoring during treatment with open-label osimertinib is monitored by the investigator per local clinical guidance. It also states that serious adverse events and AESIs are reported in the eCRF but were not analyzed or tabulated at the time of primary analysis, and that safety assessments are to be performed as per local clinical practice and not collected as part of study data capture in line with the pro...

Safety interpretation. Because the ClinicalTrials.gov record explicitly state that serious adverse events and AESIs were not analyzed or tabulated at the time of primary analysis, the 55/143 and 11/73 figures should not be presented as if they were accompanied by a formal hypothesis test, confidence interval, or adjusted between-arm comparison. The denominator information is retained exactly as reported.

13. Biomarker-Specific PFS Analyses

Three secondary analyses focus on PFS events in biomarker-defined populations. The registry reports Cox proportional-hazards models and hazard ratios for these analyses.

AnalysisHR95% CIAnalysis note
Patients with EGFR Ex19del or L858R mutation 0.17 0.10–0.29 PFS in Ex19Del positive patients; a hazard ratio < 1 favours osimertinib
Patients with EGFR Ex19del or L858R mutation 0.32 0.19–0.56 PFS in L858R positive patients; a hazard ratio < 1 favours osimertinib
EGFR Ex19del or L858R detectable in plasma-derived ctDNA 0.22 0.15–0.34 Negative at screening; a hazard ratio < 1 favours osimertinib

The two mutation-specific entries concern distinct mutation categories identified in the analysis notes, while the third concerns detectability in plasma-derived ctDNA. The registry extract does not provide P-values for these three analyses, so the HR and confidence interval are the appropriate reported statistical quantities here.

14. Understanding the Hazard Ratios Across Endpoints

EndpointHR95% CIP-value
Primary PFS by BICR0.160.10–0.24<0.001
CNS PFS by BICR0.170.09–0.32<0.001
Overall Survival0.810.42–1.560.530
Time to Death or Distant Metastases0.210.11–0.38<0.001
Time to Study Treatment Discontinuation0.210.14–0.32<0.001
Time to First Subsequent Treatment0.130.08–0.21<0.001
Time to Second Subsequent Treatment0.510.28–0.910.022
PFS20.620.35–1.080.088

The estimates vary across endpoints because the endpoints measure different clinical events or event combinations. A hazard ratio should therefore be interpreted within its endpoint definition rather than treating all HRs as interchangeable measures of one underlying outcome.

A key statistical distinction

The primary PFS HR of 0.16 and the OS HR of 0.81 are not contradictory simply because they differ. PFS measures progression or death according to its registered definition, while OS measures death from any cause. Different endpoints can have different event timing, censoring patterns, and relationships to subsequent treatment.

15. Odds Ratios for Objective Response and Disease Control

Objective response rate

OR 2.77

95% CI: 1.54–5.08   ·   P < 0.001

Method: Logistic regression  ·  Full analysis set

The odds ratio above 1 favors osimertinib according to the registry's analysis note. An OR of 2.77 means the estimated odds of objective response were 2.77 times those in the placebo group under the reported logistic model.

Disease control rate

OR 2.06

95% CI: 0.94–4.47   ·   P = 0.069

Method: Logistic regression  ·  Full analysis set

The disease-control estimate is also above 1, but its confidence interval includes 1 and its reported P-value is 0.069. The appropriate statistical description is therefore the reported estimate, uncertainty interval, and hypothesis-test result rather than converting the result into a probability of treatment benefit.

16. Why This Trial Matters Statistically

LAURA is a useful teaching case because it combines several major clinical-trial statistical structures within one randomized comparison.

ConceptHow it appears in LAURA
RandomizationParticipants were randomized to two parallel treatment arms.
BlindingThe registry reports double masking.
Time-to-event analysisThe primary endpoint is progression-free survival.
Log-rank testUsed for the primary PFS comparison and multiple secondary time-to-event endpoints.
Hazard ratioUsed to quantify relative treatment effects for time-to-event outcomes.
Cox modelReported for the mutation-specific PFS analyses.
Logistic regressionReported for objective response rate and disease control rate.
Odds ratioUsed for the two reported binary efficacy endpoints.
Confidence intervalsTwo-sided 95% CIs accompany the posted effect estimates.
Intention-to-treat conceptIdentified in the analysis text for the posted efficacy analyses.
Biomarker-defined analysesSeparate PFS analyses are reported for EGFR mutation and plasma-derived ctDNA categories.
Safety denominatorSerious adverse events are reported as affected/at risk by arm.

The trial therefore illustrates an important principle in clinical biostatistics: The statistical method should follow the structure of the endpoint. Time-to-event endpoints require methods that account for event timing and censoring, whereas binary endpoints can be modeled using logistic regression.

17. Limitations

18. What the Primary PFS Result Does — and Does Not — Mean

What the HR means

The primary PFS HR of 0.16 indicates a substantially lower estimated instantaneous hazard of progression or death for osimertinib relative to placebo under the reported analysis.

What the HR does not mean

The HR is not the proportion of patients who remained progression-free, is not an absolute risk difference, and does not mean that every participant experienced the same proportional change in risk.

What the confidence interval adds

The 95% CI of 0.10–0.24 quantifies uncertainty around the primary estimate. The interval is therefore essential to interpreting the precision of the reported HR rather than treating 0.16 as an exact population value.

What the P-value adds

The P-value of <0.001 summarizes the result of the reported hypothesis test. It should not be interpreted as the probability that the null hypothesis is true or as a measure of how large the treatment effect is.

19. Endpoint Definitions and Statistical Interpretation

Progression-free survival

Combines objective disease progression and death in the absence of progression into a time-to-event endpoint.

Overall survival

Measures time from randomisation to death by any cause.

Objective response rate

Uses a binary response framework and is analyzed in the registry using logistic regression.

Disease control rate

Is another binary endpoint analyzed using logistic regression and an odds ratio.

Keeping these definitions separate prevents a common statistical mistake: treating all reported treatment effects as if they measure the same outcome. An HR for PFS, an HR for OS, and an OR for response are mathematically and clinically different quantities.

20. Clinical Interpretation vs Statistical Interpretation

Statistical interpretation

The primary PFS comparison produced an HR of 0.16 with a two-sided 95% CI of 0.10–0.24 and P < 0.001 in the full analysis set. The registry identifies the hypothesis as superiority.

Clinical interpretation

The reported endpoints describe different dimensions of disease control and treatment experience. PFS, OS, CNS PFS, subsequent-treatment timing, response, and safety should therefore be considered as distinct pieces of the trial evidence rather than collapsed into a single statistic.

21. Registry Caveats and What the Data Do Not Establish

The ClinicalTrials.gov record is sufficient to describe the primary statistical result and a substantial set of secondary analyses, but it does not provide every component that would normally appear in a complete statistical analysis plan.

TopicWhat can be stated from the ClinicalTrials.gov record
Primary endpointOne registered time-to-event endpoint: PFS by BICR.
Primary methodLog-rank test.
Primary effect measureHazard ratio.
Primary analysis populationFull analysis set.
HypothesisSuperiority.
Confidence intervalTwo-sided 95% CI.
MultiplicityNot specified in the ClinicalTrials.gov record.
Interim analysisNot specified in the ClinicalTrials.gov record.
Missing-data methodNot specified in the ClinicalTrials.gov record.
StratificationNot specified in the ClinicalTrials.gov record.
Bayesian methodsNot reported in the ClinicalTrials.gov record.
Non-inferiority marginNot applicable to the reported superiority hypothesis; no non-inferiority margin is reported.

22. A Compact Statistical Summary

QuestionReported answer
What was the primary endpoint?PFS by BICR.
What population was analyzed?Full analysis set.
What method was used?Log-rank test.
What was the primary effect estimate?HR 0.16.
How precise was the estimate?95% CI 0.10–0.24.
What was the reported P-value?<0.001.
What was the hypothesis type?Superiority.
What other major methods were reported?Cox proportional-hazards model and logistic regression.
What binary outcomes were analyzed?Objective response rate and disease control rate.
What safety information is posted in the ClinicalTrials.gov record?Serious adverse events by arm as affected/at risk: 55/143 for osimertinib and 11/73 for placebo.

23. Related Tutorials

Learn more about the methods used in this trial:

24. Related Calculators

These tools connect directly to the main statistical structures used in the LAURA analysis:

25. Sources

Continue through Clinical Biostats

Explore the statistical concepts behind randomized trials, time-to-event endpoints, regression models, confidence intervals, and clinical-trial analysis.

26. Record Summary

LAURA provides a detailed example of a randomized phase 3 clinical-trial analysis centered on a time-to-event primary endpoint. The registry reports PFS by BICR as the primary endpoint, analyzed in the full analysis set with a log-rank test and a hazard ratio of 0.16 (95% CI 0.10–0.24; P < 0.001). Secondary analyses extend the statistical picture to CNS PFS, overall survival, time to distant metastases or death, treatment discontinuation, subsequent treatment, PFS2, biomarker-defined PFS, objective response rate, and disease control rate.

The statistical lesson is broader than the primary P-value. The primary HR communicates the relative time-to-event effect; the confidence interval communicates its precision; the log-rank test provides the reported hypothesis-test framework; Cox models are used for selected biomarker-defined PFS analyses; and logistic regression provides a different framework for binary response outcomes. Reading these quantities together produces a more complete understanding of the trial than any single number can provide.

Clinical Biostats methodology: A trial-results page should distinguish the registered endpoint definition, the reported statistical analysis, the numerical estimate, and the educational interpretation. Where the ClinicalTrials.gov record does not report a design or analysis feature, this page does not infer it from outside sources.