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Stage IV / Recurrent NSCLC Phase 3 Open-Label NCT02041533

CheckMate-026: Complete Statistical Analysis of Nivolumab in Stage IV or Recurrent Non-Small Cell Lung Cancer

An independent statistical review of the randomized phase 3 CheckMate-026 trial comparing nivolumab with investigator's choice chemotherapy as first-line therapy for stage IV or recurrent PD-L1+ non-small cell lung cancer.

Trial status: COMPLETED  ·  Enrollment: 541  ·  Primary completion: July 1, 2016
Scope of this record

This page separates reported trial results from statistical interpretation. Trial-specific numbers and reported analyses are restricted to the ClinicalTrials.gov data posted on ClinicalTrials.gov for CheckMate-026. General explanations of statistical methods are educational descriptions of those methods.

Registry note: This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record.

1. Trial at a Glance

CheckMate-026 was an open-label, randomized, parallel, phase 3 trial evaluating nivolumab versus investigator's choice chemotherapy as first-line therapy for participants with stage IV or recurrent non-small cell lung cancer. The registry reports 541 enrolled participants, two treatment arms, one registered primary endpoint, six posted outcome measures, and five posted statistical analyses.

541
Enrolled
Total trial enrollment
2
Arms
Randomized parallel design
1
Primary Endpoint
Time-to-event
5
Statistical Analyses
Posted in registry results
FeatureCheckMate-026
Trial nameCheckMate-026
PhasePhase 3
StatusCOMPLETED
PopulationStage IV or recurrent non-small cell lung cancer
DesignRandomized, parallel, open-label
AllocationRandomized
Primary purposeTreatment
Enrollment541
Lead sponsorBristol-Myers Squibb
StartMarch 27, 2014
Primary completionJuly 1, 2016
ClinicalTrials.govNCT02041533

2. Clinical Question

The central statistical question was whether first-line nivolumab differed from investigator's choice chemotherapy with respect to progression-free survival in participants with PD-L1 expression ≥ 5%. The registered primary hypothesis type was superiority.

Population

Participants with stage IV or recurrent non-small cell lung cancer, with the primary efficacy analysis restricted to all randomized participants with PD-L1 expression ≥ 5%.

Intervention

Nivolumab. The registry also identifies nivolumab as a biological intervention.

Comparator

Investigator's choice of chemotherapy, with gemcitabine, cisplatin, carboplatin, paclitaxel, and pemetrexed listed among the trial interventions.

Primary question

Among randomized participants with PD-L1 expression ≥ 5%, how does nivolumab compare with investigator's choice chemotherapy for progression-free survival?

3. Trial Design

01
Randomize541 enrolled
02
Two ArmsNivolumab vs chemotherapy
03
Open-LabelNo masking
04
AssessTumor progression / death
05
AnalyzeStratified survival methods
ARM 1

Nivolumab

  • Nivolumab was the biological intervention.
  • The primary comparison was nivolumab versus investigator's choice chemotherapy.
  • Serious adverse events affected 195 of 267 participants at risk in the reported safety data.
ARM 2

Investigator's Choice of Chemotherapy

  • Investigator's choice chemotherapy was the comparator.
  • Listed chemotherapy interventions included gemcitabine, cisplatin, carboplatin, paclitaxel, and pemetrexed.
  • Serious adverse events affected 203 of 263 participants at risk in the reported safety data.
Additional treatment group in the safety data: the registry also reports a Post Chemotherapy Optional Nivolumab group, in which serious adverse events affected 110 of 159 participants at risk. This group is presented separately from the two randomized groups in the reported safety information.

4. Trial Timeline

March 27, 2014

Trial start

The registry lists March 27, 2014 as the study start date.

July 1, 2016

Primary completion

The registry lists July 1, 2016 as the primary completion date.

August 2016

Primary PFS assessment window

The registered primary endpoint was assessed up to August 2016, with the registry time frame described as approximately 28 months.

Approximately 89 months

Reported overall-survival analysis window

The posted secondary overall-survival analyses use a time frame from randomization to death, up to approximately 89 months.

5. Primary Endpoint

EndpointRegistry definition / time framePrimary statistical analysis
Progression-Free Survival in Participants With PD-L1 Expression ≥ 5% From date of randomization until date of documented tumor progression (assessed up to August 2016, approximately 28 months)). Progression-Free Survival (PFS) was defined as the time between the date of randomization and the first date of documented tumor progression, as determined by the Independent Radiology Review Committee (IRRC) per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1, or death due to any cause, whichever occurs first. Stratified log-rank test with stratified Cox proportional-hazards model

The primary endpoint is a time-to-event endpoint. Its analysis therefore focuses on the timing of progression or death rather than simply classifying each participant as having experienced an event or not.

6. Primary Result: Progression-Free Survival in Participants With PD-L1 Expression ≥ 5%

The registry reports a formal superiority analysis among all randomized participants with PD-L1 expression ≥ 5%, comparing nivolumab with investigator's choice of chemotherapy.

Hazard ratio for progression or death

1.15

95% CI: 0.91–1.45   ·   P = 0.2511

Analysis: stratified log-rank test and stratified Cox proportional-hazards model.

Primary endpointNivolumab vs chemotherapy
Analysis populationAll randomized participants with PD-L1 expression ≥ 5%
EndpointProgression-Free Survival
Effect measureHazard ratio
Hazard ratio1.15
95% CI0.91–1.45
P-value0.2511
HypothesisSuperiority
StratificationHistology (squamous vs. non-squamous) as entered into the IVRS
Clinical Biostats interpretation

The reported hazard ratio of 1.15 is the estimated hazard of progression or death for nivolumab relative to investigator's choice chemotherapy under the stratified Cox model. Because the estimate is above 1, the estimated instantaneous event rate is higher for nivolumab in this analysis; equivalently, 1.15 represents an estimated 15% higher hazard relative to chemotherapy under the model.

The hazard ratio does not mean that 15% more participants necessarily progressed or died. A hazard ratio is a relative time-to-event measure, not an absolute event-rate difference, a risk ratio, or a percentage of patients who benefited or failed treatment.

The 95% confidence interval of 0.91–1.45 describes statistical uncertainty around the estimated hazard ratio under the analysis model. It includes 1, so the data are compatible with a range of relative hazard values on both sides of the no-difference value.

The P-value of 0.2511 measures the compatibility of the observed test statistic with the specified null hypothesis under the statistical testing framework. It is not a measure of the magnitude or clinical importance of the hazard ratio, and it does not describe the probability that either treatment is effective.

The analysis was stratified by histology, and the reported model was a stratified Cox proportional-hazards model. As with other Cox-model analyses, interpretation of a single hazard ratio requires attention to the proportional-hazards assumption and to censoring and follow-up patterns.

Educational note: the ClinicalTrials.gov record provides the hazard ratio, confidence interval, P-value, analysis population, and method, but do not provide the underlying individual participant event and censoring times needed to reconstruct a Kaplan-Meier curve.

7. Secondary Efficacy Results

The registry contains four additional time-to-event analyses and one binary response analysis. These analyses use the same broad randomized treatment comparison but differ in endpoint, analysis population, and statistical method.

Progression-Free Survival in All Randomized Participants

Hazard ratio

1.17

95% CI: 0.95–1.43

Stratified Cox proportional-hazards model.

Clinical Biostats interpretation

The hazard ratio of 1.17 represents the estimated hazard of progression or death for nivolumab relative to investigator's choice chemotherapy among all randomized participants. Under the model, the estimate corresponds to an approximately 17% higher estimated hazard in the nivolumab group relative to chemotherapy.

The 95% CI of 0.95–1.43 spans 1.00, indicating uncertainty around the direction and magnitude of the relative treatment effect. The interval is not a range of individual patient outcomes.

No P-value is posted on ClinicalTrials.gov for this secondary analysis in the ClinicalTrials.gov record. The absence of a posted P-value means that the page does not assign a formal hypothesis-test result beyond the reported hazard ratio and confidence interval.

Overall Survival in Participants With PD-L1 Expression ≥ 5%

Hazard ratio

0.97

95% CI: 0.79–1.20

Time frame: from date of randomization to date of death, up to approximately 89 months.

Clinical Biostats interpretation

The hazard ratio of 0.97 estimates the relative instantaneous hazard of death for nivolumab versus investigator's choice chemotherapy among randomized participants with PD-L1 expression ≥ 5%. An HR below 1 corresponds to a lower estimated hazard under the fitted model, but an estimate close to 1 indicates little separation on this relative scale.

The 95% CI of 0.79–1.20 includes 1.00. It therefore allows for both a lower and a higher hazard of death for nivolumab relative to chemotherapy within the uncertainty represented by the interval.

No P-value is reported for this analysis in the ClinicalTrials.gov record. The hazard ratio should not be interpreted as a percentage reduction in mortality or as an absolute survival difference.

Overall Survival in All Randomized Participants

Hazard ratio

1.03

95% CI: 0.86–1.24

Time frame: from date of randomization to date of death, up to approximately 89 months.

Clinical Biostats interpretation

The hazard ratio of 1.03 estimates the hazard of death for nivolumab relative to investigator's choice chemotherapy in all randomized participants. The point estimate is close to 1, meaning the estimated relative hazards are close on this model-based scale.

The 95% CI of 0.86–1.24 includes 1.00. It represents uncertainty around the estimated hazard ratio and should not be read as the range of survival experiences for individual participants.

No P-value is posted for this secondary analysis in the ClinicalTrials.gov record. A hazard ratio by itself does not establish a clinically meaningful absolute difference in survival.

Objective Response Rate in Participants With PD-L1 Expression ≥ 5%

Odds ratio for objective response

0.70

95% CI: 0.46–1.06   ·   Two-sided

Analysis: Cochran-Mantel-Haenszel test, stratified by histology.

Secondary endpointEffect measureEstimate95% CIP-valueMethod
Progression-Free Survival in All Randomized ParticipantsHazard ratio1.170.95–1.43Not postedStratified Cox proportional-hazards model
Overall Survival in Participants With PD-L1 Expression ≥ 5%Hazard ratio0.970.79–1.20Not postedStratified Cox proportional-hazards model
Overall Survival in All Randomized ParticipantsHazard ratio1.030.86–1.24Not postedStratified Cox proportional-hazards model
Objective Response Rate in Participants With PD-L1 Expression ≥ 5%Odds ratio0.700.46–1.06Not postedCochran-Mantel-Haenszel test
Clinical Biostats interpretation

The odds ratio of 0.70 compares the odds of objective response for nivolumab with the odds of objective response for investigator's choice chemotherapy, using the reported Mantel-Haenszel stratified analysis. An odds ratio below 1 does not directly mean that the probability of response was 30% lower; odds and probabilities are different quantities.

The 95% CI of 0.46–1.06 spans 1.00, so the interval includes both lower and higher odds of response for nivolumab relative to chemotherapy.

The P-value is not posted on ClinicalTrials.gov for this posted secondary analysis. The reported two-sided confidence interval should therefore be presented as the available measure of statistical uncertainty rather than supplemented with an inferred P-value.

8. Statistical Results Summary

EndpointPopulationEffect95% CIP-valueMethod
Primary PFS, PD-L1 ≥ 5% All randomized participants with PD-L1 expression ≥ 5% HR 1.15 0.91–1.45 0.2511 Stratified log-rank; stratified Cox model
PFS, all randomized All randomized participants HR 1.17 0.95–1.43 Not posted Stratified Cox model
OS, PD-L1 ≥ 5% All randomized participants with PD-L1 expression ≥ 5% HR 0.97 0.79–1.20 Not posted Stratified Cox model
OS, all randomized All randomized participants HR 1.03 0.86–1.24 Not posted Stratified Cox model
ORR, PD-L1 ≥ 5% All randomized participants with PD-L1 expression ≥ 5% OR 0.70 0.46–1.06 Not posted Cochran-Mantel-Haenszel test

This table illustrates an important statistical distinction: the primary endpoint has a formally posted hypothesis test with P = 0.2511, whereas the ClinicalTrials.gov record for the four secondary analyses provide effect estimates and confidence intervals but no corresponding P-values.

9. Serious Adverse Events

The ClinicalTrials.gov record reports serious adverse events by treatment group as affected participants divided by participants at risk. These figures should be kept separate from efficacy analyses because safety populations and treatment exposure can be defined differently from randomized efficacy populations.

Reported groupParticipants affectedParticipants at riskReported measure
Nivolumab195267195/267
Investigator Choice of Chemotherapy203263203/263
Post Chemotherapy Optional Nivolumab110159110/159
Safety interpretation: The Post Chemotherapy Optional Nivolumab group is reported separately from the two randomized comparison groups. It should not be combined with the randomized nivolumab arm when describing the randomized treatment comparison. The ClinicalTrials.gov record also do not provide a formal statistical comparison of serious adverse-event rates.

10. Statistical Methodology

Kaplan-Meier estimation

Kaplan-Meier estimation is the standard descriptive framework for a time-to-event endpoint such as progression-free survival or overall survival. It estimates the probability of remaining event-free over time while allowing participants to be right-censored when their event status is not observed through the end of available follow-up.

Conceptual form
S(t) = ∏ti ≤ t (1 − di/ni)

Here, di is the number of events at time ti, while ni is the number at risk immediately before that time.

The ClinicalTrials.gov record does not provide the participant-level event and censoring times needed to reproduce the Kaplan-Meier curve. The method is therefore useful for understanding the registered endpoint, but a reconstructed curve should not be presented from the summary statistics alone.

Stratified log-rank test

The primary PFS analysis used a log-rank test stratified by histology, specifically squamous versus non-squamous, as entered into the IVRS. Stratification allows the time-to-event comparison to account for the prespecified stratification factor rather than treating all participants as belonging to one unstratified risk set.

Cox proportional-hazards model

The primary analysis also used a stratified Cox proportional-hazards model. The model expresses the treatment comparison through a hazard ratio, with the reported hazard ratio defined as nivolumab relative to investigator's choice chemotherapy.

Interpretation of the hazard ratio
HR < 1  →  lower estimated instantaneous event rate in nivolumab

HR = 1 corresponds to equal estimated hazards under the model. HR > 1 corresponds to a higher estimated instantaneous event rate for nivolumab relative to the comparator.

Cochran-Mantel-Haenszel analysis

The objective response rate analysis used the Cochran-Mantel-Haenszel test, with the analysis stratified by histology. The resulting effect measure was a strata-adjusted odds ratio for nivolumab over investigator's choice of chemotherapy.

Odds ratio

For a binary endpoint, an odds ratio compares the odds of an event between two groups. It is not identical to a risk ratio. The distinction becomes particularly important when the outcome is not rare, because an odds ratio can differ substantially from the corresponding ratio of probabilities.

Confidence intervals

A two-sided 95% confidence interval describes uncertainty around an estimated effect under the statistical model and sampling framework. For ratios such as hazard ratios and odds ratios, the no-difference value is 1.00. An interval that crosses 1.00 therefore includes both directions of relative effect.

11. Statistical Methods Explained

Why was a stratified log-rank test used?

The registered primary analysis used a log-rank test stratified by histology. A stratified log-rank procedure compares time-to-event experience between randomized groups while accounting for the specified strata. In this trial, the reported strata were squamous versus non-squamous histology as entered into the IVRS.

What does a hazard ratio of 1.15 mean?

A hazard ratio of 1.15 means that the fitted model estimates the instantaneous hazard of progression or death to be 1.15 times as high for nivolumab as for investigator's choice chemotherapy. The simple interpretation of the point estimate is an approximately 15% higher estimated hazard, but this is not equivalent to saying that 15% more participants experienced progression or death.

Why is the confidence interval important?

The point estimate is only one summary of the treatment comparison. The 95% CI of 0.91–1.45 for the primary PFS analysis shows the uncertainty around that estimate. Because the interval extends below and above 1.00, the ClinicalTrials.gov record does not identify a narrow range entirely on one side of the no-difference value.

Why does the P-value not measure effect size?

The primary P-value of 0.2511 is a hypothesis-testing quantity. It describes how compatible the observed test statistic is with the specified null hypothesis under the test's assumptions. It does not tell us how large the hazard ratio is, how clinically important the effect is, or the probability that one treatment is superior.

Why is the odds ratio different from a risk ratio?

The OR of 0.70 for objective response compares odds rather than probabilities. Odds are defined as the probability of an event divided by the probability of no event. Consequently, an OR of 0.70 cannot be translated directly into a 30% reduction in the probability of response without additional information.

Why does stratification matter?

Stratification allows the analysis to account for a factor used to structure the randomized comparison. In the primary PFS analysis, histology was the reported stratification factor. In the ORR analysis, the Cochran-Mantel-Haenszel approach likewise adjusted for histology.

12. Primary Analysis Population and Stratification

FeatureRegistry-supported detail
Primary analysis populationAll randomized participants with PD-L1 expression ≥ 5%
Primary endpointProgression-Free Survival
Primary comparisonNivolumab vs Investigator Choice of Chemotherapy
Primary testLog Rank
Primary modelStratified Cox proportional hazard model
Primary stratificationHistology (squamous vs. non-squamous) as entered into the IVRS
Hypothesis typeSuperiority

The analysis population is important because the primary result does not describe all 541 enrolled participants without qualification. It specifically refers to all randomized participants with PD-L1 expression ≥ 5%. The secondary all-randomized analyses address a broader randomized population.

Registry-data boundary: The ClinicalTrials.gov record does not provide a baseline characteristics table, treatment-arm randomized sample sizes, subgroup forest-plot estimates, or participant-level censoring information. Those items are therefore not reconstructed here.

13. Understanding the Primary Endpoint

Progression-free survival combines two possible events into a single time-to-event endpoint: documented tumor progression or death from any cause, whichever occurs first. This definition makes PFS different from a simple tumor-response proportion because it incorporates when the event occurs.

What is measured?

Time from randomization to the first qualifying progression event or death, according to the registered definition.

Why time matters

Two participants can both experience progression while having different progression-free times. Time-to-event methods retain this temporal information.

What is censoring?

Censoring occurs when a participant's event time is not observed within the relevant follow-up period. Survival methods use the available follow-up without treating every censored participant as an event.

What does HR summarize?

The hazard ratio summarizes the relative instantaneous event rate under the fitted Cox model rather than giving an absolute difference in event probability.

14. Interpreting the Primary PFS Result

Point estimate

The primary hazard ratio was 1.15. Because the comparison was defined as nivolumab to investigator's choice chemotherapy, the point estimate is above 1. Under the model, this corresponds to a higher estimated instantaneous hazard of progression or death for nivolumab.

Precision

The 95% CI was 0.91–1.45. This interval is considerably more informative than the point estimate alone because it displays the statistical uncertainty surrounding the estimated relative hazard.

Hypothesis testing

The reported two-sided P-value was 0.2511. The registered hypothesis type was superiority. The P-value is evidence about the specified hypothesis test, not a direct measure of treatment effect size or patient-level benefit.

Model interpretation

The Cox hazard ratio is a model-based summary. It should not automatically be translated into an absolute probability difference, median survival difference, or percentage of patients who benefited.

15. Secondary Time-to-Event Analyses

The secondary analyses show why the analysis population and endpoint should always accompany a hazard ratio.

EndpointPopulationHR95% CIInterpretive point
PFS All randomized participants 1.17 0.95–1.43 The broader population produces an estimate above 1, with the confidence interval crossing 1.
OS PD-L1 expression ≥ 5% 0.97 0.79–1.20 The point estimate is close to 1 and the interval crosses 1.
OS All randomized participants 1.03 0.86–1.24 The point estimate is close to 1 and the interval crosses 1.

These estimates should not be collapsed into a single overall treatment effect. Each corresponds to a different endpoint or analysis population. In particular, the two OS analyses differ in whether the population is restricted to participants with PD-L1 expression ≥ 5% or includes all randomized participants.

16. Objective Response Rate and the Cochran-Mantel-Haenszel Method

Objective Response Rate in participants with PD-L1 expression ≥ 5% was analyzed as a binary endpoint using the Cochran-Mantel-Haenszel test. The analysis was stratified by histology, and the reported effect measure was a strata-adjusted odds ratio.

Conceptual Mantel-Haenszel comparison
ORMH = strata-adjusted odds ratio

The important idea is that the overall treatment comparison is constructed while accounting for the specified stratification variable rather than simply pooling all observations without regard to strata.

The reported OR of 0.70 has a 95% CI of 0.46–1.06. The interval includes 1.00, so the ClinicalTrials.gov record does not support a narrow one-direction interpretation of the treatment effect based on the interval alone.

17. Statistical Interpretation vs Clinical Interpretation

Statistical interpretation

The primary PFS analysis estimated an HR of 1.15 with a two-sided 95% CI of 0.91–1.45 and P = 0.2511. The analysis used a stratified log-rank test and stratified Cox model.

Clinical interpretation

The ClinicalTrials.gov record alone do not provide enough information to quantify median PFS, absolute survival probabilities, response percentages, or patient-level benefit. Clinical interpretation therefore should not be expanded beyond the reported statistical estimates.

This distinction is important. Statistical analysis describes the evidence produced by the prespecified comparison. Clinical interpretation requires additional context, including absolute event probabilities, treatment exposure, safety, patient characteristics, and the clinical consequences of the measured endpoint.

18. Important Limitations and Interpretation Issues

19. Why This Trial Matters Statistically

CheckMate-026 is a useful statistical teaching case because the registry results connect several core methods in clinical-trial analysis: randomized comparison, time-to-event endpoints, stratification, log-rank testing, Cox proportional-hazards modeling, hazard ratios, confidence intervals, and categorical-data analysis using the Cochran-Mantel-Haenszel framework.

ConceptHow it appears in CheckMate-026
RandomizationThe trial uses randomized allocation in a parallel phase 3 design.
Time-to-event endpointThe registered primary endpoint is progression-free survival.
Stratified analysisThe primary PFS analysis was stratified by histology.
Log-rank testThe primary PFS comparison used a stratified log-rank test.
Cox modelA stratified Cox proportional-hazards model was used for the primary PFS analysis and reported secondary time-to-event analyses.
Hazard ratioPFS and OS results are expressed as hazard ratios comparing nivolumab with investigator's choice chemotherapy.
Confidence interval95% two-sided confidence intervals accompany the reported effect estimates.
Categorical analysisObjective response rate was analyzed using a Cochran-Mantel-Haenszel approach.
Odds ratioThe ORR analysis reports a strata-adjusted odds ratio.
Analysis populationsThe primary PFS population is PD-L1 expression ≥ 5%; other analyses use all randomized participants.

20. What the Hazard Ratio Does — and Does Not — Mean

Primary PFS hazard ratio

The primary PFS hazard ratio of 1.15 means that, under the stratified Cox model and with nivolumab as the numerator of the comparison, the estimated instantaneous hazard of progression or death was 1.15 times that associated with investigator's choice chemotherapy.

It does not mean that 15% more participants progressed, that 15% more participants died, or that every individual patient had a 15% higher probability of progression or death.

Why the confidence interval matters

The 95% CI of 0.91–1.45 expresses uncertainty around the primary hazard-ratio estimate. It includes the no-difference value of 1.00, so the point estimate should not be interpreted independently of the interval.

Why the P-value matters differently

The P-value of 0.2511 addresses the statistical hypothesis test associated with the primary analysis. It does not measure effect magnitude. Effect magnitude is conveyed by the hazard ratio, while precision is conveyed by the confidence interval.

21. Results by Statistical Question

QuestionReported resultHow to read it
Does nivolumab have a lower estimated PFS hazard in the PD-L1 ≥ 5% primary population? HR 1.15; 95% CI 0.91–1.45; P = 0.2511 The point estimate is above 1, while the confidence interval includes 1.
What is the PFS hazard ratio in all randomized participants? HR 1.17; 95% CI 0.95–1.43 The point estimate is above 1; the interval includes 1.
What is the OS hazard ratio in the PD-L1 ≥ 5% population? HR 0.97; 95% CI 0.79–1.20 The point estimate is close to 1; the interval includes 1.
What is the OS hazard ratio in all randomized participants? HR 1.03; 95% CI 0.86–1.24 The point estimate is close to 1; the interval includes 1.
What is the ORR odds ratio in the PD-L1 ≥ 5% population? OR 0.70; 95% CI 0.46–1.06 The point estimate is below 1; the interval includes 1.

22. Data Boundaries for This Analysis

The ClinicalTrials.gov record contains enough information to describe the registered design, primary endpoint, five posted statistical analyses, and reported serious adverse-event counts. They do not contain several types of information commonly included in a full clinical-trial publication.

Not included in the ClinicalTrials.gov record

Median survival estimates, time-specific survival probabilities, detailed baseline characteristics, subgroup hazard ratios, or forest-plot results.

Not reconstructed

No Kaplan-Meier curves, event counts by randomized efficacy arm, or derived response percentages are created from incomplete summary information.

Not inferred

No randomization ratio, treatment-arm sample size, crossover rate, interim boundary, multiplicity adjustment, or missing-data method is inferred when it is absent from the ClinicalTrials.gov record.

Why this matters

Keeping these boundaries explicit prevents secondary information from being presented as though it were part of the registry evidence.

23. Related Tutorials

Learn more about the methods used in this trial:

24. Related Calculators

25. Sources

Continue with the statistical methods

Explore the survival-analysis, categorical-data, confidence-interval, and clinical-trial methods connected to the CheckMate-026 analysis.

26. Record Summary

CheckMate-026 provides a compact example of several fundamental clinical-trial statistical methods. The trial was a randomized, parallel, open-label phase 3 study with 541 enrolled participants and a registered primary time-to-event endpoint of progression-free survival in participants with PD-L1 expression ≥ 5%. The primary analysis used a histology-stratified log-rank test and a stratified Cox proportional-hazards model, producing an HR of 1.15 with a two-sided 95% CI of 0.91–1.45 and P = 0.2511.

The posted secondary analyses demonstrate the importance of keeping the endpoint and analysis population attached to every effect estimate. PFS in all randomized participants produced an HR of 1.17, OS produced HRs of 0.97 in the PD-L1 ≥ 5% population and 1.03 in all randomized participants, and objective response rate produced an odds ratio of 0.70 using a histology-stratified Cochran-Mantel-Haenszel analysis. The reported serious adverse-event data likewise require attention to the population being described, particularly because a separate Post Chemotherapy Optional Nivolumab group is reported.

Clinical Biostats methodology: A trial-results page should distinguish the registered endpoint, analysis population, effect measure, uncertainty interval, and hypothesis test rather than treating a single number as the complete statistical story. Where the ClinicalTrials.gov record does not contain an estimate, baseline characteristic, or methodological detail, this page does not reconstruct or infer it.