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Gastric / GEJ Adenocarcinoma Phase 3 Time-to-Event Analysis NCT03504397

SPOTLIGHT: Complete Statistical Analysis of Zolbetuximab in Gastric and GEJ Adenocarcinoma

An independent statistical review of the randomized phase 3 SPOTLIGHT trial comparing mFOLFOX6 plus zolbetuximab with mFOLFOX6 plus placebo in adults with locally advanced unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma.

Trial period: 2018-06-21 to primary completion 2022-09-09  ·  Enrollment: 565  ·  Status: Active, not recruiting
Scope of this record

This page separates reported trial results from statistical interpretation. Trial-specific numerical results and design facts are restricted to the ClinicalTrials.gov record for NCT03504397. The registry provides the official trial record.

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

SPOTLIGHT was a randomized, double-blind, parallel phase 3 trial evaluating mFOLFOX6 plus zolbetuximab versus mFOLFOX6 plus placebo in adults with locally advanced unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma.

565
Enrollment
Adults enrolled
2
Arms
Parallel treatment groups
0.734
Primary PFS HR
95% CI 0.591–0.910
0.0024
PFS P-value
Two-sided log-rank
FeatureSPOTLIGHT
Trial nameSPOTLIGHT
NCT IDNCT03504397
PhasePhase 3
StatusActive, not recruiting
DesignRandomized, double-blind, parallel
AllocationRandomized
Primary purposeTreatment
Enrollment565
Primary endpointProgression Free Survival (PFS)
Primary endpoint typeTime-to-event
Primary hypothesisSuperiority
Lead sponsorAstellas Pharma Global Development, Inc.
Sponsor typeIndustry
Start2018-06-21
Primary completion2022-09-09

2. Clinical Question

The primary statistical question was whether mFOLFOX6 plus zolbetuximab produced a different progression-free survival experience from mFOLFOX6 plus placebo in adults with locally advanced unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma.

Population

Adults with locally advanced unresectable gastroesophageal junction adenocarcinoma or cancer, locally advanced unresectable gastric adenocarcinoma or cancer, metastatic gastric adenocarcinoma or cancer, or metastatic gastroesophageal junction adenocarcinoma.

Intervention

Zolbetuximab administered with mFOLFOX6, consisting of oxaliplatin, folinic acid, and fluorouracil.

Comparator

Placebo administered with mFOLFOX6, consisting of oxaliplatin, folinic acid, and fluorouracil.

Primary question

Does mFOLFOX6 plus zolbetuximab improve progression-free survival compared with mFOLFOX6 plus placebo?

3. Trial Design

01
Randomize565 participants
02
InterveneTwo randomized arms
03
BlindDouble-blind design
04
AssessPFS, OS, response, TTCD, DOR
05
AnalyzeLog-rank and CMH methods
ARM A

mFOLFOX6 + Zolbetuximab

  • Zolbetuximab
  • Oxaliplatin
  • Folinic acid
  • Fluorouracil
ARM B

mFOLFOX6 + Placebo

  • Placebo
  • Oxaliplatin
  • Folinic acid
  • Fluorouracil

The design is randomized, parallel, and double-blind. Randomization is important because it establishes the treatment groups before outcomes are observed, while blinding is intended to reduce the influence of treatment knowledge on trial conduct and assessment.

Design limitation: the ClinicalTrials.gov record identifies the trial as randomized and double-blind but do not provide a numerical randomization ratio, treatment-specific randomized sample sizes, treatment doses, treatment-cycle schedules, or a crossover scheme. Those details are therefore not reconstructed here.

4. Endpoints

EndpointRegistry definition / time frameTypeAnalysis
Progression Free Survival (PFS) From date of randomization until the date of first documented radiological progression or date of death from any cause. PFS was defined as time from randomization until radiological progressive disease per RECIST 1.1 by independent review committee or death from any cause, whichever was earliest. Time-to-event Log-rank test; HR
Overall Survival (OS) From the date of randomization until 62 months and 18 days. Time-to-event Log-rank test; HR
Time to Confirmed Deterioration — Physical Functioning From the date of randomization until 62 months and 18 days, using physical functioning as measured by EORTC QLQ-C30. Time-to-event Log-rank test; HR
Time to Confirmed Deterioration — Abdominal Pain and Discomfort From the date of randomization until 62 months and 18 days, using the Oesophago-gastric Questionnaire (OG25) on abdominal pain and discomfort as measured by EORTC QLQ-OG25. Time-to-event Log-rank test; HR
Time to Confirmed Deterioration — Global Health Status From the date of randomization until 62 months and 18 days, using Global Health Status as measured by EORTC QLQ-C30. Time-to-event Log-rank test; HR
Duration Of Response (DOR) From date of first response (CR/PR) until 62 months and 18 days. Time-to-event Log-rank test; HR
Objective Response Rate (ORR) From the date of randomization until 62 months and 18 days. Binary Cochran-Mantel-Haenszel test

The registry lists Progression Free Survival (PFS) as the single primary endpoint. The other posted analyses are secondary endpoints. This distinction matters because a primary endpoint is the outcome around which the principal confirmatory statistical question is organized, whereas secondary endpoints provide additional evidence about survival, response, and patient-reported deterioration.

5. Statistical Methodology

Analysis populations

The primary PFS analysis was performed in the Full Analysis Set (FAS). The same FAS was used for the posted OS, time-to-confirmed-deterioration, and ORR analyses. The DOR analysis used the FAS — All Objective Responders.

Analysis populationEndpoint use in the posted analyses
FASPFS, OS, physical-functioning TTCD, abdominal-pain/discomfort TTCD, global-health-status TTCD, and ORR
FAS — All Objective RespondersDuration of Response

Time-to-event framework

Six of the seven posted statistical analyses use a time-to-event framework. These endpoints do not simply ask whether an event occurred; they consider when the event occurred. That distinction is important because two treatment groups can have the same eventual event proportion while having materially different event timing.

Log-rank testing

The registry reports the log-rank test for the primary PFS comparison and each of the posted secondary time-to-event comparisons. The log-rank test evaluates whether the event-time distributions differ between randomized groups over the observed follow-up.

Conceptual time-to-event comparison
H0: survival distributions are the same    vs    H1: survival distributions differ

For SPOTLIGHT, the reported hypothesis type is superiority. The effect measure accompanying the log-rank analysis is the hazard ratio.

Hazard ratio

The hazard ratio is the reported effect measure for the six posted time-to-event analyses. A hazard ratio below 1 indicates a lower estimated instantaneous event rate in the zolbetuximab group relative to the placebo group, whereas a value above 1 indicates a higher estimated instantaneous event rate.

Interpretation of the hazard ratio
HR = instantaneous event rate in zolbetuximab group ÷ instantaneous event rate in placebo group

This is a relative time-to-event measure. It is not an absolute risk difference, a probability of benefit for an individual patient, or a statement that every patient experiences the same proportional change in event risk.

Cochran-Mantel-Haenszel analysis

Objective response rate was analyzed using the Cochran-Mantel-Haenszel (CMH) test. The registry specifies a 1-sided CMH test and identifies Region, Number of Metastatic Sites, and Prior Gastrectomy as the stratification factors.

The CMH approach is useful when a binary outcome is compared across treatment groups while accounting for prespecified strata. Conceptually, it avoids treating the trial as though all participants belonged to one completely homogeneous population when the analysis has explicitly defined clinically relevant strata.

Stratified time-to-event analysis

The registry specifically documents stratification for the global-health-status TTCD and DOR analyses. The three stated stratification factors were Region (Asia vs Non-Asia), Number of organs with metastatic sites (0 to 2 vs ≥ 3), and Prior gastrectomy (Yes or No).

Stratification factorLevels reported
RegionAsia vs Non-Asia
Number of organs with metastatic sites0 to 2 vs ≥ 3
Prior gastrectomyYes or No

6. Results: Primary Endpoint — Progression-Free Survival

The registry reports a formal primary analysis of PFS in the FAS comparing mFOLFOX6 plus zolbetuximab with mFOLFOX6 plus placebo. The analysis used a two-sided log-rank test and reported the effect as a hazard ratio.

Hazard ratio for progression or death

0.734

95% CI: 0.591–0.910   ·   P = 0.0024

Analysis population: FAS  ·  Hypothesis: Superiority

Primary endpointZolbetuximab + mFOLFOX6Placebo + mFOLFOX6Statistical result
Progression Free Survival (PFS) Compared with placebo group Reference treatment group HR 0.734; 95% CI 0.591–0.910; P = 0.0024
Clinical Biostats interpretation

An HR of 0.734 means that the estimated instantaneous rate of progression or death was approximately 73.4% of the corresponding rate in the mFOLFOX6-plus-placebo group under the time-to-event analysis. Equivalently, 1 − 0.734 = 0.266, so the estimate corresponds to a 26.6% lower estimated hazard of progression or death.

The HR does not mean that 26.6% of patients avoided progression, that every patient experienced a 26.6% reduction in risk, or that the probability of remaining progression-free at a particular time was exactly 26.6% higher. Hazard ratios describe relative event rates over follow-up rather than a single absolute probability.

The 95% confidence interval of 0.591–0.910 describes uncertainty around the estimated hazard ratio. It indicates that the observed estimate is not being presented as an exact treatment effect. The interval also remains below 1, which is consistent with the reported superiority hypothesis test.

The P = 0.0024 value addresses the statistical evidence against the null hypothesis under the reported testing framework. It does not measure the size of the treatment effect, does not say that there is a 0.24% probability that the null hypothesis is true, and does not describe the probability that an individual patient will benefit.

Because PFS is a time-to-event endpoint, interpretation also depends on censoring and the assumptions underlying the hazard-ratio representation. The registry reports the log-rank method and HR but does not provide sufficient information here to independently assess proportional hazards, the censoring distribution, or the detailed analysis plan.

7. Secondary Endpoint Results

Overall Survival

Hazard ratio for overall survival

0.784

95% CI: 0.644–0.954   ·   P = 0.0075

Analysis population: FAS  ·  Time frame: from randomization until 62 months and 18 days

The OS analysis used a two-sided log-rank test with a hazard ratio as the effect measure. An HR of 0.784 corresponds to an estimated instantaneous rate of death approximately 78.4% of that in the placebo comparison group, or approximately a 21.6% lower estimated hazard based on 1 − 0.784.

How to interpret the OS result

The 95% CI of 0.644–0.954 quantifies uncertainty around the estimated HR. It does not provide a range of individual survival times and should not be interpreted as saying that individual patients have between 64.4% and 95.4% of the risk of death.

The reported P = 0.0075 is evidence from the stated two-sided log-rank comparison. It is not a measure of the magnitude of the survival difference. The magnitude is described by the HR, while absolute survival probabilities or median survival times would provide different clinical perspectives; those quantities are not reported in the ClinicalTrials.gov record.

Time to Confirmed Deterioration — Physical Functioning

Hazard ratio for confirmed deterioration in physical functioning

1.295

95% CI: 0.994–1.687   ·   P = 0.0280

Analysis population: FAS  ·  EORTC QLQ-C30 physical functioning

For this endpoint, the HR is above 1. Under the reported hazard-ratio framework, that corresponds to a higher estimated instantaneous rate of confirmed deterioration in physical functioning in the zolbetuximab group relative to the placebo group. An HR of 1.295 corresponds to approximately a 29.5% higher estimated hazard of the event.

The 95% CI of 0.994–1.687 is relatively wide and lies very close to 1 at its lower boundary. The reported P-value is 0.0280. These quantities should be read together rather than treating the P-value as a measure of effect size.

Time to Confirmed Deterioration — Abdominal Pain and Discomfort

Hazard ratio for confirmed deterioration in abdominal pain and discomfort

0.713

95% CI: 0.475–1.071   ·   P = 0.0508

Analysis population: FAS  ·  EORTC QLQ-OG25

The HR of 0.713 corresponds to an estimated instantaneous event rate approximately 71.3% of that in the placebo group, or approximately a 28.7% lower estimated hazard of confirmed deterioration under this endpoint definition.

However, the 95% CI of 0.475–1.071 crosses 1. The reported P = 0.0508 also illustrates why a P-value should not be read in isolation. The effect estimate, its confidence interval, and the endpoint's place among multiple secondary outcomes all contribute to the appropriate interpretation.

Time to Confirmed Deterioration — Global Health Status

Hazard ratio for confirmed deterioration in global health status

1.142

95% CI: 0.874–1.492   ·   P = 0.1685

Analysis population: FAS  ·  Stratified log-rank analysis

The HR of 1.142 corresponds to an estimated instantaneous event rate approximately 14.2% higher in the zolbetuximab group under the reported analysis. The confidence interval of 0.874–1.492 includes 1, and the reported P-value is 0.1685.

This analysis was explicitly stratified by Region, Number of organs with metastatic sites, and Prior gastrectomy. That stratification means the comparison was not treated as a completely unadjusted pooled comparison across all participants.

Duration Of Response

Hazard ratio for duration of response

0.789

95% CI: 0.573–1.087   ·   P = 0.0721

Analysis population: FAS — All Objective Responders

The DOR analysis begins at first response rather than at randomization. An HR of 0.789 corresponds to an estimated instantaneous event rate approximately 78.9% of that in the comparator group among objective responders, or approximately a 21.1% lower estimated hazard of the DOR event.

The 95% CI of 0.573–1.087 crosses 1, and the reported P-value is 0.0721. An important statistical distinction is that DOR is analyzed only among participants who achieved an objective response. It therefore addresses durability conditional on response and does not replace the randomized primary PFS analysis.

Objective Response Rate

Cochran-Mantel-Haenszel comparison

P = 0.4536

1-sided CMH test  ·  Analysis population: FAS

Stratification factors: Region, Number of Metastatic Sites, and Prior Gastrectomy

Unlike the other posted results, ORR is a binary endpoint rather than a time-to-event endpoint. The registry reports a 1-sided CMH test but does not provide an ORR estimate for either randomized group in the ClinicalTrials.gov record. Accordingly, no treatment-group response percentages are inferred here.

The absence of an effect estimate is important: P = 0.4536 is the reported result of the specified CMH test, but a P-value alone does not communicate the magnitude or direction of a difference in response rates.

8. Safety Results

The ClinicalTrials.gov record reports serious adverse events by arm as affected participants divided by participants at risk. These counts are presented exactly as reported.

InterventionSerious adverse eventsInterpretation of reported count
Zolbetuximab133 / 279133 affected among 279 at risk
Placebo129 / 278129 affected among 278 at risk
5-fluorouracil262 / 557262 affected among 557 at risk
Folinic Acid / Leucovorin262 / 557262 affected among 557 at risk
Oxaliplatin262 / 557262 affected among 557 at risk

The chemotherapy-component entries have the same affected and at-risk counts in the ClinicalTrials.gov record. They should not be interpreted as independent randomized treatment-group comparisons because oxaliplatin, folinic acid/leucovorin, and 5-fluorouracil are components of the chemotherapy regimen.

Safety interpretation: The ClinicalTrials.gov record reports serious adverse events by intervention component but do not provide a full adverse-event table, event severity distribution, discontinuation rates, or treatment-related attribution. Those additional safety measures are therefore not reconstructed or inferred.

9. Statistical Methods Explained

Why was a log-rank test used for PFS?

PFS is a time-to-event endpoint, and some participants may not have experienced progression or death by the time of analysis. A log-rank test is designed to compare the event-time distributions between groups while incorporating the timing of events and censoring. It therefore uses more information than a simple comparison of the proportion of participants who eventually experienced progression.

What does an HR of 0.734 mean?

The primary PFS HR of 0.734 indicates an estimated instantaneous progression-or-death rate about 73.4% of that in the comparator group. The complementary quantity, 1 − 0.734, is 0.266, so the estimate can be described as a 26.6% lower estimated hazard. This does not mean that 26.6% more patients remained progression-free at every time point.

Why does the confidence interval matter?

The point estimate is only one summary of the observed treatment comparison. The 95% CI of 0.591–0.910 communicates uncertainty around the primary HR estimate. A narrow interval would indicate greater precision than a wide interval, all else being equal. The interval does not describe the range of treatment effects that individual patients experience.

Why does the P-value not measure effect size?

The P-value reflects how compatible the observed data are with a specified null hypothesis under the statistical test. It is affected by both the size of an observed difference and the amount of information available. The HR and its confidence interval are therefore needed to understand the estimated magnitude and precision of the PFS comparison.

Why does an HR above 1 matter for a deterioration endpoint?

For the physical-functioning TTCD endpoint, the HR was 1.295. Because the event being analyzed is confirmed deterioration, an HR above 1 corresponds to a higher estimated event rate in the zolbetuximab group. The meaning of the direction depends on what the event represents; an HR below 1 is not automatically beneficial for every possible endpoint.

Why was a CMH test used for ORR?

ORR is binary: a participant either meets the response definition or does not. The CMH test provides a way to compare treatment groups while accounting for specified strata. In SPOTLIGHT, the registry identifies Region, Number of Metastatic Sites, and Prior Gastrectomy as the stratification factors for the 1-sided CMH analysis.

Why is DOR analyzed in responders?

DOR begins at the first documented response, so participants who never respond do not enter the responder-based time origin. This makes DOR a measure of the persistence of response rather than a replacement for an intention-to-treat endpoint such as PFS. Conditioning on response also means DOR should be interpreted differently from a randomized comparison beginning at treatment assignment.

10. Stratified Analysis

Several posted analyses explicitly use stratification. The registry specifies the same three stratification factors for the global-health-status TTCD and DOR analyses, and the ORR analysis uses those factors in the CMH framework.

FactorStrataRole reported in the registry
RegionAsia vs Non-AsiaStratification factor
Number of organs with metastatic sites0 to 2 vs ≥ 3Stratification factor
Prior gastrectomyYes or NoStratification factor

Stratification can improve the alignment between the analysis and the design when important baseline factors are expected to influence the endpoint. It does not mean that the treatment effect is separately estimated with equal precision inside every stratum. The overall stratified result remains the principal summary for the specified analysis.

11. P-Values, Confidence Intervals, and the Superiority Framework

The posted analyses identify superiority as the hypothesis type. The primary PFS result therefore asks whether the randomized treatment comparison provides evidence of a difference in the direction represented by the superiority hypothesis.

EndpointEffect measure95% CIP-valueHypothesis
PFSHR 0.7340.591–0.9100.0024Superiority
OSHR 0.7840.644–0.9540.0075Superiority
Physical functioning TTCDHR 1.2950.994–1.6870.0280Superiority
Abdominal pain/discomfort TTCDHR 0.7130.475–1.0710.0508Superiority
Global health status TTCDHR 1.1420.874–1.4920.1685Superiority
DORHR 0.7890.573–1.0870.0721Superiority
ORRCMH testNot reported0.4536Superiority

These seven results should not be read as though they were all interchangeable primary tests. Only PFS is identified as the primary endpoint in the ClinicalTrials.gov record. The other analyses are secondary. The ClinicalTrials.gov record does not provide a multiplicity-adjustment procedure or endpoint hierarchy beyond identifying the primary endpoint, so no additional multiplicity conclusion is imposed here.

Important statistical distinction: a secondary endpoint with a P-value below a conventional threshold should not automatically be treated as having the same confirmatory status as the registered primary endpoint. Conversely, a P-value above such a threshold does not prove that there is no treatment effect. The effect estimate, confidence interval, endpoint definition, analysis population, and prespecified role of the endpoint all matter.

12. Reading the Primary Hazard Ratio Carefully

Relative effect

The primary PFS HR of 0.734 indicates a lower estimated instantaneous rate of progression or death in the zolbetuximab-plus-mFOLFOX6 group under the reported analysis. The corresponding 26.6% figure is a relative hazard interpretation, not an absolute percentage-point difference in PFS.

Precision

The 95% CI of 0.591–0.910 shows the uncertainty associated with the HR estimate. The confidence interval is particularly useful because it gives more information than the point estimate alone about how precisely the treatment effect was estimated.

Statistical evidence

The reported two-sided P = 0.0024 indicates evidence against the null hypothesis under the specified log-rank testing framework. It should not be translated into a probability that the treatment works or into the magnitude of benefit.

What is not reported

The ClinicalTrials.gov record does not provide median PFS, median OS, fixed-time survival probabilities, numbers of progression events, Kaplan-Meier coordinates, or a treatment-specific absolute PFS difference. Those quantities are therefore not calculated from the HR and confidence interval.

13. Interpreting the Secondary Endpoints as a Set

The secondary analyses cover several distinct clinical questions. OS addresses death from any cause. TTCD endpoints examine time until confirmed deterioration in specified patient-reported measures. DOR examines the duration of response among objective responders. ORR asks whether a response occurred. These are related but not interchangeable outcomes.

QuestionEndpointStatistical perspective
Does treatment affect time until death?OSTime-to-event; HR 0.784
Does treatment affect time until physical-functioning deterioration?Physical-functioning TTCDTime-to-event; HR 1.295
Does treatment affect time until abdominal pain/discomfort deterioration?Abdominal pain/discomfort TTCDTime-to-event; HR 0.713
Does treatment affect time until global-health-status deterioration?Global-health-status TTCDTime-to-event; HR 1.142
Among responders, how long does response persist?DORTime-to-event; HR 0.789
Does treatment affect the proportion achieving objective response?ORRBinary; 1-sided CMH P = 0.4536

This endpoint diversity is statistically useful because it prevents the entire evidence base from being reduced to a single number. At the same time, it means each result needs to be interpreted according to its own event definition and analysis population.

14. Limitations

15. Why This Trial Matters Statistically

SPOTLIGHT is a useful teaching case because it illustrates how a randomized phase 3 trial can combine a primary time-to-event endpoint with several secondary time-to-event and binary endpoints. The statistical story is not contained in the P-value alone; it requires attention to endpoint definition, analysis population, effect measure, confidence interval, stratification, and the distinction between primary and secondary analyses.

ConceptHow it appears in SPOTLIGHT
RandomizationRandomized parallel-group phase 3 design with 565 enrolled participants
BlindingDouble-blind trial design
Time-to-event analysisPFS, OS, three TTCD endpoints, and DOR
Hazard ratioEffect measure for the posted time-to-event analyses
Log-rank testReported method for PFS and the secondary time-to-event analyses
Confidence interval95% two-sided intervals accompany the reported HR estimates
Stratified analysisRegion, metastatic-site count, and prior gastrectomy are identified as stratification factors in specified analyses
CMH test1-sided Cochran-Mantel-Haenszel analysis for ORR
Binary endpointORR contrasts with the time-to-event endpoints
Analysis populationFAS for most analyses; FAS among objective responders for DOR
Superiority testingAll seven posted statistical analyses identify superiority as the hypothesis type

16. A Practical Workflow for Analyzing SPOTLIGHT-Type Trials

01
DefineIdentify the event and time origin
02
CompareUse the stated survival test
03
EstimateInterpret the HR and CI
04
ContextCheck population and strata
05
InterpretSeparate primary from secondary evidence

This workflow highlights why statistical analysis begins before the P-value is read. First identify what constitutes the event and when follow-up starts. Then identify the analysis population and statistical test. Next interpret the effect estimate and its uncertainty. Finally, place the result within the endpoint hierarchy and trial design.

17. Time-to-Event Endpoints: What Is Being Compared?

For PFS, the registry defines the endpoint from randomization until the earliest of radiological progression or death from any cause. This creates a composite event definition: either component can end a participant's progression-free follow-up.

PFS event rule
PFS event time = min(first documented radiological progression, death from any cause)

The registry definition specifies radiological progressive disease according to RECIST 1.1 by independent review committee or death from any cause, whichever occurs first.

This matters because a participant who dies before documented radiological progression still experiences a PFS event. PFS therefore cannot be interpreted as simply "time until a scan shows progression."

18. What the Registry Results Do and Do Not Establish

What is directly reported

The primary PFS HR is 0.734 with a 95% CI of 0.591–0.910 and P = 0.0024. The registry also reports six secondary statistical analyses, their methods, populations, and available effect estimates or P-values.

What requires caution

The ClinicalTrials.gov record does not provide every quantity needed to reconstruct the full survival experience, including median event times, event counts, survival probabilities at selected time points, or individual participant follow-up.

What should not be inferred

An HR should not be converted into an absolute probability of benefit. A P-value should not be interpreted as a probability that the treatment hypothesis is true.

Why endpoint context matters

PFS, OS, TTCD, DOR, and ORR have different time origins, event definitions, and analysis populations. Their effect estimates therefore cannot be treated as interchangeable measures of the same outcome.

19. Related Tutorials

Learn more about the methods used in this trial:

20. Related Calculators

21. Sources

Continue with the statistical methods behind SPOTLIGHT

Explore survival-analysis tutorials, statistical calculators, and additional Clinical Biostats clinical-trial analyses.

22. Record Summary

SPOTLIGHT provides a detailed example of randomized clinical-trial analysis centered on a time-to-event primary endpoint. The primary PFS analysis used a two-sided log-rank test in the FAS and reported an HR of 0.734 with a 95% CI of 0.591–0.910 and P = 0.0024. Secondary analyses extended the statistical framework to OS, confirmed deterioration in several patient-reported measures, DOR, and ORR using log-rank or CMH methods as specified in the registry.

The most important statistical lesson is that these results should be interpreted as a collection of endpoint-specific analyses rather than as one universal treatment-effect number. The primary PFS result has a defined time origin, event definition, analysis population, effect measure, confidence interval, and hypothesis test. The secondary results answer different questions and use different statistical populations or methods.

Clinical Biostats methodology: A trial-results page should distinguish the reported statistical evidence from its educational interpretation. For SPOTLIGHT, that means preserving the registry's endpoint definitions and numerical estimates while explaining what hazard ratios, confidence intervals, P-values, stratification, and binary-response analyses actually measure.