A Study Comparing Two Different Chemotherapy Types in Chinese Patients With Advanced Non Small Cell Lung Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study Comparing Two Different Chemotherapy Types in Chinese Patients With Advanced Non Small Cell Lung Cancer (NCT01005680), a randomized phase 3 study. The primary outcome is Overall Survival (OS).

2. Clinical Question

The study was designed to compare efficacy and safety for two chemotherapy combinations used as first-line treatment. Its primary endpoint was overall survival, defined as the time from randomization to death from any cause. Participants who were alive were censored at the date of last contact. The registry describes an intent-to-treat population: participants were analyzed according to the group to which they were randomly assigned.

The comparison is between treatment strategies as assigned in this randomized study, rather than a comparison of individual drugs in isolation. Both groups received cisplatin, while the other named chemotherapy drug differed. The record identifies the study as phase 3, randomized, and parallel-group, with no masking. It lists enrollment of 256 participants. The primary results include 126 participants in the PC group and 130 in the GC group.

The main statistical question is whether the overall-survival experience differed between the groups during the reported follow-up. The posted estimate is a hazard ratio from a Cox proportional-hazards analysis, accompanied by a 95% confidence interval and a p-value. Those statistics describe the estimated comparison and its uncertainty; they do not by themselves establish that the treatments are identical or that any observed difference is clinically important. The registry record does not report a prespecified threshold for a clinically important difference.

3. Trial Design

This was a randomized phase 3 parallel-group study with no masking. The registry lists a total enrollment of 256. The study title identifies Chinese patients with advanced non-small cell lung cancer, and the official title specifies advanced non-squamous disease. The stated purpose was to compare the efficacy and safety of two first-line chemotherapy combinations.

The two groups were pemetrexed plus cisplatin (PC) and gemcitabine plus cisplatin (GC). The primary analysis population was intent-to-treat: participants were analyzed according to their randomized assignment. The overall-survival results list 126 participants for PC and 130 for GC. The arm descriptions in the registry record do not give further regimen details, such as dose or schedule, so those details are not reported in the registry record.

The registry lists the study as completed. The recorded start is 2009-11, and primary completion is recorded as 2012-11. Overall survival was followed from randomization to death from any cause, with living participants censored at their last contact. Its stated timeframe extends up to 35.8 months post-randomization. Progression-free survival has a separate timeframe extending up to 33.0 months post-randomization.

The registry identifies Eli Lilly and Company as the sponsor. It reports 9 outcome measures and 7 analyses. The record does not report the original sample-size justification, the planned allocation ratio, or whether interim analyses were planned. Although the posted results show arm sizes, those numbers do not establish what assumptions were used when the original study was designed. The record also does not give detailed inclusion and exclusion criteria, site information, or the procedures used to maintain randomization.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intent-to-Treat: all participants and are analyzed according to the treatment group they were randomly assigned. Censored participants: PC=37, GC=39.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

Population: All randomized participants.

6. Primary Endpoint

The registry lists the primary outcome as Overall Survival (OS), measured over Randomization to date of death from any cause up to 35.8 months post-randomization.

The primary endpoint, overall survival, measures the time from randomization until death from any cause. Participants still alive were censored at the date of their last contact. The registry states that the outcome was assessed up to 35.8 months post-randomization.

Time-to-event outcomes are useful when participants can have different lengths of follow-up and when the timing of an event matters. Rather than treating every participant as if their outcome were fully observed over the same period, survival methods incorporate information up to an event or censoring time. Censoring means that the event time is not observed during the participant’s available follow-up; it does not establish what happened after the last contact.

The registry reports median overall survival for each group and a hazard ratio from a Cox proportional-hazards analysis. The median describes the time by which half of the relevant group has experienced the event, under the survival analysis. The hazard ratio provides a relative comparison of event rates over follow-up under the model. The registry’s primary results report median overall survival of 17.54 months for PC, with a 95% confidence interval of 13.34 to 22.67 months, and 15.51 months for GC, with a 95% confidence interval of 13.7 to 19.29 months. The median summaries and hazard ratio answer related but different questions; neither alone describes every feature of the survival curves.

7. Results Posted in the Registry

• Pemetrexed Plus Cisplatin (PC) vs Gemcitabine Plus Cisplatin (GC): hazard ratio 1.03 (95% CI 0.77–1.39), reported p = 0.822 (as reported in the registry).

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Progression Free Survival (PFS)

• Endpoint type: Time to event: compared as a hazard ratio.
• Test: Hazard ratio as reported by the sponsor (Cox Proportional Hazard); it was not recalculated.
• Result:
  • Pemetrexed Plus Cisplatin (PC) vs Gemcitabine Plus Cisplatin (GC): hazard ratio 1.06 (95% CI 0.82–1.37), reported p = 0.640 (as reported in the registry).
• Interpretation:
  • The 95% confidence interval includes no difference (a ratio of 1), so these data do not show a statistically significant difference between Pemetrexed Plus Cisplatin (PC) vs Gemcitabine Plus Cisplatin (GC) and the control. The interval gives the range of effects that remain compatible with the data.

Time to Progressive Disease (TtPD)

• Endpoint type: Time to event: compared as a hazard ratio.
• Test: Hazard ratio as reported by the sponsor (Cox Proportional Hazard); it was not recalculated.
• Result:
  • Pemetrexed Plus Cisplatin (PC) vs Gemcitabine Plus Cisplatin (GC): hazard ratio 1.01 (95% CI 0.78–1.32), reported p = 0.928 (as reported in the registry).
• Interpretation:
  • The 95% confidence interval includes no difference (a ratio of 1), so these data do not show a statistically significant difference between Pemetrexed Plus Cisplatin (PC) vs Gemcitabine Plus Cisplatin (GC) and the control. The interval gives the range of effects that remain compatible with the data.

Duration of Response (DoR)

• Endpoint type: Time to event: compared as a hazard ratio.
• Test: Hazard ratio as reported by the sponsor (Cox Proportional Hazard); it was not recalculated.
• Result:
  • Pemetrexed Plus Cisplatin (PC) vs Gemcitabine Plus Cisplatin (GC): hazard ratio 0.96 (95% CI 0.51–1.79), reported p = 0.887 (as reported in the registry).
• Interpretation:
  • The 95% confidence interval includes no difference (a ratio of 1), so these data do not show a statistically significant difference between Pemetrexed Plus Cisplatin (PC) vs Gemcitabine Plus Cisplatin (GC) and the control. The interval gives the range of effects that remain compatible with the data.

The reported secondary time-to-event comparisons follow a broadly similar pattern to the primary result: the posted hazard-ratio estimates are near 1, and the reported 95% confidence intervals include 1. The group medians for progression-free survival and time to progressive disease are close in the posted results. Duration of response is reported among smaller responder groups than the primary intent-to-treat population. Taken together, these outcomes do not provide a clearly separated pattern of comparative estimates in the registry record.

These endpoints address different aspects of disease course and are not interchangeable with overall survival. Progression-free survival counts progression or death, while time to progressive disease concerns progression. Duration of response applies to participants with a response and measures time from first response to progression or death. The registry also lists time to treatment failure, tumor response rate, and risk/benefit ratio as secondary outcomes, but specific results for those outcomes are not reported in the registry record.

Secondary outcomes can add context, but they generally carry less weight than the primary endpoint when many outcomes are examined. In general, testing multiple outcomes creates more opportunities for chance findings, especially when no adjustment is made. The registry record does not report whether multiplicity adjustments or a hierarchy for interpreting secondary endpoints were planned. Consequently, the secondary results should be treated as supportive descriptions rather than as independent confirmation of the primary comparison. They do not alter the main uncertainty in the overall-survival estimate.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Progression Free Survival (PFS)
• Time to Progressive Disease (TtPD)
• Duration of Response (DoR)
• Time to Treatment Failure (TtTF)
• Tumor Response Rate
• Risk/Benefit Ratio

9. Statistical Interpretation

10. Statistical Methods Explained

The main comparative method reported for overall survival is a Cox proportional-hazards analysis. The registry gives the hazard ratio, its 95% confidence interval, and a p-value. It also reports group-specific median survival estimates and confidence intervals. These statistics summarize different aspects of the observed time-to-event data.

What does a hazard ratio describe?

In general, a hazard is the instantaneous event rate among participants who have not yet had the event, conditional on the model and the information available up to that time. A hazard ratio compares those rates between groups. A value of 1 indicates equal hazards under the model; values below or above 1 indicate different estimated relative hazards. The interpretation of direction depends on which group is placed in the numerator. The registry labels the comparison PC versus GC and reports a hazard ratio of 1.03 for overall survival.

A hazard ratio is not a ratio of medians, nor is it the probability that a participant will die during follow-up. It is a model-based relative summary over time. When the relative hazards change over follow-up, a single hazard ratio may not capture that changing pattern well. The registry names the Cox proportional-hazards method, but does not report whether the proportional-hazards assumption was assessed, how it was assessed, or what was found. Those details are not reported in the registry record.

What does the median add?

In general, a median time-to-event estimate describes the point in time by which half of the group is estimated to have experienced the event. The median is not a comparison adjusted for the other group. Each group’s median has its own uncertainty interval; those separate intervals should not be treated as a direct interval for the difference between medians. For overall survival, the posted medians are 17.54 months for PC and 15.51 months for GC. Their intervals are reported separately from the Cox comparison.

How should censoring be understood?

For overall survival, the registry defines censoring for participants who were alive at last contact. Censoring records that the event was not observed by the end of available follow-up; it does not mean that the participant remained alive indefinitely. The record reports 37 censored participants for PC and 39 for GC. Survival analyses use the time observed before censoring, subject to assumptions about how censoring relates to the event process. The registry does not describe the methods used to investigate those assumptions or the handling of missing outcome information beyond the stated censoring definition.

What does the confidence interval express?

In general, a confidence interval describes the range of values reasonably compatible with the data and the statistical model at its stated confidence level. A 95% confidence interval reflects a procedure that, under its assumptions, would cover the fixed target value in 95% of repeated applications. It is not a statement that there is a 95% probability that this particular interval contains the true value. The overall-survival hazard-ratio interval is 0.77 to 1.39. Its span conveys uncertainty about the comparative estimate, including values both below and above 1.

What role does the p-value play?

In general, a p-value assesses how unusual the data or a more extreme result would be if a specified null hypothesis and the analysis assumptions held. It does not quantify the probability that the null is true, and it should not be used as a stand-alone measure of importance. The reported overall-survival p-value is 0.822. The registry lists the Cox method and the p-value, but detailed specification of the hypothesis test, model covariates, or any adjustment procedures is not reported in the registry record.

The record identifies an intent-to-treat approach for the primary outcome. In general, analyzing participants according to randomized assignment preserves the comparison created by randomization and estimates the effect of assignment to the treatment groups. The registry does not report whether any additional analysis populations or adjusted analyses were used. The posted numbers should therefore be interpreted as the analyses specifically described in the record, without assuming unreported modeling or sensitivity procedures.

11. Confidence Intervals and Precision

The precision of the primary comparative result is reflected most directly in the confidence interval for the hazard ratio. The reported estimate is 1.03, with a 95% confidence interval from 0.77 to 1.39. The interval includes 1 and covers values on either side, so the data do not pin down a single relative-hazard value. The estimate is compatible with more than one possible direction and magnitude of comparative effect under the reported model.

The group-specific median estimates also have uncertainty. For PC, the median is 17.54 months, with a 95% confidence interval of 13.34 to 22.67 months. For GC, the median is 15.51 months, with a 95% confidence interval of 13.7 to 19.29 months. These intervals describe uncertainty in each group’s median separately. They are not a formal confidence interval for the difference between the group medians.

In general, confidence intervals are more informative than a significance label alone because they show a range of estimates consistent with the data and model. A wide interval signals that the estimate is not highly precise. An interval that includes the null value does not prove no effect; it indicates that the data have not excluded that value at the stated confidence level. Conversely, the point estimate should not be treated as the only plausible value.

Interpretation also depends on what differences would matter for the research question. The registry record does not report a threshold for a clinically meaningful survival difference. Without such a benchmark, the statistical uncertainty can be described, but the record does not support classifying the full range of compatible effects as either clinically trivial or important. The reported confidence interval is therefore central to reading the primary result, alongside the point estimate and p-value.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are illustrations based on the observed effect, not the original trial’s design assumptions. The original sample-size justification and planning assumptions are not reported in the registry record. For these illustrations, the stated assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. For time-to-event outcomes, the figures are total events, calculated using the Schoenfeld approach, not participants per arm.

The 80% power column represents the number of total events that the planning calculation estimates would be needed for an 80% chance of detecting the specified effect if that effect were true and the assumptions held. The 90% power column gives the corresponding event requirement for a 90% chance. For overall survival, planning for 100% of the observed effect gives 35,934 total events for 80% power and 48,105 total events for 90% power. Planning for 75% of the observed effect gives 63,881 and 85,519 total events, respectively; planning for 50% gives 143,733 and 192,417.

Smaller effects are harder to distinguish from random variation, so detecting a smaller effect generally requires more information and, for time-to-event outcomes, more events. These figures are not participant counts per arm, and event requirements cannot be read as the number enrolled. They are planning illustrations rather than a description of the study’s actual enrollment target or recruitment plan. This is not observed power: it does not measure the probability that the completed study detected its effect, and it cannot resolve uncertainty in the observed result.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

d is the total number of events needed (Schoenfeld's formula) with 1:1 allocation and proportional hazards.

Worked calculation for this trial

1. Hazard ratio HR = 1.030, so ln(HR) = 0.0296.
2. d = 4 × (1.96 + 0.842)² / [ln(1.030)]² = 35,933.0, rounded up to 35,934 events in total for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
hr <- 1.03                              # observed hazard ratio
events_needed <- function(power, frac = 1) ceiling(round(4 * (z_a + qnorm(power))^2 / log(hr^frac)^2, 6))   # Schoenfeld, 1:1 allocation
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: events = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(events_needed(0.80, f), big.mark = ","), format(events_needed(0.90, f), big.mark = ",")))

# Simulation: given d total events under proportional hazards, events in the treatment arm are Binomial(d, hr / (1 + hr)).
# The score (log-rank type) statistic is (D1 - d / 2) / sqrt(d / 4).
set.seed(1005680)
d    <- events_needed(0.80)
reps <- 20000
D1 <- rbinom(reps, d, hr / (1 + hr))
z  <- (D1 - d / 2) / sqrt(d / 4)
cat(sprintf("Simulated power with %s events: %.3f (%d replicates)\n", format(d, big.mark = ","), mean(abs(z) > z_a), reps))

Output from running the code

100% of observed effect: events = 35,934 (80% power), 48,105 (90% power)
 75% of observed effect: events = 63,881 (80% power), 85,519 (90% power)
 50% of observed effect: events = 143,733 (80% power), 192,417 (90% power)
Simulated power with 35,934 events: 0.796 (20000 replicates)

The simulation uses the fact that, with d events in total and proportional hazards, the number of events in the treatment arm is binomial. It is an approximation that conditions on the total number of events, and it should land close to the target power.

14. Analyses Reported by the Sponsor

The registry reports the sponsor’s Cox proportional-hazards analysis for overall survival as a hazard ratio of 1.03, with a 95% confidence interval of 0.77 to 1.39 and p = 0.822. The posted arm-specific median estimates are 17.54 months for PC and 15.51 months for GC. The comparative hazard ratio and its uncertainty, rather than a subtraction of the group medians, are the reported model-based comparison.

The registry record does not flag a discrepancy between the sponsor’s reported analysis and the unadjusted recalculation. The sponsor’s analysis is therefore the primary reference for the comparative result. An unadjusted recalculation from summary statistics is not a substitute for an analysis using participant-level time-to-event information and the sponsor’s specified model. It may not reproduce model details that are not available in the posted summary.

The record names the Cox proportional-hazards method but does not provide its full specification, including whether covariates were included or how model assumptions were evaluated. The reported estimate should be read as the sponsor analysis recorded in the registry, with those methodological details not reported in the registry record. The p-value and confidence interval describe uncertainty under that analysis; neither one establishes equivalence or clinical importance.

15. Multiplicity, Missing Data and Analysis Populations

The registry identifies overall survival as the primary outcome and lists several secondary outcomes, including progression-free survival, time to progressive disease, duration of response, time to treatment failure, tumor response rate, and risk/benefit ratio. The posted record includes results for some secondary time-to-event outcomes, but not specific results for all listed outcomes. It does not report a multiplicity strategy, such as a prespecified testing hierarchy or an adjustment of significance levels across outcomes. Whether such procedures were included in the full protocol is not reported in the registry record.

In general, when many hypotheses are tested, the chance of at least one apparently notable result arising by chance can increase. This is why secondary results are usually interpreted in the context of a prespecified analysis plan and any multiplicity control. Without that information in the registry, the reported secondary p-values should not be treated as if they necessarily controlled the overall chance of false-positive findings. The record does not report whether interim analyses were planned or whether any adjustment for interim looks was used.

The primary outcome population is identified as intent-to-treat, with participants analyzed in their randomized groups. The registry defines overall-survival censoring for living participants as occurring at last contact and reports 37 censored participants in PC and 39 in GC. It does not provide detailed information about missing data for other outcomes, reasons for loss to follow-up, or sensitivity analyses addressing missing outcomes. The handling of those issues is not reported in the registry record.

The reported analyses name a Cox proportional-hazards method, but the registry does not describe covariate adjustment, model diagnostics, or any checks of proportional hazards. It also does not state a prespecified clinically meaningful effect threshold. These omissions limit assessment of how fully the posted analyses reflect the original plan and how secondary findings should be weighted. They do not invalidate the posted statistics, but they make it important to distinguish reported analysis details from unreported protocol procedures.

16. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: lung infection (1.6%), venous thrombosis limb (1.6%), bone marrow failure (1.6%), fatigue (0.8%), pyrexia (0.8%).

The registry reports serious adverse events for 125 participants at risk in the PC group, with 8 affected, and 127 participants at risk in the GC group, with 9 affected. It also reports other adverse events for 125 participants at risk in PC, with 120 affected, and 127 at risk in GC, with 123 affected. These are group counts, and the registry record does not provide additional detail in the listed summary about severity grading beyond the serious-versus-other categories.

The record lists lung infection, venous thrombosis limb, and bone marrow failure at 1.6% each among the top serious terms, and fatigue, pyrexia, and neutrophil count decreased at 0.8% each. The listed terms are presented without a group attribution in the registry record, so they should not be assigned to one arm based on these figures. Death counts are not reported in the registry record.

These safety counts describe reported events in the posted record; they do not establish causation or provide a complete comparative safety assessment. Interpretation depends on event definitions, ascertainment, follow-up, and how recurrent events were counted, details that are not reported in the registry record. The counts should be considered alongside the study’s efficacy outcomes without treating them as a recommendation about treatment.

17. What the Result Does, and Does Not, Mean

The posted primary analysis estimates overall survival in a randomized comparison of PC and GC. The reported hazard ratio is 1.03, with a 95% confidence interval of 0.77 to 1.39 and p = 0.822. The group median estimates are 17.54 months for PC and 15.51 months for GC. Together, these results show an estimated comparison close to 1 but with uncertainty that includes values in either direction.

The result does not establish that the two treatment groups have identical overall survival. A non-significant p-value is not proof of equivalence, and the confidence interval includes a range of possible relative hazard values. Equivalence or non-inferiority would require an appropriate prespecified margin and analysis; such a margin is not reported in the registry record. Nor does the point estimate alone demonstrate a clinically important difference.

The findings concern the randomized groups and the outcomes recorded under the study’s follow-up. They do not automatically apply to other patient populations, other treatment regimens, or different clinical settings. The title identifies Chinese patients, and the official title specifies advanced non-squamous non-small cell lung cancer. The record does not provide enough detail to characterize the broader range of patients who may or may not have been eligible.

Overall survival, progression-related outcomes, response duration, and safety measures answer distinct questions. The registry’s secondary time-to-event estimates broadly show uncertainty around comparisons, while some listed secondary outcomes have no posted results in this record. The safety counts likewise describe recorded events but do not, by themselves, resolve the comparative benefit-risk balance. The appropriate statistical reading is therefore bounded: describe the estimates, their uncertainty, and the record’s scope without turning them into a treatment recommendation.

18. Why This Trial Matters Statistically

This trial illustrates why the headline estimate and its precision need to be read together. The overall-survival hazard ratio is close to 1, but its 95% confidence interval extends from 0.77 to 1.39. The p-value of 0.822 does not establish that the regimens are equivalent; the interval indicates that the comparative estimate remains uncertain over a range of values.

It also demonstrates that distinct survival summaries are not interchangeable. The registry reports a median for each group and a Cox hazard ratio for the comparison. Group medians describe each group’s time-to-event distribution, while the hazard ratio is a model-based relative comparison over follow-up. Separate median confidence intervals do not directly quantify the difference between groups. Keeping these estimands distinct helps avoid turning a descriptive contrast into an unsupported comparative claim.

The posted study is randomized and analyzed by assigned group for the primary outcome, which provides a clear framework for the comparison. At the same time, important aspects of interpretation depend on details not reported in the registry record, including the original sample-size rationale, the full statistical plan, multiplicity procedures, and model checks. Registry results are informative, but they are not a substitute for a complete protocol and analysis plan when those details matter.

Finally, the planning illustrations emphasize the role of effect size and event information in time-to-event research. Detecting smaller effects generally requires more events, and planning estimates based on the observed effect are not the same as the trial’s original design rationale or its achieved power. The distinction is essential when reading retrospective planning calculations alongside completed trial results.

19. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The registry record leaves several details important for interpretation unreported. It does not give the original sample-size justification or the trial’s design assumptions, so the posted planning illustrations should not be mistaken for the study’s planned enrollment rationale. It also does not report whether interim analyses were planned, whether multiplicity was controlled, or whether a clinically meaningful difference was defined in advance.

The reported Cox analysis is not described in detail. Covariate adjustment, assessment of the proportional-hazards assumption, and sensitivity analyses are not reported in the registry record. For overall survival, censoring is defined at last contact for participants still alive, and censored counts are given, but detailed follow-up completeness, reasons for censoring, and analyses of censoring assumptions are not reported.

The record includes arm sizes for the primary outcome and serious and other adverse-event counts, but it does not provide regimen doses or schedules in the arm descriptions. The listed serious adverse-event terms do not identify treatment groups in the summary, and deaths are not reported in the registry record. Specific results are also not posted for all listed secondary outcomes. These gaps limit detailed assessment of treatment delivery, outcome ascertainment, and the full secondary and safety profile.

The study title describes Chinese patients, and its official title specifies advanced non-squamous non-small cell lung cancer, but detailed eligibility criteria and site information are not given. The degree to which these results apply beyond the enrolled study population cannot be established from the registry information alone. These limitations qualify interpretation of the posted results; they do not change the values reported for the analyses that are available.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: A Study Comparing Two Different Chemotherapy Types in Chinese Patients With Advanced Non Small Cell Lung Cancer — NCT01005680.
• Registry record last updated 2013-12-13; status last verified 2013-10.
• Results first posted 2013-12-13.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

23. Record Summary

The registry record describes a completed randomized phase 3 parallel-group study comparing pemetrexed plus cisplatin with gemcitabine plus cisplatin as first-line treatment for advanced non-squamous non-small cell lung cancer. Enrollment was 256, and the primary endpoint was overall survival in an intent-to-treat population.

The reported overall-survival medians were 17.54 months for PC and 15.51 months for GC. The sponsor-reported Cox hazard ratio was 1.03, with a 95% confidence interval of 0.77 to 1.39 and p = 0.822. The estimate is close to 1, but its interval reflects uncertainty and does not establish equivalence. Secondary time-to-event comparisons show a broadly similar pattern of estimates with uncertainty. The registry also reports adverse-event counts, while some listed secondary outcomes and important design and analysis details are not reported in the registry record.