Cabazitaxel Compared to Topotecan for the Treatment of Small Cell Lung Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Cabazitaxel Compared to Topotecan for the Treatment of Small Cell Lung Cancer (NCT01500720), a randomized phase 2 study. The primary outcome is Progression Free Survival (PFS).

2. Clinical Question

The question is specific to participants whose small cell lung cancer had progressed during or after first-line platinum-based chemotherapy. It does not directly address other cancer types, treatment settings or populations not described in the eligibility information. The registry identifies overall survival, progression-free rate at week 12 and overall objective tumor response rate as secondary outcomes. Safety and health-related quality of life were also listed among the secondary objectives, though the registry record does not post a health-related quality-of-life result among the secondary outcomes summarized in the results.

3. Trial Design

This was a randomized phase II study of cabazitaxel versus topotecan in small cell lung cancer. The registry lists a parallel-group model and no masking. Thus, participants and study personnel were not masked according to the record. The registry records enrollment of 179 and a completed study. The start is recorded as 2012-03 and primary completion as 2014-04.

The study population was described as participants with sensitive or resistant/refractory small cell lung cancer following first-line platinum-based chemotherapy. The primary objective concerned progression-free survival. Secondary objectives included disease progression-free rate at 12 weeks, response rate and duration of response using RECIST 1.1, overall survival, safety using NCI-CTC version 4.03, and health-related quality of life. The posted secondary results include progression-free rate at week 12 and overall objective tumor response rate, as well as overall survival among the named secondary outcomes; the posted record does not provide an overall-survival estimate.

The primary endpoint analysis population is described as intent-to-treat, including all randomized participants. The arm-level primary results list 90 participants for cabazitaxel and 89 for topotecan. The safety results use different at-risk counts, which are reported separately under safety. The registry does not explain these differences or provide a participant flow account in the information available in the record.

Although the study was randomized, the registry record does not report the randomization sequence method, allocation concealment, stratification factors, treatment schedules, protocol deviations or details of follow-up after the stated primary completion. These design details should not be inferred from the trial title or its statistical analysis method. The original sample-size justification and the trial's prespecified design assumptions are not reported in the registry record.

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.

Before assignment: A total of 232 participants were screened of which 53 were screen failure and 179 were randomized.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intent-to-treat (ITT) population included all randomized participants.

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: Randomized population included all randomized participants, and was analyzed according to the randomized treatment.

6. Primary Endpoint

The registry lists the primary outcome as Progression Free Survival (PFS), measured over Randomization to first tumor progression/clinical deterioration or death (maximum 7.6 months).

Progression-free survival measures the time from randomization until the first documented tumor progression or death from any cause, whichever occurs first. The registry specifies a maximum timeframe of 7.6 months and reports median progression-free survival estimated with the Kaplan-Meier method. Progression was defined using RECIST version 1.1: an increase of at least 20% in the sum of target-lesion diameters relative to the smallest sum on study, with an absolute increase of at least 5 mm, or unequivocal progression of an existing non-target lesion. The appearance of new lesions also counted as progression.

This endpoint combines tumor progression and death, so it captures the time until either event rather than measuring tumor response alone. The median is the time by which the estimated event-free proportion has reached the midpoint of its distribution. A Kaplan-Meier estimate can account for participants whose event time is not observed during follow-up by using their available follow-up up to censoring; the registry does not report the censoring details for this analysis.

Progression-free survival is used in oncology trials because it reflects both progression and death over the observed period. It is distinct from overall survival, which concerns time to death, and from response rate, which counts tumor responses under specified criteria. The registry states that the intent-to-treat population included all randomized participants, but does not report additional endpoint-specific handling rules for missing assessments or treatment changes.

7. Results Posted in the Registry

• Cabazitaxel vs Topotecan: hazard ratio 2.17 (95% CI 1.56–3.01), reported p < 0.001 (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 Rate at Week 12

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Topotecan: 52.8% (47/89) versus 18.9% (17/90) on control; risk difference 33.9 percentage points (95% CI 20.8 to 47.1), risk ratio 2.80 (1.75–4.48); unadjusted two-proportion z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically higher for Topotecan than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Overall Objective Tumor Response Rate

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Topotecan: 10.1% (9/89) versus 0.0% (0/90) on control; risk difference 10.1 percentage points (95% CI 3.8 to 16.4); unadjusted two-proportion z-test p = 0.002.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically higher for Topotecan than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The secondary outcome estimates form a pattern that is directionally consistent across the two posted binary endpoints: the topotecan group has the higher progression-free rate at week 12 and the higher overall objective tumor response rate. This pattern is consistent with the posted primary medians, which are longer for topotecan. These outcomes provide additional descriptions of disease control and tumor response, but they do not replace the primary time-to-event analysis.

The secondary endpoints address different aspects of outcome. Progression-free rate at a fixed time point describes status at that time, while objective tumor response rate concerns response under the outcome definition. Neither is interchangeable with time to progression or death over follow-up. The registry identifies overall survival as a secondary outcome but does not report its result in the record. Health-related quality of life and response duration were also among the stated secondary objectives, but the record does not provide those results in the posted secondary outcomes.

The registry's secondary comparisons are unadjusted recalculations, and no sponsor-reported analyses are listed for them. Unadjusted results carry less weight when several outcomes are examined because the chance of at least one apparently notable result can increase as more comparisons are considered. The record does not report a multiplicity adjustment or a prespecified hierarchy for interpreting these secondary outcomes. Their p-values should therefore be treated as exploratory evidence rather than as independent confirmatory findings.

The secondary pattern can be read as context for the primary result, not as a separate basis for a broad conclusion. Differences in endpoint definition, follow-up, missing outcome handling and analysis method may affect how directly the endpoints align. These details are not fully reported in the registry record. The available results support a descriptive comparison of the posted outcomes while leaving those analysis questions unresolved.

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

• Overall Survival
• Progression Free Rate at Week 12
• Overall Objective Tumor Response Rate

9. Statistical Interpretation

10. Statistical Methods Explained

How is a median time-to-event result read?

For progression-free survival, each participant contributes follow-up from randomization until documented progression or death, if either occurs. The median is the estimated time at which the Kaplan-Meier progression-free survival curve reaches its midpoint. It is a summary of the timing of events, not an average, and it does not say that every participant experienced an event at the median time. The registry gives median estimates and confidence intervals for each group.

In time-to-event analysis, some participants may not have an observed event during the available follow-up. Their information can still contribute until the end of their observed follow-up, after which they are censored. This approach relies on assumptions about censoring and the quality of event ascertainment. The registry identifies the Kaplan-Meier method for estimating medians but does not report censoring counts, reasons for censoring or additional sensitivity analyses.

What does the hazard ratio describe?

A Cox proportional hazards model compares event rates over follow-up through a hazard ratio. General explanation: a hazard is an instantaneous event rate among participants who have not yet experienced the event. A hazard ratio is not a ratio of medians, and it is not a direct measure of how many months separate the groups. Interpretation depends on which group is the reference and how the event is coded. The registry reports the hazard ratio for cabazitaxel versus topotecan but does not state that coding direction in the result description, so its estimate is best presented as reported.

The proportional hazards model assumes that the relative hazard is sufficiently stable over time for a single hazard ratio to be meaningful. The registry does not report an assessment of this assumption. The reported analysis used a stratified two-sided log-rank test. General explanation: stratification allows comparisons to be made within specified strata before combining information across them. The strata and the rationale for stratification are not reported in the registry record.

What does the log-rank test assess?

The log-rank test compares the observed timing of events between groups over follow-up, accounting for the time-to-event structure. A two-sided test evaluates departures in either direction rather than limiting the test to a prespecified direction. The sponsor-reported p-value is < 0.001. A p-value describes how compatible the observed data are with the test's null hypothesis under its assumptions; it is not the probability that the null hypothesis is true, nor does it measure the size or practical importance of a difference.

The result is reported as a stratified two-sided log-rank test alongside a Cox proportional hazard estimate. The registry does not describe further model diagnostics, covariate adjustment or sensitivity analyses. No adjusted hazard ratio is reported in the registry record beyond the stated sponsor analysis.

How are binary endpoints analyzed?

Progression-free rate at week 12 and overall objective tumor response rate are proportions: each describes the share of participants meeting the endpoint definition in a group. The posted group estimates are accompanied by 95% confidence intervals. The registry also supplies unadjusted recalculations of between-group risk differences for these outcomes, with unadjusted p-values. These recalculations use the posted summary counts and are not sponsor-reported analyses. A risk difference expresses the absolute difference between group proportions, while a confidence interval represents uncertainty around that estimate.

General explanation: binary endpoint estimates can be sensitive to how missing outcome assessments are classified and to the analysis population. The registry describes the primary analysis population but does not provide endpoint-specific missing-data rules for these secondary outcomes. The estimates should therefore be read with the record's reporting limits in mind.

Why do confidence intervals and p-values answer different questions?

A confidence interval communicates a range of values compatible with the data and analysis under the method's assumptions. A p-value addresses compatibility with a specified null hypothesis. Neither replaces the other: the interval helps readers assess the range and precision of the estimated effect, while the p-value does not show the full range of plausible effect sizes. Statistical significance should not be treated as a measure of clinical importance.

The primary comparison is sponsor-reported. The secondary binary comparisons in the registry are unadjusted recalculations, and no sponsor analyses for those secondary comparisons are listed. This distinction matters because the analyses do not share the same reporting status or evidential role. The registry record does not report a multiplicity adjustment, a prespecified hierarchy for secondary outcomes or a complete statistical analysis plan.

11. Confidence Intervals and Precision

The primary group estimates have different interval widths. Cabazitaxel's median progression-free survival is 1.4 months, with a 95% confidence interval of 1.4 to 1.5 months. Topotecan's median is 3.0 months, with a 95% confidence interval of 2.7 to 4.1 months. These intervals describe uncertainty in the median estimates under the Kaplan-Meier method; they do not show the range of individual participants' times.

The sponsor-reported hazard ratio is 2.169, with a 95% confidence interval of 1.563 to 3.01. This interval excludes 1, which is consistent with the reported p < 0.001 under the stated analysis. Because the registry does not state the hazard-ratio reference coding, the interval is most safely interpreted as precision around the reported ratio rather than as an independently directional statement.

For the week-12 progression-free rate, the group confidence intervals are 11.4% to 28.5% for cabazitaxel and 41.9% to 63.5% for topotecan. For overall objective tumor response rate, they are 0.0% to 4.9% and 4.5% to 19.0%, respectively. These intervals convey uncertainty in the group proportions; overlap or non-overlap of separate group intervals is not a substitute for the relevant between-group analysis.

General explanation: confidence intervals are affected by the amount and distribution of information available for an estimate. A wider interval indicates less precision than a narrower interval, but precision does not determine whether an outcome is important. The registry does not report all details needed to assess the effects of censoring, missing assessments or model assumptions on these intervals. Results should therefore be interpreted alongside the study design and the stated analysis limitations.

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 illustrations are based on the observed effect, not on the trial's original design justification. For the time-to-event outcome, the entries are total events, not participants per arm. For the binary outcomes, entries are participants per arm. The time-to-event illustration uses 53 total events for 80% power and 71 total events for 90% power when planning for 100% of the observed effect; at 75% of the observed effect, the corresponding entries are 94 and 125 total events; at 50% of the observed effect, they are 210 and 281 total events.

For the week-12 binary endpoint, planning for 100% of the observed effect gives 31 participants per arm for 80% power and 40 participants per arm for 90% power. Planning for 75% of the observed effect gives 52 participants per arm for 80% power and 69 participants per arm for 90% power. Planning for 50% of the observed effect gives 108 participants per arm for 80% power and 144 participants per arm for 90% power.

The illustrations assume a two-sided significance level of 0.05, equal allocation between the two arms and a normal approximation. The effect to detect is the stated fraction of the observed effect. The 80% and 90% power columns describe the planned probability of detecting an effect of that size under the assumptions if the effect is present. Smaller effects need more participants or events to detect with the same target power. These figures are planning illustrations, not observed power. The trial's own original sample-size assumptions are not reported in the registry record.

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 = 2.169, so ln(HR) = 0.7743.
2. d = 4 × (1.96 + 0.842)² / [ln(2.169)]² = 52.4, rounded up to 53 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 <- 2.169                              # 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(1500720)
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 = 53 (80% power), 71 (90% power)
 75% of observed effect: events = 94 (80% power), 125 (90% power)
 50% of observed effect: events = 210 (80% power), 281 (90% power)
Simulated power with 53 events: 0.795 (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 sponsor-reported primary analysis gives a hazard ratio of 2.169, with a 95% confidence interval of 1.563 to 3.01 and p < 0.001. The method is listed as a stratified two-sided log-rank test, with a Cox proportional hazard estimate. This is the trial's reported primary comparison and takes precedence over any simple recalculation from posted summaries. The registry marks no discrepancy between the reported analysis and the posted result.

The registry's secondary binary comparisons are not presented as sponsor analyses. Their risk differences and unadjusted p-values are recalculations from posted group summary statistics. Such calculations cannot reproduce an analysis that might use individual participant data, adjustment, stratification or other procedures unless those methods and data are available. No sponsor-reported analyses are listed for the posted secondary endpoints in the record.

The distinction is not that one analysis is automatically correct and another incorrect. It is that the primary time-to-event result is explicitly reported by the sponsor, while the secondary comparisons are unadjusted recalculations. The record does not provide an analysis plan or detailed information about the sponsor's model beyond the method named. The hazard-ratio direction is not defined in the description, so the reported ratio should be quoted without assuming its reference coding.

15. Multiplicity, Missing Data and Analysis Populations

The registry lists multiple secondary objectives and outcomes, including progression-free rate at week 12, response rate, duration of response, overall survival, safety and health-related quality of life. The posted secondary outcomes include overall survival, progression-free rate at week 12 and overall objective tumor response rate, but an overall-survival result is not reported in the registry record. The record does not report results for health-related quality of life or duration of response.

When several endpoints are examined, an unadjusted p-value does not account for the number of comparisons. General explanation: testing multiple outcomes can increase the chance of a nominally small p-value occurring by chance across the set of tests. The registry does not report whether multiplicity was controlled, whether a hierarchy was specified or whether secondary outcomes were intended to support confirmatory claims. The unadjusted secondary p-values should be interpreted cautiously.

The primary endpoint analysis is described as intent-to-treat and includes all randomized participants. This supports retaining participants in their randomized groups for the primary analysis, but the registry does not provide a detailed account of how missing assessments, censoring, treatment discontinuation or protocol deviations were handled. It also does not report missing-data sensitivity analyses. These omissions limit assessment of whether missing outcome information could influence the estimates.

The safety results use at-risk counts that differ from the arm-level counts posted for the primary outcome. The record does not explain the reasons for those denominators. It also does not report a complete participant flow description in the information available. For the secondary endpoints, endpoint-specific analysis populations and missing-data rules are not reported in the registry record.

These reporting gaps do not establish that the analyses were inappropriate; they mean that readers cannot verify the relevant procedures from the registry record alone. The original statistical analysis plan, interim-analysis information, multiplicity strategy and full missing-data methods are not reported in the registry record.

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: febrile neutropenia (11.4%), thrombocytopenia (11.4%), pneumonia (6.8%), anaemia (6.8%), disease progression (6.7%).

The registry reports serious adverse events in the safety groups using at-risk denominators of 89 for cabazitaxel and 88 for topotecan. Serious adverse events affected 36 participants in the cabazitaxel group and 41 in the topotecan group. Other adverse events affected 67 participants among 89 at risk for cabazitaxel and 75 among 88 at risk for topotecan. These are separate categories as presented in the record; the record does not explain their classification or overlap.

The listed serious adverse event terms include febrile neutropenia and thrombocytopenia at 11.4% each, pneumonia and anaemia at 6.8% each, disease progression at 6.7%, and neutropenic infection at 5.7%. These terms are reported with percentages, but the registry excerpt does not give further detail about event severity grading, duration, recurrence or attribution for each term.

Deaths are not reported in the registry record. The at-risk counts differ from the primary outcome group counts, and the record does not explain the difference. Adverse-event counts alone do not establish comparative safety, particularly without fuller information on exposure, event definitions, follow-up and statistical comparisons. They should be read as the posted safety reporting rather than as a complete account of all possible harms.

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

The primary results describe a randomized comparison of cabazitaxel and topotecan for progression-free survival among participants with small cell lung cancer progressing during or after first-line platinum-based chemotherapy. The posted median estimates are 1.4 months for cabazitaxel and 3.0 months for topotecan. The sponsor-reported hazard ratio is 2.169, with a 95% confidence interval of 1.563 to 3.01 and p < 0.001. The hazard-ratio coding direction is not explained in the registry record, so the estimate should not be given a direction beyond its stated comparison label.

The result is evidence of a difference in the reported primary comparison under its analysis method. It does not, by itself, establish the clinical importance of the difference or show how outcomes would compare in settings not represented by the trial. The 95% confidence intervals communicate uncertainty in the estimates, while the p-value addresses compatibility with the test's null hypothesis. Neither provides a complete assessment of benefit, harm or patient experience.

The study was open-label, and the registry does not report details of random sequence generation, allocation concealment, adherence, missing-data handling or model diagnostics. These are relevant when assessing potential bias and the robustness of the analysis. The primary endpoint timeframe is limited to a maximum of 7.6 months as described in the record, and the overall-survival result is not reported. Longer-term outcomes cannot be inferred from the posted progression-free survival result.

The secondary results offer additional but less definitive context. They are unadjusted recalculations, with no sponsor analyses listed for those endpoints and no multiplicity strategy reported. The safety figures describe posted event counts, not a complete comparative safety analysis. The results should therefore be understood as evidence from this specific phase II trial and its registry reporting, not as a complete account of all clinical outcomes.

18. Why This Trial Matters Statistically

This trial illustrates how a time-to-event primary endpoint can be summarized in complementary ways. The group medians describe the estimated timing of progression or death, while the hazard ratio compares event rates across follow-up under a Cox model. These measures answer related but different questions, and their interpretation depends on the endpoint definition and analysis assumptions. The registry's absence of hazard-ratio reference coding is a practical reminder to report relative estimates with their direction and reference group clearly defined.

The randomized design provides a basis for comparing the assigned groups, while the open-label status and incomplete reporting of allocation, missing-data and model details constrain what can be assessed from the record. The distinction between a sponsor-reported primary analysis and unadjusted secondary recalculations also matters: their methods and evidential roles should not be conflated.

The registry includes planning illustrations based on observed effects. Such illustrations can help show how required information changes as a target effect becomes smaller or desired power increases, but they are not a reconstruction of the original trial design. The trial's original sample-size assumptions are not reported in the registry record, and the planning results are not observed power.

Finally, the registry names several secondary objectives but posts only some results in the available record. The difference between planned objectives and reported outcomes, together with the absence of a stated multiplicity strategy, limits how strongly secondary findings can be interpreted. This is a useful example of why statistical conclusions depend not only on estimates and p-values, but also on the completeness and transparency of trial reporting.

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 does not report the randomization sequence method or allocation concealment, so the safeguards used to prevent foreknowledge of assignment cannot be assessed. The study was not masked. The record also does not describe treatment schedules, adherence, protocol deviations or subsequent treatment, limiting assessment of how treatment delivery may have affected outcomes.

The hazard ratio is reported with a comparison label, but its reference coding and event coding are not explained. The record does not report an assessment of the proportional hazards assumption, the strata used for the stratified log-rank test, or sensitivity analyses. The primary endpoint timeframe is described as a maximum of 7.6 months, limiting conclusions about longer-term outcomes.

The registry describes the primary population as intent-to-treat, but does not give endpoint-specific missing-data procedures, censoring counts or reasons, or a participant flow account in the information summarized. It does not explain why the safety at-risk counts differ from the primary outcome group counts. These gaps make it difficult to assess how exclusions, missing assessments or follow-up patterns could affect estimates.

Overall survival is listed as a secondary outcome but its result is not reported in the registry record. Results for health-related quality of life and duration of response are also not posted among the listed secondary results, despite their inclusion in the stated objectives. The record does not report multiplicity control or a hierarchy for secondary outcomes. These limitations concern the completeness of available reporting and do not establish that unreported analyses were not conducted.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Cabazitaxel Compared to Topotecan for the Treatment of Small Cell Lung Cancer — NCT01500720.
• Registry record last updated 2015-04-13; status last verified 2015-03.
• Results first posted 2015-04-13.
• 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 describes NCT01500720 as a completed randomized phase II, parallel-group, open-label study of cabazitaxel versus topotecan in small cell lung cancer with progression during or after first-line platinum-based chemotherapy. Enrollment is recorded as 179. The study start is listed as 2012-03 and primary completion as 2014-04.

The primary endpoint was progression-free survival in the intent-to-treat population. The sponsor-reported analysis used a stratified two-sided log-rank test and reported a Cox proportional hazard estimate of 2.169, with a 95% confidence interval of 1.563 to 3.01 and p < 0.001. The registry also posts secondary outcome estimates and safety counts, but does not report an overall-survival result or a multiplicity strategy.

The record does not report the original sample-size justification, detailed missing-data methods, hazard-ratio reference coding or several other design and analysis details. Those limits should be kept in view when interpreting the posted estimates.