This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Phase 3 Trial in Squamous Non Small Cell Lung Cancer Subjects Comparing Ipilimumab Plus Paclitaxel and Carboplatin Versus Placebo Plus Paclitaxel and Carboplatin (NCT02279732), a randomized phase 3 study. The primary outcome is Overall Survival (OS) of All Randomized Participants Who Received at Least One Dose of Blinded Study Therapy.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02279732 |
| Phase | Phase 3 |
| Condition | Lung Cancer (NSCLC) |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 342 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Bristol-Myers Squibb |
| Results posted | Yes |
2. Clinical Question
Population
People with stage IV or recurrent non-small cell lung cancer with squamous histology were eligible for the study. The primary endpoint population was participants who were randomized and received at least 1 dose of blinded study therapy.
Intervention
The experimental regimen combined ipilimumab with paclitaxel and carboplatin. The registry describes paclitaxel and carboplatin as intravenous treatments and lists ipilimumab as an intervention.
Comparator
The comparison regimen combined placebo with paclitaxel and carboplatin. The study was randomized, parallel-group, and quadruple-masked.
Primary question
The stated question was whether adding ipilimumab to paclitaxel and carboplatin would extend overall survival compared with placebo plus the same chemotherapy regimen. The registry record says no data were collected for this primary endpoint.
This is a question about survival time in a specified cancer population, not a comparison of ipilimumab alone with no treatment. Both groups were assigned paclitaxel and carboplatin; the randomized contrast concerned ipilimumab versus placebo in addition to those drugs. Randomization is intended to make treatment groups comparable, on average, with respect to factors that might otherwise influence outcomes. Masking is intended to limit the influence of treatment knowledge on care or assessment, although the registry record does not describe how masking was maintained.
The study record lists enrollment of 342 and a completed status. That enrollment figure does not establish how many participants contributed data to the primary endpoint: the record explicitly states that no data were collected for it after enrollment and randomization were discontinued. The primary question therefore remains unanswered by the posted endpoint results. The presence of descriptions of treatment arms and secondary outcomes does not supply an estimate of the primary survival contrast.
3. Trial Design
This was a randomized, parallel-group, quadruple-masked Phase 3 study. Its official title describes a multicenter, multinational trial. The two groups received paclitaxel and carboplatin with either ipilimumab or placebo. The registry lists enrollment of 342 and a completed study status.
The study started on 2014-10-13, and the recorded primary completion date is 2018-05-03. The primary outcome timeframe is described as approximately 43 months post study start. These dates and the timeframe do not mean that primary endpoint data were collected: the registry record says the sponsor decided to discontinue enrollment and randomization effective 25-Sep-2015, and that no data were collected for the primary endpoint as a result.
The primary outcome was overall survival among randomized participants who received at least 1 dose of blinded study therapy. The listed arms contain 98 participants for ipilimumab plus paclitaxel and carboplatin and 106 for placebo plus paclitaxel and carboplatin. The primary-outcome values and confidence intervals are absent. Because the record also identifies the primary endpoint population as treated randomized participants, enrollment alone should not be read as the analysis population size.
Two secondary outcomes are named: overall survival of all randomized participants, and progression-free survival among all randomized participants who received at least one dose of blinded study therapy, assessed using modified World Health Organization criteria. Their estimates and statistical comparisons are not reported in the registry record. No protocol details about the planned allocation procedure, treatment adherence, follow-up schedule, or analysis strategy beyond the listed endpoint definitions are 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: 342 participants enrolled, 295 were randomized to ipilimumab (148) and placebo arms (147). After chemotherapy, double blinded study treatment, which was the focus of the study, was started.Of all randomized participants, only 98 (ipilimumab arm) and 106 (placebo arm) participants received at least one dose of blinded study therapy.
Overall Study
| Stage | Ipi + PAC/CAR | Placebo + PAC/CAR |
|---|---|---|
| STARTED | 98 | 106 |
| COMPLETED | 0 | 0 |
| NOT COMPLETED | 98 | 106 |
Reasons for not completing this period:
| Reason | Ipi + PAC/CAR | Placebo + PAC/CAR |
|---|---|---|
| Death | 23 | 20 |
| Disease Progression | 13 | 3 |
| Withdrawal by Subject | 2 | 7 |
| Adverse Event | 1 | 2 |
| Administrative Reason By Sponsor | 0 | 2 |
| Study Drug Toxicity | 2 | 0 |
| Lost to Follow-up | 0 | 1 |
| Maximum Clinical Benefit | 1 | 0 |
| Subject Requested to Discontinue | 0 | 1 |
| Other | 53 | 67 |
| Other | 3 | 3 |
Analysis population for the primary outcome, as defined in the registry: All participants who were randomized and received at least 1 dose of blinded study therapy.The sponsor decided to discontinue enrollment and randomization in the study CA184-153 effective 25-Sep-2015. As a result, no data was collected for this primary endpoint
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 who received at least one dose of blinded study therapy.
| Characteristic | Unit | Ipi + PAC/CAR | Placebo + PAC/CAR | Total |
|---|---|---|---|---|
| Participants analysed | 98 | 106 | 204 | |
| Age, Continuous | Years | 60.9 (SD 6.89) | 59.8 (SD 8.22) | 60.3 (SD 7.61) |
| Sex: Female, Male: Female | Participants | 11 | 13 | 24 |
| Sex: Female, Male: Male | Participants | 87 | 93 | 180 |
| Race/Ethnicity, Customized: Chinese | Participants | 81 | 80 | 161 |
| Race/Ethnicity, Customized: Non-Chinese | Participants | 17 | 26 | 43 |
6. Primary Endpoint
The registry lists the primary outcome as Overall Survival (OS) of All Randomized Participants Who Received at Least One Dose of Blinded Study Therapy, measured over Approximately 43 months post study start.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | 95% Confidence Interval |
| Unit | months |
| Endpoint classification | Time-to-Event Analysis |
The primary endpoint is overall survival, measured from randomization until death. For participants who had not died, the endpoint was censored at the last date they were known to be alive. Censoring means that the exact survival time is not observed for that participant; the analysis uses the available follow-up up to the censoring time rather than treating that time as a death.
The outcome is specified as a median with a 95% confidence interval, in months. In general, the median survival time is the point at which the estimated survival curve reaches the midpoint of its probability scale. A confidence interval expresses uncertainty around an estimate under the assumptions of the statistical method. It does not show the range of survival times for individual participants.
Overall survival is used in time-to-event research because it records time until death rather than only whether death occurred by a particular visit. It can account for differing lengths of follow-up and for participants whose death has not been observed by the end of their available follow-up. Those advantages depend on adequate outcome collection and appropriate handling of censoring.
For this trial, the registry record says no data were collected for the primary endpoint after enrollment and randomization were discontinued. Consequently, no median overall-survival estimate or confidence interval is reported. The stated endpoint definition explains what the study intended to measure, but it does not provide an observed treatment comparison.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies overall survival as the primary outcome, but it does not report an estimate for either group. The arm entries contain participant counts, while the median values and confidence limits are missing. More importantly, the primary outcome description explicitly states that no data were collected for this endpoint after the sponsor discontinued enrollment and randomization. There is therefore no posted primary survival result from which to judge the size or precision of a treatment contrast.
The planned comparison is clear: ipilimumab added to paclitaxel and carboplatin versus placebo added to the same chemotherapy. The registry record does not provide a median survival difference, a hazard ratio, a confidence interval for a comparative effect, or a p-value for that primary comparison. None should be inferred from the arm labels, enrollment, study status, or safety counts.
In general, a hazard ratio is a relative comparison of event rates over follow-up under a model. It is not the same quantity as a difference between median survival times, and it does not by itself describe an individual's chance of survival. A hazard ratio and its confidence interval can help characterize a time-to-event contrast when reported, but the registry record does not report such an estimate for this primary endpoint. Accordingly, no direction, magnitude, or precision of an overall-survival effect can be stated from the posted record.
The record lists two secondary outcomes, overall survival in all randomized participants and progression-free survival among randomized participants who received at least one dose of blinded study therapy, using modified WHO criteria. It does not report estimates or analyses for those outcomes either. The record lists three outcome measures and no analysis records; the existence of named outcomes is not evidence that results were available.
The safety entries are descriptive counts for the two groups. They do not substitute for the missing survival endpoint, and the group counts alone do not establish a causal benefit or harm. Without an endpoint estimate and its uncertainty, the principal statistical conclusion is limited: the registry documents the intended randomized comparison and the absence of collected primary endpoint data, rather than a measured survival effect.
9. Statistical Methods Explained
The endpoint is a time-to-event outcome. In general, time-to-event methods use both the time at which an event is observed and the time at which follow-up ends for participants without an observed event. This approach distinguishes a participant known to have died from a participant whose survival status is known only up to a censoring date. The registry defines overall survival as time from randomization to death and says that participants not known to have died were censored at the last date they were known to be alive.
What does a median survival estimate describe?
In general, a median survival estimate is derived from the estimated survival curve. It marks the time at which the curve reaches its midpoint, rather than describing the arithmetic average of observed follow-up times. A 95% confidence interval describes statistical uncertainty around that estimate under the method's assumptions. A narrower interval generally indicates greater precision than a wider interval, but neither interval is a range containing most individual survival times.
The registry specifies a median and a 95% confidence interval in months. It does not report either group's median or interval. There is therefore no estimate to interpret, and no basis for comparing the groups by their medians. The listed timeframe, approximately 43 months post study start, is a registry timeframe description; it does not override the statement that primary endpoint data were not collected.
How is a time-to-event treatment contrast usually expressed?
In general, a hazard ratio compares the event rate between groups over follow-up, subject to the assumptions of the model used. It is a relative measure and is not interchangeable with a difference in median survival. A confidence interval around a hazard ratio represents uncertainty in that relative estimate. A p-value, if reported, addresses compatibility of the observed data with a specified null hypothesis under the analysis method; it does not measure the probability that a treatment is effective.
The registry record does not report a primary hazard ratio, confidence interval for a comparative effect, or p-value. The available information therefore cannot support a numerical or directional statement about the treatment contrast. The record's outcome specification is not itself an analysis method, and no unreported model or test should be assumed.
What do planning calculations mean?
General sample-size illustrations are planning tools, not observed trial findings and not estimates of the trial's achieved power. The registry record's stated illustration 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 defined as a stated fraction of the observed effect. For time-to-event outcomes, the illustrations refer to a total number of events, while other illustrations refer to participants per arm. These assumptions describe a planning calculation, not the trial's own design or analysis plan. The registry record does not report the trial's sample-size justification.
When an illustration uses a fraction of an observed effect, that is a hypothetical planning target relative to the effect used in that calculation. It is not a new observed result and should not be presented as evidence that the trial had a particular power. No observed effect for the primary endpoint is available in the registry record, and no sample-size illustration should be mistaken for a result of this trial.
Why does missing endpoint information matter?
Time-to-event estimation requires event and censoring information. If primary endpoint data were not collected, an estimated survival curve, median, or hazard ratio cannot be recovered from the enrollment counts or from the endpoint definition alone. The absence is more fundamental than an imprecise estimate: there is no posted primary outcome estimate whose confidence interval can be assessed.
In general, model assumptions and censoring procedures matter because the analysis depends on how follow-up ends and on whether censoring is informative about the outcome. The registry record does not report detailed follow-up patterns, missing-data methods, or a specific primary analysis procedure. It would therefore be inappropriate to attribute any particular estimator, test, or model to the sponsor beyond what the record states.
The named progression-free-survival outcome uses modified WHO criteria, according to the registry description. General response-based time-to-event outcomes require a defined assessment rule and follow-up process. The registry does not provide outcome estimates or the detailed assessment schedule for this endpoint. Its name and criteria do not establish a treatment effect.
10. Multiplicity, Missing Data and Analysis Populations
The registry record names the primary overall-survival outcome and two secondary outcomes. It does not report a multiplicity procedure for controlling the chance of false-positive findings across outcomes or analyses. It also does not report an interim-analysis plan, stopping boundaries, or other details of repeated statistical testing. These details should not be inferred from the Phase 3 designation or the randomized design.
The primary endpoint has a particularly consequential data limitation: the registry says that the sponsor discontinued enrollment and randomization effective 25-Sep-2015 and that no data were collected for the primary endpoint as a result. This is not simply a report of some participants being censored during ordinary follow-up. The record provides no primary endpoint results to interpret.
Overall survival and progression-free survival are listed as secondary outcomes, but their estimates and analysis results are not reported in the registry record. The record does not describe how missing secondary outcome data were handled, whether all listed outcomes were analyzed, or whether any analysis population differed from the stated populations. The analysis population for the primary endpoint is described as randomized participants who received at least 1 dose of blinded study therapy, but the record does not give detailed participant-flow information for that population.
In general, missing outcome data can reduce precision and can introduce bias when the likelihood of missingness is related to outcome status. Here, the key limitation is that the primary endpoint is stated to have no collected data, so an estimate and its uncertainty cannot be evaluated. The record does not report a missing-data analysis or sensitivity analysis that would address this absence.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Ipi + PAC/CAR | 40 | 98 | 40.8% |
| Placebo + PAC/CAR | 33 | 106 | 31.1% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Ipi + PAC/CAR | 15 of 98 |
| Placebo + PAC/CAR | 9 of 106 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Ipi + PAC/CAR | 91 of 98 |
| Placebo + PAC/CAR | 87 of 106 |
Most frequent serious adverse event terms
| Event term | Organ system | Ipi + PAC/CAR | Placebo + PAC/CAR |
|---|---|---|---|
| Malignant neoplasm progression | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 7 of 98 | 4 of 106 |
| Pneumonia | Infections and infestations | 6 of 98 | 2 of 106 |
| Anaemia | Blood and lymphatic system disorders | 3 of 98 | 4 of 106 |
| Pyrexia | General disorders | 3 of 98 | 2 of 106 |
| Dyspnoea | Respiratory, thoracic and mediastinal disorders | 4 of 98 | 1 of 106 |
| Haemoptysis | Respiratory, thoracic and mediastinal disorders | 1 of 98 | 4 of 106 |
| Bone marrow failure | Blood and lymphatic system disorders | 1 of 98 | 3 of 106 |
| Neutropenia | Blood and lymphatic system disorders | 2 of 98 | 2 of 106 |
| Lung infection | Infections and infestations | 4 of 98 | 0 of 106 |
| Febrile neutropenia | Blood and lymphatic system disorders | 0 of 98 | 3 of 106 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Ipi + PAC/CAR | Placebo + PAC/CAR |
|---|---|---|---|
| Neutropenia | Blood and lymphatic system disorders | 36 of 98 | 47 of 106 |
| Leukopenia | Blood and lymphatic system disorders | 35 of 98 | 42 of 106 |
| Anaemia | Blood and lymphatic system disorders | 34 of 98 | 35 of 106 |
| Haemoglobin decreased | Investigations | 35 of 98 | 28 of 106 |
| Thrombocytopenia | Blood and lymphatic system disorders | 27 of 98 | 30 of 106 |
| Decreased appetite | Metabolism and nutrition disorders | 26 of 98 | 17 of 106 |
| Diarrhoea | Gastrointestinal disorders | 21 of 98 | 11 of 106 |
| Fatigue | General disorders | 17 of 98 | 15 of 106 |
| Alanine aminotransferase increased | Investigations | 14 of 98 | 15 of 106 |
| White blood cell count decreased | Investigations | 14 of 98 | 15 of 106 |
Serious events with the highest arm-level rate: malignant neoplasm progression (7.1%), pneumonia (6.1%), lung infection (4.1%), dyspnoea (4.1%), anaemia (3.8%).
The registry lists serious adverse events for 40 participants among 98 at risk in the ipilimumab group, and for 33 among 106 at risk in the placebo group. It lists other adverse events for 91 among 98 at risk in the ipilimumab group and 87 among 106 at risk in the placebo group. The record also lists 15 deaths in the ipilimumab group and 9 in the placebo group.
These are descriptive counts. They are not adjusted comparisons, and no uncertainty estimates or statistical tests for these safety counts are reported in the registry record. The death counts do not establish that deaths were caused by study treatment; the record does not provide causal attribution for these figures. Counts of participants affected are also distinct from counts of separate event episodes, which are not detailed in the record.
The most frequently listed serious-event terms include malignant neoplasm progression at 7.1%, pneumonia at 6.1%, lung infection at 4.1%, dyspnoea at 4.1%, anaemia at 3.8%, and haemoptysis at 3.8%. These percentages are registry entries for the listed terms. They should be read as reported event descriptions, not as evidence of a comparative treatment effect. The safety information does not fill the gap in primary overall-survival data.
12. What the Result Does, and Does Not, Mean
The registry record documents a randomized comparison of ipilimumab plus paclitaxel and carboplatin against placebo plus paclitaxel and carboplatin in people with squamous non-small cell lung cancer. It identifies overall survival as the primary endpoint and defines how survival time and censoring were intended to be measured. It also records that the study was completed and gives an enrollment figure of 342.
What the record does not provide is a primary overall-survival estimate. The sponsor discontinued enrollment and randomization effective 25-Sep-2015, and the registry states that no data were collected for the primary endpoint. Without group estimates and uncertainty measures, the posted information cannot show whether the survival outcomes differed, how large any difference might have been, or how precisely a difference could be estimated.
The listed secondary outcomes likewise have no reported results in the registry record. The safety counts and serious-event terms are descriptive and do not answer the primary survival question. Nor do the enrollment figure, study status, or treatment descriptions make up for missing endpoint observations.
In general, a randomized trial can provide a controlled treatment comparison when the outcome is measured and analyzed as planned. Randomization alone does not guarantee that an interpretable result will be available for every endpoint. Here, the statistical meaning is limited by the absence of primary endpoint data, rather than by a reported estimate that happens to be uncertain or inconclusive.
These registry entries do not establish that either regimen improves or fails to improve survival, and they are not a recommendation about treatment. They describe what can and cannot be learned from the registry record: the comparison was planned and conducted as a randomized study, but the central survival result is unavailable in the posted record.
13. Why This Trial Matters Statistically
This study illustrates why a trial's design and its reported outcomes need to be read separately. Randomization, masking, and a clearly defined survival endpoint describe how a comparison was intended to work. They do not produce an effect estimate when the endpoint data were not collected. For statistical interpretation, the missing primary outcome is more important than the presence of detailed treatment-arm descriptions or a completed study status.
It also demonstrates the difference between a planned endpoint and an observed result. Overall survival is defined from randomization to death, with censoring for participants not known to have died. The registry provides that definition and a median-with-confidence-interval summary plan, but gives no values. A reader cannot assess the direction, magnitude, or precision of a treatment contrast from an endpoint specification alone.
The record is also a reminder to keep safety counts in their proper role. Adverse-event and death counts may describe what was reported in each group, but they are not a substitute for an absent primary efficacy estimate. Without uncertainty estimates, causal attribution, or a reported comparative analysis, simple differences in counts should not be treated as evidence of treatment effect.
Finally, planning illustrations and trial results answer different questions. Planning assumptions can illustrate what a future study might be designed to detect, whereas observed results depend on collected outcomes and an analysis. The registry record's stated planning assumptions do not create an observed survival effect or provide evidence of achieved power. The central statistical lesson is to distinguish design, data collection, and analysis: each is necessary for a complete interpretation, and the record documents a major gap at the data-collection stage for the primary endpoint.
14. 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 primary limitation specific to this study is the registry's explicit statement that no data were collected for the primary overall-survival endpoint after enrollment and randomization were discontinued. No median, confidence interval, hazard ratio, or comparative test is reported for that endpoint. This prevents evaluation of the primary question rather than merely making its estimate less precise.
The record gives limited information about the reasons for discontinuation beyond stating that the sponsor decided to discontinue enrollment and randomization. It does not report a statistical analysis plan, sample-size justification, interim-analysis procedures, or multiplicity adjustment. Those details are not reported in the registry record and should not be reconstructed from general expectations about Phase 3 trials.
Although two secondary outcomes are named, their results and analysis details are not reported. The record does not describe detailed participant flow, follow-up completeness, missing-data procedures, or the methods used to analyze the secondary outcomes. The stated primary endpoint population is narrower than all randomized participants because it requires receipt of at least 1 dose of blinded study therapy; the record does not provide enough detail to assess how participants moved into or out of that population.
The safety information is also limited to reported counts and selected serious-event terms. Comparative uncertainty, event-level detail, and causal attribution are not reported. These limitations mean the safety descriptions should remain descriptive and separate from conclusions about the intended survival endpoint.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Phase 3 Trial in Squamous Non Small Cell Lung Cancer Subjects Comparing Ipilimumab Plus Paclitaxel and Carboplatin Versus Placebo Plus Paclitaxel and Carboplatin — NCT02279732.
- Registry record last updated 2019-08-28; status last verified 2019-07.
- Results first posted 2019-08-28.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The registry describes a completed randomized, parallel-group, quadruple-masked Phase 3 trial comparing ipilimumab plus paclitaxel and carboplatin with placebo plus paclitaxel and carboplatin in squamous non-small cell lung cancer. Enrollment was 342. The listed primary outcome was overall survival among randomized participants who received at least 1 dose of blinded study therapy.
The record states that enrollment and randomization were discontinued effective 25-Sep-2015 and that no data were collected for the primary endpoint. No primary survival estimate or comparative analysis is reported. Two secondary outcomes are listed, but their results are not reported in the registry record. Safety entries include serious and other adverse-event counts, deaths, and selected serious-event terms; these are descriptive and do not replace the missing primary result.