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 Safety and Efficacy Trial of Ipilimumab Versus Pemetrexed in Non-Squamous Non-Small Cell Lung Cancer (NCT01471197), a randomized phase 2 study. The primary outcome is Overall Survival of Participants During the Study - All Treated Participants.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01471197 |
| Phase | Phase 2 |
| Condition | Lung Cancer - Non Small Cell |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 9 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Bristol-Myers Squibb |
| Results posted | Yes |
2. Clinical Question
Population
The trial concerned subjects with recurrent or stage IV non-squamous non-small cell lung cancer who had not progressed after four cycles of platinum-based first-line chemotherapy. The primary outcome population was all participants who received at least one dose of either study drug.
Intervention
The experimental treatment was ipilimumab. The safety record identifies its group as ipilimumab 10 mg/kg. The brief summary frames the clinical question as whether ipilimumab would prolong survival.
Comparator
The comparison treatment was pemetrexed, identified in the safety record as 500 mg/m^2. The trial used randomized allocation and a parallel design, with no masking.
Primary question
The primary outcome was overall survival, defined as time from randomization until death. The intended comparison was whether survival would be prolonged with ipilimumab relative to pemetrexed. Because the study terminated early, the registry record says the planned statistical analyses were not performed, so it does not establish a comparative survival effect.
3. Trial Design
This was a randomized, open-label, parallel Phase 2 trial sponsored by Bristol-Myers Squibb. Participants were assigned to ipilimumab or pemetrexed; the registry record does not report the allocation ratio or further details about how randomization was carried out. Masking was not used. The arm descriptions contain no additional treatment details, although the safety groups are identified as ipilimumab 10 mg/kg and pemetrexed 500 mg/m^2.
The study enrolled 9 participants and is listed as terminated. Its start was recorded as 2012-07 and its primary completion as 2013-02. The registry record does not state why the study was terminated, so the reason should not be inferred from the status alone.
The primary outcome was overall survival among all participants who received at least one dose of either study drug. The record defines survival from randomization to death, with censoring for participants known to be alive at termination and the last-patient, last-visit point. It describes survival in increasing monthly categories rather than giving a single treatment-effect estimate.
Secondary outcomes included counts of participants who died within 30 days and 31 days after the last dose, and counts of participants with deaths, adverse events, serious adverse events, and adverse events leading to discontinuation. The registry record lists 3 outcome measures and 0 analyses. It states that the primary survival analysis was planned after approximately 132 deaths, but that statistical analyses were not performed after early termination.
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: 9 participants enrolled; 8 participants randomized; 1 participant not randomized due to disease progression and death.
Overall Study
| Stage | Ipilimumab 10 mg/kg | Pemetrexed 500 mg/m^2 |
|---|---|---|
| STARTED | 6 | 2 |
| COMPLETED | 0 | 0 |
| NOT COMPLETED | 6 | 2 |
Reasons for not completing this period:
| Reason | Ipilimumab 10 mg/kg | Pemetrexed 500 mg/m^2 |
|---|---|---|
| Disease Progression | 4 | 2 |
| Death | 1 | 0 |
| Study Drug Toxicity | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: All participants who received at least one dose of either study drug.
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 participants who received at least one dose of either study medication.
| Characteristic | Unit | Ipilimumab 10 mg/kg | Pemetrexed 500 mg/m^2 | Total |
|---|---|---|---|---|
| Participants analysed | 6 | 2 | 8 | |
| Age, Continuous | years | 62.7 (SD 8.85) | 61.0 (SD 1.41) | 62.3 (SD 7.54) |
| Age, Customized: Less than (<) 65 years | participants | 4 | 2 | 6 |
| Age, Customized: Greater than, equal to (>=) 65 years | participants | 2 | 0 | 2 |
| Sex: Female, Male: Female | Participants | 2 | 1 | 3 |
| Sex: Female, Male: Male | Participants | 4 | 1 | 5 |
| Eastern Cooperative Oncology Group Performance Status: ECOG PS 0 | participants | 3 | 1 | 4 |
| Eastern Cooperative Oncology Group Performance Status: ECOG PS 1 | participants | 3 | 1 | 4 |
6. Primary Endpoint
The registry lists the primary outcome as Overall Survival of Participants During the Study - All Treated Participants, measured over Date of Randomization to date of death, up to last patient, last visit, approximately 7 months after study started.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
Overall survival measures the time from randomization until death. It is a time-to-event endpoint: the event is death, and the measurement incorporates when the event occurs rather than only whether it occurred by a single fixed assessment. The registry record defines the endpoint for all participants who received at least one dose of either study drug.
For participants who had not died by termination and the last-patient, last-visit point, the record says survival was censored on the last date they were known to be alive. Censoring preserves information about the period during which a participant was known to be alive, while recognizing that the later time of death is not observed in the record. As a general statistical principle, interpretation of a time-to-event analysis depends on the follow-up and censoring process, as well as on the events observed.
Overall survival was chosen to address the stated question of whether ipilimumab would prolong survival compared with pemetrexed. However, the record describes survival in increasing monthly categories and says the study ended before the planned analysis. It does not report a comparative survival estimate, confidence interval, or statistical test. Therefore, the endpoint’s clinical purpose can be described, but the comparative result cannot be quantified from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The trial was designed to compare overall survival between ipilimumab and pemetrexed in participants with recurrent or stage IV non-squamous non-small cell lung cancer who had not progressed after four cycles of platinum-based first-line chemotherapy. The registry record reports enrollment of 9 participants and a terminated study. It also explicitly states that, because of early termination, statistical analyses were not performed for the primary endpoint.
Consequently, the record does not provide a treatment-effect estimate for overall survival. It reports no hazard ratio, median survival by group, confidence interval, or p-value for the primary comparison. Those quantities are not reported in the registry record. The outcome is described in monthly categories, but the category counts are not included in the available record. The stated plan to analyze survival after approximately 132 deaths is not a result and should not be mistaken for an observed event count.
As a general statistical concept, an estimate describes the direction and size of an observed difference, while a confidence interval describes the range of values compatible with the data under the analysis assumptions. A p-value addresses how unusual the data would be under a specified null hypothesis. None of these comparative inferential results is reported for overall survival in this record, so there is no basis for judging the size, precision, or statistical significance of a survival difference.
The safety information is descriptive. For the ipilimumab group, the record lists 6 at risk and 5 affected for serious adverse events, and 6 at risk and 5 affected for other adverse events. For the pemetrexed group, it lists 2 at risk and 1 affected for serious adverse events, and 2 at risk and 2 affected for other adverse events. These counts do not substitute for the missing survival analysis. The record also lists serious-event terms with percentages, but does not give the corresponding event counts alongside those percentages.
These results should be read as an incomplete registry record for a terminated trial, not as evidence of a measured survival advantage or disadvantage. The record gives the trial question, design, endpoint definition, and some safety counts, but does not report the statistical result needed to compare survival between the treatments.
9. Statistical Methods Explained
What does randomization contribute?
Randomized allocation is intended to make treatment assignment independent of participants’ characteristics, on average, so that a comparison between groups can support a causal interpretation when the study is conducted and analyzed appropriately. This is a general explanation of the design principle, not a claim that every prognostic factor was balanced in this trial. The registry record says allocation was randomized, but does not report the allocation ratio, sequence-generation method, concealment procedures, or baseline balance. With enrollment of 9 participants, the record does not establish that the groups were balanced on relevant characteristics.
What does the parallel, open-label design mean?
A parallel design assigns participants to a treatment group and follows them in that group, rather than switching each participant between treatments. The trial compared ipilimumab with pemetrexed in this way. Open-label means masking was not used, as the registry record states. In general, lack of masking can affect subjective assessments and decisions influenced by knowledge of treatment assignment. Death is a relatively objective event, but follow-up and documentation practices can still matter. The record does not describe those practices or report any masking procedures beyond the designation that masking was absent.
How is overall survival analyzed in general?
Overall survival is a time-to-event outcome. Each participant contributes follow-up from the stated starting point until death or censoring. The registry defines the starting point as randomization, and death as the event. Participants known to be alive at the end of observation are censored at their last known alive date. Censoring is not the same as recording a death; it indicates that the event time after the last known observation is not available. In general, time-to-event methods use the event times and censored observations together rather than treating censored participants as if they had died or had complete follow-up.
The registry record says the outcome is presented in increasing monthly categories of survival. It does not report the category values or counts in the record, and it says statistical analyses were not performed. Thus, the endpoint definition and planned presentation are known, but an inferential estimate cannot be reconstructed from this description.
What does the planned event count tell readers?
The record says the overall-survival analysis was to be performed when approximately 132 deaths were observed. That is a stated analysis trigger, not a count of deaths observed in this trial and not evidence that the planned analysis occurred. The record specifically attributes the absence of statistical analyses to early termination. It does not report the statistical model, the handling of ties, covariate adjustment, or the planned treatment-effect measure. Those details are not reported in the registry record.
How should precision be considered?
In general, a treatment-effect estimate is more informative when accompanied by a measure of precision, such as a confidence interval. The interval indicates which effect sizes remain compatible with the data and analysis assumptions; it does not guarantee that the true effect lies within the interval. Since the registry record reports no primary comparative estimate or confidence interval, the precision of any survival contrast cannot be assessed from this record. The enrollment figure alone cannot supply that missing information, and no observed power can be inferred from it.
What can the planning description establish?
The registry record includes a general description of sample-size planning assumptions: a two-sided significance level of 0.05, equal allocation, a normal approximation, and an effect defined as a stated fraction of an observed effect. It also says time-to-event planning uses a total event count and other planning illustrations use participants per arm. These are planning conventions, not observed trial results. The record does not report a trial-specific sample-size justification or a completed primary analysis from which the observed effect could be evaluated. The planned analysis after approximately 132 deaths should likewise not be interpreted as a sample-size result or as an estimate of power.
Over-dispersion is a general issue for count outcomes when variation exceeds what a simple count model assumes. The primary endpoint is time to death, not an over-dispersed count, and the record gives no model details to assess. No claim about whether over-dispersion was relevant to any secondary outcome can be made from the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists 3 outcome measures: the primary overall-survival outcome and secondary outcomes concerning deaths after the last dose and deaths and adverse events, including serious events and events leading to discontinuation. It reports 0 analyses. The primary survival outcome itself is described using increasing monthly categories, and the record identifies multiple categories or time points; it was not reduced to a single comparison in the posted results.
Multiplicity concerns arise in general when several outcomes, time points, or comparisons are examined, because repeated testing can increase the chance of a positive result under a null hypothesis. The registry record does not report a testing hierarchy, multiplicity adjustment, or a prespecified approach for interpreting the multiple listed outcomes. These methods are not reported in the registry record. Since statistical analyses were not performed for the primary endpoint, the record does not provide a family of inferential results to evaluate for multiplicity.
The primary outcome population is defined as participants who received at least one dose of either study drug. Secondary outcome titles also refer to all treated participants. The record does not explain whether other analysis populations were planned or used, or whether participants were analyzed according to randomized assignment.
For overall survival, participants who had not died by termination and last-patient, last-visit were censored at their last known alive date. This describes how that endpoint’s follow-up was handled for those participants. Other missing-data procedures, including imputation, are not reported in the registry record. The record does not describe missing values for the secondary outcomes, withdrawals, or the completeness of follow-up. It also does not report interim analyses or a statistical analysis plan.
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 |
|---|---|---|---|
| Ipilimumab 10 mg/kg | 5 | 6 | 83.3% |
| Pemetrexed 500 mg/m^2 | 1 | 2 | 50.0% |
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 |
|---|---|
| Ipilimumab 10 mg/kg | 5 of 6 |
| Pemetrexed 500 mg/m^2 | 2 of 2 |
Most frequent serious adverse event terms
| Event term | Organ system | Ipilimumab 10 mg/kg | Pemetrexed 500 mg/m^2 |
|---|---|---|---|
| Arterial injury | Injury, poisoning and procedural complications | 1 of 6 | 0 of 2 |
| Bronchitis | Infections and infestations | 1 of 6 | 0 of 2 |
| Urticaria | Skin and subcutaneous tissue disorders | 1 of 6 | 0 of 2 |
| Acute myocardial infarction | Cardiac disorders | 1 of 6 | 0 of 2 |
| Colitis | Gastrointestinal disorders | 1 of 6 | 0 of 2 |
| Hypopituitarism | Endocrine disorders | 1 of 6 | 0 of 2 |
| Fracture | Injury, poisoning and procedural complications | 0 of 6 | 1 of 2 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Ipilimumab 10 mg/kg | Pemetrexed 500 mg/m^2 |
|---|---|---|---|
| Rash | Skin and subcutaneous tissue disorders | 4 of 6 | 0 of 2 |
| Diarrhoea | Gastrointestinal disorders | 3 of 6 | 0 of 2 |
| Decreased appetite | Metabolism and nutrition disorders | 2 of 6 | 0 of 2 |
| Asthenia | General disorders | 2 of 6 | 0 of 2 |
| Fatigue | General disorders | 2 of 6 | 0 of 2 |
| Diabetes mellitus | Metabolism and nutrition disorders | 1 of 6 | 0 of 2 |
| Dyspepsia | Gastrointestinal disorders | 1 of 6 | 0 of 2 |
| Headache | Nervous system disorders | 1 of 6 | 0 of 2 |
| Lipase increased | Investigations | 1 of 6 | 0 of 2 |
| Nasopharyngitis | Infections and infestations | 1 of 6 | 0 of 2 |
Serious events with the highest arm-level rate: fracture (50.0%), arterial injury (16.7%), bronchitis (16.7%), urticaria (16.7%), acute myocardial infarction (16.7%).
The safety record presents counts by treatment group. For ipilimumab 10 mg/kg, 6 participants were listed as at risk and 5 as affected for serious adverse events; the corresponding figures for other adverse events were 6 at risk and 5 affected. For pemetrexed 500 mg/m^2, the serious adverse-event figures were 2 at risk and 1 affected, while the other-adverse-event figures were 2 at risk and 2 affected.
These are descriptive counts, not a randomized comparison adjusted for follow-up or participant characteristics. The record does not report a statistical comparison, confidence interval, or detailed event-level accounting. The group-specific death counts are not reported in the registry record. Secondary outcome titles mention deaths within 30 days and 31 days after the last dose, but the corresponding results are not reported.
The record lists fracture at 50.0%, and arterial injury, bronchitis, urticaria, acute myocardial infarction, and colitis each at 16.7%, among the top serious-event terms. The corresponding counts and the denominator used for these percentages are not reported in the registry record. These percentages should therefore be read as listed event-term summaries, not as directly comparable group-specific risks. Counts and percentages alone do not establish a causal relationship to treatment.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a randomized, open-label Phase 2 trial was conducted to compare ipilimumab with pemetrexed for overall survival in the specified lung cancer population. It also records enrollment of 9 participants, a terminated status, the endpoint definition, and some adverse-event counts. These registry entries describe the study and its posted results; they do not supply a completed efficacy comparison.
The record explicitly says that statistical analyses were not performed because of early termination. It therefore does not show whether survival differed between treatment groups, how large any difference might have been, or how precise such a difference would be. No comparative survival estimate, confidence interval, or p-value is reported. The planned analysis after approximately 132 deaths is not evidence that this number of deaths occurred.
The safety counts provide a limited descriptive account of participants recorded as affected in each group. They do not by themselves identify whether an event was caused by treatment, establish a difference in risk, or support a formal comparative safety conclusion. The listed percentages for serious-event terms also lack reported corresponding counts and denominator details in the registry record.
In general, absence of a reported statistical result is not the same as a finding of no effect. It means the registry record does not provide the analysis needed to estimate or test an effect. Likewise, early termination alone does not explain why the study ended or what its unobserved results might have been. The reason for termination is not reported in the registry record.
The appropriate interpretation is limited: the trial asked a comparative survival question, but the record does not provide an analyzed answer. No conclusion that one treatment prolonged survival or failed to prolong survival is supported by the posted results.
13. Why This Trial Matters Statistically
This trial is statistically notable because its primary question concerns a time-to-event outcome, yet the registry record does not report the planned inferential analysis. Overall survival was defined from randomization until death, with censoring for participants known to be alive at the end of follow-up. That framework makes clear why follow-up duration and event information are central: a treatment comparison depends not only on group assignment but also on when deaths occurred and how censored observations were handled.
The record states that an analysis was planned when approximately 132 deaths were observed, but also says that early termination meant statistical analyses were not performed. This distinction matters. A target or trigger in a plan is not an observed event count, and a protocol intention does not create an estimate when the analysis is absent. The record gives no survival contrast or precision measure for readers to assess.
The study also illustrates the difference between descriptive safety reporting and comparative inference. Group counts and event-term percentages can characterize what was recorded, but without a reported analysis they do not quantify an adjusted treatment difference or its uncertainty. In general, small groups and limited follow-up can make estimates imprecise, but the record does not provide the information needed to quantify that precision.
Finally, registry completeness affects statistical interpretation. The record identifies the trial’s question, design, endpoint, some safety summaries, and the reason statistical analyses were not available, but it does not report a statistical analysis plan, the termination rationale, or a primary treatment-effect estimate. The case underscores that a clearly stated endpoint and analysis intention are not substitutes for a completed and reported analysis.
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 central limitation is that the registry record states that statistical analyses of the primary overall-survival endpoint were not performed after early termination. It therefore reports no comparative survival estimate, uncertainty interval, or hypothesis-test result. Monthly survival-category counts are not reported in the registry record, so the primary outcome cannot be reconstructed from the description.
The record reports enrollment of 9 participants but does not give the number randomized to each arm or describe the allocation ratio. Safety groups have at-risk counts, but these should not be treated as randomized group sizes without confirmation. The record does not report baseline characteristics, treatment exposure, or follow-up by treatment group.
The reason for termination is not reported in the registry record. Neither is a trial-specific sample-size justification, a statistical analysis plan, an interim-analysis plan, or details of the intended survival model. The stated analysis trigger of approximately 132 deaths does not establish that the planned analysis was completed.
Safety reporting is also limited. Group-level counts are available for participants affected by serious and other adverse events, but death counts are not reported. For the listed serious-event terms, the record provides percentages without corresponding counts or denominator details. It does not give a statistical comparison or enough detail to determine how event terms were counted.
Missing-data procedures beyond the stated censoring rule for overall survival are not reported in the registry record. The available information therefore supports description of the design and posted safety summaries, but not a complete efficacy or comparative safety assessment.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety and Efficacy Trial of Ipilimumab Versus Pemetrexed in Non-Squamous Non-Small Cell Lung Cancer — NCT01471197.
- Registry record last updated 2014-05-12; status last verified 2014-04.
- Results first posted 2014-05-12.
- 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.
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18. Record Summary
NCT01471197 is a randomized, open-label, parallel Phase 2 trial comparing ipilimumab with pemetrexed in recurrent or stage IV non-squamous non-small cell lung cancer after four cycles of platinum-based first-line chemotherapy without progression. The record reports enrollment of 9 participants, a start of 2012-07, primary completion in 2013-02, and terminated status.
The primary outcome was overall survival among participants who received at least one dose. The registry record says the planned survival analysis was not performed because of early termination. It reports no comparative survival estimate. Posted safety counts include serious and other adverse events by group, while death counts and further statistical comparisons are not reported in the registry record.