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 Nivolumab With or Without Ipilimumab in Treating Patients With Refractory Metastatic Anal Canal Cancer (NCT02314169), a randomized phase 2 study. The primary outcome is Progression-free Survival (PFS) (Part B).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02314169 |
| Phase | Phase 2 |
| Condition | Anal Canal Squamous Cell Carcinoma, Metastatic Anal Canal Carcinoma, Stage IV Anal Cancer AJCC v8 |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 143 |
| Arms in the primary outcome | 2 |
| Lead sponsor | National Cancer Institute (NCI) |
| Results posted | Yes |
2. Clinical Question
Population
Patients with refractory metastatic squamous cell carcinoma of the anal canal. The registry describes cancer that has not responded to previous treatment and has spread beyond its original site. The registry record lists anal canal squamous cell carcinoma, metastatic anal canal carcinoma, and Stage IV anal cancer AJCC v8 as conditions.
Intervention
In Part B Arm II, patients received nivolumab and ipilimumab. Nivolumab was given intravenously every 4 weeks, and ipilimumab intravenously every 8 weeks. Treatment continued in the absence of progression or unacceptable toxicity.
Comparator
Part B Arm I received nivolumab intravenously every 4 weeks. Treatment continued in the absence of progression or unacceptable toxicity. The registry also describes a Part A nivolumab group with a different dosing schedule, but the primary comparison concerns the two Part B arms.
Primary question
In Part B, how did progression-free survival compare between nivolumab alone and nivolumab plus ipilimumab? The registry defines the primary endpoint as time from randomization to disease progression or death, whichever occurred first, assessed up to 2 years.
This is a comparison of two treatment strategies in a phase II study, not a comparison with no treatment or with a different class of therapy. The primary outcome is time-to-event: it captures how long patients remain alive without recorded disease progression, according to the registry definition. The posted results give a median for each Part B arm and a 90% confidence interval around each median, along with a log-rank test for the comparison.
The registry lists randomized allocation, no masking, and a parallel model. It reports enrollment of 143, but that enrollment figure should not be read as the number analyzed for every outcome. The primary Part B results list 52 patients in the nivolumab arm and 48 in the combination arm. The registry record does not report the eligibility criteria in enough detail to establish which patient characteristics may limit generalizability beyond the listed cancer diagnoses and refractory metastatic setting.
3. Trial Design
NCT02314169 is a randomized, open-label phase II study sponsored by the National Cancer Institute. The registry lists a parallel design and no masking. Enrollment is listed as 143. The study began on 2015-05-13, has primary completion listed as 2025-02-15, and is marked active, not recruiting.
The record describes three treatment groups across Part A and Part B. Part A patients received nivolumab intravenously over 60 minutes once every two weeks. Part B Arm I received nivolumab over 30 minutes once every 4 weeks, and Part B Arm II received the same nivolumab schedule plus ipilimumab over 30 minutes once every 8 weeks. Treatment in each description continued in the absence of disease progression or unacceptable toxicity. CT scans, MRI, and blood sample collection are listed during the study.
The primary outcome is progression-free survival in Part B. The posted primary results include 52 patients in Part B Arm I and 48 in Part B Arm II. The analysis reports Kaplan-Meier median estimates with 90% confidence intervals and a log-rank comparison. The registry lists additional outcomes, including overall survival, overall response rate, and treatment-related toxicity measures. These outcomes address different aspects of the study and should not be treated as interchangeable with the primary endpoint.
The registry record does not report the randomization procedure, the allocation ratio, the protocol’s sample-size justification, or whether interim analyses were planned or conducted. It also does not report a detailed statistical analysis plan. The study’s listed enrollment therefore should not be taken as evidence of how the target was set or whether recruitment matched a prespecified power calculation.
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
| Stage | Part A (Nivolumab) | Part B Arm I (Nivolumab) | Part B Arm II (Nivolumab, Ipilimumab) |
|---|---|---|---|
| STARTED | 39 | 53 | 51 |
| COMPLETED | 37 | 49 | 47 |
| NOT COMPLETED | 2 | 4 | 4 |
Reasons for not completing this period:
| Reason | Part A (Nivolumab) | Part B Arm I (Nivolumab) | Part B Arm II (Nivolumab, Ipilimumab) |
|---|---|---|---|
| Withdrawal by Subject | 0 | 3 | 1 |
| Protocol Violation | 0 | 1 | 3 |
| Did not meet an eligibility criterion and not treated | 2 | 0 | 0 |
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: The patients included in this baseline analysis were all patients who consented to the study.
| Characteristic | Unit | Part A (Nivolumab) | Part B1 (Nivolumab) | Part B2 (Nivolumab + Ipilimumab) | Total |
|---|---|---|---|---|---|
| Participants analysed | 39 | 53 | 51 | 143 | |
| Age, Continuous | years | 56 (31 to 71) | 59 (45 to 81) | 60 (36 to 77) | 59 (31 to 81) |
| Sex: Female, Male: Female | Participants | 28 | 42 | 39 | 109 |
| Sex: Female, Male: Male | Participants | 11 | 11 | 12 | 34 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 1 | 0 | 1 | 2 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 37 | 53 | 47 | 137 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 1 | 0 | 3 | 4 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 2 | 2 | 0 | 4 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 3 | 1 | 3 | 7 |
| Race (NIH/OMB): White | Participants | 34 | 50 | 47 | 131 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 1 | 1 |
| Region of Enrollment: United States | participants | 39 | 53 | 51 | 143 |
6. Primary Endpoint
The registry lists the primary outcome as Progression-free Survival (PFS) (Part B), measured over Time period from the date of randomization to the date of PD or death whichever occurred first, assessed up to 2 years.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | 90% Confidence Interval |
| Unit | months |
| Endpoint classification | Time-to-Event Analysis |
Progression-free survival (PFS) measures the time until disease progression or death, whichever occurs first. In the registry’s primary endpoint definition, the clock begins at randomization, with assessment up to 2 years. The endpoint description also refers to time from initiation of nivolumab until disease progression. These two descriptions use different starting points, and the registry record does not explain the wording difference.
PFS is a time-to-event outcome. It incorporates both whether an event occurs and when it occurs, rather than reducing follow-up to a simple count of patients with progression. The median is the time at which the estimated event-free proportion reaches the midpoint of the Kaplan-Meier curve. It is not an average, and it does not describe the experience of every participant.
In general, time-to-event analysis can use information from participants who have not had a recorded event by the end of their observed follow-up, provided their follow-up is handled as censoring under the analysis. The registry record does not report the censoring rules, completeness of follow-up, or details of how progression was assessed. Those details matter when judging how much information supports the median estimates and whether outcome assessment was comparable between the open-label groups.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
In Part B, the posted median PFS was 2.9 months for nivolumab and 3.7 months for nivolumab plus ipilimumab. The corresponding 90% confidence intervals were 1.9 to 3.8 months and 2.0 to 5.6 months. These intervals indicate uncertainty around the estimated medians; the combination-arm interval is particularly broad. The registry reports a log-rank p-value of 0.25 for the comparison.
The reported p-value does not provide evidence of a statistically clear difference by the log-rank test at conventional significance levels. It does not establish that the strategies are equivalent, nor does it prove that any difference is absent. The median estimates differ, but the confidence intervals are estimates with uncertainty, not guarantees about the range of individual outcomes. The registry does not report a hazard ratio for the primary PFS comparison, so the relative event rate over follow-up cannot be characterized from a reported primary hazard ratio.
In general, a confidence interval expresses the uncertainty associated with an estimate under the statistical method used; it is not a range that contains the true value with certainty. The overlap between the two median confidence intervals is not itself a formal test of the between-arm difference. The log-rank result is the registry’s reported test for the primary comparison, and it should be interpreted alongside the median estimates rather than replaced by a visual comparison of the intervals.
The numbers analyzed for PFS are smaller than the total enrollment listed for the study, and the registry record does not explain the analysis population or why the endpoint groups have these sizes. The displayed median estimates therefore should not be read as results for every enrolled participant. Follow-up is described as assessed up to 2 years, but the record does not report the amount of follow-up available for each group, event counts for this endpoint, or the number censored.
The primary result is consequently best understood as an uncertain comparison in this phase II study: the posted medians differ, while the reported log-rank test does not show a statistically clear separation. It does not answer whether either regimen is superior in other settings, and it does not establish equivalence. Interpretation is also limited by the absence of a reported primary hazard ratio, detailed analysis-population information, and further follow-up and censoring details in the registry record.
9. Statistical Methods Explained
What does a median time-to-event estimate mean?
For PFS, the Kaplan-Meier method estimates the probability of remaining free of progression or death over time. The median is the point at which the estimated probability has reached one half. It summarizes the curve at a particular point; it does not describe the full shape of the curve or show whether the groups differ consistently across all follow-up times.
The reported median PFS estimates are 2.9 months for nivolumab and 3.7 months for nivolumab plus ipilimumab. The intervals around them are 90% confidence intervals. A confidence interval communicates statistical uncertainty under the method used, and its width reflects how precisely the estimate is determined. A broader interval allows a wider range of plausible median values. In general, time-to-event estimates can be affected by the number and timing of events and by how much follow-up is available. The registry record does not report the PFS event counts or detailed follow-up distribution.
What does the log-rank test assess?
The log-rank test compares the event-time experience of two groups over the observed follow-up. It is not simply a test of whether the two medians are numerically different. The reported p-value of 0.25 indicates that the registry’s test does not show a statistically clear difference between the Part B groups. A p-value is not the probability that the treatments are equal, or the probability that the observed result happened by chance. It describes how compatible the data are with the test’s null model, subject to the analysis assumptions.
In general, the log-rank test is most straightforward to interpret when the groups’ event patterns are reasonably consistent over time. The registry record does not report checks of this condition, the shape of the PFS curves, or additional analyses of the time pattern. Since a primary hazard ratio is not reported, the result cannot be recast as a single relative event-rate estimate from the posted primary analysis.
Why do the confidence intervals not settle the comparison?
The confidence intervals are attached to each arm’s median; they are not a confidence interval for the difference between medians. Their overlap is not a substitute for the reported log-rank test. Nor does a lack of a statistically clear difference prove equivalence. An equivalence or non-inferiority conclusion would require a prespecified margin and an analysis designed for that question; such a margin is not reported in the registry record.
In general, estimates and tests answer related but distinct questions. The medians describe a point on each estimated survival curve, while the log-rank test uses information across event times. Both should be read with their uncertainty and with the limitations of the posted data in mind.
How should the planning illustrations be read?
Planning illustrations based on observed effects translate an observed contrast into hypothetical sample-size requirements under stated assumptions. The record describes a two-sided significance level of 0.05, equal allocation, and a normal approximation; it considers planning for 100%, 75%, or 50% of the observed effect. For time-to-event outcomes, the illustration concerns total events, while the other illustrations concern participants per arm.
These are not the study’s original design calculations, observed power, or evidence that the trial was adequately or inadequately powered. The protocol’s sample-size justification is not reported in the registry record. Observed-effect-based planning can be unstable because the observed effect itself is uncertain, especially in a study with limited information. Smaller effects generally require more information to detect, but the illustrations should not be read as a promise that a future study of a particular size will produce a particular result.
What details would help evaluate the analysis?
For time-to-event outcomes, the censoring rules, event counts, follow-up distribution, and handling of participants with incomplete outcome data help readers assess the analysis. For the primary PFS comparison, these details are not reported in the registry record. The record also does not report a detailed analysis plan, the statistical assumptions assessed, or the analysis population definition. This absence does not show that the analyses were improperly conducted; it limits what can be independently evaluated from the registry results alone.
10. Analyses Reported by the Sponsor
| Method | Estimate | 95% CI | P-value |
|---|---|---|---|
| Log Rank | not reported | 0.250 |
The registry reports a log-rank p-value of 0.25 for the primary Part B PFS comparison, alongside the arm-specific medians and 90% confidence intervals. No primary PFS hazard ratio is reported. The posted median summaries do not by themselves provide enough information to recalculate a log-rank test or a hazard ratio, so there is no simple unadjusted recalculation to set against the sponsor’s primary test.
For overall survival, the registry reports a Cox proportional-hazards estimate with a 90% confidence interval. The record’s stated approach for time-to-event outcomes uses the sponsor-reported hazard ratio rather than a recalculation from the medians. The hazard-ratio interval spans values on either side of 1, so it does not establish a clear relative difference in the reported analysis.
For overall response rate, the registry reports a chi-squared p-value of 0.89. A simple unadjusted recalculation from the posted group summaries gives p = 0.632. These are not identical results because the reported test and a recalculation from summary statistics need not use the same method or assumptions. The registry does not report enough detail to reconcile the two p-values fully. The sponsor’s reported analysis is the official registry analysis; the recalculation is a supplementary, unadjusted check and should not replace it.
11. Multiplicity, Missing Data and Analysis Populations
The registry lists multiple outcome measures and analyses, including PFS, overall survival, response, and treatment-related toxicities. The registry record does not report whether the study used a prespecified hierarchy among these outcomes, adjusted for multiple comparisons, or designated which secondary results were confirmatory. Without that information, nominal p-values from secondary analyses should be interpreted cautiously. In general, testing multiple outcomes can increase the chance that at least one result appears statistically notable even when there is no underlying difference.
The registry record also does not report a detailed missing-data plan, the number of participants with incomplete outcome information for each analysis, or the methods used to handle missing observations. For time-to-event outcomes, the handling of incomplete follow-up and censoring can affect the amount of information available and the estimated curves. For response outcomes, the analysis population and how unevaluable participants were treated can affect the reported proportion. Those details are not reported in the registry record.
The record does not report the analysis populations used for the primary and secondary outcomes, such as whether results were based on all randomized participants or another defined group. It also does not report the randomization procedure, protocol-based sample-size justification, or whether interim analyses were planned or conducted. These omissions do not establish that a particular method was or was not used; they limit the ability to assess adherence to a prespecified plan and the robustness of the posted analyses.
Because the study is listed as randomized but not masked, the allocation method and outcome-assessment procedures would be relevant to interpretation. The registry lists imaging assessments but does not report whether progression assessments were reviewed independently or whether assessors were blinded. For an endpoint involving disease progression, these details could help readers understand the potential for differences in assessment. The registry record does not provide them.
12. 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 |
|---|---|---|---|
| Part A (Nivolumab) | 14 | 37 | 37.8% |
| Part B1 (Nivolumab) | 25 | 52 | 48.1% |
| Part B2 (Nivolumab + Ipilimumab) | 19 | 48 | 39.6% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Part A (Nivolumab) | 16 of 37 |
| Part B1 (Nivolumab) | 28 of 52 |
| Part B2 (Nivolumab + Ipilimumab) | 30 of 48 |
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 |
|---|---|
| Part A (Nivolumab) | 36 of 37 |
| Part B1 (Nivolumab) | 48 of 52 |
| Part B2 (Nivolumab + Ipilimumab) | 46 of 48 |
Most frequent serious adverse event terms
| Event term | Organ system | Part A (Nivolumab) | Part B1 (Nivolumab) | Part B2 (Nivolumab + Ipilimumab) |
|---|---|---|---|---|
| Abdominal pain | Gastrointestinal disorders | 2 of 37 | 2 of 52 | 3 of 48 |
| Fever | General disorders | 4 of 37 | 0 of 52 | 1 of 48 |
| Disease progression | General disorders | 0 of 37 | 1 of 52 | 3 of 48 |
| Pneumonitis | Respiratory, thoracic and mediastinal disorders | 0 of 37 | 0 of 52 | 4 of 48 |
| Urinary tract infection | Infections and infestations | 2 of 37 | 0 of 52 | 1 of 48 |
| Urinary tract obstruction | Renal and urinary disorders | 0 of 37 | 3 of 52 | 0 of 48 |
| Abdominal distension | Gastrointestinal disorders | 0 of 37 | 1 of 52 | 1 of 48 |
| Acute kidney injury | Renal and urinary disorders | 2 of 37 | 0 of 52 | 0 of 48 |
| Alkaline phosphatase increased | Hepatobiliary disorders | 1 of 37 | 0 of 52 | 1 of 48 |
| Anemia | Blood and lymphatic system disorders | 1 of 37 | 0 of 52 | 1 of 48 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Part A (Nivolumab) | Part B1 (Nivolumab) | Part B2 (Nivolumab + Ipilimumab) |
|---|---|---|---|---|
| Fatigue | General disorders | 20 of 37 | 21 of 52 | 20 of 48 |
| Anemia | Blood and lymphatic system disorders | 16 of 37 | 15 of 52 | 16 of 48 |
| Nausea | Gastrointestinal disorders | 12 of 37 | 12 of 52 | 13 of 48 |
| Diarrhea | Gastrointestinal disorders | 11 of 37 | 12 of 52 | 12 of 48 |
| Anorexia | Metabolism and nutrition disorders | 8 of 37 | 11 of 52 | 11 of 48 |
| Constipation | Gastrointestinal disorders | 11 of 37 | 9 of 52 | 6 of 48 |
| Abdominal pain | Gastrointestinal disorders | 4 of 37 | 11 of 52 | 10 of 48 |
| Vomiting | Gastrointestinal disorders | 11 of 37 | 6 of 52 | 7 of 48 |
| Creatinine increased | Investigations | 12 of 37 | 7 of 52 | 3 of 48 |
| Hyponatremia | Metabolism and nutrition disorders | 6 of 37 | 9 of 52 | 7 of 48 |
Serious events with the highest arm-level rate: fever (10.8%), pneumonitis (8.3%), abdominal pain (6.2%), disease progression (6.2%), urinary tract obstruction (5.8%).
The adverse-event summary lists serious-event affected counts of 14 among 37 patients at risk in Part A, 25 among 52 in Part B Arm I, and 19 among 48 in Part B Arm II. These are group-specific registry figures. They should not be interpreted as a direct comparison of treatment risk without more information about event definitions, observation time, attribution, and the analysis method. The registry also lists other adverse events affecting patients in each group, but those counts are not equivalent to serious-event counts.
The registry lists fever, pneumonitis, abdominal pain, disease progression, urinary tract obstruction, and acute kidney injury among the top serious-event terms, with percentages reported for each. The denominator and whether these percentages refer to the whole study or a particular analysis group are not reported in the registry record. The record also lists deaths by group, but does not specify in this summary whether they were treatment-related. They should not be interpreted as treatment-caused deaths.
In general, adverse-event summaries describe events observed during study follow-up; they do not by themselves establish that a treatment caused an event or quantify comparative risk. The registry’s secondary-outcome descriptions include treatment-related toxicities and grade 3/4/5 adverse events, but the available summary does not provide enough detail to infer event timing, duration, or attribution for each listed figure.
13. What the Result Does, and Does Not, Mean
The primary result describes the observed PFS estimates and the sponsor’s comparison for the two Part B groups. The medians are 2.9 months and 3.7 months, and the log-rank p-value is 0.25. This is not a statistically clear separation in the reported test. It is also not evidence that the groups are equivalent, that no difference exists, or that a difference of a particular size has been ruled out.
The confidence intervals communicate uncertainty in the median estimates, and the combination-arm interval is wide. The registry does not report a primary hazard ratio or a confidence interval for a between-group PFS effect. As a result, the posted primary analysis does not quantify the relative event rate in a single effect estimate. The amount of follow-up, event counts, censoring details, and analysis population are also not reported in the registry record, limiting assessment of precision and robustness.
The results do not establish what would happen in populations outside the listed refractory metastatic anal canal cancer setting, or under treatment schedules different from those described. The study is phase II, and its registry record does not report the protocol’s sample-size justification or whether the secondary outcomes were adjusted for multiple comparisons. Those features matter when judging how far the results can support confirmatory conclusions.
In general, a statistically non-significant test is not proof of no effect, while a numerical difference between estimates is not proof of a treatment effect. Interpretation requires the estimated effects, their uncertainty, the design, and the analysis plan. The registry results offer a comparison of the posted outcomes in the listed study groups; they do not, by themselves, establish a definitive conclusion about the relative clinical value of the regimens.
14. Why This Trial Matters Statistically
This trial presents a useful statistical distinction between comparing medians and comparing full time-to-event experience. The posted primary endpoint is a Kaplan-Meier median for each group, while the between-group test is a log-rank test. These summaries are related but answer different questions. Readers should not infer a formal difference simply because the medians are numerically different, nor infer equivalence from a test that does not show a statistically clear separation.
The study also illustrates why uncertainty matters. The median estimates have 90% confidence intervals, and the combination-arm interval spans a broad range. Looking only at point estimates can make a comparison seem more certain than the data support. The registry does not report a primary hazard ratio, event counts, or enough follow-up detail to provide a fuller account of the comparative time-to-event effect.
There are multiple outcome types in the registry: time to progression or death, overall survival, response, and toxicity. Each outcome has its own estimand, analysis method, and potential sources of missing information. They should not be collapsed into a single verdict. The absence of reported multiplicity procedures and analysis-population details is particularly relevant when interpreting secondary results.
Finally, the posted planning illustrations demonstrate the difference between retrospective effect-based sample-size calculations and a trial’s original design justification. Such illustrations are not observed power and do not show that the study was designed around the observed result. The protocol’s justification is not reported in the registry record. This makes the trial a reminder to distinguish statistical output from design rationale and to treat unreported methodological details as uncertainty, not as evidence that a particular procedure was used.
15. 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’s primary endpoint descriptions use different starting points: the timeframe defines PFS from randomization, while the endpoint description refers to initiation of nivolumab. The record does not explain this difference. Readers cannot determine from the registry alone which wording governed the analysis.
The primary result reports medians and a log-rank p-value but no primary hazard ratio. The registry also does not report PFS event counts, the censoring approach, follow-up distribution, or whether the proportionality of event patterns was assessed. Those omissions limit the ability to characterize the magnitude and time pattern of the comparison beyond the posted summaries.
The study is listed as randomized and unmasked, but the registry record does not describe the randomization process, allocation concealment, or whether progression assessment was independently reviewed or blinded. These details are especially relevant when the primary outcome includes a disease-progression assessment. The available information does not establish that these procedures were absent; it means they are not reported in the registry record.
There are different group sizes across outcomes. The record does not explain the analysis-population definitions, missing observations, or why the numbers used for response differ from those listed for the PFS groups. The secondary outcomes also cover multiple comparisons, while a multiplicity plan is not reported. These factors limit direct comparison across endpoints and the confirmatory interpretation of secondary findings.
Finally, the registry does not report the study’s original sample-size rationale or interim-analysis plan. The effect-based planning illustrations should therefore remain hypothetical planning aids, not evidence about the trial’s original statistical design or its observed power.
16. Related Tutorials
17. Related Statistical Calculators
18. Sources
- ClinicalTrials.gov: Nivolumab With or Without Ipilimumab in Treating Patients With Refractory Metastatic Anal Canal Cancer — NCT02314169.
- Registry record last updated 2026-09-22; status last verified 2026-09.
- Results first posted 2018-08-07.
- 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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19. Record Summary
NCT02314169 is a randomized, open-label phase II study of nivolumab with or without ipilimumab in refractory metastatic squamous cell carcinoma of the anal canal. The registry lists enrollment of 143 and describes Part A and Part B treatment groups. The primary Part B comparison is progression-free survival for nivolumab alone versus the combination.
Posted median PFS estimates are 2.9 months and 3.7 months, with 90% confidence intervals of 1.9 to 3.8 months and 2.0 to 5.6 months. The reported log-rank p-value is 0.25. The registry record does not report a primary hazard ratio, detailed missing-data or analysis-population methods, a multiplicity plan, or the protocol’s sample-size justification. Secondary outcomes and safety summaries add context but do not resolve the uncertainty in the primary comparison.