MDX-010 in Treating Patients With Stage IV Pancreatic Cancer That Cannot Be Removed By Surgery: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for MDX-010 in Treating Patients With Stage IV Pancreatic Cancer That Cannot Be Removed By Surgery (NCT00112580), a registered phase 2 study. The primary outcome is Percentage of Participants Achieving Complete Response (CR) or Partial Response (PR).

2. Clinical Question

The trial asks whether participants with pancreatic cancer treated with ipilimumab achieved a complete or partial response according to RECIST criteria. The registry gives the primary endpoint as the percentage of participants achieving either response, assessed from the first dose to 3 weeks following the end of the treatment cycle, up to 24 weeks.

3. Trial Design

This was a Phase II trial of ipilimumab for pancreatic cancer, with the registry status listed as completed. Bristol-Myers Squibb is named as the sponsor. The recorded start date is 2005-07-31, and the primary completion date is 2009-06-30. Enrollment was 27.

The official title describes a trial of single-agent ipilimumab for locally advanced or metastatic pancreatic adenocarcinoma. The public title instead refers to stage IV pancreatic cancer that cannot be removed by surgery. These are the descriptions used in the registry; further eligibility details are not reported in the registry record.

Masking is listed as none. The record identifies ipilimumab as the intervention and describes no comparator. Allocation is not stated, and the registry notes that this was not a randomized comparison. Consequently, the design does not provide a randomized control group for a direct treatment contrast. The registry record does not report additional details about treatment scheduling, dose administration beyond the adverse-event group label, or the conduct of follow-up.

The primary outcome is a binary response measure: whether participants achieved complete response or partial response under RECIST criteria. Its stated population is all treated participants, and its timeframe runs from first dose to 3 weeks following the end of the treatment cycle, up to 24 weeks. Although the registry lists one outcome measure, it lists no analyses. The response result, analysis method, and further details of the statistical plan 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: 27 participants were treated.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All treated 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.

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants Achieving Complete Response (CR) or Partial Response (PR), measured over From first dose to 3 weeks following the end of the treatment cycle, up to 24 weeks..

The primary endpoint is the percentage of participants who achieved a complete response or partial response according to RECIST criteria. A complete response is defined in the registry as disappearance of all target lesions. A partial response is defined as at least a 30% decrease in the sum of the longest diameter of target lesions, taking the baseline sum as the reference.

This is a binary outcome at the participant level: each treated participant either meets the stated response definition or does not. Expressing the number meeting the definition as a percentage can make the outcome easier to interpret across studies with different numbers of participants, but the percentage depends on a clearly specified denominator. The registry identifies the endpoint population as all treated participants.

Response criteria offer a structured way to classify changes in target lesions, rather than relying only on an unstandardized description. The endpoint’s stated timeframe is from the first dose to 3 weeks following the end of the treatment cycle, up to 24 weeks. The registry record does not report how many participants met either response definition, the resulting percentage, or an uncertainty interval. It therefore does not establish the observed response frequency.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies a percentage endpoint and gives its clinical classification rule, but it does not report an analysis of that endpoint. The concepts below explain how this kind of outcome is generally interpreted; they do not describe unreported methods used in this trial.

What does a percentage response measure?

For a binary outcome, each participant is classified into one of two categories for the endpoint: meeting the response definition or not meeting it. The response percentage expresses the number meeting the definition in relation to the endpoint population. It is important to distinguish the number enrolled from the number included in an analysis. Here, the registry names all treated participants as the primary endpoint population but does not report the response numerator or denominator.

The classification rule matters because it determines which observations count as responses. In this trial, complete response means disappearance of all target lesions, and partial response means at least a 30% decrease in the sum of the longest diameter of target lesions relative to baseline. The registry attributes these definitions to RECIST criteria. The recorded assessment window begins at first dose and extends to 3 weeks following the end of the treatment cycle, up to 24 weeks. How observations at particular visits were selected or adjudicated is not reported in the registry record.

Why does uncertainty matter?

A point estimate, such as a response percentage, describes the observed participants, but it does not by itself show how precisely the underlying response frequency has been estimated. A confidence interval is a range calculated by a statistical procedure to communicate uncertainty around an estimate. In general, wider intervals indicate less precision, while narrower intervals indicate greater precision under the method’s assumptions. No confidence interval for this endpoint is reported in the registry record, so its precision cannot be evaluated from the endpoint entry.

For a binary outcome, the amount of information depends on the number of participants assessed and how the outcome is distributed between the response categories. A small study can produce an estimate that is sensitive to the classification of a few participants. This is a general statistical consideration, not a calculation of uncertainty for this trial. The registry’s enrollment count alone does not establish the number assessed for response or the endpoint’s precision.

What can a one-group result establish?

In general, an outcome percentage from a group receiving one intervention estimates the outcome frequency in that group, subject to the endpoint definition, follow-up, and missingness. It does not, by itself, estimate how outcomes would differ under a comparator. A randomized comparison uses between-group information to estimate a contrast; the registry describes no comparator and states that this was not a randomized comparison. No treatment contrast can be recovered from the primary outcome entry.

Any interpretation of a single-group percentage also depends on the analysis population and how participants without an evaluable response are handled. Those details are not reported in the registry record. It is therefore not possible to determine whether missing endpoint observations were excluded, counted in a particular category, or handled by another method.

What do the planning illustrations mean?

The registry’s planning description characterizes sample-size calculations as illustrations based on an observed effect, not as the trial’s own design justification. It describes a two-sided significance level of 0.05, equal allocation between two hypothetical arms, and a normal approximation, with the effect to detect expressed as a stated fraction of the observed effect. For non-time-to-event outcomes, the calculations are described as participants per arm; for time-to-event outcomes, they are described as total events.

These are general planning assumptions, not evidence that this trial randomized participants between two arms or used those assumptions to set enrollment. They do not constitute observed power. The registry record does not report the trial’s sample-size justification. Since it also does not report the primary response result or an observed effect estimate, the inputs and implications of any such illustration cannot be independently assessed from the record.

What can be concluded from the posted analyses?

The registry lists one outcome measure and no analyses. That describes the analysis information present in the registry record; it does not establish whether analyses were conducted elsewhere or whether results were available outside the record. No p-value, confidence interval, adjusted estimate, or other primary endpoint analysis is reported. General statistical principles cannot fill in those missing trial-specific results.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Locally Advanced Cohort", "Metastatic Cohort")
n      <- c(8, 19)
events <- c(0, 0)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Locally Advanced Cohort  8  0  0.0  0.0  36.9  0.0  32.4  0.3  33.6
ARM  Metastatic Cohort  19  0  0.0  0.0  17.6  0.0  16.8  0.1  16.8

11. Multiplicity, Missing Data and Analysis Populations

Multiplicity concerns arise when several outcomes, comparisons, timepoints, or analyses are tested. When many statistical tests are conducted, the chance of at least one apparently notable result can increase unless the analysis plan accounts for the testing structure. This is a general principle, not a finding about the conduct of this trial.

The registry lists one outcome measure and no analyses. It does not report whether additional outcomes or analyses were conducted, how any multiple testing was handled, or whether an analysis plan specified a hierarchy among outcomes. The registry record does not report interim analyses or the detailed statistical plan. It is therefore not possible to determine from this record whether multiplicity adjustments were planned or used.

Missing-data handling is also not reported in the registry record. Although the endpoint population is described as all treated participants, the endpoint denominator, the number with an evaluable response, and the handling of participants without an assessment are not given. In general, different approaches to missing outcomes can affect a percentage estimate, particularly if the reason observations are missing is related to the outcome. No missing-data method or sensitivity analysis is reported.

The record does not provide enough information to determine whether the primary analysis followed an intention-to-treat, treated-participant, or other analysis population. The endpoint description specifies all treated participants, but does not state how this population was operationalized or whether it matched the analyzed group. These absences limit reproducibility and interpretation; they do not establish that a particular method was or was not used outside the registry record.

12. Safety Results

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

Deaths

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: abdominal pain (22.2%), bile duct obstruction (14.8%), hyperbilirubinaemia (11.1%), deep vein thrombosis (11.1%), fatigue (7.4%).

The adverse-event entry lists 27 participants at risk for serious adverse events, 20 affected by serious adverse events, 27 at risk for other adverse events, 26 affected by other adverse events, and 12 deaths. The record does not give further detail about the timing of these events, their causes, or the relationship of each event to ipilimumab. These counts should be read as registry safety summaries, not as evidence that the intervention caused the events.

The listed serious-event terms and percentages are abdominal pain, 22.2%; bile duct obstruction, 14.8%; hyperbilirubinaemia, 11.1%; deep vein thrombosis, 11.1%; fatigue, 7.4%; and infection, 7.4%. The registry does not explain in this entry whether participants could contribute to more than one term, or specify the denominator used for each percentage. The percentages therefore should not be added or treated as mutually exclusive categories.

The deaths entry is a count, but the record does not report causes or timing. These safety figures do not supply the missing primary response result, and they do not establish a comparison with another treatment group.

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

The registry record establishes that a completed Phase II trial evaluated single-agent ipilimumab in a pancreatic cancer population and identified RECIST complete or partial response as its primary endpoint. It gives the endpoint definitions and assessment timeframe, along with an enrollment count of 27. These are useful details about the intended question and the trial’s recorded scope.

The record does not report the number or percentage of participants who achieved a response. It also does not report an analysis, confidence interval, or p-value for that outcome. Therefore, the posted primary outcome information cannot show how often response occurred or how precisely that frequency was estimated. It cannot support a conclusion that the intervention did or did not produce a particular response rate.

The study is not described as a randomized comparison, and no comparator arm is specified. Even if a response percentage were available, a single-group result would describe outcomes in the treated group; it would not, by itself, quantify a causal difference relative to another treatment. The absence of a comparator is a design limitation for comparative inference, not evidence for or against an effect.

The serious adverse-event figures provide separate safety information, but the registry entry does not establish event causality or provide comparative safety estimates. The response endpoint and safety summaries answer different questions and should not be combined into a single judgment.

Overall, the available record supports a description of the trial’s design features and reported safety counts, while leaving the primary efficacy result and key analysis details unreported. This distinction is important: a missing registry result is not the same as a zero response, a negative result, or proof that no analysis was conducted.

14. Why This Trial Matters Statistically

This trial illustrates why a registered endpoint and a registered result are not interchangeable. The outcome is described with a recognizable response definition, a stated participant population, and a specified assessment window. Yet the registry record does not report the response count or percentage, so the endpoint’s observed value and precision cannot be evaluated from that record.

It also highlights the distinction between describing outcomes in a treated group and estimating a comparative treatment effect. The record identifies no comparator and states that the trial was not a randomized comparison. Those design features determine the kind of statistical interpretation possible: a single-group outcome can describe that group, but it does not itself supply a randomized contrast.

The enrollment count and endpoint population label are not enough to reconstruct an analysis. A reader also needs the denominator actually assessed, the outcome count, and information about how missing observations were handled. Those details are not reported for the primary endpoint. Without them, even a basic response percentage cannot be checked or interpreted for precision.

Finally, the separate safety counts show why a registry may contain clinically relevant numerical information while still omitting the primary efficacy analysis. The safety entries must be interpreted within their own limits, including the lack of event attribution and comparative data. For biostatistical reading, the central lesson is to separate trial design, endpoint definition, analysis results, and uncertainty, and not to substitute information from one category for information missing in another.

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.

Several trial-specific limitations affect interpretation of the registry record. Most importantly, the primary response result is not reported: there is no response count, percentage, or analysis. The endpoint population is identified as all treated participants, but the number actually assessed and the denominator used are not stated. The record also does not describe how missing or unevaluable response assessments were handled.

The trial is not presented as a randomized comparison, no comparator is specified, and allocation is not stated. This prevents a direct randomized estimate of the difference between ipilimumab and a control group from the registry information. The title and official title describe the population differently—stage IV cancer that cannot be removed by surgery, and locally advanced or metastatic pancreatic adenocarcinoma—and the record does not provide further eligibility details to reconcile those descriptions.

The registry does not report the statistical analysis plan, sample-size justification, interim analyses, or methods for handling multiplicity. It lists one outcome measure and no analyses, but those entries do not establish what analyses may have been conducted outside the record. The response endpoint’s assessment timeframe is stated, while further details about assessment procedures are not reported.

Safety information is also limited. The record lists event counts and serious-event terms, but does not report event timing, causes, or whether events were considered related to treatment. The deaths entry has no accompanying causal explanation. These limits mean the safety figures should not be interpreted as comparative or causal estimates.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: MDX-010 in Treating Patients With Stage IV Pancreatic Cancer That Cannot Be Removed By Surgery — NCT00112580.
• Registry record last updated 2021-09-27; status last verified 2021-09.
• Results first posted 2021-09-27.
• 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.

19. Record Summary

The registry lists a completed Phase II trial sponsored by Bristol-Myers Squibb, with 27 enrolled participants. The intervention was single-agent ipilimumab. Masking is listed as none; allocation is not stated, and the record says the study was not a randomized comparison.

The primary endpoint was the percentage of all treated participants with a complete or partial response by RECIST criteria, assessed from first dose to 3 weeks following the end of the treatment cycle, up to 24 weeks. The response count, percentage, and endpoint analysis are not reported in the registry record. Serious adverse events affected 20 of 27 participants at risk; other adverse events affected 26 of 27 at risk, and 12 deaths are listed. Further event attribution and timing are not reported.