Combination of Irinotecan, Oxaliplatin and Cetuximab for Locally Advanced or Metastatic Pancreatic Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Combination of Irinotecan, Oxaliplatin and Cetuximab for Locally Advanced or Metastatic Pancreatic Cancer (NCT00871169), a na phase 2 study. The primary outcome is Overall Response Rate (ORR).

2. Clinical Question

The trial examined a three-drug combination in a phase II study of pancreatic cancer. The primary endpoint was overall response rate, or ORR: the percentage of participants with a complete response or a partial response. The endpoint description specifies assessments of target lesions by computerized tomography and gives RECIST version 1.1 criteria for classifying response.

Because the registry record lists no comparator group, the primary question is descriptive: what response rate was observed among participants receiving the combination? It is not a randomized comparison with another treatment or with no treatment. The record lists an enrollment of 61, but does not report the number included in the primary endpoint analysis or the observed ORR. It also does not report the endpoint’s confidence interval. Consequently, the magnitude and precision of the response estimate cannot be assessed from the registry record.

3. Trial Design

The registry record classifies the study as phase II and single-group, with allocation listed as not applicable and masking listed as none. The study status is completed. The listed enrollment is 61. The study start is recorded as 2008-10, and primary completion as 2015-04. The sponsor is the New Mexico Cancer Research Alliance.

The intervention is irinotecan, oxaliplatin, and cetuximab. The arm description says the goal was to administer at least 4 cycles to each patient. Treatment could stop earlier if the treating physician considered stopping to be in the patient’s best interest. Repeated treatment could be given to patients who benefited, defined in the record as having a complete response, partial response, or stabilization of disease. These statements describe the treatment plan; the record does not report how many participants received each number of cycles or how often treatment was stopped or repeated.

With a single group and no listed comparator, the study does not provide a like-for-like control comparison. The record lists toxicity as a secondary outcome in addition to the primary ORR outcome. It does not report a detailed statistical analysis plan, the analysis population for ORR, or the number of participants whose response was evaluable. Those omissions limit interpretation of how the endpoint was analyzed and how much information contributed to its estimate.

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

Reasons for not completing this period:

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: These enrolled patients received study treatment according to the protocol.

6. Primary Endpoint

The registry lists the primary outcome as Overall Response Rate (ORR), measured over 2 years.

The primary endpoint is overall response rate, expressed as a percentage of participants. The registry defines ORR as the percentage who experienced a complete response plus the percentage who experienced a partial response. It specifies RECIST version 1.1 and assessment of target lesions by computerized tomography.

Under the listed criteria, complete response means disappearance of all target lesions. Partial response requires at least a 30% decrease in the sum of the longest diameters of target lesions. Stable disease is neither a sufficient decrease for partial response nor a sufficient increase for progressive disease. Progressive disease includes a 20% increase in the sum of the longest diameters, a measurable increase in a non-target lesion, or the appearance of new lesions.

General statistical explanation: ORR condenses response classifications into a percentage combining complete and partial responses. It is useful for describing the proportion meeting those response criteria, but it does not describe how long a response lasts or summarize every other possible clinical outcome. The registry lists a timeframe of 2 years. It does not report the observed ORR or its 95% confidence interval, so the response proportion and its precision are not available in the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

General statistical explanation: the methods below describe how the listed endpoint and design are ordinarily interpreted. They are not a claim about an analysis that the registry record does not report. The record does not provide a detailed statistical analysis plan, an ORR estimate, or inferential results.

What does a single-group design show?

A single-group study describes outcomes among participants receiving the listed intervention. For a binary endpoint such as whether a participant had a complete or partial response, a basic summary is the percentage meeting the endpoint definition. That percentage is descriptive of the analyzed group. Without a comparator group, it does not estimate a randomized difference between treatments. The record lists allocation as not applicable, masking as none, and the model as single group; it also includes a caution that the study is not a randomized comparison.

This distinction matters because a response observed during a study does not, by itself, identify what caused it. A controlled comparison can help assess differences between treatment groups under its design and analysis assumptions. This study’s registry entry does not list such a control group. Any interpretation should therefore remain within the limits of a single-group description rather than being framed as a comparative treatment effect.

How is ORR defined?

The record defines ORR as the percentage of participants with a complete response plus the percentage with a partial response. Response categories are based on RECIST version 1.1. The criteria use changes in the sum of the longest diameters of target lesions, as well as specified changes in non-target lesions and the appearance of new lesions. The record says target lesions are assessed by computerized tomography.

Combining complete and partial responses gives a binary summary: each participant either meets the response definition or does not. This makes the endpoint straightforward to express as a percentage, but it does not preserve every detail of the response categories. For example, stable disease is defined separately and is not counted as a complete or partial response in the ORR definition. The treatment description nevertheless includes stabilization of disease among the outcomes that could support repeated treatment. These are separate statements about the endpoint and treatment plan.

What does a confidence interval convey?

The primary endpoint specifies a 95% confidence interval. General statistical explanation: a confidence interval presents a range of values compatible with the observed estimate under the chosen method and its assumptions. It helps readers judge precision; the point estimate alone does not communicate how uncertain the estimate may be. A confidence interval is not a guarantee that the true value lies within a particular reported interval, and its interpretation depends on the method used to construct it.

The registry record does not report the ORR estimate or interval, and it does not identify the method used to calculate the interval. The interval’s width and the method’s assumptions therefore cannot be assessed. The endpoint description states the confidence level, but that alone is not enough to recover the missing estimate or evaluate its precision.

What analysis details are absent?

The record lists 0 analyses. It does not report the primary endpoint’s analysis population, how participants without an evaluable response were handled, or whether the response assessment followed a prespecified schedule. It also does not provide a detailed statistical plan or explain how the stated 2 years timeframe was applied to endpoint ascertainment. These items should be treated as unreported rather than inferred from the endpoint definition.

General statistical explanation: the analysis population and missing-data approach matter because the denominator determines how a percentage is interpreted. Excluding participants without an evaluable assessment can produce a different descriptive result from counting them as not having a response. Neither approach can be attributed to this study from the available registry entry.

How should planning illustrations be read?

General statistical explanation: sample-size planning illustrations describe hypothetical requirements under stated assumptions; they are not results observed in a trial. The planning assumptions listed for the illustrations include a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. For time-to-event outcomes, the listed planning quantity is total events; for other outcomes, it is participants per arm. These are planning conventions, not evidence that the single-group study used a two-arm design or that it achieved a particular power.

The registry record does not report the trial’s own sample-size justification or a detailed statistical plan. The planning assumptions should not be mistaken for the trial’s actual design or analysis methods. In particular, a planning illustration cannot substitute for the missing ORR result or its confidence interval.

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("Irinotecan, Oxaliplatin, and Cetuximab")
n      <- c(58)
events <- c(4)
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  Irinotecan, Oxaliplatin, and Cetuximab  58  4  6.9  1.9  16.7  2.7  16.4  2.8  16.5

11. Multiplicity, Missing Data and Analysis Populations

The registry lists ORR as the primary outcome and toxicity as a secondary outcome, with 2 outcome measures in total. It does not report a detailed statistical analysis plan, a hierarchy of hypotheses, or a method for adjusting for multiple testing. The record lists 0 analyses. It is therefore not possible to determine whether formal hypothesis tests were planned for these outcomes or how any multiplicity was addressed.

General statistical explanation: multiplicity arises when several outcomes or statistical tests are considered. If many tests are interpreted together, the chance of at least one apparently notable result can increase unless the analysis plan accounts for that feature. Whether adjustment is appropriate depends on the goals and prespecified analysis. No approach can be attributed to this trial from the registry record.

The record also does not report an analysis population for ORR, the number with an evaluable response, or how missing response assessments were handled. It does not state whether participants who discontinued treatment, stopped early, or lacked an assessment were included in the endpoint denominator. The treatment description allows stopping earlier when the treating physician deems it in the patient’s best interest, but it does not explain how such cases were treated analytically.

General statistical explanation: missing-data handling can affect both the denominator and interpretation of a percentage endpoint. Counting only evaluable participants and treating missing assessments as nonresponse are different approaches. Since the registry does not say which approach was used, neither should be assumed. The listed enrollment and adverse-event risk counts do not establish the analysis population for ORR.

12. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: dehydration (8.6%), pain - abdomen (8.6%), ileus (bowel obstruction) (5.2%), pulmonary emboli (5.2%), vomiting (5.2%).

The registry’s adverse-event entry lists 58 at risk for both serious and other events. It records 24 affected for serious events and 56 affected for other events. These are the figures in the adverse-event record; the registry does not explain how those risk counts relate to the listed enrollment of 61. Deaths are not reported in the adverse-event entry.

The listed serious-event terms and percentages are dehydration, 8.6%; pain - abdomen, 8.6%; ileus (bowel obstruction), 5.2%; pulmonary emboli, 5.2%; vomiting, 5.2%; and acidosis, 1.7%. These are reported serious-event terms, not a complete account of every possible adverse event. The record does not provide additional detail about event timing, severity grading, recurrence, or attribution to treatment.

General statistical explanation: an affected count summarizes how many participants were recorded with an event under the registry’s reporting definitions. It does not by itself establish that the intervention caused the event. Serious and other adverse-event summaries are distinct from the primary ORR endpoint and do not indicate whether a participant had a response.

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

The registry record establishes that this was a completed phase II, single-group study of irinotecan, oxaliplatin, and cetuximab in pancreatic cancer. It defines ORR using complete and partial response categories under RECIST version 1.1, with a stated timeframe of 2 years. It also reports selected adverse-event information. These design and reporting details describe what the study addressed, but they do not supply the missing primary outcome result.

The record does not report the observed ORR, its 95% confidence interval, or a statistical analysis of that endpoint. Consequently, it cannot show how frequently participants met the response definition or how precisely that proportion was estimated. The absence of a result in the registry record should not be read as a zero response rate or as evidence of a particular response rate.

Even if a response estimate were available, the single-group design would limit comparative conclusions. There is no listed randomized control arm for separating outcomes associated with the combination from outcomes that might occur for other reasons. The record itself cautions that this is not a randomized comparison. The listed phase and enrollment do not remove that design limitation.

The adverse-event entries provide a separate description of safety reporting. They list affected counts and selected serious-event terms, but do not establish treatment causation or replace a fuller safety analysis. Information about the primary analysis population, missing response data, and detailed analysis methods is not reported in the registry record.

General statistical explanation: results are most informative when the endpoint estimate, its uncertainty, the analysis population, and the design are considered together. Here, the endpoint and design are described, but the key response estimate and several analysis details are absent. Interpretation should therefore remain limited to the study’s stated question and the information actually recorded.

14. Why This Trial Matters Statistically

This trial is statistically notable for the contrast between a clearly defined primary endpoint and the absence of a posted primary result in the registry record. ORR is specified as the percentage with a complete or partial response, and the record identifies RECIST version 1.1, computerized tomography assessment of target lesions, and a 2 years timeframe. Those details make the intended outcome recognizable, but do not reveal its observed value.

The single-group design also shapes the kind of inference the study can support. A response percentage would describe the treated group, while the absence of a comparator means the registry record does not provide a randomized estimate of a difference between treatments. Keeping descriptive and comparative claims distinct is essential when reading results from this design.

The safety record adds another statistical consideration: adverse-event summaries have their own risk and affected counts, while the listed enrollment is a separate entry. The registry does not explain the relationship between those figures or identify the ORR analysis denominator. Readers should not assume that one population definition applies to all outcomes.

Finally, the record lists 0 analyses and does not report a detailed statistical plan. Without the primary estimate, confidence interval, analysis population, and missing-data approach, important aspects of precision and reproducibility cannot be evaluated. The trial’s statistical importance in the registry record is therefore chiefly about interpreting the limits of what is reported, rather than drawing a conclusion about the magnitude of response.

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 follow directly from the registry record. The primary endpoint result is not reported: there is no ORR estimate or 95% confidence interval, despite the endpoint definition and timeframe being specified. The record lists 0 analyses, so it does not provide an analysis from which the size or precision of the primary outcome can be judged.

The study is classified as single group, with allocation listed as not applicable and masking as none. No comparator arm is listed, and the record cautions that the study is not a randomized comparison. Accordingly, the design does not provide a like-for-like control comparison.

The registry does not report the primary endpoint analysis population, the number with evaluable response assessments, the handling of missing response data, or a detailed statistical plan. It does not describe the method used to calculate the stated confidence interval. These omissions leave uncertainty about the denominator and analysis procedures.

The enrollment entry is 61, while the adverse-event group lists 58 at risk. The registry does not explain the relationship between these entries, and the adverse-event risk counts should not be taken as the ORR analysis denominator. The adverse-event entry also does not report deaths and provides only selected serious-event terms. These limits apply to interpretation of the registry record and do not establish what may be reported elsewhere.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Combination of Irinotecan, Oxaliplatin and Cetuximab for Locally Advanced or Metastatic Pancreatic Cancer — NCT00871169.
• Registry record last updated 2016-06-14; status last verified 2016-05.
• Results first posted 2016-06-14.
• 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 record describes NCT00871169, a completed phase II, single-group study sponsored by the New Mexico Cancer Research Alliance. It lists enrollment of 61 and an intervention combining irinotecan, oxaliplatin, and cetuximab for locally advanced or metastatic pancreatic cancer.

The primary endpoint is ORR, defined as the percentage of participants with a complete or partial response under RECIST version 1.1, with a timeframe of 2 years. The record lists toxicity as a secondary outcome. It reports selected serious adverse-event terms and affected counts, but does not report the ORR estimate, its confidence interval, or a detailed statistical analysis plan.