A Study of Mitomycin C, Irinotecan, and Cetuximab: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of Mitomycin C, Irinotecan, and Cetuximab (NCT00271011), a na phase 2 study. The primary outcome is Percentage of Patients With an Objective Response.

2. Clinical Question

This was an investigation of response in previously treated metastatic colorectal cancer, not a comparison between alternative regimens. The registered response definition required a sustained change in measurable disease: complete response meant disappearance of all measurable and evaluable disease for at least 4 weeks without new lesions; partial response meant at least a 30% decrease in the sum of the longest diameters of target lesions for at least 4 weeks without new lesions. Those definitions describe what would count as a response, not how many patients responded.

The study also had a safety objective. The brief summary says the study would evaluate rash associated with cetuximab, while the registered secondary outcome concerns the proportion of patients experiencing hematologic and non-hematologic adverse events. The record does not report a rash-specific result. Its safety entries should therefore be read as recorded adverse-event summaries, not as a complete account of all safety outcomes or a comparison with another treatment.

3. Trial Design

The registry describes a phase II, single-group study sponsored by the University of Michigan Rogel Cancer Center. It lists an enrollment of 13 and a status of terminated. The recorded study start is 2005-12 and the primary completion date is 2008-07. The registry says the study was discontinued and not completed because of the death of a co-investigator and another co-investigator leaving the institution.

The design has no randomized allocation and no masking. With a single group, the study can describe outcomes observed among participants who received the combination, but it cannot estimate a randomized between-treatment contrast. Any comparison with outcomes from other studies or with an assumed benchmark would require additional information and assumptions not reported in the registry record.

The intervention group is named Mitomycin C, Irinotecan and Cetuximab. The arm description states that mitomycin C was planned as a bolus infusion on day -1 of each 28 day cycle. It describes a cetuximab loading dose on cycle 1, day 1, followed by weekly cetuximab treatments on days 1, 8, 15, and 22. The record does not give a complete regimen description: the posted arm text ends before the schedule is complete, and the posted description does not state a complete irinotecan schedule. These registry entries should not be treated as a full protocol.

The primary outcome is the percentage of patients with an objective response, with a timeframe of 2 months. The registry also lists a secondary outcome for the proportion experiencing hematologic and non-hematologic adverse events. It records two outcome measures overall. The record does not describe a statistical analysis plan, a sample-size justification, interim analyses, or the analysis populations. Termination and incomplete study status make it especially important not to assume that enrollment, endpoint evaluability, and the population included in any analysis were identical.

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

Analysis population for the primary outcome, as defined in the registry: The study was discontinued and not completed due to the death of a co-investigator and a second co-investigator leaving the institution.

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 Patients With an Objective Response, measured over 2 months.

The primary endpoint is the percentage of patients with an objective response. In this study, objective response combines complete responses and partial responses. A complete response was defined as disappearance of all measurable and evaluable disease for at least 4 weeks without new lesions. A partial response was defined as at least a 30% decrease in the sum of the longest diameters of target lesions for at least 4 weeks, also without new lesions. The registered timeframe for this outcome is 2 months.

In general, an objective-response proportion is a descriptive way to summarize how often a prespecified change in measurable disease is observed in a treated group. The use of explicit response definitions helps make the endpoint less dependent on an informal judgment of improvement. Requiring the change to persist and excluding new lesions are parts of the definitions recorded for this study; the registry does not give further details about assessment procedures or review methods.

The endpoint is not a measure of how long a response lasts beyond the stated definition, nor does it by itself summarize all clinical outcomes. The registry record does not report the number of complete responses, the number of partial responses, the number assessed, or the resulting objective-response percentage. It therefore cannot establish the magnitude or precision of the primary endpoint result.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

In a single-group study, the primary response outcome is naturally expressed as a proportion: the number meeting the response definition relative to the number evaluated under the analysis rule. In general, this kind of summary describes the observed frequency within the study group. It does not, by itself, compare that frequency with what would have happened under another treatment. The registry gives no response numerator, evaluable denominator, or analysis rule for missing assessments, so no primary proportion can be reconstructed from the posted record.

What does the response definition contribute?

The registry defines complete response and partial response separately, then identifies the primary endpoint as their combined percentage. In general, prespecified categories reduce ambiguity about which observed changes count toward an endpoint. Here, the complete-response definition requires disappearance of measurable and evaluable disease for at least 4 weeks and no new lesions. The partial-response definition requires at least a 30% decrease in the sum of the longest diameters of target lesions for at least 4 weeks and no new lesions. The record does not report the assessment schedule, the rules for handling unevaluable lesions, or whether response assessments were reviewed independently.

The recorded timeframe is 2 months. A timeframe helps identify when an outcome is intended to be assessed, but it does not explain the exact timing of each assessment or how participants without an assessment at that time were treated analytically. Those details are not reported in the registry record. Nor does the timeframe make the endpoint a measure of response duration beyond the persistence requirement included in the response definitions.

What can a single-group estimate show?

General statistical interpretation distinguishes a description of outcomes in a treated group from a treatment contrast. A response proportion from this design could summarize the frequency of responses among the analyzed participants. Since allocation is not applicable and the model is single group, the registry does not provide a randomized comparator. A proportion from this study therefore could not directly estimate a difference between the combination and another regimen or control condition.

A confidence interval, in general, communicates the uncertainty around an estimated quantity under a statistical model. It is useful because an estimate from a limited sample can be compatible with a range of underlying response frequencies. The registry record does not report a confidence interval for the primary endpoint, or the endpoint estimate to which one would apply. No interval should be inferred from the enrollment entry or from the safety summaries.

What does the planning illustration represent?

The sample-size material is explicitly a planning illustration computed from an observed effect, not the trial's own design. Its stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; it describes the effect to detect as a stated fraction of the observed effect. For time-to-event material, the assumptions describe a total number of events using the Schoenfeld approach; for other material, they describe participants per arm.

These are planning assumptions, not evidence that this study had a two-arm design. The actual registered study is single group. The illustration is not an observed power calculation, does not establish the design rationale for the trial, and cannot substitute for an analysis of the trial's outcomes. The registry record does not report a protocol sample-size justification. Because the primary response result is not reported, the observed response effect underlying any illustration cannot be assessed from this record.

How should the adverse-event summaries be read?

The registry separates serious adverse events from other adverse events. For the named study group, the serious-event summary lists 13 at risk and 2 affected; the other-adverse-event summary lists 13 at risk and 13 affected. These are registry counts, not a comparative risk estimate. The record lists Death, Cause Unknown and Gastrointestinal Obstruction among the serious terms, each at 7.7%. Those percentages should be understood as the registry's reported term figures, not as evidence of causation or as a comparison with a control group.

In general, adverse-event summaries need context about definitions, observation time, event severity, attribution, and whether a participant can contribute more than one event. The registry record does not provide those details for interpreting these entries. The field for deaths is not reported in the registry record. A term labelled Death, Cause Unknown is not the same as a documented treatment-related death, and no causal conclusion follows from its listing.

Which analysis details are unavailable?

The registry records zero analyses. It does not report inferential test results, confidence intervals, covariate adjustment, analysis populations, missing-data procedures, or multiplicity handling. In general, these details matter because choices about who is analyzed and how incomplete observations are handled can affect an estimate. Without a statistical analysis plan or posted outcome results, readers cannot determine whether the endpoint was analyzed as intended or how robust any estimate would be. The record also does not report interim analyses or the rationale for stopping beyond the stated co-investigator circumstances.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists the objective-response percentage as the primary outcome and the proportion experiencing hematologic and non-hematologic adverse events as a secondary outcome. It records two outcome measures overall. No multiplicity procedure is reported in the registry record. In general, multiplicity becomes relevant when several outcomes or statistical tests are used to support conclusions, because the interpretation of chance findings depends on the testing strategy. Here, the absence of posted analysis results and a statistical analysis plan means that the handling of multiple outcomes or comparisons cannot be assessed.

Missing-data rules and analysis populations are not reported in the registry record. It does not say how patients without an assessment at the 2 months timeframe would be handled, whether an unevaluable patient would count as a nonresponse, or whether analyses used all enrolled participants or a defined evaluable group. Those are not details that can be inferred from the enrollment entry. The record also does not report a participant flow explaining enrollment, treatment exposure, endpoint assessment, and inclusion in analyses.

The study was discontinued and not completed because of the death of a co-investigator and another co-investigator leaving the institution. The record does not explain how this affected data collection or which planned analyses were completed. It records zero analyses, and the primary response result is not reported. Consequently, the amount and pattern of missing outcome information, and its potential influence on any result, are not assessable from the registry record.

No interim-analysis plan, stopping boundary, or other monitoring procedure is reported. The stated reason for discontinuation should be distinguished from a statistical stopping decision: the registry attributes discontinuation to the co-investigator circumstances and does not report an efficacy-based or safety-based stopping rule.

11. 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: death, cause unknown (7.7%), gastrointestinal obstruction (7.7%).

The registry’s safety summary separates serious adverse events from other adverse events for the Mitomycin C, Irinotecan and Cetuximab group. For serious adverse events, it lists 13 at risk and 2 affected. For other adverse events, it lists 13 at risk and 13 affected. The serious-event terms listed include Death, Cause Unknown and Gastrointestinal Obstruction, each recorded as 7.7%.

These entries do not provide a comparison with another group. The record does not report the timing or duration of observation, event grading details, attribution to study drugs, or whether the term percentages represent people or events under a more detailed coding convention. It also does not report the death count field. The term Death, Cause Unknown should not be interpreted as a confirmed treatment-related death, and the adverse-event listing alone does not establish causation.

The secondary outcome is described as the proportion of patients experiencing hematologic and non-hematologic adverse events, but the registry does not provide detailed results for those categories. The brief summary also mentions evaluation of rash associated with cetuximab, without a rash-specific result. The posted safety figures are therefore limited summaries, not a complete characterization of tolerability.

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

The study asks a clinically defined response question for a combination of mitomycin C, irinotecan, and cetuximab in previously treated metastatic colorectal cancer with wild type K-Ras. Its primary endpoint is an objective-response percentage, defined by specified complete- and partial-response criteria. However, the registry record does not report the observed response percentage, response counts, or precision estimate. The central efficacy question therefore remains unanswered by the posted results.

The design also limits what an observed response proportion could establish. A single-group study can describe outcomes among participants receiving the regimen, but has no concurrent randomized comparator. In general, that design cannot isolate a treatment effect from other influences or provide a like-for-like estimate against another regimen. The record does not report an analysis that would address those limitations.

The safety entries show serious adverse-event counts and selected terms, as well as a count for other adverse events. They do not include enough context to establish causation or characterize the full safety experience. The serious-event listing of Death, Cause Unknown is not evidence on its own that treatment caused a death. The death count field is not reported in the registry record.

The registry states that the study was terminated and not completed because of the death of a co-investigator and another co-investigator leaving the institution. It does not attribute termination to treatment efficacy or safety. The enrollment entry does not show how many participants had complete endpoint data or were included in an analysis.

Accordingly, the record describes the intended study question and some design and safety information, but does not establish the frequency or precision of objective response. It cannot support a conclusion that the combination is effective or ineffective, nor can it support a comparative treatment claim. Those conclusions would require outcome, analysis, and follow-up information not reported in the registry record.

13. Why This Trial Matters Statistically

This trial is statistically informative as an example of the distinction between a registered research question and a reported result. The registry specifies a primary endpoint and detailed response definitions, but the primary response estimate is not reported. A clear endpoint definition is necessary for interpreting an estimate; it cannot replace the estimate itself.

The single-group design is also central to interpretation. It can support a descriptive summary of outcomes among treated participants if those outcomes are reported, but it does not create a randomized comparison. General statistical reasoning therefore cautions against treating an outcome proportion as a causal contrast or as evidence of superiority over another treatment. The registry itself identifies no like-for-like comparator.

The record also illustrates why enrollment, evaluability, and analysis should not be treated as interchangeable. Enrollment is listed as 13, while the record does not describe endpoint completeness or the analysis population. Without that flow and the missing-data rules, a reader cannot determine the denominator for a primary response estimate even if a count were otherwise available.

Finally, termination is relevant to the completeness of the evidence but should be interpreted using the reason actually recorded. The study was discontinued because of the death of a co-investigator and another co-investigator leaving the institution. The record does not report that a statistical stopping rule or treatment finding drove the decision. Keeping the stated reason distinct from unreported explanations avoids attributing a conclusion that the registry does not make.

These features make the registry useful for identifying what was intended and what remains unavailable: the objective-response result, its uncertainty, and the statistical procedures used to analyze it. That separation is important when reading a terminated clinical study.

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 most consequential limitation for interpreting this specific trial is the absence of the primary endpoint result. The record describes objective response and its response criteria but does not report response counts, a percentage, or an uncertainty interval. It also does not report the number of participants assessed at the registered timeframe of 2 months.

The record gives an enrollment of 13, but does not provide participant characteristics, treatment exposure, endpoint evaluability, or a participant flow. The study population is described as previously treated metastatic colorectal cancer, with the primary objective focused on wild type K-Ras, but the record does not report how the enrolled group matched those features. The analysis population and missing-data handling are not reported.

The trial is single group, with no randomized allocation or masking. There is no concurrent control for interpreting outcomes comparatively. The registry record does not report the protocol, a statistical analysis plan, sample-size justification, interim analyses, multiplicity procedures, or inferential analyses. The planning assumptions described in the sample-size material do not establish the actual design rationale or the analysis performed.

The intervention description is incomplete. It includes some mitomycin C and cetuximab schedule details, but does not give a complete regimen schedule, including a complete irinotecan schedule. The registry also does not describe response-assessment procedures, independent review, or the duration and completeness of adverse-event observation.

Safety interpretation is limited by the absence of event timing, attribution, severity details, and a comparator. The death count field is not reported, even though Death, Cause Unknown appears among serious-event terms. The study’s terminated status and stated reason for discontinuation further mean that planned completion cannot be assumed. The record does not say which planned assessments or analyses were completed.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Study of Mitomycin C, Irinotecan, and Cetuximab — NCT00271011.
• Registry record last updated 2015-12-03; status last verified 2015-11.
• Results first posted 2014-07-10.
• 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.

18. Record Summary

NCT00271011 is a terminated phase II, single-group study of mitomycin C, irinotecan, and cetuximab in previously treated metastatic colorectal cancer. The sponsor is the University of Michigan Rogel Cancer Center. The registry lists enrollment of 13, a start date of 2005-12, and a primary completion date of 2008-07. It says the study was discontinued and not completed because of the death of a co-investigator and another co-investigator leaving the institution.

The primary outcome was the percentage of patients with an objective response at 2 months, using registered definitions for complete and partial response. The primary response result and statistical analyses are not reported in the registry record. Safety entries list serious adverse events for 2 affected among 13 at risk and other adverse events for 13 affected among 13 at risk. These entries do not provide a comparative treatment estimate or establish causation.