Adenocarcinoma of the Pancreas Treated With Panitumumab and Gemcitabine Regimen to Investigate Overall Survival as Primary Endpoint: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Adenocarcinoma of the Pancreas Treated With Panitumumab and Gemcitabine Regimen to Investigate Overall Survival as Primary Endpoint (NCT00613730), a non-randomized phase 2 study. The primary outcome is Overall Survival at 1 Year.

2. Clinical Question

This study was intended to examine a combination regimen as first-line therapy in pancreatic cancer. Its single-arm design means that the registry record does not provide a randomized comparison of the combination with another treatment or with a control condition. The study description planned enrollment of approximately 75 eligible participants across approximately 55 centers in the United States, but actual enrollment was 3. The gap between the stated plan and enrollment is important when interpreting the record: the primary question was not answered with an overall-survival result, and no comparative treatment effect can be estimated from the record.

The clinical question therefore has two parts. The planned question was whether participants receiving the regimen would be alive at the 12-month endpoint, using the stated definition of survival time. The observed record-level question is more limited: what outcome data were available after the study stopped? The registry states that the primary outcome was not evaluated, so it does not report an estimate of survival at 1 year for the enrolled participants.

3. Trial Design

This was a phase II, multi-center, open-label, non-randomized, single-group study of gemcitabine and panitumumab. The registry identifies the study as conducted in the United States and describes a plan to enroll approximately 75 eligible participants at approximately 55 centers. Actual enrollment was 3. The study status is terminated. The recorded start was 2007-01, and the primary completion date was 2009-04.

Because the study had one treatment group and no masking, participants and study personnel were not assigned to concealed or blinded treatment groups. The sole arm was Gemcitabine + panitumumab. There was no randomized allocation and no like-for-like control arm. Consequently, the design does not support an internal randomized comparison between the combination and another regimen. Any interpretation should distinguish the intended single-group assessment from a comparative trial.

The regimen description states that panitumumab 6 mg/kg was administered intravenously before gemcitabine on Day 1 of Weeks 1, 3, 5, and 7, then every 2 weeks on day 1 and 15 of each subsequent 4-week chemotherapy cycle. Gemcitabine 1000 mg/m^2 was administered intravenously once weekly on Day 1 for 7 weeks, followed by a 1-week rest. The record describes first-line treatment for locally advanced unresectable or metastatic pancreatic adenocarcinoma.

Study termination after enrollment of 3 participants limited the amount of outcome information available. The primary endpoint was not evaluated, and the registry record reports no analyses. Reasons for termination, details of the decision to stop, and any operational or recruitment explanation are not reported in the registry record. The original recruitment plan should therefore be read as the planned scale, not as the size of the study that ultimately contributed to the posted 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.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Study was terminated after enrolling 3 participants. This outcome was not evaluated.

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 Overall Survival at 1 Year, measured over 12 months.

The primary endpoint was overall survival at 1 year, with a timeframe of 12 months. The registry defines survival time as beginning on Study Day 1, the first day a participant received study treatment with the gemcitabine regimen in combination with panitumumab, and ending at death due to any cause. This definition counts death regardless of its cause, rather than limiting the endpoint to deaths attributed to pancreatic cancer or study treatment.

In general, overall survival is a time-to-event endpoint: it concerns the time from a defined starting point until death. It is often used in clinical research because the event is clearly defined and does not depend on a judgment about whether disease has progressed. Estimating survival at a particular follow-up time requires outcome and follow-up information for participants, as well as a stated method for handling incomplete follow-up and censoring. Such methods are not reported in the registry record.

For this study, the endpoint's intended meaning is clear, but an estimate is not available in the registry record. The study was terminated after enrolling 3 participants, and the outcome was not evaluated. The record therefore does not report the proportion alive at 12 months, a survival-time estimate, a confidence interval, or a hypothesis-test result. The endpoint definition should not be mistaken for evidence that the endpoint was measured or that a result was obtained.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Interpreting the statistical record begins with separating the study design, outcome definitions, and results. The design was phase II, non-randomized, open-label, and single-group. The primary endpoint was overall survival at 1 year, defined from first treatment to death from any cause. The registry states that this endpoint was not evaluated. These are distinct details: an endpoint can be specified in a protocol or registry without a result being available.

What does a single-group design allow?

In general, a single-group design describes outcomes among participants who receive the study regimen. It does not create a randomized counterfactual group showing what would have happened to comparable participants under another treatment. Randomization is useful because it assigns treatment by chance, helping balance measured and unmeasured factors across groups on average. This study had no randomized allocation and no concurrent control arm, so it cannot provide that form of between-group comparison.

Open-label describes the absence of masking in the recorded design. In general, knowledge of treatment assignment can influence some decisions or assessments, depending on the outcome and study procedures. Overall survival has an objectively defined event in this record—death from any cause—but the registry does not report details of outcome ascertainment, follow-up procedures, or analysis procedures. Those details should not be inferred from the open-label designation alone.

How should the survival endpoint be understood?

Overall survival is a time-to-event outcome. In general, an analysis of time-to-event data accounts for both the time until an event and the fact that some participants may not have experienced the event by the end of their observation. Such participants may be censored at their last known follow-up under an appropriate analysis plan. The registry definition supplies the starting event and endpoint event, but censoring rules, follow-up completeness, and the statistical method for estimating survival are not reported in the registry record.

A confidence interval, in general, gives a range of values compatible with an estimate under the model and assumptions used. It communicates uncertainty rather than guaranteeing that the true value lies in a particular interval. Since the primary outcome was not evaluated, no primary survival estimate or confidence interval is reported. A p-value would address evidence against a specified statistical null model under an analysis plan; no such primary test result is reported either.

What does the record say about analysis?

The registry reports 0 analyses. A statistical analysis plan, including any model, test, confidence-interval method, covariate adjustment, or decision rule, is not reported in the registry record. Interim analyses and stopping criteria are also not reported in the registry record. The fact that the study was terminated does not establish whether a formal interim analysis was performed or what motivated termination.

Progression-free survival and percentage of participants with overall response are listed as secondary outcomes. In general, progression-free survival is also a time-to-event measure, while a response percentage is a proportion defined by response criteria and an assessment schedule. Those criteria, schedules, analysis methods, and results are not reported in the registry record. Without them, the listed outcome names alone do not permit reconstruction of an analysis.

How should sample-size illustrations be read?

The stated assumptions describe planning illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The effect to detect is described as a stated fraction of the observed effect. These are assumptions for planning calculations, not a description of the trial's actual allocation: this study was single-group and did not randomize participants between two arms. The registry record does not report a sample-size justification for the trial itself.

In general, a sample-size calculation asks how many observations a hypothetical design would require under chosen assumptions about effect size, variability, significance level, and power. A planning illustration is not observed power, which should not be used to characterize whether a completed study has established an effect. Since the primary endpoint was not evaluated, an observed primary effect is not available in this record for substantive interpretation. Any such illustrations should therefore be kept separate from the observed enrollment and from conclusions about the study's results.

Over-dispersion is a general issue for count outcomes: it occurs when counts vary more than a simple probability model assumes, which can make standard errors too small if ignored. The record does not report a count-outcome analysis or an over-dispersion adjustment, so this concept should not be taken as a description of the study's methods. More broadly, methods not explicitly documented—including multiplicity handling, missing-data procedures, and analysis populations—remain unknown rather than inferable from the endpoint list.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome, overall survival at 1 year, and two secondary outcomes: progression-free survival and percentage of participants with overall response. When several outcomes are examined, multiplicity is a general statistical concern. Testing multiple hypotheses can increase the chance of at least one apparently unusual result under a setting where all null hypotheses are true. Common approaches include identifying one primary endpoint in advance, adjusting significance thresholds, or treating secondary analyses as exploratory. The multiplicity strategy for this study is not reported in the registry record.

The record states that the primary outcome was not evaluated and lists 0 analyses. It does not report results for the secondary outcomes. Therefore, there are no posted efficacy estimates to compare across endpoints, and no reported inferential tests whose multiplicity adjustment can be assessed. The listed outcomes alone do not establish whether they were formally analyzed or whether any adjustment was planned.

Missing-data handling is also not reported in the registry record. For a time-to-event endpoint, general analysis practice may account for incomplete observation through censoring, but the registry does not state follow-up completeness, censoring rules, or how participants without full follow-up were handled. For the response outcome, the number assessed and the treatment of unevaluable participants are not reported in the registry record.

Analysis populations are not reported in the registry record. It is therefore not possible to determine whether any planned analysis would have included all enrolled participants, only those who received treatment, or another defined population. The reported enrollment of 3 should not be treated as the denominator for each outcome unless the record explicitly reports that analysis population and denominator. No such outcome-specific population is reported.

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: asthenia (33.3%), bile duct obstruction (33.3%), hyperbilirubinaemia (33.3%), decreased appetite (33.3%), dehydration (33.3%).

The registry reports one treatment group, Gemcitabine + Panitumumab, with 3 participants at risk for serious adverse events and 2 affected. For other adverse events, it reports 3 participants at risk and 3 affected. These are the counts recorded for the study; they do not describe comparative risk because there was no control arm.

The serious adverse-event terms listed are Asthenia, Bile duct obstruction, Hyperbilirubinaemia, Decreased appetite, Dehydration, and Hyperglycaemia. Each term is reported with 33.3%. The registry does not provide event-level detail in this record, such as timing, severity grades, duration, recurrence, or attribution to study treatment. The listed percentages should be read as the registry's reported values, not as evidence that these events were caused by the regimen.

In general, adverse-event counts depend on how events are defined, collected, coded, and grouped. A participant may experience more than one event, so participant counts and event counts are not interchangeable. The record's affected-participant counts do not establish how many total events occurred. With 3 participants enrolled, the safety data are limited in scope, and no comparison with another treatment is available.

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

The registry record establishes that a phase II study of gemcitabine and panitumumab was planned for first-line treatment of locally advanced unresectable or metastatic pancreatic adenocarcinoma. It also establishes that the study was terminated after enrolling 3 participants and that overall survival at 1 year, the primary endpoint, was not evaluated. Those statements define what can be concluded from the posted record.

The record does not establish an overall-survival estimate, a progression-free-survival result, or an overall-response percentage. It also does not provide a statistical comparison between the combination and another regimen. No conclusion about the treatment's benefit or lack of benefit can be drawn from a primary outcome that was not evaluated. The absence of a reported result is not itself a result showing no effect.

The trial's single-group design is relevant even apart from early termination. In general, outcomes in one group cannot show what would have happened to similar participants receiving a different treatment. Without randomization or a concurrent comparator, observed outcomes—if reported—would need cautious interpretation as descriptions of the treated participants rather than as an isolated causal effect of treatment.

The adverse-event counts and listed serious terms provide limited descriptive safety information for the enrolled group. They do not establish causation, comparative safety, or the frequency of events in a broader population. The small enrollment means that the record covers only a limited number of participants, and the registry does not report additional details needed for a fuller assessment.

Overall, the record is informative about the study's intended design, regimen, endpoint definition, actual enrollment, termination status, and selected adverse-event counts. It is not an efficacy report. Any planning illustration should be understood as a hypothetical calculation under assumptions, not as an observed power result or a substitute for outcome data.

13. Why This Trial Matters Statistically

This study matters statistically because it illustrates the difference between a registered research question and an analyzed result. The registry clearly defines overall survival at 1 year and its starting point, but also states that the study ended after enrolling 3 participants and that the outcome was not evaluated. A detailed endpoint definition is useful for understanding what was intended, but it cannot supply the missing estimate.

The record also highlights why enrollment and design must be considered together. The planned study description called for approximately 75 participants across approximately 55 centers, while actual enrollment was 3. The record does not report why the study ended. Statistically, the actual enrollment limits the available information, and the absence of endpoint analysis prevents assessment of an estimated effect or its precision.

Its single-arm structure is another important feature. Without randomization and a concurrent control group, the study could not make a direct randomized comparison. This distinction matters because a study can be designed to describe outcomes after treatment without being able to isolate the treatment's effect relative to another option.

Finally, the registered secondary endpoints and safety counts should not be mistaken for completed efficacy analyses. The record lists progression-free survival and overall response but reports no analyses. It does give adverse-event counts and terms, yet those data address a different question from whether the primary survival endpoint was met. Reading each type of information according to its role helps prevent a registry entry from being interpreted as a fuller trial result than it contains.

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.

Several trial-specific limitations constrain interpretation. The most direct is that the study was terminated after enrolling 3 participants and the primary endpoint was not evaluated. The record therefore lacks a reported overall-survival result at 1 year. It also reports 0 analyses, and results for the listed secondary outcomes are not reported in the registry record.

The design was non-randomized and single-group, with no comparator. Even if outcome measurements had been reported, the design would not provide a randomized estimate of how outcomes differed from those under another treatment. Open-label conduct is recorded, but further information on outcome assessment and protections against assessment bias is not reported in the registry record.

The planned enrollment of approximately 75 participants was not reached; actual enrollment was 3. The reason for termination, recruitment experience, and any explanation of enrollment shortfall are not reported in the registry record. Baseline participant characteristics, follow-up duration for each participant, and completeness of outcome ascertainment are also not reported in the registry record.

The registry does not report the statistical analysis plan, methods for handling missing data or censoring, analysis populations, interim analyses, or multiplicity procedures. These omissions mean the intended inferential framework cannot be evaluated from the record. Adverse-event information is likewise limited: the record gives affected-participant counts and several serious-event terms but does not report event timing, severity grades, attribution, or detailed event counts.

These limitations describe the information available in the registry record, not the reasons the study ended or the clinical meaning of any unreported participant outcomes. Those details are not reported in the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Adenocarcinoma of the Pancreas Treated With Panitumumab and Gemcitabine Regimen to Investigate Overall Survival as Primary Endpoint — NCT00613730.
• Registry record last updated 2014-01-06; status last verified 2013-11.
• Results first posted 2014-01-06.
• 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

This was a phase II, multi-center, open-label, non-randomized, single-group study of first-line gemcitabine and panitumumab for locally advanced unresectable or metastatic pancreatic adenocarcinoma. The planned enrollment was approximately 75 participants at approximately 55 centers in the United States; actual enrollment was 3. The registry records the study as terminated.

The primary endpoint was overall survival at 1 year, measured from the first day of study treatment to death from any cause. The registry states that this outcome was not evaluated. Progression-free survival and percentage of participants with overall response are listed as secondary outcomes, with no results reported in the registry record.

The registry reports 2 participants affected by serious adverse events among 3 at risk, and 3 affected by other adverse events among 3 at risk. Six serious-event terms are listed, each with 33.3%. The record reports 0 analyses and does not provide a randomized comparison or a primary efficacy estimate.