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 Bevacizumab With or Without Docetaxel in Treating Patients With Previously Treated Metastatic Pancreatic Cancer (NCT00066677), a randomized phase 2 study. The primary outcome is Progression-free Survival.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00066677 |
| Phase | Phase 2 |
| Condition | Pancreatic Cancer |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 32 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Fox Chase Cancer Center |
| Results posted | Yes |
2. Clinical Question
Population
Patients with previously treated metastatic pancreatic adenocarcinoma were eligible for the study. The registry record identifies pancreatic cancer as the condition and describes the trial population as patients with metastatic disease. It does not report detailed eligibility criteria, such as specific prior treatments or clinical characteristics.
Intervention
The combination group received bevacizumab, listed in the record as rhuMAB-VEGF, with docetaxel. Bevacizumab was administered by intravenous infusion every 2 weeks. Docetaxel was administered intravenously on days 1, 8, and 15 of each 28-day cycle. Treatment continued until disease progression, unacceptable toxicity, or patient preference, as described in the record.
Comparator
The comparison group received bevacizumab alone, administered by intravenous infusion every 2 weeks. The trial used randomized allocation and a parallel-group design. Masking was listed as none, so the record describes the study as unmasked.
Primary question
The primary endpoint was progression-free survival. The clinical question was whether the recorded time to progression or death differed between the bevacizumab-alone group and the group receiving bevacizumab with docetaxel. The registry reports median progression-free survival for each group, but does not report a comparative hazard ratio or a statistical test for this primary endpoint. The study description says it was stopped under an early stopping rule for futility.
3. Trial Design
This was a randomized, open-label, parallel-group Phase II trial sponsored by Fox Chase Cancer Center. It enrolled 32 participants, with 16 assigned to bevacizumab alone and 16 assigned to bevacizumab with docetaxel. The registry record lists the study start as 2003-10 and primary completion as 2008-11. Its status is terminated.
The treatment groups differed by the addition of docetaxel to bevacizumab. In the monotherapy group, bevacizumab was given as an intravenous infusion every 2 weeks. In the combination group, bevacizumab was given on the same schedule, with docetaxel administered intravenously on days 1, 8, and 15 of each 28-day cycle. The registry describes treatment as continuing until disease progression, unacceptable toxicity, or patient preference.
Random allocation helps make a comparison between assigned groups less vulnerable to systematic differences at the start of a trial. The record does not report the sequence-generation method, allocation concealment, or stratification factors, so those features cannot be assessed from the registry information. Because masking was listed as none, treatment assignment was not masked according to the record. This can matter for outcomes involving clinical judgment or reporting, although the extent of any effect cannot be determined from the available information.
The registry describes the study as stopping according to an early stopping rule for futility. It also states that all patients who entered the study have died. The criteria for stopping, the timing and conduct of any interim review, and the statistical evidence used to apply the stopping rule are not reported in the registry record. Those details should not be inferred from the termination status alone.
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 | rhuMAB-VEGF | rhuMAB-VEGF and Docetaxel |
|---|---|---|
| STARTED | 16 | 16 |
| COMPLETED | 16 | 16 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: The study was stopped according to the early stopping rule for futility. All patients who entered the study have died.
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.
| Characteristic | Unit | rhuMAB-VEGF | rhuMAB-VEGF and Docetaxel | Total |
|---|---|---|---|---|
| Participants analysed | 16 | 16 | 32 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 6 | 11 | 17 |
| Age, Categorical: >=65 years | Participants | 10 | 5 | 15 |
| Sex: Female, Male: Female | Participants | 10 | 8 | 18 |
| Sex: Female, Male: Male | Participants | 6 | 8 | 14 |
| Region of Enrollment: United States | participants | 16 | 16 | 32 |
6. Primary Endpoint
The registry lists the primary outcome as Progression-free Survival, measured over 4 months.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Full Range |
| Unit | days |
| Endpoint classification | Time-to-Event Analysis |
Progression-free survival measures the time until a participant experiences disease progression or dies, according to the endpoint definition used in the study. It combines these events into a time-to-event outcome. This can summarize how long participants remain alive without recorded progression, while accounting for the timing of events rather than treating all participants as having only a yes-or-no outcome.
The registry lists progression-free survival as the primary endpoint, with a timeframe of 4 months and results expressed as medians in days. The median is the point in the observed time distribution at which half of the observations lie on either side. It describes the center of the recorded times, but does not by itself describe the shape of the full time-to-event distribution or quantify the relative event rate between groups.
Time-to-event outcomes are useful when participants may experience the event at different times and when follow-up duration can vary. A comparative analysis often uses the full event-time information, for example through a hazard ratio, rather than comparing medians alone. The registry record does not report a hazard ratio, confidence interval, or statistical test for the primary endpoint. Therefore, the posted group medians are descriptive and do not establish the size or precision of a comparative effect.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
Median progression-free survival was 43 days in the bevacizumab-alone group and 48 days in the bevacizumab-plus-docetaxel group. The reported full range was 28 to 120 days in each group. These are descriptive summaries of the recorded time-to-event outcome. A difference between the two medians should not be treated as a formal estimate of treatment effect: the registry does not report a primary-endpoint hazard ratio, confidence interval, or test of the between-group comparison.
The record says that the study was stopped according to an early stopping rule for futility and that all patients who entered the study have died. This context is important for understanding why the registry reports a terminated study rather than a completed ongoing comparison. However, the futility boundary, review timing, analysis used to make the decision, and underlying statistical results are not reported in the registry record. The termination statement therefore cannot be translated into an unreported effect estimate or a claim about whether the treatments differ.
For the secondary thromboembolic outcome, the posted comparison is unadjusted. Its p-value is 0.626, and the reported risk-difference confidence interval includes zero. In general, a confidence interval describes the range of effect values reasonably compatible with the data and analysis assumptions. An interval that includes zero for a risk difference does not provide clear evidence of a difference in the event proportions. The estimate is also imprecise, consistent with the small group sizes and limited event counts. The registry does not report adjusted analyses for this outcome.
The numerical secondary finding should be read as exploratory rather than as confirmatory evidence. Several secondary outcomes are listed, but the record does not provide results for objective response rate or overall survival. It also does not report an approach to controlling the chance of false-positive findings across multiple outcomes. An unadjusted result from one secondary comparison consequently carries less weight than a prespecified, fully reported primary analysis, especially when that primary analysis is not available in the registry record.
The safety record indicates that serious adverse events affected 13 of 16 participants in the bevacizumab-alone group and 15 of 16 in the combination group. These counts describe participants with serious adverse events, not the total number of separate events, and do not establish that treatment caused them. Interpretation is limited because the registry does not provide the timing, duration, severity grading details, or attribution of each event in the summary presented.
9. Statistical Methods Explained
The principal result is a time-to-event endpoint summarized by medians and full ranges. This is different from comparing a simple event proportion at one fixed time. A time-to-event analysis uses information about when events occur and can also account for participants whose event time is not observed during follow-up, if the analysis and censoring information are available. The registry does not report censoring details or a primary-endpoint analysis method, so those aspects cannot be evaluated.
What does a median time tell us?
A median is a compact description of the middle of a distribution. It can be useful when time-to-event data are skewed, as is common when many participants have events at different times. But medians alone leave out much of the event-time pattern. Two groups can have similar medians while differing at other points in their distributions, or have different medians without a clearly estimated overall contrast. A median also does not indicate the precision of the estimate unless an uncertainty measure, such as a confidence interval, is reported.
The registry reports medians and full ranges for progression-free survival but no confidence intervals for those medians. It also does not report a hazard ratio or another formal comparison for this endpoint. A hazard ratio, when appropriate, summarizes the relative event rate over follow-up under its model assumptions. Because no such sponsor-reported result appears in the record, the primary result should be described using the posted medians, without constructing a comparative estimate from them.
How should the secondary risk difference be read?
The thromboembolic comparison is reported as a risk difference, which contrasts the event proportions in the two groups. A risk difference of zero represents equal event proportions; values on either side indicate the direction of the observed contrast. The confidence interval for this comparison includes zero, so the posted data are compatible with no difference as well as with effects in either direction. The broad interval reflects substantial uncertainty. It should not be read as proof that the groups are equivalent.
The posted p-value is unadjusted. A p-value measures how unusual data at least as incompatible with a specified null hypothesis would be, assuming that hypothesis and the analysis model. It is not the probability that the null hypothesis is true, nor does it measure clinical importance. The unadjusted p-value of 0.626 does not supply evidence of a clear difference in this secondary outcome. Since the outcome is one of several listed secondary endpoints, and no multiplicity procedure is reported, it should be interpreted cautiously.
Why do small event counts affect precision?
When event counts and group sizes are limited, estimates of event proportions and their contrasts can vary substantially with a small change in the observed data. This is reflected in uncertainty intervals that cover a wide range of possibilities. General statistical principle: sparse data make it difficult to distinguish a modest underlying difference from random variation. This does not make the recorded counts invalid; it limits how precisely they estimate a broader treatment effect.
The registry also lists risk-ratio and odds-ratio summaries for the thromboembolic comparison. These measures express relative rather than absolute contrasts. They can look different in scale from a risk difference and are not interchangeable interpretations. Since the relative-effect intervals are broad and the event counts are limited, they do not remove the uncertainty evident in the risk-difference analysis. No adjustment for other participant characteristics is reported.
What do the planning illustrations mean?
The registry includes sample-size planning illustrations derived from the observed secondary effect. These are planning scenarios, not a measure of the trial's observed power and not evidence that a future study will achieve a particular result. The stated assumptions are a two-sided significance level of 0.05, equal allocation, and a normal approximation. The illustrations consider planning for 100%, 75%, and 50% of the observed effect. Under those assumptions, the record gives participants per arm for 80% and 90% power.
Because these illustrations use an effect observed in a small trial, the effect used as the planning basis may itself be uncertain. The illustrations are not the original trial's sample-size justification: that justification is not reported in the registry record. The record also does not describe the trial's original power target or the assumptions used when designing it. Planning calculations should therefore be treated as conditional examples rather than as retrospective evidence that the study was or was not adequately powered.
What information is missing for a full appraisal?
The registry does not report a detailed statistical analysis plan, the primary analysis population, handling of missing observations, or methods for checking model assumptions. It does not provide a primary-endpoint comparative estimate or its uncertainty. These omissions prevent a full assessment of the planned-versus-reported analysis and of how precisely the primary endpoint compares the groups. General statistical principle: transparent reporting of endpoint definitions, analysis populations, censoring, and uncertainty helps distinguish descriptive summaries from inferential conclusions.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary endpoint and several secondary outcomes, but does not report how the analyses were organized or whether any secondary outcomes were intended to support confirmatory claims. It does not describe a multiplicity strategy, such as adjustment of significance thresholds or a prespecified testing sequence. When multiple outcomes are examined, the chance of at least one apparently notable result due to random variation can increase. General statistical principle: multiplicity planning helps distinguish confirmatory tests from exploratory analyses. Without a reported strategy, unadjusted secondary findings should be interpreted as exploratory.
Missing-data procedures are not reported in the registry record. For a time-to-event endpoint, information about censoring and follow-up is important because not every participant necessarily has an observed event during a specified period. Although the registry states that all participants who entered the study have died, it does not describe how progression was assessed, whether any progression observations were missing, or how death and progression times were handled in the analysis. Those details should not be inferred from the outcome summary.
The record gives group sizes for the posted primary endpoint summaries and the secondary event comparison, but does not identify a formal analysis population such as intention-to-treat or per-protocol. It also does not report whether all randomized participants were included in every analysis, or how deviations from assigned treatment were treated. The absence of these details limits assessment of potential exclusions and of the alignment between randomized assignment and analyzed groups.
No detailed statistical plan, interim-analysis methods, or stopping boundary is reported. The record states that the trial stopped under an early stopping rule for futility, but does not describe how the rule was specified or applied. Early stopping can affect the amount of information collected and the interpretation of estimates, but the consequences in this study cannot be quantified from the registry record. The missing analysis and stopping details are important context, not grounds for inventing a statistical explanation for termination.
11. 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 |
|---|---|---|---|
| rhuMAB-VEGF | 13 | 16 | 81.2% |
| rhuMAB-VEGF and Docetaxel | 15 | 16 | 93.8% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| rhuMAB-VEGF | 16 of 16 |
| rhuMAB-VEGF and Docetaxel | 16 of 16 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| rhuMAB-VEGF | 0 of 16 |
| rhuMAB-VEGF and Docetaxel | 0 of 16 |
Most frequent serious adverse event terms
| Event term | Organ system | rhuMAB-VEGF | rhuMAB-VEGF and Docetaxel |
|---|---|---|---|
| Fatigue | General disorders | 13 of 16 | 15 of 16 |
| Anemia | Blood and lymphatic system disorders | 12 of 16 | 15 of 16 |
| Anorexia | General disorders | 10 of 16 | 11 of 16 |
| Hypoalbuminemia | General disorders | 9 of 16 | 10 of 16 |
| Nausea and vomiting | General disorders | 7 of 16 | 9 of 16 |
| Leukopenia | Blood and lymphatic system disorders | 5 of 16 | 11 of 16 |
| Proteinuria | General disorders | 6 of 16 | 8 of 16 |
| Neutropenia | Blood and lymphatic system disorders | 4 of 16 | 7 of 16 |
| Dehydration | General disorders | 3 of 16 | 4 of 16 |
| diarrhea | General disorders | 3 of 16 | 4 of 16 |
Serious events with the highest arm-level rate: fatigue (93.8%), anemia (93.8%), anorexia (68.8%), leukopenia (68.8%), hypoalbuminemia (62.5%).
The registry records serious adverse events in 13 of 16 participants assigned to bevacizumab alone and 15 of 16 assigned to bevacizumab with docetaxel. These figures count participants affected; they are not counts of every serious event. The record also lists fatigue and anemia among the most frequent serious adverse-event terms, each at 93.8%, with anorexia and leukopenia each at 68.8%, hypoalbuminemia at 62.5%, and nausea and vomiting at 56.2%. The summary does not specify the group attribution for each listed percentage, so the percentages should not be assigned to a particular group.
Adverse-event summaries describe events observed during the study; they do not by themselves establish that a treatment caused an event. The registry's reported counts do not provide, in this summary, event timing, duration, severity breakdown, or investigator attribution. The record lists zero participants with other adverse events in each group, but that entry should not be mistaken for evidence that no non-serious symptoms occurred unless the registry's categorization and reporting are understood. Comparisons of safety counts are descriptive and based on limited group sizes.
12. What the Result Does, and Does Not, Mean
The posted results describe a small randomized Phase II comparison of bevacizumab alone with bevacizumab plus docetaxel in previously treated metastatic pancreatic cancer. The primary endpoint summaries give median progression-free survival of 43 days and 48 days, respectively, with the same reported full range of 28 to 120 days. These figures describe the recorded distributions, but the registry does not report a comparative hazard ratio, confidence interval, or statistical test for progression-free survival.
The study's termination under an early stopping rule for futility is part of the record, as is the statement that all patients who entered the study have died. The information available does not identify the futility criterion or the analysis behind the stopping decision. Accordingly, neither the descriptive medians nor the termination status alone can quantify a treatment effect or establish that the regimens are equivalent.
The available secondary event comparison is unadjusted and uncertain, and results for other listed secondary outcomes are not reported. Serious adverse-event counts are also descriptive and cannot establish causation. These findings are best understood as a limited record of outcomes in the enrolled groups, rather than a complete account of comparative efficacy and safety.
The registry does not report enough detail to assess the primary analysis method, missing-data handling, analysis populations, or multiplicity procedures. Those gaps matter because statistical conclusions depend not only on point summaries, but also on how data were analyzed and how uncertainty was quantified. The posted information therefore supports a careful description of the observed results and their limitations, not medical advice or a definitive treatment recommendation.
13. Why This Trial Matters Statistically
This trial illustrates an important distinction between reporting group summaries and reporting a comparative treatment effect. Medians can describe the center of each observed time-to-event distribution, but they do not show how precisely the groups differ. A comparative estimate with an uncertainty interval would help readers assess both the direction and precision of the primary result. The registry record does not report such an estimate for progression-free survival.
The record also shows why a stopping statement needs statistical context. A trial stopped for futility has an important design and interpretation history, but the label alone does not reveal the stopping boundary, interim evidence, or expected operating characteristics. Without those details, readers cannot reconstruct the decision or determine how stopping affected the reported estimates.
Secondary outcomes and safety summaries add useful descriptive context, yet limited counts and unadjusted comparisons constrain inference. Multiple endpoints call for clear distinctions between confirmatory and exploratory analyses. Reporting the analysis plan, analysis populations, missing-data approach, and multiplicity strategy would make those distinctions easier to evaluate.
Finally, planning illustrations based on an observed effect are not observed power and do not replace the original sample-size rationale. They show how future sample-size requirements depend on the effect one aims to detect and the stated assumptions. This record is therefore a useful example of how randomized allocation and numerical summaries can coexist with substantial uncertainty about the primary comparison and its analysis.
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 registry record does not report detailed eligibility criteria, baseline characteristics, or the distribution of prior treatments. Without those details, readers cannot assess how similar the assigned groups were on prognostic factors or how closely the enrolled population represents a broader clinical population. Randomization is helpful for group comparability, but the available record does not describe allocation concealment or sequence generation.
The primary result is limited to medians and ranges. No confidence intervals for the medians, primary-endpoint hazard ratio, or formal comparison test are reported. The endpoint's timeframe is listed as 4 months, but the record does not provide a fuller description of assessment schedules or censoring. These omissions limit interpretation of the time-to-event summaries, particularly alongside the stated early stopping for futility.
The record does not explain the stopping rule, when it was applied, or the evidence reviewed. Nor does it report the statistical analysis plan, multiplicity approach, missing-data procedures, or analysis populations. These are trial-specific limitations because they prevent readers from determining how the registered outcomes were analyzed and whether all randomized participants contributed to each result.
Only one of the listed secondary outcomes has a posted numerical comparison. Results for objective response rate and overall survival are not reported in the registry record. Safety reporting includes participant counts and selected serious adverse-event terms, but the summary lacks detail on event timing and attribution. The available information therefore provides an incomplete view of both efficacy outcomes and the safety experience.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Bevacizumab With or Without Docetaxel in Treating Patients With Previously Treated Metastatic Pancreatic Cancer — NCT00066677.
- Registry record last updated 2021-03-05; status last verified 2021-02.
- Results first posted 2021-03-05.
- 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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18. Record Summary
NCT00066677 was a randomized, unmasked, parallel-group Phase II trial sponsored by Fox Chase Cancer Center. It compared bevacizumab alone with bevacizumab plus docetaxel in previously treated metastatic pancreatic cancer. The registry records enrollment of 32 participants and lists the study status as terminated.
Progression-free survival was the primary endpoint. The posted medians were 43 days for bevacizumab alone and 48 days for the combination group, with a full range of 28 to 120 days in each group. The record states that the study stopped under an early stopping rule for futility and that all patients who entered the study have died. It does not report a comparative primary-endpoint analysis.
Thromboembolic events are the only secondary outcome with a posted numerical comparison; results for objective response rate and overall survival are not reported in the registry record. Serious adverse events were reported in both groups. The record does not report detailed analysis methods, multiplicity handling, missing-data procedures, or the stopping-rule criteria.