Erlotinib and RAD001 (Everolimus) in Patients With Previously Treated Advanced Pancreatic Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Erlotinib and RAD001 (Everolimus) in Patients With Previously Treated Advanced Pancreatic Cancer (NCT00640978), a na phase 2 study. The primary outcome is Number of Participants Surviving at 6 Months.

2. Clinical Question

3. Trial Design

The registry record describes a phase II study of erlotinib plus RAD001 (everolimus) in patients with previously treated advanced pancreatic cancer. It lists M.D. Anderson Cancer Center as the sponsor, an enrollment of 16, and a single-group model. The allocation field is recorded as not applicable, and masking is listed as none. This is not a randomized comparison: all listed treatment information concerns the combination group, and there is no like-for-like control arm in the record.

The regimen is described as erlotinib 150 mg orally daily for 28 Days together with RAD001 30 mg orally weekly for 4 Weeks. These are the treatment details recorded for the group; the registry information summarized for this study does not describe additional treatment, dose changes, or adherence. The start is recorded as 2008-03, and primary completion as 2010-03. The overall status is terminated. The reason for termination is not reported in the registry record.

The stated primary objective was overall survival (OS) at six months. The secondary objectives were progression-free survival (PFS) and response rate (RR). The registry record lists one outcome measure, the number of participants surviving at six months, and zero analyses. It does not give numerical results for the primary endpoint or the secondary objectives. The brief description says that safety was also to be studied, while the adverse-event record supplies group counts for serious and other adverse events. Those safety counts do not substitute for an efficacy comparison, and the single-group design does not establish how outcomes would have differed under another treatment or no study treatment.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: Of the sixteen registered, one (1) participant was enrolled but did not receive the planned treatment.

Overall Study

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 Number of Participants Surviving at 6 Months, measured over 6 months.

The primary endpoint is the number of participants alive at six months among participants receiving the combination after previous treatment for advanced pancreatic cancer. Overall survival is a time-to-event concept: it concerns the time until death, with participants who have not died by a specified assessment point considered alive at that point. The registry operationalizes its primary outcome as a count at the six-month landmark, rather than reporting a survival estimate in the information available for this study.

A fixed-time survival endpoint can give a clinically interpretable snapshot of whether participants are alive at a stated follow-up point. It can be useful in an early-phase study when the objective is to describe outcomes in a defined group. However, a count alone does not show when deaths occurred, how follow-up varied, or how many participants had incomplete follow-up. Those details matter when interpreting survival, especially if participants are not all observed for the same duration.

The record does not report the number alive at six months, a denominator for the endpoint result, a confidence interval, or a method for handling incomplete follow-up. It therefore supports identifying what the endpoint was intended to measure, but not estimating the observed survival level or its precision.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a single-group design estimate?

In a single-group study, outcomes are described among participants who receive the listed intervention. This can be informative for documenting what happened in that group, including whether further study may be reasonable. It does not create a concurrent comparison group. Without one, the study cannot isolate the treatment's contribution from the natural course of illness, earlier treatment, patient selection, or other factors that may affect outcomes. A descriptive outcome and a causal treatment effect are different statistical quantities.

Here, the registry records a single-group model and no masking. Allocation is not applicable, consistent with the absence of a randomized allocation between listed groups. The study therefore should not be interpreted as a randomized trial comparing erlotinib plus RAD001 against another regimen. The record's designation as phase II describes the study phase, but does not by itself specify an analysis method or establish that a particular statistical plan was used.

How should the survival endpoint be understood?

Overall survival concerns time until death. The primary outcome is described as a count of participants alive at six months, so it is a fixed-time summary of survival status. In general, time-to-event analyses can use information about when events occur and can account for participants whose event has not occurred by the end of observation. A count at a landmark is less informative about event timing and can be affected by incomplete follow-up. The registry record does not report whether a time-to-event estimator, censoring method, or another analysis was used.

For a survival estimate, a confidence interval communicates statistical uncertainty around the estimate. It is not a guarantee that the true value lies within the interval; rather, it reflects the variability expected under the method's assumptions. The record does not report a survival estimate or confidence interval, so there is no precision interval to interpret. No new estimate can be recovered from the enrollment figure alone.

What do the outcome and analysis listings tell readers?

The record lists one outcome measure, the number of participants surviving at six months, and zero analyses. The primary objective names PFS and response rate as secondary objectives, but no corresponding numerical results or analysis outputs are reported in the record. An objective describes a question investigators intended to address; it is not itself an outcome result. Readers should distinguish between an endpoint's definition and a reported estimate for that endpoint.

For binary outcomes, a count is often interpreted alongside a denominator, yielding an estimate of the frequency of the event in the defined population. Statistical uncertainty can then be described with an interval or another method appropriate to the design and data. The primary endpoint is presented as a count, but the record does not give the observed count, a result denominator, or an uncertainty interval. No proportion or other derived summary should be inferred from the enrollment figure.

What are the sample-size illustrations?

The planning illustration is described as a calculation based on the observed effect, not as the trial's own design. Its stated assumptions include a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The effect to detect is defined as a stated fraction of the observed effect. For time-to-event outcomes, the illustration concerns the total number of events; for other outcomes, it concerns participants per arm.

These assumptions describe a hypothetical planning exercise. They do not turn the single-group study into a two-arm randomized trial, and they are not evidence that the study was planned with those assumptions. The actual design rationale and sample-size justification are not reported in the registry record. A planning calculation based on an observed effect also depends on the effect estimate used; it should not be confused with observed power, which is not a useful substitute for reporting an estimate and its uncertainty. No planning sample-size results are reported in the information summarized for this study.

Why can over-dispersion matter in general?

In general, a statistical model can be too optimistic if it assumes that observations vary less than they actually do. Over-dispersion means that observed variation exceeds what a model's assumptions expect. If it is ignored, standard errors may be underestimated and confidence intervals may be too narrow. This issue can arise in some count or clustered-data settings, but the registry record does not identify an over-dispersion analysis for this trial. It would not be appropriate to assert that such a model was used or required based on the available record.

More broadly, analysis choices should follow the outcome type, follow-up structure, and prespecified plan. The registry record does not report an inferential statistical plan, model specification, or adjustment strategy. The methods that generated any unposted outcomes are therefore not available for assessment. General statistical explanations can clarify what a method would mean, but they cannot fill in methods or results that the record does not report.

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("Erlotinib + RAD001")
n      <- c(15)
events <- c(15)
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  Erlotinib + RAD001  15  15  100.0  78.2  100.0  79.6  100.0  79.4  99.8

11. Multiplicity, Missing Data and Analysis Populations

The study description names a primary objective of overall survival at six months and secondary objectives of progression-free survival and response rate. Considering several outcomes can create multiplicity: when many hypotheses are tested, the chance of at least one apparently unusual result can increase. Statistical plans sometimes address this by defining a hierarchy, allocating error rates, or treating secondary analyses as exploratory. The registry record does not report a multiplicity strategy, so it is not possible to determine whether or how the secondary objectives were accounted for in formal testing.

The record lists one outcome measure and zero analyses. It does not report numerical results for the primary outcome or the named secondary objectives. It also does not report a missing-data method, an analysis population, rules for outcome evaluability, or how incomplete survival follow-up was handled. These are important because participants without complete outcome information may not contribute to a particular estimate in the same way as participants with complete follow-up.

The registry enrollment is 16, but the record does not state how many participants were included in an analysis of the six-month endpoint. Enrollment alone should not be treated as the endpoint denominator. The record also does not describe whether analyses were based on all enrolled participants, participants who began treatment, or another defined population. These items are not reported in the registry record, so assumptions about them would be speculative.

Without reported methods and results, readers cannot assess the impact of missing observations, selective outcome reporting, or multiple comparisons. This is an information limitation, not proof that particular methods were or were not used outside the registry record.

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 non-serious adverse event terms

For the Erlotinib + RAD001 group, the registry lists 16 participants at risk for serious adverse events and 0 affected. For other adverse events, it lists 16 at risk and 16 affected. These are registry counts, not a comparison between treatment groups. The record lists no top serious adverse-event terms.

The serious adverse-event count describes the number of participants recorded as affected, not the number of event episodes or their duration. The other adverse-event count is a separate category in the record; the fact that it lists 16 affected does not establish the nature, severity, timing, or clinical importance of those events. The categories should not be combined or treated as interchangeable.

The deaths field is not populated in the listed adverse-event information. It is therefore not possible to interpret that field as a reported death count. More generally, adverse-event counts do not establish that an event was caused by treatment. The registry information summarized for this study does not provide event-level details, exposure-adjusted rates, a control group, or a fuller safety analysis. These limitations constrain safety interpretation.

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

This record establishes that a phase II, single-group study evaluated a regimen of erlotinib with RAD001 (everolimus) in previously treated advanced pancreatic cancer. It identifies overall survival at six months as the primary objective and defines the outcome as the number of participants alive at that time. It also describes PFS and response rate as secondary objectives and includes counts for serious and other adverse events.

It does not establish the observed six-month survival result. The numerical result for the primary endpoint is not reported in the registry record, and numerical results for the secondary objectives are also absent. No confidence interval or inferential analysis is reported. Consequently, the record does not permit a reader to quantify the outcome, assess its statistical precision, or judge how compatible it is with a range of possible underlying results.

The single-group design also limits causal interpretation. Even if outcome values were reported, the absence of a randomized control group would mean that observed survival or response could not be attributed to the combination by comparison with an alternative. The record does not provide the basis for estimating what would have happened to a comparable group receiving another treatment.

The safety counts are descriptive and incomplete as a basis for a broad risk assessment. They give participant counts for serious and other adverse events but do not provide a detailed account of event types, timing, severity, or attribution. The terminated status likewise does not explain why the study ended or what conclusions investigators reached.

The appropriate conclusion is narrow: the registry record describes the question, design, regimen, and some safety counts, but does not report the efficacy results needed to answer its primary question. This absence is not evidence that the combination did or did not change survival, progression, response, or safety outcomes.

14. Why This Trial Matters Statistically

This trial is statistically instructive because its stated clinical question and its design need to be read together. The primary objective concerns survival at a defined follow-up point, but the listed design is single-group. The study can describe outcomes among participants receiving the combination, yet it lacks a concurrent randomized control group for a like-for-like treatment comparison. Recognizing that distinction prevents a descriptive result from being mistaken for a causal effect.

The record also illustrates why an endpoint definition is not equivalent to an endpoint result. It clearly names the number of participants alive at six months, but the numerical result and its uncertainty are not reported. Without those quantities, neither the magnitude nor precision of the outcome can be assessed. A study's enrollment figure does not fill that gap, because the record does not give an endpoint denominator or account of follow-up completeness.

There is a further distinction between an analysis plan and a planning illustration. The sample-size assumptions describe a hypothetical calculation based on an observed effect, including equal allocation between two arms, whereas the recorded trial design is single-group. The illustration should not be mistaken for the study's actual design rationale, or as evidence of observed power. The rationale for the trial's planned size is not reported in the registry record.

Finally, the record connects efficacy reporting, missing-data transparency, multiplicity, and safety interpretation. It lists secondary objectives but no corresponding numerical results, and it offers limited adverse-event counts without detailed event descriptions. These features show why statistical interpretation depends not only on a study's question but also on transparent reporting of estimates, uncertainty, analysis populations, and methods.

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 limitations are specific to the information recorded for this study. The primary endpoint is defined, but its observed count and denominator are not reported. There is no reported survival estimate or confidence interval, so the outcome's magnitude and precision cannot be assessed. The registry record also lists zero analyses, leaving no reported inferential results to evaluate.

The study is single-group, with no randomized comparator. This limits any causal comparison of the combination with another treatment or control condition. The registry does not report detailed eligibility criteria, the reason for termination, or a sample-size justification. The listed enrollment of 16 should not be assumed to equal the number with complete endpoint follow-up or the number included in an analysis.

The primary objective is accompanied by secondary objectives for PFS and response rate, but their numerical results are not reported in the registry record. A strategy for multiplicity is also not reported. The record does not describe missing-data handling, the endpoint analysis population, outcome assessment details, or a statistical model. These omissions prevent evaluation of how incomplete follow-up or analysis choices may have affected results.

Safety information is limited to counts of participants affected by serious and other adverse events. The record does not give detailed event terms, timing, severity, attribution, or a populated deaths field. The reason the study was terminated is not reported, and the status alone does not explain what conclusions can be drawn from the study's conduct.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Erlotinib and RAD001 (Everolimus) in Patients With Previously Treated Advanced Pancreatic Cancer — NCT00640978.
• Registry record last updated 2026-07-07; status last verified 2026-06.
• Results first posted 2011-09-27.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

The registry describes a phase II, single-group study sponsored by M.D. Anderson Cancer Center in patients with previously treated advanced pancreatic cancer. It records enrollment of 16, a start of 2008-03, primary completion of 2010-03, and status as terminated. The regimen was erlotinib 150 mg orally daily for 28 Days with RAD001 30 mg orally weekly for 4 Weeks.

The primary outcome was the number of participants alive at six months. PFS and response rate were named as secondary objectives. The registry record does not report numerical efficacy results, a confidence interval, or an analysis. It lists zero analyses. For safety, it records 0 affected by serious adverse events and 16 affected by other adverse events in the group, with 16 at risk in each category. The reason for termination is not reported in the registry record.