Vaccine Therapy in Treating Patients With Liver or Lung Metastases From Colorectal Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Vaccine Therapy in Treating Patients With Liver or Lung Metastases From Colorectal Cancer (NCT00103142), a randomized phase 2 study. The primary outcome is Recurrence-free Survival at 2 Years.

2. Clinical Question

3. Trial Design

This was a completed, randomized, parallel-group phase II trial with no masking. The registry lists an enrollment of 74 and gives the study start as 2005-02 and primary completion as 2009-06. The sponsor is listed as Michael Morse, MD. The registry record does not report the method used to generate the random allocation sequence or the process used to conceal allocation before assignment.

The comparison was between PANVAC-V and PANVAC-F given with autologous dendritic cells, and PANVAC-V and PANVAC-F given with GM-CSF. The vaccine approach used a gene-modified virus; the dendritic-cell approach involved cells collected from the participant and loaded with vaccine. For the GM-CSF group, the registry gives administration days for PANVAC-V, PANVAC-F, and sargramostim. The description of the dendritic-cell schedule is incomplete in the registry record, so its full regimen cannot be reconstructed from that description.

The primary outcome was recurrence-free survival at 2 years, measured from the date of metastasectomy. Relapse was defined as documented disease recurrence at any site. The registry reports endpoint counts of 13.0 among 16.0 for the dendritic-cell group and 10.0 among 20.0 for the GM-CSF group. The registry enrollment and the endpoint group counts are different quantities; why the posted primary endpoint counts cover those group sizes is not reported in the registry record.

The registry lists a secondary immune-response outcome assessed by an ELISpot assay at 13 weeks. It also records that the trial was completed. The trial’s original sample-size justification, planned allocation ratio, intended analysis population, and detailed statistical analysis plan are not reported in the registry record. The posted comparisons therefore describe the available registry results rather than a complete account of the original design or conduct.

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: The study was designed to treat 72 subjects. Total number of enrollment is 74 because enrollment reflects the number of subjects that signed consent and were randomized to the study but did not necessarily receive study drug or complete study drug.

Overall Study

Reasons for not completing this period:

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

Population: 37 PANVAC-V + PANVAC-F + DC arm patients and 37 PANVAC-V + PANVAC-F + GM-CSF arm. One participant in PANVAC-V + PANVAC-F + DC Arm was consented and contributed baseline data, but was not considered to have started or enrolled in the study patients signed consent.

6. Primary Endpoint

The registry lists the primary outcome as Recurrence-free Survival at 2 Years, measured over 2 years.

Recurrence-free survival at 2 years is the primary endpoint. In this trial, the registry defines its time origin as the date of metastasectomy and defines relapse as documented disease recurrence at any site. The endpoint therefore concerns whether recurrence has been documented during the specified follow-up period after removal of the metastases. The posted result is expressed as participant counts and as a comparison of the proportions represented by those counts.

Time-to-event outcomes are commonly used when the timing of recurrence matters and follow-up can vary. They can preserve information about when an event occurs, rather than treating all events as interchangeable counts. However, the registry’s primary result is presented as a binary endpoint at 2 years, with counts and a risk-difference comparison. It does not provide a time-to-event curve, event-time estimates, censoring details, or a fuller account of how incomplete follow-up was handled. Those details are not reported in the registry record.

The outcome is clinically relevant to a trial conducted after metastasectomy because it records recurrence after the operation. Its interpretation depends on the endpoint definition, the follow-up information available, and how participants without complete observation were handled. The registry description provides the time origin and relapse definition, but does not explain missing-data procedures, the analysis population, or whether the posted participant counts represent a particular prespecified analysis set. The result should consequently be read as the registry’s recorded endpoint comparison, with those reporting limits in mind.

7. Results Posted in the Registry

• PANVAC-V + PANVAC-F + GM-CSF: 50.0% (10/20) versus 81.2% (13/16) on control; risk difference -31.2 percentage points (95% CI -60.3 to -2.2), risk ratio 0.62 (0.37–1.01); unadjusted two-proportion z-test p = 0.052.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Positive Immune Response as Measured by (Enzyme-linked Immunosorbent Spot) ELISpot Assay

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • PANVAC-V + PANVAC-F + GM-CSF: 12.5% (4/32) versus 25.7% (9/35) on control; risk difference -13.2 percentage points (95% CI -31.7 to 5.3), risk ratio 0.49 (0.17–1.43); unadjusted two-proportion z-test p = 0.172.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between PANVAC-V + PANVAC-F + GM-CSF and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists one secondary endpoint: a positive immune response measured by ELISpot at 13 weeks. Its posted proportions are 0.257 for PANVAC with dendritic cells and 0.125 for PANVAC with GM-CSF, with a risk difference of -0.132 for GM-CSF relative to dendritic cells. The confidence interval extends from -0.317 to 0.052, and the unadjusted p-value is 0.172. These results point in the same direction as the primary point estimate, but the secondary comparison is also uncertain and its interval includes zero.

The immune-response measure is biologically distinct from recurrence-free survival. It records an assay-based immune response at an earlier assessment time, whereas the primary endpoint concerns documented disease recurrence over follow-up after metastasectomy. A pattern in the immune measure cannot be treated as confirmation of a difference in recurrence-free survival, nor does the primary result establish an immune-response effect. The outcomes answer different questions and have different measurement and follow-up features.

Unadjusted secondary results generally carry less evidential weight when several outcomes or comparisons may be examined. In general, making multiple comparisons increases the opportunity to observe an apparently notable result even when there is no underlying difference. Appropriate interpretation depends on whether outcomes and analyses were prespecified and whether a multiplicity strategy was used. The registry does not report a multiplicity plan, and its analysis record contains no reported analyses.

The overall pattern is therefore descriptive: the posted point estimates for the primary and secondary outcomes both favor the dendritic-cell group in the direction of higher recorded proportions, but the secondary result is not precise enough to establish a clear contrast. The secondary endpoint should be considered supportive context rather than independent confirmation, especially because the registry does not report whether it was one of several planned immunologic measures or how its analysis was selected.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Positive Immune Response as Measured by (Enzyme-linked Immunosorbent Spot) ELISpot Assay

9. Statistical Interpretation

10. Statistical Methods Explained

The primary comparison is a binary-outcome comparison at a defined follow-up point. A participant is represented as either having the recorded endpoint or not having it for this analysis. The registry gives the group counts and the proportions used in the comparison. For the primary endpoint, the reported proportion is 0.812 for PANVAC with dendritic cells and 0.5 for PANVAC with GM-CSF. The registry reports the risk difference as -0.312 for GM-CSF relative to dendritic cells.

What does a risk difference express?

In general, a risk difference subtracts one group’s event proportion from the other group’s event proportion. Its sign depends on the order of the groups. Here, the comparison is specified as GM-CSF relative to dendritic cells, so the negative estimate means that the recorded proportion is lower in the GM-CSF group. A risk difference is on the same scale as the proportions being compared. It is an absolute contrast, unlike a relative measure that expresses one group in relation to another.

The primary endpoint is described as recurrence-free survival, while the posted result is handled as a binary count at 2 years. That presentation makes the comparison accessible as proportions at a specified time, but does not show when recurrences occurred or how censoring and follow-up time were incorporated. A time-to-event analysis can use timing information and account for differing observation periods under its assumptions. The registry does not report such an analysis for the posted primary result, and no survival curve or hazard estimate is included in the listed analysis results.

How should the confidence interval be read?

In general, a confidence interval describes the range of effect estimates compatible with the observed data under the method’s assumptions. It is not a guarantee that the true effect lies within the reported endpoints, and it does not represent the range of outcomes for individual participants. The primary risk-difference interval runs from -0.603 to -0.022. It indicates substantial uncertainty about the magnitude of the contrast, while its endpoints remain on the negative side of zero. The interval’s width is important: a point estimate alone would conceal how much the data allow the estimated difference to vary.

The unadjusted p-value is 0.052. In general, a p-value describes how unusual data at least as incompatible with a null comparison would be if the null model and the analysis assumptions held. It is not the probability that the null hypothesis is true, and it does not measure the probability that the result arose by chance in a simple, assumption-free sense. A threshold-based interpretation should not replace attention to the estimate, interval, design, and reporting limitations. The registry does not identify a prespecified significance threshold or provide a full testing plan.

What does “unadjusted” mean in this comparison?

In general, an unadjusted comparison uses the posted group data without accounting for other variables through a statistical model. Such a contrast is straightforward to interpret, but it may not address differences in prognostic characteristics, follow-up, or other factors. Randomization is intended to support comparability of groups, although chance imbalances can remain, especially in a phase II study with modest endpoint group counts. The registry does not report baseline characteristics or an adjusted primary analysis, so the extent to which covariates were considered cannot be assessed.

The registry also reports relative measures for the primary contrast: a risk ratio of 0.615 with a confidence interval from 0.374 to 1.012, and an odds ratio of 0.231 with a confidence interval from 0.050 to 1.067. These measures use different scales and should not be read as interchangeable with the risk difference. Their intervals express uncertainty and include values close to, or on both sides of, the null value for the respective relative measure. The risk difference remains the clearest expression of the absolute contrast in the posted comparison.

Why does over-dispersion matter in general?

Over-dispersion is a general concern when observed variation is greater than a model expects. It can make standard errors too small and confidence intervals too narrow if the analysis assumes less variability than the data contain. This concern is especially relevant for count outcomes or clustered observations. The primary endpoint is posted as a binary outcome and the registry provides no dispersion parameter or model description. Over-dispersion is therefore not something that can be evaluated from the posted primary result; the general principle is useful when considering other analyses, but it should not be presumed to have affected this comparison.

The registry’s reported analyses list is empty. No model specification, covariate adjustment, handling of censoring, or missing-data procedure is described for the primary endpoint. Consequently, the numerical summaries support a descriptive reading of the recorded groups and a conventional unadjusted comparison, but they do not permit verification of the analysis implementation or reconstruction of the full analysis population.

11. Confidence Intervals and Precision

The primary risk-difference estimate is -0.312, with a 95% confidence interval from -0.603 to -0.022. The interval is wide relative to the scale of the estimate, which signals limited precision. Although the full interval lies below zero, the range allows considerable variation in the size of the difference. The estimate should not be reduced to a yes-or-no conclusion based only on whether the interval includes zero.

Precision is influenced by the amount of information in the data and by how often the endpoint occurs. The primary endpoint counts are 13.0 among 16.0 for the dendritic-cell group and 10.0 among 20.0 for the GM-CSF group. With such small group counts, individual observations can have a noticeable effect on the proportions and the estimated difference. The registry does not report a precision target or the original sample-size justification, so it is not possible to determine whether the trial was designed to estimate this contrast with a particular degree of precision.

The relative-effect estimates also have broad uncertainty: the reported risk ratio is 0.615, with an interval from 0.374 to 1.012, and the odds ratio is 0.231, with an interval from 0.050 to 1.067. Relative measures can look more or less dramatic than an absolute difference because they use another scale. Their uncertainty should be read in relation to their own null values and not as a substitute for the absolute risk difference.

Confidence intervals describe statistical uncertainty under the analysis assumptions; they do not include every source of uncertainty. Incomplete reporting about follow-up, missing outcomes, analysis populations, and multiplicity leaves additional uncertainty that is not captured by the interval. The interval also does not establish how well the findings would generalize beyond the trial population.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are illustrative calculations based on the observed effect, rather than the trial’s original design assumptions. For these non-time-to-event outcomes, the figures refer to participants per arm, not total events. The calculation assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The target effect is set to the stated fraction of the observed effect. The original trial’s sample-size assumptions and justification are not reported in the registry record.

For the primary endpoint, planning for 100% of the observed effect gives 36 participants per arm for 80% power and 47 participants per arm for 90% power. Planning for 75% of the observed effect gives 60 participants per arm for 80% power and 79 participants per arm for 90% power. Planning for 50% of the observed effect gives 125 participants per arm for 80% power and 166 participants per arm for 90% power.

In general, power is the chance that a study will detect an effect of the specified size under the stated assumptions, if that effect is present. The 80% and 90% columns therefore describe different target probabilities of detecting the assumed effect, not different estimates of what happened in this trial. A smaller effect is harder to detect, so planning for a smaller fraction of the observed effect requires more participants per arm. The planning numbers are not observed power.

These illustrations depend on an effect estimated from the trial itself. When a small study produces an uncertain effect estimate, planning from that estimate can yield unstable projections. The figures are useful for understanding how assumed effect size and desired power relate to sample size, but they do not establish what the trial originally planned or what size a future study should use.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.812; treatment proportion p₁ = 0.500; average p̄ = 0.656.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.6717 = 1.3165.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.6343 = 0.5338.
4. n = (1.3165 + 0.5338)² / (-0.3125)² = 35.1, rounded up to 36 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
p0 <- 0.8125                          # control proportion
p1 <- 0.5                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(103142)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 36 (80% power), 47 (90% power)
 75% of observed effect: n per arm = 60 (80% power), 79 (90% power)
 50% of observed effect: n per arm = 125 (80% power), 166 (90% power)
power.prop.test: 35.1 
Simulated power at n = 36 per arm: 0.827 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when a study evaluates several outcomes, time points, subgroups, or statistical contrasts. In general, the more opportunities there are to test a hypothesis, the greater the chance that at least one comparison will appear noteworthy by chance. A prespecified strategy can address this issue by defining which outcomes are primary and how other tests should be interpreted or adjusted. The registry identifies a primary recurrence-free survival endpoint and lists a secondary ELISpot immune-response endpoint, but does not report a multiplicity procedure or a complete list of planned analyses.

The registry’s reported analyses list is empty, despite posted estimates and unadjusted p-values. There is no reported description of a statistical analysis plan, prespecified testing hierarchy, covariate adjustment, or treatment of secondary comparisons. It is therefore not possible to determine whether the posted comparisons reflect the complete planned analysis or whether other comparisons were considered. The primary result should be interpreted as the registered comparison presented, while the secondary result warrants additional caution because the handling of multiple testing is not reported.

Missing-data methods are also not reported in the registry record. The primary endpoint rows include 16.0 and 20.0 participants, whereas the immune-response rows include 35.0 and 32.0. The registry enrollment is 74. The reason for the differing endpoint denominators is not reported. They could reflect different endpoint availability or analysis populations, but the registry does not establish the explanation. No imputation method, censoring rule, or sensitivity analysis for missing outcomes is described.

The population field for the primary outcome is blank, and the registry does not identify the primary analysis set as intention-to-treat, per-protocol, or another population. Randomization is part of the design, but the posted endpoint counts alone do not establish whether all randomized participants were included in the analysis or how departures from assigned treatment were handled. These reporting gaps matter because analysis population and missingness can affect both the size and interpretation of a treatment contrast.

Accordingly, the confidence interval and p-value capture only the uncertainty represented by the reported comparison under its analysis assumptions. They do not resolve uncertainty about selective outcome reporting, multiplicity, missing observations, or which participants were included. These issues should be kept separate from the numerical uncertainty in the effect estimate.

15. 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 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry reports serious adverse events for two groups labelled Arm I and Arm II, without mapping those labels to the treatment names in the posted safety data. It records zero serious adverse events among 35 participants at risk in Arm I and zero among 36 participants at risk in Arm II. No serious adverse event terms are listed. The registry does not report death counts for either group.

Other adverse events are recorded for 35 of 35 participants at risk in Arm I and 35 of 36 participants at risk in Arm II. These are registry counts, and the record does not provide the event terms or severity breakdown in the information presented. The other-adverse-event counts should not be interpreted as counts of distinct event episodes; they describe participants marked as affected in the registry’s category.

Zero reported serious adverse events does not establish that serious harms were absent. Rare events may not appear in a trial of this size, and the registry does not provide detailed event definitions, follow-up duration for safety collection, or an account of missing safety observations. Because the safety groups are not linked to treatment names in the posted safety information, a treatment-specific safety comparison cannot be made from these figures.

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

The primary result describes a lower recorded two-year recurrence-free survival proportion in the PANVAC-plus-GM-CSF group than in the PANVAC-plus-dendritic-cell group. The estimated risk difference is -0.312, with a 95% confidence interval from -0.603 to -0.022. This is a summary of the participants and outcomes represented in the registry’s primary endpoint rows. It is not, by itself, proof that one treatment strategy caused a difference in recurrence.

The interval indicates that the magnitude of the contrast is uncertain. The unadjusted p-value is 0.052, and the registry does not report a full statistical analysis plan or adjusted analysis. A p-value near a conventional cutoff should not be treated as a decisive dividing line between an effect and no effect. The estimate, its interval, outcome definition, and study limitations all contribute to interpretation.

The secondary immune-response result has a point estimate in the same direction, but it measures a different outcome at a different time and has an interval that includes zero. It does not independently establish the primary outcome contrast. The registry also does not report whether multiplicity was addressed or whether the listed secondary outcome represents all planned secondary analyses.

The trial was randomized and unmasked. Randomization supports a comparison between assigned groups, but does not remove uncertainty from small endpoint counts, missing or unavailable outcomes, or incomplete reporting. The primary endpoint denominators are smaller than the registry enrollment, and the reason is not reported. The analysis population and handling of missing endpoint information are likewise not reported.

These findings should be understood as registry-reported evidence from a phase II comparison after resection of colorectal cancer metastases. They do not establish what would happen for every patient, and they do not justify a medical decision. The trial’s posted data support a description of the observed contrast and its statistical precision, while leaving important questions about analysis methods and outcome availability unanswered.

17. Why This Trial Matters Statistically

This trial is statistically interesting because it compares two active biological treatment strategies in a randomized phase II setting and reports both a clinical endpoint and an immune-response endpoint. The primary outcome is recurrence-free survival after metastasectomy, a clinically meaningful endpoint whose interpretation depends on clear event definitions and follow-up. The registry specifies the time origin and defines relapse as documented recurrence at any site, giving readers an essential basis for understanding what was counted.

The results also illustrate why effect estimates and uncertainty should be considered together. The primary risk difference is negative, and its confidence interval lies below zero, but the interval is broad. The unadjusted p-value is 0.052. These summaries do not tell a simple, definitive story; they show a directional contrast alongside limited precision and incomplete reporting about the analysis.

The secondary immune-response measure helps illustrate the difference between a biological marker and a clinical endpoint. Its point estimate is aligned with the primary result, but it is not the same outcome and cannot settle the primary question. Without a reported multiplicity strategy, secondary findings are appropriately interpreted as exploratory context rather than a separate confirmation.

The record also makes visible a common challenge in trial interpretation: enrollment and endpoint analysis counts can differ, while the reason may not be documented. Without a stated analysis population and missing-data approach, readers cannot fully trace how the posted result relates to the randomized trial population. The safety record likewise illustrates the importance of treatment-linked reporting and details about adverse-event definitions. These are not merely administrative matters; they shape how confidently the numerical results can be interpreted.

18. 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 primary endpoint is presented as a binary result at 2 years, even though recurrence-free survival is a time-to-event concept. The registry does not report event times, censoring information, a survival analysis, or a curve. The posted result therefore cannot show how recurrences were distributed over follow-up or how participants with incomplete observation were handled.

The endpoint group counts are 16.0 and 20.0, while enrollment is 74. The registry does not explain the difference or identify the analysis population. The secondary outcome has different group counts, and the reason for that difference is also not reported. Without participant flow information, it is difficult to assess whether outcome availability or inclusion criteria influenced the estimates.

The registry record does not report baseline characteristics, the original sample-size justification, the statistical analysis plan, or an adjusted primary analysis. Random allocation is reported, but the sequence-generation and allocation-concealment methods are not. Masking was absent, which is relevant because treatment knowledge can potentially affect outcome assessment or reporting; the registry does not describe safeguards against assessment bias.

The registry lists one secondary endpoint and no reported analyses, while presenting unadjusted comparisons. The planned number of outcomes and comparisons, any multiplicity adjustment, and whether analyses were prespecified are not reported. Safety data use group labels that are not linked to the treatment names in those data. Serious adverse event terms are not listed, and death counts are not reported.

These limitations do not erase the posted numerical results, but they restrict how fully the results can be audited and interpreted. In particular, they make it difficult to distinguish the effects of limited precision from the effects of incomplete outcome reporting or analysis-population selection.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Vaccine Therapy in Treating Patients With Liver or Lung Metastases From Colorectal Cancer — NCT00103142.
• Registry record last updated 2015-10-14; status last verified 2015-10.
• Results first posted 2014-04-07.
• 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.

22. Record Summary

The registry describes a completed, randomized, unmasked phase II parallel-group trial of PANVAC vaccination with autologous dendritic cells versus PANVAC vaccination with GM-CSF after resection of colorectal cancer liver or lung metastases. Enrollment is listed as 74. The primary endpoint was recurrence-free survival at 2 years from metastasectomy, with relapse defined as documented recurrence at any site.

The posted primary comparison records 13.0 among 16.0 for the dendritic-cell group and 10.0 among 20.0 for the GM-CSF group. The unadjusted risk difference for GM-CSF relative to dendritic cells is -0.312, with a 95% confidence interval from -0.603 to -0.022 and p = 0.052. One secondary endpoint reports ELISpot immune response at 13 weeks.

The registry does not report the original sample-size justification, full analysis plan, analysis population, missing-data methods, or multiplicity strategy. The reason for the endpoint denominators and the mapping of safety group labels to treatments are also not reported in the registry record.