SurVaxM Vaccine Therapy and Temozolomide in Treating Patients With Newly Diagnosed Glioblastoma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for SurVaxM Vaccine Therapy and Temozolomide in Treating Patients With Newly Diagnosed Glioblastoma (NCT02455557), a na phase 2 study. The primary outcome is Progression-free Survival (PFS).

2. Clinical Question

In statistical terms, this is a question about the observed course of participants receiving the study regimen, not a direct test of whether adding SurVaxM changes outcomes compared with temozolomide alone. A single-group design can describe outcomes and safety in the participants studied, but it cannot by itself separate treatment effects from the course that might have occurred without the vaccine. The registry summary also states that it is not known whether temozolomide is more effective with or without vaccine therapy.

3. Trial Design

This is a phase II, single-group study sponsored by Roswell Park Cancer Institute. The registry lists an enrollment of 66, no masking, and allocation as not applicable. The study began on 2015-05-04, and the primary completion date is listed as 2019-10-23. Its current status is active, not recruiting. These record details describe the study structure and status; they do not establish that all enrolled participants contributed to every endpoint.

The treatment group is described as receiving SurVaxM with temozolomide. According to the arm description, the first priming dose of the peptide vaccine in emulsion with montanide, together with sargramostim, is given within 7-28 days after completion of chemoradiation. The priming phase repeats every 2 weeks for a total of 4 doses, followed by dosing every 12 weeks during a period that is not fully specified in the registry text. The schedule for temozolomide is not reported in the registry record.

The primary outcome is 6-month progression-free survival, defined as the percentage of patients without tumor progression or death from any cause 6 months after diagnosis by biopsy. The record lists immune responses to SurVaxM and predictors of response, grade 3 or 4 toxicities according to National Cancer Institute Common Toxicity Criteria for Adverse Events Version 4, and overall survival as secondary outcomes. There are 4 outcome measures in total, but the registry record does not report numerical results for the primary endpoint or detailed results for these secondary outcomes.

Because the study has one treatment group and no masking, its design is suited to recording outcomes under the study regimen but does not create a like-for-like treatment comparison. The registry does not report a randomized comparison or a separate control arm. Details such as the full eligibility criteria, the rationale for the enrollment target, and the complete follow-up plan are not reported in the registry 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: All treated and eligible patients that completed the priming dose

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: All treated and eligible patients

6. Primary Endpoint

The registry lists the primary outcome as Progression-free Survival (PFS), measured over Date of diagnosis to the date of first observed disease progression or death due to any cause, assessed at 6 months.

The primary endpoint is 6-month progression-free survival, expressed as a percentage. It represents the estimated share of the specified population—treated and eligible participants who completed the priming dose—who remain free of tumor progression and death from any cause through 6 months after diagnosis by biopsy. The time origin and assessment point matter: this endpoint concerns the interval from diagnosis to the first observed progression or death, with the status summarized at the stated 6-month point.

Progression-free survival combines progression and death into a single endpoint. That can describe how long participants remain alive without documented disease progression, rather than reporting only tumor progression or only survival. The registry specifies Kaplan-Meier methods, which are generally used to estimate time-to-event outcomes while accounting for participants whose event time is not observed during the available follow-up. This is a general explanation of the method; the registry does not report how many participants were censored or the follow-up distribution.

A confidence interval is intended to convey statistical uncertainty around the estimate. The registry says corresponding confidence intervals will be computed, but neither the estimate nor its interval is reported in the registry record. The observed value and its precision therefore cannot be assessed from the registry information presented.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does Kaplan-Meier estimation mean?

Kaplan-Meier estimation is a general statistical method for summarizing time until an event. For this study, the event is the first observed tumor progression or death from any cause, and the registry defines the time origin as diagnosis by biopsy. The method estimates the probability of remaining free of the event over time. The registry specifies the 6-month percentage as the primary measure.

A strength of a time-to-event method is that it can use information from participants whose event has not occurred by the time their observation ends. Such participants are censored at their last known event-free time rather than automatically counted as having an event. This approach depends on appropriate follow-up and censoring assumptions. The registry record does not report the number censored, reasons for censoring, or diagnostic checks of those assumptions, so their influence on the estimate cannot be evaluated.

What does the confidence interval add?

A confidence interval communicates uncertainty in an estimate, rather than only giving a single point value. In general, a narrower interval indicates greater precision, while a wider interval indicates more uncertainty. Its width depends on factors including the number of participants with relevant follow-up and the timing of events. The endpoint description says corresponding confidence intervals will be computed, but the numerical estimate and interval are not reported in the registry record. Precision therefore cannot be judged from the endpoint description alone.

Why does the single-group design matter?

With one treatment group, the analysis can estimate outcomes observed among participants receiving the regimen. It cannot directly estimate what would have happened to the same eligible population under a different treatment. Random assignment to concurrent groups is one way to make a treatment comparison less vulnerable to systematic differences between groups; this record lists allocation as not applicable and describes a single-group model. General comparisons with historical results would require careful consideration of differences in eligibility, treatment, endpoint definitions, and follow-up. Such comparative details are not reported in the registry record.

No masking is listed. In general, lack of masking can affect outcomes that depend on clinical judgment or participant reporting, although the extent depends on how outcomes are assessed. The registry specifies progression or death as the endpoint events but does not report details of blinded outcome adjudication or assessment procedures. It is not possible to determine from the record whether assessment was independent of treatment knowledge.

How should the safety counts be understood?

Safety counts are descriptive summaries of reported events or affected participants in the treatment group. The record lists participants at risk and affected counts for serious and other adverse events, as well as selected serious-event terms and percentages. These counts do not provide a randomized comparison or establish causality. They also do not, on their own, show when events occurred, how long participants were exposed, whether one person experienced multiple events, or how severity and relatedness were adjudicated. Those details are not reported in the registry record.

What do planning calculations represent?

Planning illustrations based on an observed effect are not observed trial results and are not the trial's own design justification. General sample-size planning asks how much information would be needed to detect a specified effect under stated assumptions. The stated assumptions for such illustrations include a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a fraction of the observed effect. Time-to-event illustrations count total events; other illustrations report participants per arm. These are planning conventions, not evidence that the single-group trial was powered for a comparative test. The trial's own sample-size justification and statistical design assumptions are not reported in the registry record. No planning illustration should be interpreted as observed power.

The record lists zero analyses, and no numerical primary endpoint result is reported. Without the analysis output, readers cannot inspect the estimate, its uncertainty, or supporting details such as the number at risk over time. The endpoint definition and named method explain what was intended to be calculated, but they do not replace the missing result.

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("Treatment (SurVaxM, Temozolomide)")
n      <- c(64)
events <- c(61)
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  Treatment (SurVaxM, Temozolomide)  64  61  95.3  86.9  99.0  87.1  98.4  87.1  98.3

11. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary endpoint and secondary outcomes covering immune responses and predictors of response, grade 3 or 4 toxicities, and overall survival. Examining multiple outcomes can raise multiplicity concerns: when many statistical questions are tested, the chance of at least one apparently unusual result can increase. This is a general statistical issue. The registry record does not report a multiplicity strategy, such as a hierarchy of tests or an adjustment for multiple comparisons, so it is not possible to determine how multiple outcomes were handled inferentially.

The primary analysis population is described as all treated and eligible participants who completed the priming dose. The number meeting that definition is not reported in the registry record. The record does not report a separate intention-to-treat population, a per-protocol population, or how participants who did not complete priming were handled in other analyses. The enrollment of 66 should not be assumed to equal the primary analysis denominator.

Missing endpoint data and incomplete follow-up can affect time-to-event estimates. The registry describes Kaplan-Meier estimation, but does not report the amount or pattern of missing data, numbers censored, reasons for loss to follow-up, or any imputation or sensitivity analyses. It also does not report how missing immune-response or safety measurements were handled. These omissions limit assessment of whether missing information could alter the results.

The analysis plan, including prespecified hypotheses, adjustment methods, and interim analyses, is not reported in the registry record. No claims about those procedures can be drawn from the endpoint definitions alone.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: confusional state (7.6%), fall (4.5%), seizure (4.5%), hip fracture (3.0%), aphasia (3.0%).

For the treatment group, the registry lists 66 participants at risk for serious adverse events and 22 affected. For other adverse events, it lists 66 at risk and 65 affected. These are group-level counts; the registry record does not provide event-level timing or clarify whether the counts represent participants with at least one event versus another counting convention. The serious-event terms listed include confusional state (7.6%), fall (4.5%), seizure (4.5%), hip fracture (3.0%), aphasia (3.0%), and pulmonary embolism (3.0%).

The listed percentages should be read as registry-reported values, not as evidence of treatment causation or comparative risk. There is no control group in this single-group study, and the record does not report exposure-adjusted rates, event duration, recurrence, or a breakdown by relatedness to treatment. It also lists 36 deaths, but the follow-up period, causes, and attribution for those deaths are not reported in the registry record. The counts describe what was recorded; they cannot show whether the regimen increased or decreased risk relative to another treatment.

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

The record establishes that the study examined SurVaxM with temozolomide in newly diagnosed, survivin-positive glioblastoma and specified 6-month progression-free survival as its primary endpoint. It also records a treatment-group enrollment of 66 and selected adverse-event counts. These are useful descriptions of the study question, structure, and recorded safety information.

However, the numerical primary endpoint estimate and its confidence interval are not reported in the registry record. As a result, the posted information does not establish the observed 6-month progression-free survival percentage or its precision. Nor does it show the number included in the endpoint population, which is defined as treated and eligible participants who completed priming. Without those results and details, the primary outcome cannot be quantitatively interpreted.

The design also limits what can be concluded about comparative effects. A single group receiving vaccine and temozolomide provides no concurrent estimate of outcomes under temozolomide without vaccine. Observed outcomes in this group cannot isolate the contribution of SurVaxM from the contribution of other treatment, participant characteristics, or the natural course of disease. The registry does not report a randomized comparison.

The safety counts likewise do not establish causation or comparative safety. They describe events recorded among participants in the treatment group; no control group or exposure-adjusted comparison is reported. The listed deaths cannot be interpreted as treatment-related or as a substitute for the specified progression-free survival endpoint, because the record does not give their causes, attribution, or follow-up window.

Accordingly, the registry information supports a description of the planned endpoint and selected observed safety counts, but not a conclusion that the treatment caused a particular clinical outcome or performed better or worse than an alternative. Such conclusions would require reported outcome estimates, their uncertainty, and a suitable comparative design.

14. Why This Trial Matters Statistically

This trial is statistically notable because its primary question is framed as a time-to-event outcome while the study itself has a single treatment group. Kaplan-Meier estimation is a standard general approach for describing progression-free survival when participants may have different lengths of follow-up. It can make use of censored observations, but interpretation still depends on clear follow-up information and suitable assumptions. The registry names the method without reporting the estimate, confidence interval, censoring details, or numbers at risk over time.

The distinction between describing outcomes and estimating a treatment effect is especially important. A single-group estimate can characterize what happened among the enrolled participants, but it cannot directly compare that course with a concurrent alternative. This matters for interpreting both the primary endpoint and the safety counts. The enrollment figure and the named analysis method do not overcome the absence of a control group.

The study also illustrates why the analysis population matters. The primary endpoint is defined for treated and eligible participants who completed priming, not simply everyone enrolled. The size and characteristics of that endpoint population are not reported in the registry record. Without that information, readers cannot tell how much the analysis differs from the enrolled group or assess the effect of exclusions and incomplete treatment.

Finally, the registry makes the difference between a planned endpoint and a posted result apparent. The endpoint definition and intended confidence interval describe how the outcome was to be summarized; they are not the estimate itself. Since the numerical primary result is not reported, claims about magnitude and precision are unavailable. The record can therefore inform statistical interpretation of the design, while leaving the central quantitative outcome unresolved.

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.

The primary limitation for interpreting outcomes is that the registry record does not report a numerical 6-month progression-free survival estimate or its confidence interval. It also does not report the number of participants in the defined primary analysis population, the number censored, or the amount of follow-up available. These omissions prevent assessment of both the result and its precision.

The design is single-group, with no randomized or concurrent control arm. Consequently, the record cannot support a direct comparison of SurVaxM plus temozolomide with temozolomide alone. The absence of masking is listed, but the registry does not describe outcome adjudication or whether progression assessments were independently reviewed. This limits evaluation of how outcome assessment may have been conducted.

The treatment description is incomplete: the vaccine priming schedule is described, but the later schedule is truncated and the temozolomide schedule is not reported in the registry record. The full eligibility criteria, sample-size justification, detailed statistical plan, handling of missing data, and multiplicity approach are also not reported. Their absence makes it difficult to assess whether the analysis followed prespecified procedures or how robust results might be to alternative assumptions.

Safety data are presented as counts and selected percentages without a control group, exposure-adjusted rates, event timing, detailed attribution, or a stated follow-up window for deaths. Therefore, the counts cannot establish comparative risks or treatment causation. These limitations apply to interpretation of the registry information and should not be filled in by assumptions about the study procedures.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: SurVaxM Vaccine Therapy and Temozolomide in Treating Patients With Newly Diagnosed Glioblastoma — NCT02455557.
• Registry record last updated 2026-10-22; status last verified 2026-10.
• Results first posted 2021-02-01.
• 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 NCT02455557 as a phase II, single-group study of SurVaxM with temozolomide in survivin-positive, newly diagnosed glioblastoma. Enrollment is listed as 66, masking as none, and status as active, not recruiting. The primary endpoint is 6-month progression-free survival, defined as freedom from progression or death and intended to be estimated using Kaplan-Meier methods.

The primary endpoint estimate and confidence interval are not reported in the registry record. The record lists 22 participants affected by serious adverse events among 66 at risk, 65 affected by other adverse events among 66 at risk, and 36 deaths. It does not provide a concurrent comparator, so these findings are descriptive rather than comparative. Details on missing data, multiplicity, the analysis population size, and the trial's own sample-size justification are not reported in the registry record.