Blockade of PD-1 in Conjunction With the Dendritic Cell/AML Vaccine Following Chemotherapy Induced Remission: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Blockade of PD-1 in Conjunction With the Dendritic Cell/AML Vaccine Following Chemotherapy Induced Remission (NCT01096602), a na phase 2 study. The primary outcome is Number of Participants With Adverse Events Associated With DC/AML Tumor Vaccine.

2. Clinical Question

The study focuses on safety monitoring in a post-chemotherapy setting. Its primary outcome is a participant count, rather than a comparison of how often an outcome occurred under different treatments. The registry describes the vaccine as investigational and frames the study purpose as assessing safety following remission.

The registry also lists immune expansion after vaccination, expansion of leukemia-specific CD4 and CD8 T-cells, and disease response among its secondary outcomes. Results for those outcomes are not reported in the registry record. The record does not describe a control treatment or a randomized comparison, so it does not answer whether vaccination changes outcomes relative to another strategy.

3. Trial Design

This is a phase 2, completed, single-group study sponsored by Beth Israel Deaconess Medical Center. The registry lists the study start as 2010-05 and primary completion as 2023-12. The listed enrollment is 63. However, the posted safety group is titled “Group 1 / Patients Treated” and includes 17 participants at risk. The registry record does not explain the relationship between the enrollment figure and the treated safety group, so the two figures should not be treated as interchangeable.

Participants received the DC AML Fusion Vaccine after chemotherapy-induced remission. The study description says patients were treated with the vaccine alone following standard-of-care chemotherapy. It does not provide the chemotherapy regimens, vaccine schedule, dose, eligibility criteria, or detailed treatment procedures in the information reported for this analysis.

The study is listed as single-group, unmasked, and with allocation recorded as not applicable. There is no concurrent control arm in the posted design. Accordingly, the safety counts describe events recorded among treated participants; they do not represent a randomized comparison or an estimate of the difference between vaccine and control groups.

The registry lists four outcome measures and zero analyses. The primary outcome concerns participants with adverse events associated with the vaccine. Secondary outcomes concern immune expansion and disease response, but their results are not reported in the registry record. A detailed statistical analysis plan, including the planned analysis population and methods for handling missing observations, is 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.

Enrollment Through Vaccine Generation

Reasons for not completing this period:

Treatment With At Least One Vaccine

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.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Adverse Events Associated With DC/AML Tumor Vaccine, measured over 6 months after the last vaccine, up to 9 months.

The primary outcome is the number of participants with adverse events associated with the DC/AML tumor vaccine. It is a participant count, with participants as the unit. The registry describes monthly adverse-event monitoring through 6 months following the last vaccine, up to 9 months, or until disease progression, whichever occurred first. This endpoint therefore concerns whether participants experienced an event during the stated monitoring period, not the total number of separate events per participant or the length of time before an event.

Safety counts are used in early clinical investigation to describe the types and frequency of events observed while people receive an investigational intervention. A count can make the observed safety experience clear, but it does not by itself show whether an event was caused by the intervention. Attribution depends on clinical assessment and definitions that are not detailed in the registry record.

The posted safety results list 0 of 17 participants with serious adverse events and 13 of 17 with other adverse events. The record does not give further event-level details, such as the particular events, their severity beyond the serious-versus-other grouping, or their timing. It also does not report a confidence interval for the primary count. These results describe what was recorded in the treated group, rather than establishing the likelihood of events in a broader population.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a participant count represent?

The primary outcome is a count of participants with adverse events, rather than a count of every event that occurred. If a participant experienced more than one event, a participant-level count would still count that person once for the relevant category. The registry describes the outcome unit as participants. The posted safety summary lists 17 participants at risk and reports 0 with serious adverse events and 13 with other adverse events.

In general, a participant count is most readily interpreted alongside its denominator and a clear event definition. The denominator identifies how many people contributed to the summary; the event definition determines which experiences qualify. Here, the registry gives the denominator and broad event groupings, but does not report detailed definitions or individual event descriptions. The record also does not state whether participants with incomplete follow-up were handled in a particular way.

Why distinguish serious from other adverse events?

Seriousness and severity are related but distinct concepts in clinical safety reporting. In general, seriousness refers to specified consequences or regulatory criteria, whereas severity describes the intensity of an event. The posted results distinguish serious adverse events from other adverse events, but do not give severity grades or the criteria used for classification. The two categories should therefore be read according to the registry's labels rather than treated as a complete description of the clinical importance of each event.

The record reports 0 participants with serious adverse events and 13 with other adverse events. The zero is an observed count within the reported group and monitoring context. In general, a zero count does not establish that an event cannot occur; it indicates only that no qualifying event was recorded in that observed group under the recorded conditions. The absence of an interval estimate means the registry results do not quantify the uncertainty around that count.

What can a single-group design estimate?

A single-group study can describe events and outcomes among participants who received the intervention. It does not, on its own, estimate how those outcomes differ from what would have happened under a comparator treatment. In general, a concurrent control group helps account for events related to the underlying condition, background care, and the passage of time. Without such a group, observed events cannot be attributed to the vaccine solely because they occurred after vaccination.

This distinction also applies to the deaths recorded in the safety group. The registry gives a count of 3 deaths but does not report their causes or attribution. The count is a descriptive observation, not a comparative estimate and not evidence, by itself, that the intervention caused or prevented deaths.

How should precision and statistical tests be understood?

A confidence interval is a general statistical tool that expresses the uncertainty around an estimated quantity. For a participant event count or rate, an interval can show how imprecise an estimate may be when the observed group is limited. The registry does not report a confidence interval for the primary outcome, so the precision cannot be read from an interval estimate. A point count alone should not be treated as an exact estimate of the frequency expected in future patients.

A hypothesis test addresses a specified statistical comparison or question. The registry lists zero analyses and does not report a test, p-value, adjusted estimate, or detailed analysis plan. There is no reported statistical comparison between treatment groups, consistent with the single-group design. No unreported test or inferential result can be inferred from the counts alone.

What do the sample-size assumptions describe?

The registry's sample-size assumptions describe planning illustrations based on an observed effect, a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. They specify that the effect to detect is a stated fraction of the observed effect. These are assumptions for hypothetical planning calculations, not a description of this single-group trial's design. The record does not report a trial-specific sample-size justification.

In general, a planning calculation asks how many participants might be needed for a future study under chosen assumptions about the effect, variability, significance level, and power. Such an illustration does not establish what this trial was designed to detect, and it is not observed power. The registry information does not include the resulting participant-per-arm estimates, so no numerical planning target can be interpreted from this record.

More broadly, statistical conclusions depend on the analysis population, outcome definitions, follow-up completeness, and the method used to account for missing information. The registry record does not report those details for the posted safety summaries. The counts remain useful as a description of the events recorded in the treated group, but they do not answer questions about unobserved events, comparative effects, or outcomes in a wider population.

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("Group 1 / Patients Treated")
n      <- c(17)
events <- c(13)
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  Group 1 / Patients Treated  17  13  76.5  50.1  93.2  52.7  90.4  52.4  90.3

11. Multiplicity, Missing Data and Analysis Populations

The registry lists four outcome measures: the primary adverse-event count and secondary measures concerning immune expansion and disease response. It does not report results for the secondary outcomes or explain how multiple outcomes were handled statistically. When a study evaluates several outcomes, multiplicity can arise because repeated testing increases the chance of at least one apparently notable finding under a set of null hypotheses. In general, investigators may address this through a prespecified hierarchy, adjustment, or careful emphasis on estimation and interpretation. The registry record does not report a multiplicity strategy, and no such strategy should be inferred.

The record lists zero analyses and does not report hypothesis tests, confidence intervals, or adjusted estimates. It is therefore not possible to determine whether any formal testing was planned or conducted beyond the posted descriptive safety counts. Nor is it possible to assess whether the listed secondary outcomes were analyzed but not reported, were not analyzed, or were unavailable for another reason.

Missing-data methods and the analysis population are not reported in the registry record. The safety group contains 17 participants at risk, while enrollment is listed as 63; the record does not explain the difference or report participant flow, exclusions, withdrawal, or completeness of follow-up. The endpoint monitoring description allows monitoring to end at disease progression or after the specified post-vaccination period, but does not describe how incomplete observation was handled in the summary.

In general, missing outcome information can affect the interpretation of a count if participants had different follow-up or if the chance of missingness was related to their health or event status. Without participant-flow details and an explicit analysis population, the extent and direction of any such effect cannot be assessed.

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 non-serious adverse event terms

The registry reports serious adverse events in 0 of 17 participants at risk and other adverse events in 13 of 17 participants at risk. These are participant counts within the treated group, not comparisons with an untreated or standard-care control group. The record describes monthly monitoring through 6 months following the last vaccine, up to 9 months, or until disease progression, whichever occurred first.

The registry also records 3 deaths. It does not report their causes, timing, relationship to vaccination, or relationship to disease progression. The death count should therefore be read as a separate descriptive safety figure, not as evidence of vaccine-related mortality. The record does not provide event-level descriptions or clarify the relationship between deaths and the adverse-event categories.

In general, a serious adverse-event count and an overall adverse-event count answer different descriptive questions. Neither alone establishes causality. Because follow-up can end at progression or after the stated monitoring period, the figures should be understood within that reported observation window and not as complete lifetime safety outcomes.

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

The posted results document a safety experience among the treated participants: no serious adverse events were recorded among the 17 participants at risk, other adverse events were recorded among 13 participants, and 3 deaths were listed. The registry describes monitoring after vaccination and gives the point at which monitoring could end. These findings are descriptive observations from the reported group and follow-up context.

They do not establish that the vaccine caused the reported events or deaths. They also do not establish that the vaccine prevented events. In a single-group study, there is no concurrent comparison that can separate outcomes associated with the vaccine from outcomes associated with AML, prior chemotherapy, disease progression, or other circumstances. The record does not provide detailed attribution or event-level information to clarify those possibilities.

The results also do not establish comparative efficacy. Although the registry lists disease response and immune expansion among secondary outcomes, their results are not reported in the registry record. Without those results, and without a control group, the record does not show whether the vaccine changed disease response or immune measures relative to another strategy.

The counts should not be generalized mechanically to all people with AML or to different treatment settings. The registry lists 63 enrolled, while the posted safety group contains 17 participants at risk, and does not explain the relationship between these figures. It also does not report an interval estimate that would quantify uncertainty around the observed counts. The findings therefore describe the posted safety group, rather than furnishing a precise estimate for a broader population.

In general, the appropriate distinction is between documenting what was observed and making a causal or comparative claim. The registry supports the former: it records adverse-event and death counts in the treated group. The information reported does not support a treatment-effect conclusion, a complete safety profile, or an inference about outcomes that were not reported.

14. Why This Trial Matters Statistically

This trial is statistically informative as an example of the difference between a safety description and a comparative treatment estimate. A single-group design can record what happened after participants received an intervention, and the posted counts make that observation explicit. But without a concurrent comparator, the design cannot estimate how outcomes differed from an alternative treatment or from the course of disease under background care.

The denominator is also essential to interpretation. The safety summaries are based on 17 participants at risk, whereas the listed enrollment is 63. Because the registry record does not explain this difference, readers should keep the enrollment and safety figures distinct and avoid treating the safety group as the full enrolled cohort.

Precision matters alongside the count. In general, an event count is an estimate based on observed participants, and a confidence interval can convey uncertainty around that estimate. No confidence interval is reported for the primary outcome. The zero serious adverse-event count is consequently a statement about the observed group, not proof that serious events are absent in the population that might receive the vaccine.

The registry also lists immune and disease-response outcomes without reporting their results, and reports zero analyses. This makes clear why outcome labels alone do not support conclusions: interpretation depends on the observed data, analysis methods, follow-up, and completeness of reporting. Here, the record supports a narrow descriptive reading of the safety results, while leaving comparative effectiveness and several planned areas of interest unresolved.

Finally, sample-size planning assumptions should not be mistaken for features of the trial itself. The registry describes hypothetical planning assumptions involving two arms even though the actual study is single-group. Keeping design, planning calculations, and observed outcomes separate is necessary for sound statistical interpretation.

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 registry does not explain why 63 participants were enrolled but the posted treated safety group contains 17 participants at risk. Participant flow, reasons for non-treatment or exclusion, and the relation of the safety group to the full enrolled cohort are not reported in the registry record. This limits interpretation of how broadly the posted safety counts represent study participation.

Although the registry gives a monitoring window, it does not report individual follow-up duration, completeness of monitoring, or how participants with incomplete observation contributed to the safety summaries. Monitoring was described as monthly through 6 months following the last vaccine, up to 9 months, or until disease progression, whichever occurred first. The consequences of differing observation periods cannot be assessed from the reported counts.

The adverse-event information is limited to broad categories and participant counts. Event names, severity grades, timing, duration, management, and attribution are not reported in the registry record. The record also reports 3 deaths without cause, timing, or relationship to treatment. These omissions prevent a detailed assessment of the safety experience.

The design has no concurrent comparator, and masking is listed as none. Consequently, the data do not isolate events attributable to the vaccine from those related to AML, prior chemotherapy, disease progression, or other factors. The registry does not report detailed eligibility criteria, vaccine dosing and schedule, chemotherapy regimens, or a statistical analysis plan, which further constrains assessment of applicability and analytic choices.

Results for the listed immune expansion and disease response outcomes are not reported in the registry record. No confidence intervals or inferential analyses are reported for the primary safety outcome. Together, these limitations mean the record offers a limited descriptive account rather than a comprehensive or comparative evaluation.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Blockade of PD-1 in Conjunction With the Dendritic Cell/AML Vaccine Following Chemotherapy Induced Remission — NCT01096602.
• Registry record last updated 2026-07-14; status last verified 2026-07.
• Results first posted 2026-07-14.
• 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

NCT01096602 is a completed phase 2, single-group study sponsored by Beth Israel Deaconess Medical Center. It evaluated the DC AML Fusion Vaccine after chemotherapy-induced remission in people with AML. The registry lists enrollment of 63, with the safety results reported for a treated group of 17 participants at risk. The study is listed as unmasked, with allocation not applicable.

The primary outcome is the number of participants with adverse events associated with the vaccine, monitored after vaccination. The posted safety results record 0 participants with serious adverse events, 13 with other adverse events, and 3 deaths. Causes and attribution for the deaths are not reported in the registry record.

The registry lists secondary outcomes concerning immune expansion and disease response, but their results are not reported. It also lists zero analyses. The record does not provide a concurrent control comparison, a detailed statistical analysis plan, or an explanation for the difference between enrollment and the treated safety group. The findings are therefore descriptive safety counts, not comparative estimates.