TVEC and Preop Radiation for Sarcoma (8 ml Dose): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for TVEC and Preop Radiation for Sarcoma (8 ml Dose) (NCT04599062), a non-randomized phase 1, phase 2 study. The primary outcome is Number of Participants With Dose Limiting Toxicities (DLTs).

2. Clinical Question

3. Trial Design

This is a Phase 1 and Phase 2 study with non-randomized allocation, no masking, and a single-group model. It evaluates talimogene laherparepvec in combination with radiotherapy in patients with soft tissue sarcoma. The registry describes a Phase I cohort and a Phase II cohort. Because there is no randomized control group, these cohorts should not be read as treatment and control arms in a randomized comparison.

The Phase I description includes two dose schedules: Dose 0, up to 8.0 mL of 108 PFU/mL dosed weekly, and Dose -1, up to 8.0 mL of 108 PFU/mL dosed every 2 weeks. The Phase II description specifies Dose 0, up to 8.0 mL of 108 PFU/mL dosed weekly. The primary outcome population is narrower: 6 participants enrolled in the Phase I portion at Dose 0 who completed treatment, radiation, and surgical resection. The registry record does not explain how that outcome population relates to all participants enrolled.

The enrollment field reports 8, while the brief summary says approximately 46 people will take part. These are different statements in the registry record; the record does not explain the discrepancy or identify which figure represents enrollment at the time of the posted results. The study is listed as active, not recruiting. Its recorded start date is 2020-09-10, and its primary completion date is 2023-02-07. No further protocol details about the conduct of the phases or the basis for these enrollment figures are reported in the registry record.

The secondary outcomes listed are overall response rate, 2 Year Progression-Free Survival, and 2 Year Overall Survival. The record lists 5 outcome measures and 0 analyses. It does not report the statistical plan, any interim analyses, or details of outcome assessment beyond the descriptions given.

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: 6 participants enrolled in the Phase 1 portion (Talimogene Laherparepvec Dose 0) and completed treatment, radiation, and surgical resection.

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 Dose Limiting Toxicities (DLTs), measured over 14 weeks.

The primary endpoint counts participants with dose-limiting toxicities (DLTs) over a 14-week timeframe. A participant is counted as having a DLT if a qualifying talimogene laherparepvec-related toxicity, or toxicity related to the combination of talimogene laherparepvec and radiation therapy, occurs during treatment or up to 4 weeks after the last talimogene laherparepvec injection. The definition includes immune-mediated adverse events of Grade 3 or greater, allergic reactions of Grade 3 or greater, plasmacytoma of any grade, and other unexpected hematologic or non-hematologic toxicities of Grade 3 or greater. It also lists exceptions, including any-grade alopecia and expected radiation-related skin toxicity.

A DLT count is used in safety studies to describe how often prespecified toxicities occur under the treatment conditions being assessed. In general, prespecifying the qualifying events and observation period makes the endpoint more consistent and interpretable than an unspecified count of all symptoms. The endpoint is a participant count, not a measure of the total number of toxicity episodes or their duration.

The registry record identifies 6 participants in the Phase I Dose 0 portion who completed treatment, radiation, and surgical resection as the population for this outcome. It does not report how many of them had a DLT. Without that observed count, the primary endpoint’s result cannot be stated.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Several features of the statistical information determine what can and cannot be concluded. The primary endpoint is a count of participants with a binary event status: each participant either meets the specified DLT definition or does not. The record supplies the definition, timeframe, and named Phase I Dose 0 outcome population, but does not supply the observed DLT count. Statistical methods can describe how such a count might be analysed in general, but they cannot recover the missing result.

What does a participant count represent?

In general, a participant count for a binary outcome records the number of people meeting an endpoint definition, rather than the number of separate event episodes. A count is easiest to interpret alongside the population assessed and the period over which the event was monitored. For this study, the registry record gives a 14-week timeframe and identifies 6 Phase I Dose 0 participants who completed treatment, radiation, and surgery for the primary outcome. The observed DLT count is not reported in the registry record, so the count cannot be related to that population in a numerical result.

Counts are descriptive. They do not by themselves describe how precisely an underlying event rate has been estimated. In general, an interval estimate can show the range of values compatible with the observed data under a stated method and assumptions. The registry record does not report an interval estimate for the primary endpoint. No confidence interval should be inferred from the listed population alone.

Why does the design matter?

The trial is non-randomized and uses a single-group model. In general, random allocation helps make groups comparable in expectation, while a single-group study does not create a randomized counterfactual group. The record’s Phase I and Phase II cohorts are study cohorts, not a randomized treatment-versus-control contrast. Their counts can be described separately, but a difference between them would not, on its own, isolate a causal treatment effect. The registry record does not report an adjusted comparison or a statistical model for comparing the cohorts.

Phase I includes Dose 0 and Dose -1 schedules in its arm description; Phase II lists Dose 0. The primary outcome population is specifically described as Phase I Dose 0 participants who completed treatment, radiation, and surgery. These details matter because the outcome population should not be silently treated as identical to all enrolled participants or to everyone described in the arm listings. The record does not report the participant flow needed to reconcile all populations.

What does the sample-size illustration mean?

In general, a sample-size calculation estimates how many participants would be needed under specified assumptions to detect a chosen effect at a chosen significance level and power. The assumptions stated for the planning illustration are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the target is a stated fraction of the observed effect. For time-to-event outcomes, the stated illustration uses a total number of events, while other outcomes use participants per arm.

These calculations are planning illustrations based on the observed effect, not observed power and not proof that the trial was designed with those assumptions. The registry record does not report the primary observed effect, the trial’s own sample-size justification, or an intended analysis plan. Without those details, the illustrations cannot establish whether the study was adequately sized for its primary safety question. A planning calculation also does not change the uncertainty in results from a small or incomplete observed dataset.

How should uncertainty and event rates be handled?

In general, estimating a proportion from a participant count requires a clearly defined denominator and an analysis population. If participants have different follow-up or if outcome status is unavailable for some participants, the handling of that information can affect the estimate. The registry record does not describe missing outcome data, participant follow-up for the DLT endpoint, or a missing-data method. It is therefore not possible to determine from the record whether every participant in the named population had complete outcome ascertainment.

In general, a confidence interval communicates sampling uncertainty around an estimate, while a p-value addresses compatibility with a specified null model under its assumptions. Neither replaces the need to understand the endpoint definition, population, and study design. The registry record reports 0 analyses and gives no p-values or confidence intervals for the adverse-event counts. No formal inferential conclusion should be attributed to those counts.

Over-dispersion is a general issue when outcome variation is greater than expected under a chosen statistical model. It can make standard errors too small if the model does not account for the extra variation. The primary endpoint is a participant-level binary count, and the registry record does not report a fitted model or a dispersion parameter. There is no basis for claiming that over-dispersion was assessed or that a particular model was used.

Overall, the record supports a design-based reading and a limited descriptive reading of the adverse-event counts. It does not provide the primary DLT result or the inferential statistics needed for a more precise assessment. Details such as the statistical plan, interim analyses, missing-data procedures, and model specifications are not reported in the registry record.

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("Talimogene Laherparepvec in Combination With Radio")
n      <- c(6)
events <- c(0)
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  Talimogene Laherparepvec in Combination With Radio  6  0  0.0  0.0  45.9  0.0  39.0  0.4  41.0

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists multiple outcomes: the primary count of participants with DLTs, overall response rate, 2 Year Progression-Free Survival, and 2 Year Overall Survival. It also lists 5 outcome measures, but reports 0 analyses. No family of hypotheses, testing sequence, multiplicity adjustment, or hierarchy among secondary outcomes is reported in the registry record. It is therefore not possible to determine whether or how the risk of false-positive findings across multiple analyses was managed.

The primary outcome description identifies a Phase I Dose 0 population and a 14-week timeframe. The registry record does not report the observed DLT count, an analysis population beyond that description, or how participants with incomplete outcome information were handled. Missing-data rates, reasons for missingness, and imputation or sensitivity methods are not reported in the registry record. Without these details, the completeness of outcome ascertainment cannot be evaluated.

In general, missing outcome data can affect both the estimate and its uncertainty, especially if the probability of missingness is related to participant characteristics or outcomes. This is a general statistical concern, not a claim that missing data occurred in this study. The registry record does not state whether any primary outcome data were missing.

The record also does not report an interim-analysis plan, stopping boundaries, a prespecified statistical analysis plan, or the method used to select the analysis population. Those details should not be inferred from the listed phases, outcomes, or sample-size assumptions. The stated planning assumptions are not evidence that the same methods were used for the trial’s analyses.

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 adverse-event record reports no participants with serious adverse events in either listed cohort: 0 in Phase I and 0 in Phase II. It separately reports other adverse events in 6 participants in Phase I and 2 in Phase II. The record reports no deaths in either cohort. These are participant counts as classified in the registry record, not counts of separate event episodes.

The serious-event counts and other-event counts describe different categories and should not be combined or treated as interchangeable. In particular, a report of 0 participants with serious adverse events does not mean there were no adverse events of any kind. The record’s other-adverse-event counts indicate that such events were reported in both cohorts.

The adverse-event summary does not list serious event terms. It also does not provide the terms for the other events in the registry record used for this interpretation, or their grades, timing, duration, treatment relationship, or management. The record therefore supports a limited description of the counts, not a detailed safety profile. The DLT definition is a separate endpoint definition; the record does not report its observed participant count, and the adverse-event counts cannot be used to derive it.

These data are descriptive and come from a non-randomized study without a like-for-like control group. They should not be read as establishing how the combination compares with another treatment or what would occur in a broader population.

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

The registry record establishes that the study evaluates talimogene laherparepvec with radiation therapy in soft tissue sarcoma and that its primary safety question concerns DLTs over a 14-week timeframe. It also defines the toxicities that qualify and describes the Phase I Dose 0 outcome population. This information clarifies what the endpoint is intended to capture, but it does not provide the observed DLT result.

The posted adverse-event counts show 0 participants with serious adverse events in each listed cohort, 6 participants with other adverse events in Phase I, and 2 in Phase II. The record also reports 0 deaths in each cohort. These figures are descriptive. Since the record does not give event terms and other clinical detail for the other adverse events, their nature and importance cannot be characterized from these counts alone.

The results do not establish a comparative effect. Allocation was non-randomized, the model was single group, and the registry record identifies no like-for-like control group. The Phase I and Phase II cohorts should not be treated as randomized alternatives. Their counts do not by themselves show that one schedule is safer or more effective than another.

The registry record lists response and survival outcomes, but does not report their results. It also does not report analyses, uncertainty intervals, or a statistical analysis plan. Consequently, the information available does not support conclusions about the precision of the primary result, the comparative efficacy of the combination, or its generalizability beyond the study population.

In general, an endpoint definition describes what investigators intend to count; an observed outcome describes what happened among the participants assessed. Those are different kinds of information. Here, the DLT definition is available, but the observed DLT count is not. The record is therefore informative about the study question and design, while leaving its primary safety result unreported.

14. Why This Trial Matters Statistically

This trial is statistically notable because it asks a safety question in a non-randomized, single-group setting and defines a specific participant-level endpoint. A clearly specified DLT definition can make the safety question more reproducible by stating which toxicities count and the observation window. At the same time, the absence of a randomized control group limits what the study can establish comparatively.

The record separates Phase I and Phase II cohorts and describes different dose schedules in the Phase I arm. This makes it important to keep the endpoint population in view: the primary outcome description concerns Phase I Dose 0 participants who completed treatment, radiation, and surgical resection. A result for that population would not automatically describe every enrolled participant or every cohort. In the registry record, the observed DLT count is not reported, so even this focused safety question remains unanswered by the posted result information.

The record also illustrates why counts need context. Serious adverse events are reported as 0 in each cohort, while other adverse events are reported in both. Without event terms, follow-up details, and uncertainty estimates, these figures offer only a limited description. They cannot show the frequency of particular kinds of toxicity or support a comparative safety claim.

Finally, the stated sample-size assumptions are planning assumptions, not observed power and not necessarily the study’s own design justification. The registry record does not report the trial’s sample-size rationale or its analysis plan. Keeping these distinctions clear prevents planning calculations, endpoint definitions, and descriptive counts from being mistaken for a complete statistical result.

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 in interpreting the posted results is that the number of participants with DLTs is not reported in the registry record. Although the endpoint definition, timeframe, and Phase I Dose 0 outcome population are described, the central primary result cannot be quantified. Confidence intervals or other measures of precision for that endpoint are also not reported.

The trial is non-randomized, has no masking, and is described as a single-group study. The Phase I and Phase II cohorts are not a like-for-like control comparison. These design features limit causal and comparative interpretation. The registry record does not report an adjusted analysis that might address differences between cohorts, and no such analysis should be assumed.

The enrollment field reports 8, while the brief summary states that approximately 46 people will take part. The registry record does not explain this difference. The primary endpoint population is described separately as 6 Phase I Dose 0 participants who completed treatment, radiation, and surgery; the participant flow connecting these figures is not reported. This makes the relationship among the registry enrollment, summary estimate, and endpoint population unclear.

The adverse-event information is limited to participant counts for serious and other events and deaths. Event terms and further detail about severity, timing, duration, and treatment relationship are not reported in the registry record. Results for the listed response and survival outcomes are also not reported. Missing-data procedures, interim analyses, multiplicity handling, the statistical analysis plan, and the study’s own sample-size justification are not reported in the registry record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: TVEC and Preop Radiation for Sarcoma (8 ml Dose) — NCT04599062.
• Registry record last updated 2026-01-29; status last verified 2026-01.
• Results first posted 2023-06-22.
• 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 1 and Phase 2, non-randomized, unmasked, single-group study of talimogene laherparepvec with radiotherapy for soft tissue sarcoma. Phase I includes Dose 0 and Dose -1 schedules; Phase II specifies Dose 0. The primary endpoint is the number of participants with DLTs over 14 weeks, with the outcome population described as Phase I Dose 0 participants who completed treatment, radiation, and surgical resection.

The observed DLT count is not reported in the registry record. The adverse-event summary reports 0 participants with serious adverse events in each cohort, other adverse events in 6 Phase I participants and 2 Phase II participants, and 0 deaths in each cohort. The record lists overall response rate, 2 Year Progression-Free Survival, and 2 Year Overall Survival as secondary outcomes, but does not report their results. It lists 0 analyses and does not report a statistical analysis plan or the study’s sample-size justification.