Tecemotide (L-BLP25) in Prostate Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Tecemotide (L-BLP25) in Prostate Cancer (NCT01496131), a randomized phase 2 study. The primary outcome is Number of Subjects With Change From Baseline in the Mucinous Glycoprotein 1 (MUC1) Specific Systemic T-Cells Immune Response at Day 60 (Pre-Radiation).

2. Clinical Question

The clinical question was whether adding tecemotide to standard treatment was associated with a different immune-response outcome before radiation, and whether the posted outcomes offered additional information about PSA-based progression or recurrence. The record describes a trial in untreated prostate cancer and gives the treatment strategies, but does not report enough detail to characterize all eligibility criteria, treatment schedules, or the rationale for choosing the immune endpoint. The outcome descriptions should therefore be read as registry-defined measures rather than as a complete account of the clinical protocol.

3. Trial Design

NCT01496131 is a completed, randomized Phase II study of tecemotide (L-BLP25) in combination with standard androgen deprivation therapy and radiation therapy for untreated intermediate- and high-risk prostate cancer. The registry reports enrollment of 28. The trial used a parallel-group design and had no masking. Its recorded start date is 2011-10-24, and its primary completion date is 2016-11-25.

The two arm descriptions distinguish standard therapy from standard therapy plus tecemotide. Standard therapy is defined as radiation therapy combined with androgen deprivation therapy. The experimental arm adds tecemotide (L-BLP25) to that regimen. The intervention list also names radiation therapy, goserelin, cyclophosphamide, and tecemotide; the registry arm descriptions do not specify how each listed intervention was assigned or administered.

Randomization can reduce systematic differences between treatment groups at assignment, but it does not ensure that small groups will be balanced on every characteristic. The registry does not report the randomization method, allocation concealment, or stratification factors. Masking is recorded as none, so the study was unmasked; the record does not explain whether outcome assessment or laboratory procedures were conducted without knowledge of treatment assignment.

The posted primary outcome analysis is restricted to participants considered evaluable and positive to the viral pool in peripheral blood mononuclear cells. Its analyzed group sizes are 9 for standard therapy and 8 for standard therapy plus tecemotide. Those outcome-specific counts are not interchangeable with the enrollment figure or with the group sizes used for the PSA outcome, which are 14 in each arm. The record does not report a sample-size justification, interim analysis plan, or full statistical analysis plan.

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

Analysis population for the primary outcome, as defined in the registry: Analysis population included only subjects who had scored positive to viral pool in peripheral blood mononuclear cells and were considered as evaluable. Here, "Number of Participants Analyzed" signifies subjects evaluable for this outcome measure.

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: Baseline population included all randomized subjects.

6. Primary Endpoint

The registry lists the primary outcome as Number of Subjects With Change From Baseline in the Mucinous Glycoprotein 1 (MUC1) Specific Systemic T-Cells Immune Response at Day 60 (Pre-Radiation), measured over Baseline and Day 60 (Pre-Radiation).

The primary endpoint is the number of participants with a change from baseline in MUC1-specific systemic T-cell immune response at Day 60, before radiation. Baseline is defined as the measurement before the first dose of study medication on Day 1. The registry describes measurement by intracellular cytokine antigen-specific staining after in vitro stimulation with overlapping 15-mer peptide pools encoding the tumor-associated antigen MUC-1.

This is an immune-response endpoint: it counts participants meeting the registry’s change criterion, rather than reporting the size of each participant’s immune response or a continuous group average. The record does not state the threshold or direction that qualified as a change, so the counts cannot show whether responses increased, decreased, or differed by a particular magnitude. The endpoint’s population is also restricted to evaluable participants who scored positive to the viral pool in peripheral blood mononuclear cells. That restriction matters for interpretation because the reported counts do not describe all enrolled participants.

Immune measures can serve as biological outcomes in studies evaluating an intervention intended to affect an immune response. In general, a biological measure may help characterize a treatment’s effect on a proposed pathway, but it is not automatically a direct measure of clinical benefit. The registry does not establish a relationship between this immune-response measure and later disease outcomes.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The trial is described as randomized, parallel-group, and unmasked. In general, randomization assigns participants to treatment groups through a chance-based process, helping limit systematic differences at assignment. A parallel-group design means participants remain in an assigned treatment group for comparison rather than crossing between regimens. These design labels do not by themselves resolve concerns about small group sizes, missing outcomes, or differences in who was evaluable. The registry does not report the randomization procedure, allocation concealment, or a detailed analysis plan.

What does a count endpoint represent?

The primary outcome is a binary count: participants are classified according to whether they met the registry’s definition of a change in MUC1-specific systemic T-cell response. The posted data give the number meeting that criterion and the number analyzed in each arm. A count is easy to describe, but it does not show the magnitude of response for each participant. The registry does not state the change threshold, direction, or decision rule, which limits interpretation of what the count represents biologically.

The analyzed population is particularly important. For the primary outcome, only participants who scored positive to the viral pool in peripheral blood mononuclear cells and were considered evaluable were included. This means the endpoint counts are conditional on that eligibility for analysis. They do not necessarily represent all randomized participants. In general, a restricted evaluable analysis can be affected if inclusion depends on factors related to treatment or outcome. The record does not describe how many participants failed the evaluability criteria or why, and it does not report a separate analysis of all randomized participants for this endpoint.

Why is the primary comparison not estimable?

The registry explicitly indicates that values are missing or not estimable for a two-arm comparison of the primary binary endpoint. Thus, although arm-specific counts are posted, the registry does not provide an inferential comparison for them. No risk difference, confidence interval, or p-value should be inferred from the counts as though it were a reported analysis. The record does not explain why the comparison could not be estimated. It also does not report a sponsor analysis that resolves this limitation.

How should the PSA comparison be read?

The PSA-based outcome reports participants with progression or recurrence status from randomization up to 24 months. The posted comparison gives an unadjusted risk difference of -0.143 and a confidence interval from -0.326 to 0.040, with p = 0.142. The confidence interval describes the range of values compatible with the data under the analysis assumptions; it conveys uncertainty about the estimated difference, rather than a range of individual participant outcomes. Because the interval includes zero, it does not rule out no difference. Its breadth also indicates limited precision.

The listed comparison is an unadjusted recalculation based on the posted summary statistics. It does not account for covariates or other design features. No sponsor-reported analysis is listed for this secondary outcome, and the registry does not report an adjusted estimate. The unadjusted p-value is not a measure of the probability that a treatment is effective or ineffective. It describes how compatible the observed data are with a specified null model under the calculation’s assumptions.

What do planning calculations mean?

In general, sample-size planning asks how many participants would be needed under stated assumptions to detect a chosen effect with a chosen level of statistical power. The registry’s planning description specifies a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the effect expressed as a fraction of the observed effect. Such values are planning illustrations based on the observed effect, not observed power and not evidence that the trial was designed around those assumptions. For time-to-event outcomes, the stated convention is that planning values refer to the total number of events; other outcomes use participants per arm. The registry does not report its own sample-size justification, so the planning illustration should not be treated as the trial’s original design rationale.

In general, small event counts and small analyzed groups can produce unstable estimates and wide uncertainty. A confidence interval is more informative about precision than a point estimate alone, but it remains dependent on the analysis and assumptions used to construct it. These considerations are relevant to the PSA comparison and to the restricted primary analysis. The registry does not report interim analyses, missing-data methods, multiplicity adjustment, or the full statistical analysis plan, so those aspects cannot be evaluated from the 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("Standard Therapy", "Standard Therapy Plus Tecemotide (L-BLP25)")
n      <- c(9, 8)
events <- c(2, 3)
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  Standard Therapy  9  2  22.2  2.8  60.0  6.3  54.7  6.7  55.6
ARM  Standard Therapy Plus Tecemotide (L-BLP25)  8  3  37.5  8.5  75.5  13.7  69.4  13.7  70.1

11. Multiplicity, Missing Data and Analysis Populations

The registry record does not report a statistical analysis plan describing how multiple outcomes were handled. It lists a primary immune-response endpoint and secondary outcomes that include PSA-based progression or recurrence and tumor-biopsy T-cell doubling. When multiple outcomes are examined, the chance of at least one apparently notable result can increase. In general, multiplicity procedures can help control that risk, but the record does not say whether such procedures were planned or applied. The posted PSA p-value is unadjusted and should be read accordingly.

The registry does not report a missing-data strategy, such as imputation, sensitivity analysis, or a rule for handling participants without an outcome measurement. For the primary outcome, the analysis population is explicitly limited to participants who tested positive to the viral pool and were considered evaluable. The reasons other participants were not evaluable, and the extent or pattern of missing measurements, are not reported in the registry record. Therefore, it is not possible to assess whether the analyzed participants differ systematically from those excluded.

Analysis populations also differ across outcomes. The primary immune-response counts are based on the stated evaluable population, whereas the PSA counts use 14 participants per arm. These are outcome-specific denominators; the registry does not explain the relationship between the populations or give a participant flow account. The enrollment figure alone does not resolve these questions.

The registry record does not report interim analyses, a sample-size justification for the trial itself, or a complete statistical plan. It also does not report a sponsor analysis for the PSA comparison, and the primary binary comparison is not estimable in the posted results. These omissions limit assessment of prespecification, analysis choices, and the robustness of the reported findings. They should be treated as uncertainties in the available record rather than filled in by assumption.

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: abdominal pain (7.1%), diarrhoea (7.1%), crohn's disease (7.1%), small intestinal obstruction (7.1%), osteoarthritis;hip replacement surgery (7.1%).

The serious adverse event groups each list 14 participants at risk. Serious adverse events affected 1 participant in the standard-therapy group and 2 participants in the standard-therapy-plus-tecemotide group. The registry reports 0 deaths in each group. Other adverse events affected 14 participants in each group. These are descriptive counts; the record does not provide a comparative safety analysis or uncertainty estimates for them.

The registry lists abdominal pain, diarrhoea, Crohn's disease, small intestinal obstruction, osteoarthritis;hip replacement surgery, and lumbar stenosis among the serious adverse event terms, each with a reported frequency of 7.1%. The listing does not specify the arm for each term in the registry record for this summary, so the terms should not be assigned to a particular treatment group. Nor should the term-specific figures be added: participants may have more than one event, and the record does not provide participant-level overlap.

Safety counts depend on the registry’s event definitions, observation period, and reporting conventions. The record does not give enough detail to establish whether differences reflect treatment, chance, or other factors. The small groups and descriptive reporting make these figures unsuitable as a stand-alone comparative safety assessment.

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

The posted results establish what the registry recorded, not a definitive treatment effect. For the primary immune-response outcome, the record gives arm-specific counts among evaluable participants but says a two-arm comparison is not estimable. Without a comparative estimate and uncertainty interval, those counts do not establish a difference attributable to tecemotide.

The PSA-based secondary outcome has an unadjusted comparison, but its confidence interval includes zero and the p-value is 0.142. The point estimate is therefore uncertain, and the comparison does not rule out no difference. The registry does not list a sponsor-reported analysis for this outcome. The result should not be interpreted as proof that the regimens are equivalent, nor as proof that a difference exists.

Neither outcome establishes whether a measured immune change predicts progression or recurrence. The registry does not report an analysis connecting the primary biological endpoint to the PSA outcome, and it does not provide the tumor-biopsy endpoint results. The outcome measures also apply to different analysis populations and timeframes, so they cannot be treated as interchangeable evidence.

In general, a trial can generate useful descriptive information even when its posted comparisons are inconclusive. The limitations include the restricted primary analysis population, small outcome-specific groups, an unestimable primary comparison, and incomplete reporting of analysis methods. These findings describe the registry record; they are not medical advice and should not be used alone to make treatment decisions.

14. Why This Trial Matters Statistically

This trial is statistically informative because it illustrates the difference between arm-specific counts and a usable comparative analysis. The primary outcome has counts for each arm, but the registry states that a two-arm comparison is not estimable. A reader should not infer a treatment effect merely by comparing the counts informally, especially when the analyzed population is restricted to participants meeting evaluability criteria.

It also demonstrates why denominators must be read outcome by outcome. The primary immune-response endpoint uses an evaluable subset, whereas the PSA outcome reports 14 participants per arm. Those analysis groups answer different measurement questions, and the registry does not provide a participant flow account that reconciles them. Enrollment is not a substitute for the denominator of a particular outcome.

The secondary PSA comparison illustrates the role of uncertainty. Its point estimate is accompanied by a confidence interval that includes zero, and the p-value is unadjusted. The result is not a precise or definitive comparison. In general, secondary outcomes can help describe a trial’s findings, but they carry less weight when the statistical plan and multiplicity approach are not reported.

Finally, the record separates a laboratory immune endpoint from a disease-status outcome without reporting a formal relationship between them. That distinction matters: a change in a biological measure is not itself evidence of a change in clinical outcome. The study therefore provides a useful case for examining endpoint definition, analysis populations, and the limits of registry-level inference.

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 endpoint’s reported analysis is limited to participants who scored positive to the viral pool and were considered evaluable. The registry does not report why participants were excluded from this analysis, how missing measurements were handled, or whether an analysis of all randomized participants was conducted. This restricts generalizability of the primary counts and makes possible selection effects difficult to assess.

The primary outcome is described as the number of participants with a change in immune response, but the threshold and direction defining a change are not reported in the registry record. The counts therefore do not reveal response magnitude or whether a change represents an increase or decrease. Further, the two-arm comparison is not estimable, leaving no posted effect estimate or uncertainty interval for the primary endpoint.

The detailed secondary comparison concerns PSA-based progression or recurrence. It is unadjusted, and no sponsor-reported analysis is listed. Results for the listed tumor-biopsy T-cell outcome are not reported in the registry record. There is no reported analysis connecting the immune-response endpoint to the PSA outcome.

Other limitations include the absence of a reported trial sample-size justification, full statistical analysis plan, multiplicity strategy, interim analysis details, and participant flow account. Randomization and parallel-group design are recorded, but the randomization method, allocation concealment, and any stratification factors are not described. The trial is unmasked. These gaps limit evaluation of prespecification, missingness, and potential bias. The safety information is descriptive and does not include a comparative analysis.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Tecemotide (L-BLP25) in Prostate Cancer — NCT01496131.
• Registry record last updated 2018-03-09; status last verified 2018-02.
• Results first posted 2018-03-09.
• 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

NCT01496131 is a completed, randomized, unmasked, parallel-group Phase II study of tecemotide (L-BLP25) for untreated intermediate- and high-risk prostate cancer. The registry reports enrollment of 28 and compares standard radiation therapy plus androgen deprivation therapy with the same standard therapy plus tecemotide.

The primary outcome counts participants with a change in MUC1-specific systemic T-cell immune response at Day 60 before radiation. The posted counts are 2 among 9 analyzed for standard therapy and 3 among 8 for standard therapy plus tecemotide, but a two-arm comparison is not estimable. The PSA-based secondary outcome reports 2 among 14 and 0 among 14, with an unadjusted p-value of 0.142 and an interval that includes zero. The registry does not report a sponsor analysis for that comparison. Missing-data methods, the trial’s sample-size justification, and the full statistical plan are not reported in the registry record.