This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for A Study of Sipuleucel-T With Administration of Enzalutamide in Men With Metastatic Castrate-Resistant Prostate Cancer (NCT01981122), a randomized phase 2 study. The primary outcome is To Evaluate Peripheral PA2024-specific T Cell Proliferation Response to Sipuleucel-T Over Time Via a T Cell Stimulation Index (SI)..
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01981122 |
| Phase | Phase 2 |
| Condition | Metastatic Prostate Cancer |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 52 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Dendreon |
| Results posted | Yes |
2. Clinical Question
Population
Men with metastatic castrate-resistant prostate cancer. The registry record reports enrollment of 52 participants. It does not give further eligibility details in the information available for this study.
Intervention
Sipuleucel-T administered concurrently with enzalutamide. In the concurrent arm, enzalutamide at 160 mg orally once daily was to start 2 weeks before the first leukapheresis and continue for 52 weeks, or until disease progression or unacceptable toxicity, whichever occurred first.
Comparator
Sipuleucel-T followed by enzalutamide. In the sequential arm, enzalutamide at 160 mg orally once daily was to start approximately 10 weeks after the first sipuleucel-T infusion and continue for 52 weeks, or until disease progression or unacceptable toxicity, whichever occurred first.
Primary question
How did peripheral PA2024-specific T cell proliferation response to sipuleucel-T over time compare between the concurrent and sequential schedules? The outcome was characterized using a T cell stimulation index. Numerical results of that comparison are not reported in the registry record.
The contrast of interest is the timing of enzalutamide relative to sipuleucel-T, not a comparison of sipuleucel-T with no treatment. Both groups were assigned a schedule involving both named treatments. The study was randomized, open-label, Phase 2, and used a parallel-group model. The registry describes its purpose as assessing the effects of sipuleucel-T when administered concurrently or sequentially with enzalutamide.
The primary outcome concerns an immune-cell proliferation measure, rather than a stated clinical endpoint such as disease progression or survival. The record does not report numerical arm-specific stimulation-index results, an estimated between-arm effect, or a confidence interval. Thus, the clinical question can be described from the registered objective and schedules, but the comparative primary-outcome finding cannot be characterized from the registry record.
3. Trial Design
This was a randomized, open-label, Phase 2 study with a parallel-group model. The registry lists 52 participants and a completed status. The study start is recorded as 2013-09, and primary completion as 2017-06-30. The sponsor is Dendreon. Masking is listed as none. The registry record does not report the method used to generate the random sequence, conceal allocation, or assign participants to the arms.
The two groups differed in the timing of enzalutamide alongside sipuleucel-T. The concurrent arm description specifies that enzalutamide at 160 mg orally once daily would begin 2 weeks before the first leukapheresis. The sequential arm description specifies that enzalutamide at the same dose and route would begin approximately 10 weeks after the first sipuleucel-T infusion. In both arm descriptions, enzalutamide was to continue for 52 weeks or until disease progression or unacceptable toxicity, whichever occurred first. These are the registered schedules; they do not establish how long individual participants actually received treatment.
Participants were followed for up to 52 weeks after the first dose of sipuleucel-T for the primary outcome. Immune sample draws during the treatment period, from Week 0 through Week 4, were to occur at pre-leukapheresis visits identified as Pre-Leuk 2 and Pre-Leuk 3. The record does not report the number of participants randomized to each group in the design description, the actual treatment exposure by participant, or adherence to the planned schedules.
The primary outcome description specifies comparison over time using a repeated measurement mixed model, with the stimulation index log-transformed before analysis. The registry lists one outcome measure and one analysis. It does not report the model specification in further detail, a sample-size justification, or the planned handling of interim analyses. Those details 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
| Stage | Concurrent Arm | Sequential Arm |
|---|---|---|
| STARTED | 25 | 27 |
| COMPLETED | 11 | 7 |
| NOT COMPLETED | 14 | 20 |
Reasons for not completing this period:
| Reason | Concurrent Arm | Sequential Arm |
|---|---|---|
| Withdrawal by Subject | 0 | 2 |
| Protocol Violation | 0 | 1 |
| Lost to Follow-up | 0 | 1 |
| Investigator Or Dendreon Discretion | 0 | 1 |
| Death | 14 | 15 |
Analysis population for the primary outcome, as defined in the registry: Summary of Cellular Proliferation Data Through Week 52. All patients with reported data at a specified time-point were analyzed. Number of patients at each time-point differed across the time-points resulting in patient numbers at each time-point that are not equal to the total number of patients analyzed.
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.
| Characteristic | Unit | Concurrent Arm | Sequential Arm | Total |
|---|---|---|---|---|
| Participants analysed | 25 | 27 | 52 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 10 | 4 | 14 |
| Age, Categorical: >=65 years | Participants | 15 | 23 | 38 |
| Age, Continuous | Years | 66.4 (SD 10.6) | 73.3 (SD 9.0) | 70.0 (SD 10.3) |
| Sex: Female, Male: Female | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Male | Participants | 25 | 27 | 52 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 2 | 2 |
| Race (NIH/OMB): White | Participants | 25 | 25 | 50 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | Participants | 25 | 27 | 52 |
| Height | Centimeters | 177.0 (SD 8.0) | 177.2 (SD 6.0) | 177.1 (SD 6.9) |
| Weight | Kg | 94.6 (SD 19.4) | 91.2 (SD 13.9) | 92.8 (SD 16.6) |
| Body Mass Index | Kg/m^2 | 30.3 (SD 5.1) | 29.0 (SD 4.2) | 29.6 (SD 4.6) |
| Eastern Cooperative Oncology Group (ECOG) Performance Status: ECOG 0=Fully Active; No restrictions | Participants | 22 | 19 | 41 |
| Eastern Cooperative Oncology Group (ECOG) Performance Status: ECOG 1=Restricted Strenuous Activity | Participants | 3 | 8 | 11 |
| Gleason Score: Gleason Score ≤6 | Participants | 1 | 2 | 3 |
| Gleason Score: Gleason Score 7 | Participants | 4 | 8 | 12 |
| Gleason Score: Gleason Score ≥8 | Participants | 19 | 16 | 35 |
| Gleason Score: Missing | Participants | 1 | 1 | 2 |
| Time from Diagnosis to Randomization | Years | 5.1 (SD 5.3) | 6.5 (SD 5.6) | 5.8 (SD 5.5) |
| Time in Years: 0-5 | years | 16 | 14 | 30 |
| Time in Years: 6-10 | years | 5 | 5 | 10 |
| Time in Years: 11-15 | years | 3 | 6 | 9 |
| Time in Years: 16-20 | years | 0 | 1 | 1 |
| Time in Years: 21-25 | years | 1 | 1 | 2 |
6. Primary Endpoint
The registry lists the primary outcome as To Evaluate Peripheral PA2024-specific T Cell Proliferation Response to Sipuleucel-T Over Time Via a T Cell Stimulation Index (SI)., measured over Each patient was followed for up to 52 weeks after the first dose of sipuleucel-T. Immune sample draws during the treatment period (Week 0 through Week 4) were to be performed at the patient's pre-leukapheresis visits (Pre-Leuk 2 and Pre-Leuk 3)..
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | 10^3 cells/mL |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is peripheral PA2024-specific T cell proliferation response to sipuleucel-T over time, expressed through a T cell stimulation index. The record defines the index as the median 3H uptake of 3 wells exposed to antigen divided by the median 3H thymidine uptake of 3 wells exposed to media. This operational definition compares cellular uptake under antigen exposure with uptake under the media condition.
The endpoint was collected at multiple time points, with immune sample draws during Week 0 through Week 4 scheduled at the specified pre-leukapheresis visits. Follow-up for this outcome extended up to 52 weeks after the first sipuleucel-T dose. The registry describes the aim as comparing the response over time between the concurrent and sequential arms. It labels the outcome unit as 10^3 cells/mL and identifies the measure as a mean with standard deviation dispersion, while the operational definition is a stimulation index based on uptake measurements.
The stated reason for measuring this endpoint is to characterize a cellular proliferation response in relation to the two treatment schedules. It is an immune-response measure, not itself a direct measure of symptoms, tumor control, or survival. The record does not report numerical values at the time points, a summary contrast between arms, or a confidence interval. Therefore, the endpoint’s definition and intended comparison are available, but the magnitude and precision of the observed response are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registered objective is a comparison of PA2024-specific T cell proliferation response over time between concurrent and sequential treatment schedules. The primary-outcome description says that the comparison was to use a repeated measurement mixed model and that the stimulation index was to be log-transformed. However, no arm-specific means, standard deviations, time-point estimates, model-based contrast, confidence interval, or p-value for this outcome are reported in the registry record. Without those results, the direction, size, and statistical precision of the primary comparison cannot be described.
The study lists 52 participants overall. The safety summaries identify 25 participants at risk in the concurrent group and 27 in the sequential group for both serious and other adverse events. Those safety counts do not supply the missing primary-outcome values, and they should not be treated as the number with usable immune measurements at every time point. The outcome description explicitly says that the number of patients differed across time points because only patients with reported data at a specified time point were analyzed.
The safety record reports 2 participants affected by serious adverse events in the concurrent group and 9 in the sequential group. For other adverse events, it reports 23 affected in the concurrent group and 27 in the sequential group. Death counts are 14 and 15, respectively. These are descriptive registry counts. The record does not state whether deaths or adverse events were attributed to a particular treatment, nor does it provide the timing or causes of deaths in the information available for this analysis. They cannot be used to infer a treatment effect on the primary immune endpoint.
The serious-event terms listed include Spinal Cord Compression at 7.4%, Conjunctival Haemorrhage at 4.0%, Vomiting at 4.0%, Eye Injury at 4.0%, Face Injury at 4.0%, and Fall at 4.0%. The registry does not explain the denominator behind those percentages in the available record, so their scope should not be assumed. These terms also do not establish how many events occurred per affected participant.
In general, an estimated treatment contrast describes the observed difference under a particular analysis, while a confidence interval describes its statistical uncertainty. Neither is available for the primary outcome in the registry record. Consequently, no conclusion about the comparative immune response or its precision can be drawn from the posted results. This is an absence of reported comparative endpoint results, not evidence that the groups had identical responses.
9. Statistical Methods Explained
The primary measure is continuous and is summarized in the registry as a mean with standard deviation. The underlying stimulation index is defined as the median 3H uptake across 3 antigen-exposed wells divided by the median 3H thymidine uptake across 3 media-exposed wells. The endpoint description states that this index was to be log-transformed before analysis. The record identifies a repeated measurement mixed model for comparing the response over time between arms.
What does a repeated measurement model address?
In general, repeated measurements from the same participant are related: observations from one person are not equivalent to observations from unrelated people. A repeated measurement model represents that structure while estimating how the outcome changes across measurement occasions and whether its pattern differs between groups. A mixed model can use the observed repeated measurements while accounting for within-participant dependence according to the model specification. The registry does not report the covariance structure, the fixed effects included, the exact time points in the fitted model, or the method used to estimate model parameters. Those details are not reported in the registry record.
The endpoint description says that the analysis compared PA2024-specific proliferation responses over time between the concurrent and sequential arms. It does not state which model term or contrast was treated as the primary between-arm test, whether the comparison focused on an overall group effect or a group-by-time pattern, or how the model handled departures from its assumptions. The planned model name alone does not identify those choices.
Why transform the stimulation index?
The record specifies a logarithmic transformation of the stimulation index before analysis but does not give a rationale. In general, a log transformation can make a positively skewed measurement more suitable for a model whose assumptions concern the transformed outcome. It can also change the way effects are represented: a contrast on the log scale is not the same as an arithmetic difference on the original scale. The registry does not report whether results were converted back to the original scale for presentation or how any transformed-scale estimates were interpreted.
In general, the validity of a model-based result depends on the model’s assumptions and its fit to the observed data. For repeated measurements, relevant considerations include the distribution of residuals, the dependence structure among observations from one participant, and whether the chosen model represents the trajectory adequately. The registry record does not report diagnostics, sensitivity analyses, or details sufficient to evaluate those assumptions.
What does the mean and standard deviation describe?
In general, a mean is a measure of the center of a set of observations, and a standard deviation describes their spread around that center. They are descriptive summaries and do not by themselves quantify uncertainty in an estimated difference between arms. A confidence interval for a contrast would convey uncertainty about that comparison; no such interval for the primary outcome is reported in the registry record. The record identifies the outcome as a mean with standard deviation, but it does not provide those numerical summaries by arm and time point in the information available.
The outcome population statement says that all patients with reported data at a specified time point were analyzed. It also says that patient numbers differed across time points and were not equal to the total number of patients. In general, changing numbers of observations across occasions can affect the precision and interpretation of a longitudinal comparison. A repeated measurement model may use available observations, but whether and under what assumptions this approach addresses missing measurements depends on the analysis specification. The registry does not report missing-data reasons, an imputation method, or assumptions about missingness.
What can planning calculations establish?
In general, sample-size calculations are planning tools that relate a target effect, variability, significance level, power, and allocation assumptions to a proposed study size. The registry’s stated planning illustration uses a two-sided significance level of 0.05, equal allocation, a normal approximation, and an effect defined as a stated fraction of the observed effect. It distinguishes participant counts per arm for non-time-to-event outcomes from total event counts for time-to-event outcomes. Such illustrations are not the trial’s own design justification and are not observed power. The registry record does not report the trial’s sample-size justification. No numerical planning results are available in the information reported for this analysis.
The record lists one outcome measure and one analysis, but this does not describe every decision that may have been made in the analysis. The precise statistical plan, including any adjustment or sensitivity procedures, is not reported in the registry record. In the absence of the numerical endpoint results and full model details, the method can be characterized as planned, but its implementation and the resulting estimates cannot be independently assessed from the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one outcome measure and one analysis. The primary outcome, however, concerns response over time, and the record says that patient numbers differed across time points. The available information does not enumerate the numerical time-point results or specify whether each time point was tested separately. It also does not report whether any adjustment for multiple comparisons was planned or used. Listing one outcome measure and one analysis does not establish that all multiplicity concerns were absent; the detailed statistical plan is not reported in the registry record.
The outcome population statement says that all patients with reported data at a specified time point were analyzed. It notes that the number of patients at each time point differed, so those counts were not equal to the total number of patients. This describes an available-data approach at each time point, but does not tell why observations were unavailable, whether participants withdrew, or whether missingness differed between arms. Those details are not reported in the registry record.
The record does not specify whether missing values were imputed, whether the mixed model used all available repeated observations, or what assumptions about missingness were used. In general, missing-data assumptions matter because the observed participants may not represent all randomized participants when measurements are unavailable. The record also does not identify an intention-to-treat, per-protocol, or other named analysis population for the primary outcome. Therefore, the precise population represented by the primary analysis cannot be fully characterized.
No interim-analysis plan, stopping rule, or multiplicity-control strategy is reported in the registry record. Their absence from the registered information should be read as missing reporting, not as proof that these procedures were or were not used.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Concurrent Arm | 2 | 25 | 8.0% |
| Sequential Arm | 9 | 27 | 33.3% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Concurrent Arm | 14 of 25 |
| Sequential Arm | 15 of 27 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 1.9% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Concurrent Arm | 23 of 25 |
| Sequential Arm | 27 of 27 |
Most frequent serious adverse event terms
| Event term | Organ system | Concurrent Arm | Sequential Arm |
|---|---|---|---|
| Spinal Cord Compression | Nervous system disorders | 0 of 25 | 2 of 27 |
| Anaemia | Blood and lymphatic system disorders | 0 of 25 | 1 of 27 |
| Atrial Flutter | Cardiac disorders | 0 of 25 | 1 of 27 |
| Cardiac Failure Congestive | Cardiac disorders | 0 of 25 | 1 of 27 |
| Conjunctival Haemorrhage | Eye disorders | 1 of 25 | 0 of 27 |
| Vomiting | Gastrointestinal disorders | 1 of 25 | 0 of 27 |
| Thrombosis In Device | General disorders | 0 of 25 | 1 of 27 |
| Sepsis | Infections and infestations | 0 of 25 | 1 of 27 |
| Urinary Tract Infection | Infections and infestations | 0 of 25 | 1 of 27 |
| Eye Injury | Injury, poisoning and procedural complications | 1 of 25 | 0 of 27 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Concurrent Arm | Sequential Arm |
|---|---|---|---|
| Fatigue | General disorders | 9 of 25 | 17 of 27 |
| Nausea | Gastrointestinal disorders | 7 of 25 | 7 of 27 |
| Back Pain | Musculoskeletal and connective tissue disorders | 7 of 25 | 3 of 27 |
| Dizziness | Nervous system disorders | 4 of 25 | 6 of 27 |
| Chills | General disorders | 2 of 25 | 7 of 27 |
| Paraesthesis Oral | Gastrointestinal disorders | 3 of 25 | 5 of 27 |
| Arthralgia | Musculoskeletal and connective tissue disorders | 3 of 25 | 5 of 27 |
| Paraesthesia | Nervous system disorders | 3 of 25 | 5 of 27 |
| Cough | Respiratory, thoracic and mediastinal disorders | 2 of 25 | 6 of 27 |
| Hot Flush | Vascular disorders | 3 of 25 | 5 of 27 |
Serious events with the highest arm-level rate: spinal cord compression (7.4%), conjunctival haemorrhage (4.0%), vomiting (4.0%), eye injury (4.0%), face injury (4.0%).
The registry safety groups list 25 participants at risk for serious adverse events in the concurrent arm, with 2 affected, and 27 at risk in the sequential arm, with 9 affected. For other adverse events, the corresponding counts are 25 at risk and 23 affected in the concurrent arm, and 27 at risk and 27 affected in the sequential arm. These are participant counts in the registry summaries; they do not describe the number of separate events experienced by each participant.
The registry also reports 14 deaths in the concurrent arm and 15 in the sequential arm. It does not give the causes, timing, or treatment attribution of those deaths in the information available for this analysis. They should not be interpreted as deaths caused by either treatment schedule or as evidence about comparative effectiveness.
The listed serious-event terms and percentages are Spinal Cord Compression at 7.4%, Conjunctival Haemorrhage at 4.0%, Vomiting at 4.0%, Eye Injury at 4.0%, Face Injury at 4.0%, and Fall at 4.0%. The denominator and whether these percentages refer to participants or events are not reported in the registry record. These summaries do not provide a complete account of event severity, duration, or causal assessment.
These safety figures are descriptive. The registry record does not report a statistical comparison of adverse-event risk between arms, and the counts alone do not establish that a schedule caused an event.
12. What the Result Does, and Does Not, Mean
The registered comparison is between two schedules that pair sipuleucel-T with enzalutamide: concurrent administration and sequential administration. The primary outcome is a cellular proliferation response measured through a stimulation index over time. The registry provides the outcome definition and states that the comparison was to use a repeated measurement mixed model after log transformation of the index.
What the registry record does not provide is the numerical primary-outcome result. There are no reported arm-specific estimates, time-point means, standard deviations, between-arm contrast, confidence interval, or p-value in the information available. The magnitude and direction of the observed difference, and the precision of any estimate, are therefore not known from the posted results. This lack of a reported estimate is not evidence of no difference.
The study’s outcome addresses an immune-cell response, not a direct clinical outcome. Even a reported difference in the stimulation index would not, by itself, establish a difference in symptoms, tumor progression, survival, or overall clinical benefit. The registry record does not report those outcomes as the primary comparison.
The safety summaries report adverse-event and death counts by group, but do not give attribution, timing, or a statistical comparative analysis. Counts should not be treated as causal findings. The record also notes that the number of participants with reported primary-outcome data varied across time points, which limits any assumption that every participant contributed data at every occasion.
In general, interpretation of a randomized comparison depends on the estimated effect, its uncertainty, the analysis population, missing-data handling, and the relevance of the measured outcome. Here, the registered design and endpoint can be described, but the central efficacy-style interpretation of the primary immune endpoint cannot be made without its numerical results. No claim that one schedule produced a larger or smaller response is supported by the registry information available.
13. Why This Trial Matters Statistically
Statistically, this study poses a longitudinal comparison rather than a single-time-point contrast. The primary question concerns how a cellular response changes over time under two schedules, and the registry identifies a repeated measurement mixed model for that purpose. Such a design highlights the need to distinguish differences in overall response from differences in response patterns across occasions. The registry does not report which specific model contrast was used.
The study also illustrates why outcome definitions and analysis details matter. The stimulation index is defined from antigen-exposed and media-exposed well measurements, and the index was to be log-transformed. Those choices determine what quantity the analysis represents and how its effect estimates should be interpreted. The record does not include numerical endpoint results or enough model detail to evaluate the fitted analysis.
Another statistical issue is that the number of patients with reported data differed across time points. Longitudinal interpretation therefore depends on the observations available at each occasion and on assumptions about missing measurements. The registry identifies the available-data population at each time point but does not describe the reasons for missing data or the handling assumptions.
The value of the record is consequently in clarifying the randomized comparison, treatment timing, endpoint definition, and intended analytical framework. It does not support a quantitative conclusion about the primary outcome because the estimates and their uncertainty are not reported. This distinction between a registered question and a reported result is essential when evaluating what evidence a trial record can support.
14. 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 most important limitation for interpretation is that numerical results for the primary outcome are not reported in the registry record. Without values by arm and time point, or a model-based contrast with an interval estimate, the size, direction, and precision of the stated comparison cannot be assessed. The record gives an endpoint description and analysis approach, not the result needed to answer the primary question.
The endpoint population statement indicates that numbers differed across time points because only patients with reported data at a specified time point were analyzed. The record does not provide the time-point-specific participant counts, reasons for missing measurements, imputation procedures, or assumptions used to address missing data. This prevents assessment of whether missing observations could affect the longitudinal comparison.
The repeated measurement mixed model is described at a high level, but the model’s exact terms, covariance structure, diagnostics, and sensitivity analyses are not reported. The record also does not state the analysis population by a named convention or explain whether any multiplicity adjustment was used. These omissions limit evaluation of the planned and implemented statistical analysis.
The study is listed as open-label with no masking. The registry record does not describe how this design feature was addressed in outcome measurement or analysis. The safety summaries report counts and selected serious-event terms, but do not give attribution or the denominator for the listed percentages. These limitations do not establish bias or causation; they describe information that is not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Study of Sipuleucel-T With Administration of Enzalutamide in Men With Metastatic Castrate-Resistant Prostate Cancer — NCT01981122.
- Registry record last updated 2018-10-24; status last verified 2018-09.
- Results first posted 2018-09-25.
- 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.
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18. Record Summary
The registry record describes a completed, randomized, open-label, Phase 2, parallel-group study of sipuleucel-T administered concurrently or sequentially with enzalutamide in men with metastatic castrate-resistant prostate cancer. It lists enrollment of 52 and identifies peripheral PA2024-specific T cell proliferation response over time as the primary outcome.
The outcome uses a stimulation index defined from antigen-exposed and media-exposed well uptake measurements. The stated analysis is a repeated measurement mixed model, with the index log-transformed before analysis. Immune sample draws were scheduled during Week 0 through Week 4, and follow-up extended up to 52 weeks after the first sipuleucel-T dose.
Numerical results for the primary outcome, including an arm comparison and its precision, are not reported in the registry record. Safety summaries list adverse-event counts and deaths by arm, but do not report causal attribution. The registry does not provide the detailed statistical plan, sample-size justification, or missing-data procedures.