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 Study of Combined Decompressive Spine Radiosurgery and Pembrolizumab (NCT05204290), a na early/phase 1 study. The primary outcome is Number of Participants Completing Stereotactic Body Radiation Therapy (SBRT) and One Cycle of Pembrolizumab.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05204290 |
| Phase | EARLY/Phase 1 |
| Condition | Epidural Spinal Tumors, Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 1 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Wake Forest University Health Sciences |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned patients with high-grade epidural disease of the spine. The registry also lists epidural spinal tumors and cancer as conditions. It records enrollment of 1 participant; it does not report outcome data for that participant because of privacy and confidentiality concerns.
Intervention
The study combined stereotactic body radiation therapy (SBRT) with pembrolizumab. The registry describes MRI scans of the spine before treatment and 2 months and 6 months after treatment, as well as immunotherapy with pembrolizumab. Blood draws are also listed as an intervention.
Comparator
This was a single-group study, with allocation recorded as not applicable and no masking. The registry does not identify a separate control or comparison group. Consequently, the study was not designed in the posted record as a like-for-like comparison between treatment strategies.
Primary question
The primary endpoint asks how many participants completed SBRT and one cycle of pembrolizumab, assessed at Day 5 and up to cycle 1 (Day 22). The registry description says a 95% confidence interval for feasibility would be calculated, but the outcome data are not reported.
3. Trial Design
The registry describes NCT05204290 as an early phase 1, single-group study of combined decompressive spine radiosurgery and pembrolizumab in patients with high-grade epidural disease. The study title and intervention descriptions identify stereotactic body radiation therapy (SBRT) and pembrolizumab as the treatment combination. Blood draws are also listed. The treatment-group description mentions MRI scans of the spine before treatment, 2 months after treatment, and 6 months after treatment.
Allocation is recorded as not applicable, and masking is recorded as none. The study therefore has no masked comparison and no separate control group described in the registry record. Its design is not a randomized comparison between treatment strategies. The record lists Wake Forest University Health Sciences as sponsor and an enrollment of 1 participant.
The study began on 2022-03-28, and the primary completion date is recorded as 2022-10-07. Its status is terminated. The registry record does not report why the study was terminated, whether the planned enrollment was reached, or details of a recruitment target. Those details cannot be inferred from the status alone.
The primary endpoint concerns completion of SBRT and one cycle of pembrolizumab. Secondary outcomes include change in thecal sac patency, accrual rate, pain improvement measured with the Numeric Pain Rating Scale, quality of life measured with the European Organization for Research and Treatment of Cancer QoL Group Bone Metastases Module, compression fractures, and changes in plasma. The registry lists seven outcome measures in total. It does not provide results for these outcomes.
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.
Before assignment: The study was terminated. Only 1 participant was enrolled in this study. Based on the low enrollment number, no data is reported here in order to protect and maintain participant privacy/confidentiality.
Overall Study
| Stage | Stereotactic Body Radiotherapy and Pembrolizumab Treatment |
|---|---|
| STARTED | 1 |
| COMPLETED | 1 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: The study was terminated. Only 1 participant was enrolled in this study. Based on the low enrollment number, no data is reported here in order to protect and maintain participant privacy/confidentiality.
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: The study was terminated. Only 1 participant was enrolled in this study. Based on the low enrollment number, no data is reported here in order to protect and maintain participant privacy/confidentiality.
| Characteristic | Unit | Stereotactic Body Radiotherapy and Pembrolizumab Treatment |
|---|---|---|
| Participants analysed | 0 | |
| Sex: Female, Male: Female | Participants | — |
| Sex: Female, Male: Male | Participants | — |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | — |
| Race (NIH/OMB): Asian | Participants | — |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | — |
| Race (NIH/OMB): Black or African American | Participants | — |
| Race (NIH/OMB): White | Participants | — |
| Race (NIH/OMB): More than one race | Participants | — |
| Race (NIH/OMB): Unknown or Not Reported | Participants | — |
| Region of Enrollment: United States | participants | — |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants Completing Stereotactic Body Radiation Therapy (SBRT) and One Cycle of Pembrolizumab, measured over At Day 5 and up to cycle 1 (Day 22).
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the number of participants who complete stereotactic body radiation therapy (SBRT) and one cycle of pembrolizumab. Its timeframe is stated as at Day 5 and up to cycle 1 (Day 22). The registry describes this as a measure of feasibility and says a 95% confidence interval for that endpoint would be calculated.
A feasibility endpoint asks whether participants can complete the specified study procedures or treatment, rather than directly estimating a comparative treatment effect. In general, tracking completion can help describe whether a study regimen and its required visits are practicable for the enrolled group. The registry record does not report a protocol rationale for selecting this endpoint or additional details about how completion was defined beyond the endpoint wording.
The registry reports enrollment of 1 participant but withholds outcome data to protect privacy and confidentiality. As a result, the number completing the combined endpoint is not reported in the registry record. No confidence interval or other estimate of feasibility is posted, so the endpoint cannot be quantified from the available results. The planned assessment window is reported, but the actual completion status and any reasons for non-completion are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central interpretive fact is that the study enrolled 1 participant and the registry record does not report outcome data. It explicitly states that data are not reported because of the low enrollment number and the need to protect participant privacy and confidentiality. Thus, the posted record does not establish whether the participant completed SBRT and cycle 1 of pembrolizumab, which is the primary endpoint.
The endpoint description says a 95% confidence interval for feasibility would be calculated. A confidence interval would ordinarily express the uncertainty around an estimate, but no estimate or interval is posted. The registry's statement that an interval was planned is not evidence that one was calculated or that its value is known. A numerical conclusion about feasibility cannot be drawn from the endpoint title or the planned analysis description.
The study is single-group and has no comparator group listed. Even if the endpoint data were available, this design would not provide a randomized comparison of the combination against another treatment strategy. The posted record also has no analysis entries. There are no reported results for the listed secondary outcomes, including thecal sac patency, accrual, pain, quality of life, compression fractures, or plasma changes.
The adverse-event group lists zero participants at risk and zero affected in the displayed event fields. These fields do not provide a basis for concluding that no adverse events occurred: the registry separately states that participant-level results are withheld, and the at-risk count itself is recorded as zero despite enrollment of 1 participant. The displayed fields therefore should be read as registry entries, not as a complete safety assessment.
The status is terminated, but the reason is not reported in the registry record. Termination alone does not establish whether the cause was recruitment, logistics, safety, or another factor. Taken together, the record documents the study design, its very limited enrollment, and the absence of reportable outcome data. It does not provide an estimate of the primary endpoint, an assessment of the listed secondary outcomes, or a comparative treatment effect.
9. Statistical Methods Explained
What does the endpoint estimate?
The primary endpoint counts participants completing both SBRT and one cycle of pembrolizumab within the stated timeframe. The registry describes this as a feasibility outcome and says a 95% confidence interval would be calculated. In general, an endpoint of this kind concerns completion of the defined treatment steps. It is different from an endpoint that measures a change in tumor status, pain, or quality of life.
For a binary completion outcome, an analysis might report the observed completion proportion and an interval expressing uncertainty around it. That is a general explanation, not a claim about a method used in this study. The registry record does not specify the interval method, and the result data are not reported. Without a posted completion outcome, neither the estimate nor its uncertainty can be interpreted.
What does a confidence interval mean?
In general, a confidence interval represents uncertainty in an estimated quantity under the assumptions of the analysis method. It is not a guarantee that the true value lies in any particular interval, and its precision depends on the available information and the method used. The record's description says a 95% confidence interval was planned for the primary feasibility outcome. It does not report a calculated interval, its limits, or the method used to obtain it. The planned confidence level should therefore not be mistaken for a posted result.
What does the single-group design permit?
The study is recorded as a single-group model, with allocation not applicable and masking none. In general, a single-group study can describe observations in its enrolled participants, but it does not directly compare outcomes with a concurrent control group. It cannot separate changes associated with the intervention from other influences through a randomized between-group contrast. Here, the absence of outcome reporting also prevents descriptive estimation of the primary endpoint in the enrolled participant.
Nothing in the registry record identifies a planned comparative model, an adjustment strategy, or a statistical test. The number of analysis entries is zero. Any account of a specific inferential model beyond the stated plan to calculate a confidence interval would therefore be unsupported.
How should the enrollment and precision be understood?
The registry reports enrollment of 1 participant. The record explains that outcome data are not reported because the enrollment was low and disclosure could compromise privacy and confidentiality. This means that the statistical precision of an endpoint estimate cannot be examined from the posted results. It is not appropriate to substitute a calculation based on an assumed outcome or to infer the participant's status from the study description.
In general, limited information makes estimates less precise and can leave wide uncertainty. That general principle does not supply a numerical interval for this study. The registry record does not report a sample-size justification, a target enrollment, or a planned precision criterion. It also does not report interim analyses or stopping rules. The terminated status cannot fill in those missing design details.
What can be inferred from the remaining outcomes?
The registry lists secondary measures covering thecal sac patency, accrual, pain, quality of life, compression fractures, and plasma changes. In general, multiple outcomes can describe different dimensions of a study, but interpreting them depends on their definitions, timing, collected data, and analysis methods. The record gives outcome names but does not report their results or detailed statistical methods. No conclusions about changes over time, participant experience, or safety can be drawn from the outcome list alone.
Multiplicity refers generally to the interpretive issue that can arise when many outcomes or statistical tests are considered: the chance of finding apparently notable results can increase unless an analysis plan addresses that issue. The registry record does not report a multiplicity strategy, and it contains no analysis entries. It is therefore not possible to determine whether any adjustment or hierarchy of outcomes was planned or applied.
The registry also does not report analysis-population definitions, handling of missing outcome observations, or a detailed statistical analysis plan. These are important for understanding which participants contribute to an estimate and how incomplete observations affect it. Their absence, combined with the withheld results, leaves no basis for reconstructing the analysis. General statistical principles can explain what the planned confidence interval would represent, but they cannot replace the unreported data or methods.
10. Multiplicity, Missing Data and Analysis Populations
The registry record does not report a multiplicity strategy. It lists a primary endpoint and secondary outcomes, but no hierarchy among the secondary outcomes, adjustment method, or testing procedure is described. In general, multiplicity becomes relevant when several outcomes or tests are assessed, because repeated opportunities to identify a statistically notable result can affect interpretation. That general concern does not show that any particular adjustment was required or used in this study.
The record has zero analysis entries. It does not report a statistical analysis plan, including rules for missing data, analysis populations, or how repeated measurements would be handled. These details are not reported in the registry record and cannot be reconstructed from the outcome names or timeframes alone.
The registry states that only 1 participant was enrolled and that no outcome data are reported to protect privacy and confidentiality. This is a reporting limitation, but it should not be described as proof that the participant's outcome was missing during study conduct. The distinction is between results withheld from the registry and data not collected or unavailable to investigators; the record does not clarify the latter.
The planned primary confidence interval is described, but no interval or estimate is posted. Without outcome values and analysis details, the effect of missing observations, the makeup of any analysis population, and any multiplicity handling cannot be assessed.
11. What the Result Does, and Does Not, Mean
The record documents a pilot study of combined SBRT and pembrolizumab for patients with high-grade epidural disease of the spine. It records the study as early phase 1, single group, unmasked, and terminated, with enrollment of 1 participant. Its primary question concerns completion of SBRT and cycle 1 of pembrolizumab, and the registry says a 95% confidence interval for feasibility was planned.
What the posted results do not provide is equally important. The primary completion outcome is not reported, nor are the confidence interval, secondary outcomes, or detailed analysis results. The registry explains that outcome data are withheld because of the low enrollment and privacy and confidentiality concerns. There is therefore no numerical estimate of the feasibility endpoint to interpret.
The record does not establish the reason for termination, whether the endpoint was met, or whether the treatment combination changed any listed secondary outcome. It also does not allow comparison with another treatment strategy, because no comparator group is listed. The registry's event fields, which show zero at risk and zero affected, are not a substitute for a safety result and do not establish that no events occurred.
In general, a very small study may provide limited precision and cannot support broad conclusions about outcomes beyond the participants whose data are available. For this record, however, the primary barrier is that the outcome results are not reported at all. No treatment benefit, lack of benefit, or safety conclusion should be inferred from enrollment, study status, intervention names, or the planned analysis description. The study's documented status is not itself an endpoint result.
12. Why This Trial Matters Statistically
This record illustrates the difference between a study question and an answer supported by posted results. The primary endpoint is clearly framed around completing SBRT and one cycle of pembrolizumab, and the registry describes a confidence interval intended to quantify feasibility. Yet enrollment of 1 participant and the stated privacy concern mean no outcome data are available in the registry record. The endpoint definition and planned method cannot stand in for an observed result.
The design also matters for interpretation. The study is single group, with no comparator listed and no masking. Those features define what the design could address even if outcomes were reported: it would describe the enrolled group rather than provide a randomized comparison. Recognizing that boundary prevents treating an uncontrolled observation as evidence of a comparative effect.
The record highlights how precision depends on usable outcome information. In general, a confidence interval can communicate uncertainty around an estimate, but a planned interval without a reported estimate has no interpretable limits. In this case, readers cannot assess precision, completion, or variation in the endpoint from the posted results.
Finally, the terminated status and displayed adverse-event fields demonstrate why registry entries require careful, field-by-field reading. Termination does not identify its cause, and zero entries in fields with zero participants at risk do not establish the absence of harm. The statistically responsible conclusion is narrow: the record describes the intended feasibility question and study design, but it does not report results that answer that question.
13. 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 main trial-specific limitation is enrollment of 1 participant, followed by non-reporting of outcome data to protect privacy and confidentiality. The primary endpoint therefore cannot be evaluated from the registry record. The planned 95% confidence interval is not posted, so precision cannot be assessed either.
The study is single group, with no comparator and no masking. This limits the design's ability to support comparative conclusions, independent of the missing outcome data. The record also lists the study as terminated but does not report the reason, so the circumstances of termination cannot be interpreted.
Results for the secondary outcomes are not reported. These include thecal sac patency, accrual rate, pain, quality of life, compression fractures, and plasma changes. The registry does not provide the detailed analysis methods, missing-data procedures, analysis populations, or multiplicity approach. The adverse-event fields list zero participants at risk and zero affected, which does not resolve safety in the context of the withheld outcome data.
The record does not report a sample-size justification, enrollment target, interim-analysis plan, or stopping rules. The absence of these details is not evidence that a particular design decision was or was not made. Together, the small enrollment, withheld results, and limited methodological reporting prevent estimation of feasibility or interpretation of the secondary outcomes.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: Study of Combined Decompressive Spine Radiosurgery and Pembrolizumab — NCT05204290.
- Registry record last updated 2026-06-29; status last verified 2026-03.
- Results first posted 2026-06-29.
- 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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17. Record Summary
NCT05204290 is an early phase 1, single-group, unmasked study sponsored by Wake Forest University Health Sciences. It evaluated stereotactic body radiation therapy with pembrolizumab in patients with high-grade epidural disease of the spine; blood draws are also listed. The record gives enrollment as 1 participant, study start as 2022-03-28, primary completion as 2022-10-07, and status as terminated.
The primary endpoint is the number of participants completing SBRT and one cycle of pembrolizumab, with a stated timeframe of Day 5 through cycle 1 (Day 22). A 95% confidence interval was planned, but outcome data are not reported because of the low enrollment and privacy concerns. No analysis entries or secondary outcome results are posted, and the reason for termination is not reported in the registry record.