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 Sintilimab for the Treatment of Locally Advanced, Metastatic, Recurrent, or Unresectable Undifferentiated Pleomorphic Sarcoma, SiARa Cancer Study (NCT05017103), a na phase 2 study. The primary outcome is Best Overall Response Rate.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05017103 |
| Phase | Phase 2 |
| Condition | Locally Advanced Undifferentiated Pleomorphic Sarcoma, Metastatic Undifferentiated Pleomorphic Sarcoma, Recurrent Undifferentiated Pleomorphic Sarcoma |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 6 |
| Arms in the primary outcome | n/a |
| Lead sponsor | M.D. Anderson Cancer Center |
| Results posted | Yes |
2. Clinical Question
Population
The trial concerned people with locally advanced, metastatic, recurrent, or unresectable undifferentiated pleomorphic sarcoma. The primary endpoint description specifies an evaluable population, and the record notes that 2 participants were not evaluable at 12 weeks because they passed away. Further eligibility details and the criteria for being evaluable are not reported in the registry record.
Intervention
The intervention was sintilimab, given intravenously over 30–60 minutes on day 1. The record describes cycles repeating every 3 weeks for up to 24 months, in the absence of disease progression or unacceptable toxicity.
Comparator
There was no comparator arm. The trial is recorded as a single-group study, with allocation listed as NA and masking listed as none. Its results therefore cannot provide a randomized comparison between sintilimab and another treatment or control.
Primary question
The primary endpoint was best overall response rate at 12 weeks: the proportion of evaluable participants whose best overall response was a confirmed complete response or confirmed partial response under RECIST v.1.1. The registry record does not report the number meeting that response definition or an estimated response rate.
The brief summary describes the study as investigating sintilimab in advanced forms of undifferentiated pleomorphic sarcoma. It also describes immunotherapy with monoclonal antibodies as a possible way to help the immune system attack cancer and interfere with tumor-cell growth and spread. That background is a rationale, not evidence of the trial’s outcome. The posted registry information identifies the intended endpoint but does not give the response results needed to answer how often the defined response occurred.
The study is listed as phase II and terminated. The termination reason is not reported in the registry record. Enrollment is listed as 6, but the record does not provide a primary response analysis, participant-level results, or a comparison group. These details limit the question that can be answered from the posted information: it establishes what investigators intended to measure and the setting in which sintilimab was studied, but not an estimate of the primary outcome.
3. Trial Design
This was a phase II, single-group clinical trial of sintilimab for locally advanced, metastatic, recurrent, or unresectable undifferentiated pleomorphic sarcoma. The registry lists M.D. Anderson Cancer Center as sponsor. Allocation is recorded as NA, masking as none, and the study model as single group. Thus, the registered design does not include a randomized control arm or a blinded comparison.
The intervention description states that participants received sintilimab intravenously over 30–60 minutes on day 1, with cycles repeating every 3 weeks for up to 24 months if disease progression or unacceptable toxicity did not occur. These are the treatment details recorded in the registry; additional information about dose, treatment modifications, adherence, or actual treatment exposure is not reported in the registry record.
Enrollment is listed as 6. The record gives a start date of 2021-07-13 and a primary completion date of 2024-02-20. Its current status is terminated. The reason for termination and whether the planned enrollment or follow-up was completed as intended are not reported in the registry record. The status alone does not establish why the study ended or what prompted that decision.
The primary outcome measure is best overall response rate, with a timeframe of 12 weeks. It is defined as the proportion of subjects in the evaluable population with a confirmed complete response or confirmed partial response based on RECIST v.1.1. The registry also states that 2 participants were not evaluable at 12 weeks because they passed away. It does not give the response count among evaluable participants, the denominator used for an analysis, or an analysis estimate.
There are no analyses listed in the registry record. Statistical planning details beyond the separate sample-size illustration assumptions are not reported in the registry record. In particular, the record does not report the trial’s own sample-size justification, a detailed statistical analysis plan, an interim-analysis plan, or a prespecified approach to missing primary outcome data. A single-group study can describe outcomes among its participants, but without a concurrent comparator it cannot isolate a treatment effect from other explanations for observed 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.
Overall Study
| Stage | Treatment (Sintilimab) |
|---|---|
| STARTED | 6 |
| COMPLETED | 4 |
| NOT COMPLETED | 2 |
Reasons for not completing this period:
| Reason | Treatment (Sintilimab) |
|---|---|
| Death | 2 |
Analysis population for the primary outcome, as defined in the registry: 2 participants not evaluable at 12 weeks (passed away)
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 | Treatment (Sintilimab) |
|---|---|---|
| Participants analysed | 6 | |
| Age, Continuous | years | 57 (SD 14) |
| Sex: Female, Male: Female | Participants | 3 |
| Sex: Female, Male: Male | Participants | 3 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 3 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 3 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 5 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 1 |
| Region of Enrollment: United States | participants | 6 |
6. Primary Endpoint
The registry lists the primary outcome as Best Overall Response Rate, measured over At 12 weeks.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
Best overall response rate is a binary endpoint at the participant level: each evaluable participant either meets the response definition or does not. In this trial, a response required a confirmed complete response or confirmed partial response under RECIST v.1.1. The endpoint timeframe is 12 weeks. The intended rate is the proportion of evaluable participants meeting that definition, rather than a measure of how long a response lasts or how long participants remain free of progression.
In general, response endpoints are used to describe whether a tumor meets prespecified criteria for reduction or disappearance during a defined assessment period. A standardized system such as RECIST v.1.1 makes response categories more consistent by setting common assessment rules. Confirmation is part of this trial’s stated definition; a response that is not confirmed would not meet the primary endpoint as described. The record does not provide details about assessment schedules or confirmation procedures beyond that definition.
The endpoint’s usefulness depends on having outcome assessments for the relevant population and a clear denominator. The registry says the analysis concerns the evaluable population and notes that 2 participants were not evaluable at 12 weeks because they passed away. It does not define all evaluability criteria or report how many evaluable participants had a confirmed complete or partial response. As a result, the endpoint definition is clear enough to identify the intended measure, but the posted information does not allow the response proportion to be assessed.
A response rate is a descriptive endpoint, not by itself a randomized estimate of comparative benefit. Because this study is single group, any response observed would be among participants receiving sintilimab, without a concurrent control group in the registered design. The registry record does not report a response result, so no conclusion about the frequency of response can be drawn from the posted primary outcome information.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The key statistical point is that the registry record describes a primary outcome but does not post its result. It specifies best overall response rate at 12 weeks, defined as the proportion of evaluable participants with a confirmed complete response or confirmed partial response under RECIST v.1.1. However, no response count, denominator, estimated rate, confidence interval, or hypothesis test is reported. The endpoint cannot be quantified from the record.
Enrollment is listed as 6, and the outcome description states that 2 participants were not evaluable at 12 weeks because they passed away. That information identifies an important limitation for interpreting the intended endpoint: the primary outcome applies to an evaluable population, while some participants did not have an evaluable 12-week response. The record does not report a response analysis among those who were evaluable, nor does it say how the non-evaluable participants were handled in any analysis. No missing-data method is reported in the registry record.
The single-group design also constrains interpretation. Without random assignment to a comparator, there is no concurrent reference for separating outcomes associated with treatment from the course of disease, participant selection, other care, or chance variation. In general, a single-group result can describe what happened among enrolled participants, but it does not provide the same basis for a causal treatment comparison as a randomized controlled design. Here, the primary result itself is not posted, so even a descriptive response estimate is unavailable.
The safety information is distinct from the primary efficacy endpoint. For the sintilimab group, the record lists 6 at risk and 2 affected by a serious adverse event; it also lists 0 affected by other adverse events in that group. Five serious-event terms are listed with 16.7% each: lung infection, spinal fracture, febrile neutropenia, colitis, and disease progression. The record lists 4 deaths. These entries do not show the timing, duration, severity grading, relatedness to treatment, or whether events occurred in the same participants. They should not be treated as an efficacy result or as proof of causation.
The study is recorded as terminated, but the reason is not reported in the registry record. Termination should not be interpreted as evidence for or against sintilimab’s effect. The record also lists no analyses. Without posted analysis outputs, readers cannot assess the primary response estimate, its precision, or a statistical test. The absence of a reported result is not equivalent to a result of no response or no effect.
Any sample-size planning illustrations associated with the posted material are planning exercises based on an observed effect and stated assumptions, not the trial’s observed power. Such calculations can show how a hypothetical future study might be sized under specified assumptions. They cannot replace the missing primary analysis, and they do not establish what effect this trial observed. The registry does not report a statistical plan that would explain whether those illustrations correspond to the study’s original design.
9. Statistical Methods Explained
The methods that can be described from the registry record are limited to the registered design and endpoint definition. The study is listed as phase II, single group, with allocation NA and masking none. Its primary measure is a binary participant-level response outcome at 12 weeks. The record says that best overall response rate is the proportion of evaluable participants with a confirmed complete response or confirmed partial response under RECIST v.1.1. It does not report a statistical analysis plan or a completed analysis for that outcome.
What does a response proportion represent?
In general, a proportion is a count of participants meeting a specified condition divided by the number of participants included in the relevant analysis population. For this endpoint, the condition is having a confirmed complete or partial response, and the stated population is evaluable participants. The denominator matters: a result among evaluable participants answers a different descriptive question from a result that includes participants without an evaluable assessment. The registry does not report the response numerator or analysis denominator, so no proportion can be reproduced or checked.
The endpoint is binary for each participant because the participant either meets the stated response definition or does not. This does not mean that every participant’s clinical course is fully captured by the endpoint. A single response status at a specified timeframe does not describe response duration, time to progression, or other outcomes unless those measures are separately defined and reported. The registry lists one outcome measure and does not provide those additional results.
Why does the evaluable population matter?
An evaluable population is a subset defined by whether participants meet criteria for inclusion in a particular analysis. The registry identifies the evaluable population for the primary endpoint and notes that 2 participants were not evaluable at 12 weeks because they passed away. The full criteria for evaluability, the timing and handling of other missing assessments, and the analysis approach for participants without a 12-week assessment are not reported in the registry record.
In general, excluding participants without an evaluable outcome can affect how a proportion is interpreted, especially if the reason for missingness is related to health status or outcome. That general concern does not establish the direction or size of any effect in this trial. The posted record does not give enough information to determine how the non-evaluable cases would influence a response estimate under different analysis choices.
What can a confidence interval tell readers?
In general, a confidence interval expresses uncertainty around an estimated quantity. For a response proportion, it can show a range of values compatible with the observed data under the method used. With a limited amount of information, an estimate may be imprecise, and an interval can communicate that uncertainty more fully than a point estimate alone. The registry record does not report a response estimate or confidence interval, so the precision of the primary outcome cannot be evaluated.
A confidence interval does not remedy limitations in design or missing data. It quantifies sampling uncertainty under a statistical model; it does not create a randomized comparator, account automatically for unreported outcomes, or establish that a treatment caused an observed result. Here, there is no posted primary estimate to which an interval could be attached.
What does the single-group design allow?
In general, a single-group trial can document outcomes and safety observations among participants receiving an intervention. Without a concurrent control group, it cannot directly estimate a randomized between-group contrast. Differences between trial participants and a separate historical or external population can arise for reasons other than treatment, and no such comparison is registered in the registry record about this study. The design description therefore supports a limited, within-study descriptive interpretation, not a controlled causal comparison.
The record lists no analyses. It does not report whether the primary outcome was analyzed using a particular model, whether estimates were adjusted, what hypothesis was tested, or how uncertainty was quantified. Those choices are not safe to infer from the endpoint definition or the phase designation.
How should sample-size illustrations be understood?
In general, sample-size calculations depend on assumptions about the effect to detect, the statistical error rate, allocation, and the chosen method. The planning assumptions recorded for illustrations include a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The illustrations are described as using a stated fraction of an observed effect. They are not the trial’s own design calculation, and this trial is registered as single group rather than a two-arm randomized comparison.
Any such illustration is a planning exercise, not observed power. Observed power is not a substitute for reporting the trial’s outcome estimate and its uncertainty. The registry does not report the sample-size justification used when the trial was designed. Therefore, the illustrations cannot establish the original enrollment target, explain the enrollment listed, or show whether the study was adequately powered for its primary endpoint.
Why can over-dispersion matter in general?
For outcomes that are counts, over-dispersion means that observed variability is greater than a simple statistical model expects. In general, ignoring excess variability can make uncertainty appear too small. The registered primary endpoint is a binary response measure, not a count of recurrent events, and the registry does not report an over-dispersion model for it. This general concept should not be mistaken for a method used in this trial.
Overall, the registry supports an explanation of the intended endpoint and basic design, but not a reconstruction of the analysis. A statistical interpretation of efficacy would require the response data, a stated analysis population, and an estimate with appropriate uncertainty. Those results are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
Multiplicity concerns arise when a study tests or estimates several outcomes, subgroups, timepoints, or hypotheses. In general, conducting many tests can increase the chance of at least one apparently notable result unless the analysis plan accounts for the testing strategy. The registry lists one outcome measure and 0 analyses. It does not report a multiplicity adjustment, a hierarchy of endpoints, or whether additional outcomes or subgroup analyses were conducted. The absence of these details means the multiplicity strategy is not reported in the registry record; it does not establish that no other analyses were performed.
The primary endpoint is defined for the evaluable population at 12 weeks. The record specifically notes that 2 participants were not evaluable at that time because they passed away. It does not report the number of evaluable participants, response outcomes, the approach to missing primary outcome data, or sensitivity analyses. It also does not give all criteria used to determine evaluability. Therefore, readers cannot assess whether the reported endpoint analysis, if one was performed, used a prespecified population or how alternative handling of missing outcomes might affect the result.
In general, missingness is important when the availability of an outcome may be related to participants’ health or response status. That is a methodological consideration, not a claim about the cause of missingness in this trial beyond the registry’s note that the 2 participants passed away. The record does not say whether any other assessments were missing or how deaths were incorporated into the primary endpoint analysis. No imputation, censoring, or other missing-data method is reported in the registry record.
The endpoint refers to an evaluable population, but the record does not provide an analysis population definition beyond that phrase. It does not report an intention-to-treat analysis or another named population. These omissions prevent a reader from determining whether the primary analysis included all enrolled participants, only those with a particular assessment, or another set of participants.
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 |
|---|---|---|---|
| Treatment (Sintilimab) | 2 | 6 | 33.3% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Treatment (Sintilimab) | 4 of 6 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Treatment (Sintilimab) | 0 of 6 |
Most frequent serious adverse event terms
| Event term | Organ system | Treatment (Sintilimab) |
|---|---|---|
| Lung infection | Respiratory, thoracic and mediastinal disorders | 1 of 6 |
| Spinal fracture | Musculoskeletal and connective tissue disorders | 1 of 6 |
| Febrile neutropenia | General disorders | 1 of 6 |
| Colitis | Gastrointestinal disorders | 1 of 6 |
| Disease progression | General disorders | 1 of 6 |
Serious events with the highest arm-level rate: lung infection (16.7%), spinal fracture (16.7%), febrile neutropenia (16.7%), colitis (16.7%), disease progression (16.7%).
The registry lists a safety group titled Treatment (Sintilimab). It reports 6 participants at risk for serious adverse events and 2 affected. The group entry also reports 6 at risk and 0 affected for other adverse events. The record lists 4 deaths. These are separate registry fields, and the information given does not explain their overlap, timing, or relationship to treatment.
Five serious-event terms are listed, each with 16.7%: lung infection, spinal fracture, febrile neutropenia, colitis, and disease progression. These percentages should be read as registry-reported values for the listed terms, not as estimates of comparative risk. No control group is registered, and the record does not give event-specific counts or clarify whether the terms occurred in the same participants. The percentages should not be added together.
In general, an adverse event recorded during a trial is not by itself proof that treatment caused it. Interpretation ordinarily depends on details such as timing, severity, clinical judgment about relatedness, and how events were collected. Those details are not reported in the registry record for these entries. The listed deaths also should not be assumed to have a particular cause or to correspond to the 2 participants identified as not evaluable at 12 weeks; the record does not reconcile those fields.
12. What the Result Does, and Does Not, Mean
The registry establishes that a phase II, single-group study of sintilimab was conducted for advanced forms of undifferentiated pleomorphic sarcoma, with best overall response rate at 12 weeks as its primary endpoint. It also records enrollment of 6, termination status, and a note that 2 participants were not evaluable at 12 weeks because they passed away. These registry entries describe the study and its intended outcome measure.
The posted registry information does not report the response count, response proportion, or a confidence interval. It therefore does not show how many evaluable participants had a confirmed complete or partial response, nor how precise any estimate may have been. This absence of a posted result should not be interpreted as evidence that there were no responses or that the treatment had no effect. It means that the primary outcome cannot be evaluated from the available registry information.
Even if a response estimate were available, the single-group design would not provide a randomized comparison with another treatment or a control. In general, observed outcomes in a single group can be described, but the design cannot by itself distinguish treatment effects from other influences on outcomes. No comparative causal conclusion follows from the design as registered.
The safety entries describe serious adverse events and deaths recorded for the sintilimab group, but do not establish that sintilimab caused any particular event. The record does not provide the detailed event context needed to interpret timing, severity, relatedness, or participant-level overlap. The termination status also does not explain why the study ended; the reason is not reported in the registry record.
Accordingly, the most defensible reading is narrow: the registry specifies a clinically relevant response endpoint, documents some non-evaluability and safety information, and records a terminated single-group study. It does not supply the analysis required to judge the primary endpoint’s observed frequency or precision, and it does not support a treatment comparison.
13. Why This Trial Matters Statistically
This study is statistically notable because it illustrates the difference between registering an outcome and reporting an outcome analysis. The registry defines best overall response rate at 12 weeks, including the response categories and assessment standard, but does not report the response result. Without the numerator, denominator, and an uncertainty estimate, readers cannot evaluate the primary endpoint’s magnitude or precision.
The evaluable-population definition also matters. The record states that 2 participants were not evaluable at 12 weeks because they passed away. That makes the treatment of non-evaluable outcomes an important part of interpreting any response proportion. The registry does not report the full evaluability criteria or the analysis method for those participants. This is a useful reminder that endpoint definitions need to be considered alongside the population actually analyzed and the handling of missing outcomes.
The single-group design highlights another statistical distinction: describing outcomes is not the same as estimating a controlled treatment effect. A concurrent comparator helps address how outcomes might differ without the intervention. Since no comparator arm is registered, the design cannot supply a randomized contrast. This remains true regardless of whether a descriptive response estimate is eventually available.
Finally, the safety record and termination status require careful restraint. The listed adverse events and deaths are important observations, but the registry does not provide enough detail to attribute them to treatment or reconcile them with the primary endpoint population. The reason for termination is not reported. Together, these features show why a clear endpoint, transparent analysis populations, complete outcome reporting, and cautious interpretation are central to clinical trial statistics.
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 primary limitation is the absence of a posted primary outcome analysis. Although best overall response rate is defined at 12 weeks, the registry does not report the response count, denominator, estimated proportion, confidence interval, or statistical test. The record therefore does not permit evaluation of the endpoint’s result or precision.
The endpoint is specified for an evaluable population, and the record notes that 2 participants were not evaluable at 12 weeks because they passed away. The complete criteria for evaluability and the approach to missing outcomes are not reported in the registry record. The number of evaluable participants and their response outcomes are also not given. This prevents readers from understanding how the primary analysis population was constructed.
The study is single group, without a randomized comparator. Any outcome estimate, if reported, would describe participants in the sintilimab group rather than provide a direct randomized contrast. The record does not report statistical adjustment or an external comparison that could address this design limitation.
Enrollment is listed as 6, and the study is marked terminated. The reason for termination and whether follow-up or enrollment proceeded as planned are not reported in the registry record. The record also lists 0 analyses, so it does not document completed statistical outputs, an analysis plan, a sample-size justification, or a multiplicity strategy. Planning illustrations based on an observed effect are not a substitute for the study’s own design justification or its outcome analysis.
The safety information is limited to registry counts and listed serious-event terms. Timing, severity, relatedness to treatment, event overlap, and the relationship between the death count and the participants not evaluable at 12 weeks are not reported in the registry record. These limitations restrict both efficacy and safety interpretation.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Sintilimab for the Treatment of Locally Advanced, Metastatic, Recurrent, or Unresectable Undifferentiated Pleomorphic Sarcoma, SiARa Cancer Study — NCT05017103.
- Registry record last updated 2024-12-11; status last verified 2024-10.
- Results first posted 2024-11-12.
- 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
NCT05017103 is a phase II, single-group trial of sintilimab for locally advanced, metastatic, recurrent, or unresectable undifferentiated pleomorphic sarcoma. M.D. Anderson Cancer Center is listed as sponsor. The record gives a start date of 2021-07-13, a primary completion date of 2024-02-20, enrollment of 6, and status terminated.
The primary endpoint is best overall response rate at 12 weeks, defined as the proportion of evaluable participants with a confirmed complete response or confirmed partial response under RECIST v.1.1. The record states that 2 participants were not evaluable at 12 weeks because they passed away, but does not report the response analysis. Safety entries list 2 participants affected by serious adverse events and 4 deaths. The reason for termination and the primary outcome results are not reported in the registry record.