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 Pexidartinib in Tenosynovial Giant Cell Tumor in Japan (NCT04703322), a na phase 2 study. The primary outcome is Dose-limiting Toxicity (DLT) in Part 1.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04703322 |
| Phase | Phase 2 |
| Condition | Tenosynovial Giant Cell Tumor |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 9 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Daiichi Sankyo Co., Ltd. |
| Results posted | Yes |
2. Clinical Question
Population
Adults in Japan with symptomatic tenosynovial giant cell tumor associated with severe morbidity or functional limitation, when improvement with surgery was not considered feasible. The registry record gives an enrollment of 9; it does not report how many participants were included in each specific outcome analysis.
Intervention
Oral pexidartinib at 800 mg, given as 400 mg twice daily. The study was open-label, so treatment masking was not used.
Comparator
There was no control group. The study is described as single-group, and allocation is listed as not applicable. Its results therefore do not constitute a randomized, like-for-like comparison between treatments.
Primary question
The primary endpoint asks how many participants had any-grade dose-limiting toxicity treatment-emergent adverse events from Cycle 1, Day 1 through Cycle 1, Day 28. Each cycle is 28 days. The registry record does not report the count for this endpoint, so the primary safety result cannot be characterized from the record.
The study also set out to evaluate safety, tolerability, pharmacokinetics, and efficacy. Its secondary outcomes include tumor response, range of motion, physical function, pain, and duration of response. Those outcomes address different aspects of disease and participant experience; they should not be treated as interchangeable measures of benefit or harm. The listed outcome names do not establish what the results were. For each result, interpretation depends on the analyzed population, the timing and definition of the measure, and the amount of missing information. Where those details or the outcome values are not reported in the registry record, the relevant evidence remains unclear.
3. Trial Design
This is a phase 2, multicenter, two-part, open-label study of pexidartinib in adult participants with tenosynovial giant cell tumor in Japan. The registry identifies it as single-group, with no allocation to a concurrent comparison arm and no masking. The stated enrollment is 9. That enrollment figure does not establish how many participants were included in each outcome analysis or how many received treatment.
The study began on 2021-03-15, had a primary completion date of 2023-03-20, and is listed as completed. The sponsor is Daiichi Sankyo Co., Ltd. Participants were to receive oral pexidartinib 800 mg, described as 400 mg twice daily. The registry summary describes the intended population as adults with symptomatic disease associated with severe morbidity or functional limitation and not amenable to improvement with surgery.
The primary endpoint concerns dose-limiting toxicity during the first treatment cycle. The registry defines the assessment window as Cycle 1, Day 1 to Cycle 1, Day 28, with each cycle lasting 28 days. The primary outcome is a participant count, and the named analysis population is the DLT Evaluable Set. The registry record does not report the size or full definition of that set, nor does it report the primary endpoint count.
The study also lists outcomes in Part 2, including response based on tumor volume score and RECIST Version 1.1, range of motion, physical function, pain, and duration of response. The registry record does not report results for these measures. Because the design has no concurrent control group, any observed change would be descriptive of participants in this study and would not by itself establish how outcomes would have differed under another treatment or no treatment.
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 | Pexidartinib |
|---|---|
| STARTED | 9 |
| COMPLETED | 0 |
| NOT COMPLETED | 9 |
Reasons for not completing this period:
| Reason | Pexidartinib |
|---|---|
| Ongoing | 8 |
| Withdrawal by Subject | 1 |
Analysis population for the primary outcome, as defined in the registry: All DLT TEAEs were assessed in the DLT Evaluable Set.
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: Demographic and baseline characteristics were assessed in the Safety Analysis Set.
| Characteristic | Unit | Pexidartinib |
|---|---|---|
| Participants analysed | 9 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 9 |
| Age, Categorical: >=65 years | Participants | 0 |
| Age, Continuous | years | 35.9 (SD 11.16) |
| Sex: Female, Male: Female | Participants | 4 |
| Sex: Female, Male: Male | Participants | 5 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 9 |
| 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 | 0 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Dose-limiting Toxicity (DLT) in Part 1, measured over Cycle 1, Day 1 to Cycle 1, Day 28 (each cycle is 28 days).
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with any-grade dose-limiting toxicity treatment-emergent adverse events. Its assessment window runs from Cycle 1, Day 1 through Cycle 1, Day 28; each cycle is 28 days. The named population for this endpoint is the DLT Evaluable Set. The registry record does not report the endpoint count or the size of that analysis population.
A participant count is a binary-outcome summary: each participant is classified according to whether an event meeting the endpoint definition occurred within the specified window. This makes the measure direct to read, but its interpretation depends on the event definition, observation period, and denominator. A count without the analyzed denominator cannot describe the frequency in the analysis population. In this record, the endpoint is specified as a count, but the result needed to interpret it is not reported.
In general, an early-cycle dose-limiting toxicity endpoint can characterize acute tolerability during a defined initial exposure period. It is not a complete account of later or cumulative adverse events, and it does not capture every dimension of safety. The registry record also lists safety and tolerability as study aims, but does not report a detailed endpoint definition beyond any-grade DLT treatment-emergent adverse events. The posted serious and other adverse-event counts are separate summaries and should not be substituted for the missing primary endpoint result.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry describes a completed study with an enrollment of 9 and a single-group design. It does not report the primary dose-limiting toxicity count. As a result, the central primary-endpoint finding cannot be quantified from the registry record. The named DLT Evaluable Set is the population for that outcome, but its size and the endpoint numerator are not reported. Enrollment alone should not be used as a substitute for the endpoint denominator.
The adverse-event summary records 0 serious adverse events among 9 participants at risk, 9 participants with other adverse events among 9 at risk, and 0 deaths. These are counts in the posted adverse-event summary; they are not a reported primary DLT result. The record does not give the event terms for the serious-event category. The absence of a recorded serious event in this summary does not demonstrate that serious events are impossible, nor does the count of other adverse events describe their type, severity, duration, or relationship to treatment.
No comparative effect can be estimated from a single-group study without a control arm. Even if outcome changes had been reported, change over time alone would not distinguish treatment effects from other explanations, such as the natural course of disease, measurement variation, or changes in care. Those are general limitations of uncontrolled comparisons, not findings about what occurred in this study.
The registry lists secondary outcomes spanning tumor response, function, pain, and response duration, but their result values are not reported in the registry record. Therefore, the listed outcomes cannot support a conclusion about the direction or magnitude of change, the precision of any effect, or the consistency across measures. The record also contains no analysis entries. It does not report confidence intervals, hypothesis-test results, or a statistical analysis plan that would clarify how uncertainty was handled.
In general, a confidence interval communicates the range of effect values compatible with the data under a specified statistical model. With a small study and event counts, estimates can be imprecise; an interval may be wide even when the point estimate appears clear. No interval for the primary endpoint or other outcomes is reported, so its precision cannot be assessed. The available counts are descriptive and should be read as a limited safety snapshot, not as proof of either absence of risk or a comparative treatment effect.
9. Statistical Methods Explained
The primary outcome is a participant count for an event defined over a specific period. For a binary outcome, the basic descriptive quantities are the number who meet the definition and the number assessed. The denominator matters because the same event count can have different meanings in populations of different sizes. Here, the endpoint population is called the DLT Evaluable Set, but the registry record does not report its size or the primary count. The enrollment figure is not necessarily the endpoint denominator, so it should not be used to reconstruct an unreported result.
Adverse-event counts are also descriptive. The registry records a serious-event risk set of 9, with 0 affected, and an other-adverse-event risk set of 9, with 9 affected. It separately records 0 deaths. These categories answer different questions from the primary DLT endpoint: event seriousness, other adverse events, and the endpoint-specific definition need not coincide. General statistical practice is to keep endpoint definitions and time windows distinct rather than infer one outcome from another.
When binary outcomes are analyzed, uncertainty can be expressed with a confidence interval for the event frequency or for a comparison between groups. A confidence interval is a model-based range reflecting sampling uncertainty; it is not a guarantee that the true value lies within the interval. For sparse event data, different interval methods can yield materially different limits, and the method should be specified. The registry record does not report an interval or the method used for the primary endpoint, so precision cannot be assessed from the posted record.
For a single-group study, counts and changes can describe participants who were observed, but they do not create a treatment contrast. In general, a control group helps distinguish the outcome under the intervention from what might have happened over the same period without it or under another intervention. This study is listed as single-group, with allocation not applicable; therefore, it does not provide a randomized between-group estimate. The registry record does not report a statistical model for adjusting or otherwise accounting for the lack of a comparator.
For a study with repeated measures or time-to-event outcomes, interpretation also depends on when participants were measured, how long they were followed, and how incomplete observations were handled. The listed secondary outcomes include duration of response, but the registry record does not give result estimates, follow-up details, censoring rules, or analysis methods for that outcome. General methods for time-to-event data account for differing observation times and censoring; without the relevant details, no such analysis can be reconstructed.
The registry lists 15 outcome measures and 0 analysis entries. The named secondary outcomes include response based on tumor volume score, range of motion, PROMIS Physical Function Scale, BPI Worst Pain NRS, best overall response based on RECIST Version 1.1, best overall response based on tumor volume score, and duration of response based on RECIST Version 1.1 and tumor volume score. The record does not report the numerical results or statistical procedures for these outcomes. Their presence in the outcome list should not be mistaken for evidence that a particular result was observed.
The sample-size assumptions associated with planning illustrations are not the trial's design or an observed-power analysis. The stated illustration assumptions include a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect to detect expressed as a fraction of the observed effect. For time-to-event illustrations, the stated quantity is the total number of events; for other illustrations, it is participants per arm. Those assumptions describe planning calculations, not this single-group study's actual analysis. In general, planning calculations depend on assumptions about the effect and variability, and changing those assumptions changes the required sample size. Such illustrations do not show the probability that this completed study detected an effect. The registry record does not report a trial-specific sample-size justification or statistical plan.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists 15 outcome measures, including a primary safety endpoint and secondary outcomes for tumor response, range of motion, physical function, pain, and duration of response. It names several distinct definitions of response, including tumor volume score and RECIST Version 1.1. These outcomes address different questions, and results for the listed secondary outcomes are not reported in the registry record.
When several outcomes are tested, the chance of obtaining at least one apparently notable result by chance can increase. General statistical approaches may define a primary outcome in advance, adjust for multiple testing, or treat secondary results as exploratory. The registry record does not report a multiplicity procedure, a hierarchy among secondary outcomes, or an analysis plan. It is therefore not possible to determine how any potential multiplicity was handled.
Missing-data methods can affect estimates when participants do not complete assessments or measurements are unavailable. The registry record does not report missing-data counts, reasons for missingness, imputation methods, or sensitivity analyses. It also does not describe the criteria for membership in the DLT Evaluable Set beyond naming it as the primary endpoint population. Without those details, the completeness and representativeness of the outcome analyses cannot be assessed.
The record lists 0 analysis entries. This does not supply the missing endpoint values or clarify how the listed measures were analyzed. In general, analysis-population definitions, missing-data handling, and multiplicity procedures help readers judge whether reported estimates answer the intended questions and how much reliance to place on secondary findings.
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 |
|---|---|---|---|
| Pexidartinib | 0 | 9 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Pexidartinib | 0 of 9 |
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 |
|---|---|
| Pexidartinib | 9 of 9 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Pexidartinib |
|---|---|---|
| Hair colour changes | Skin and subcutaneous tissue disorders | 7 of 9 |
| Aspartate aminotransferase increased | Investigations | 7 of 9 |
| Pruritus | Skin and subcutaneous tissue disorders | 4 of 9 |
| Alanine aminotransferase increased | Investigations | 4 of 9 |
| Blood lactate dehydrogenase increased | Investigations | 3 of 9 |
| Gamma-glutamyltransferase increased | Investigations | 3 of 9 |
| Blood alkaline phosphatase increased | Investigations | 2 of 9 |
| Blood bilirubin increased | Investigations | 2 of 9 |
| Blood creatinine phosphokinase increased | Investigations | 2 of 9 |
| Blood creatinine increased | Investigations | 2 of 9 |
The posted adverse-event summary gives 0 serious adverse events among 9 participants at risk. It also records other adverse events in 9 participants among 9 at risk, and 0 deaths. These are event-category counts in the registry record. They do not supply the types, timing, duration, severity, or treatment attribution of the other adverse events, and the serious-event terms are not reported.
The serious adverse-event count should not be read as the primary dose-limiting toxicity result. The primary endpoint has its own definition, a Cycle 1, Day 1 to Cycle 1, Day 28 assessment window, and a named DLT Evaluable Set. Its result is not reported in the registry record. A participant could meet one event definition without meeting another, so the categories should remain separate.
In general, observing no serious events in a study does not establish that the risk is zero or rule out uncommon harms. A small observed group can provide limited information about rare outcomes, and the estimate's precision depends on the number observed and the analysis method. No confidence interval or further safety analysis is reported in the registry record. The counts therefore describe the events recorded in this study summary, not the full range of possible safety outcomes.
12. What the Result Does, and Does Not, Mean
The record documents a phase 2 study of pexidartinib in adults with symptomatic tenosynovial giant cell tumor in Japan. It identifies a single-group, open-label design and specifies an early-cycle primary safety endpoint. It also records adverse-event counts, including 0 serious adverse events among 9 at risk, other adverse events in 9 among 9 at risk, and 0 deaths. Those figures describe the posted safety summary; they do not establish a comparative effect.
The primary endpoint result and the values for the listed secondary outcomes are not reported in the registry record. Accordingly, the record cannot establish how many participants met the DLT definition, the magnitude or direction of changes in tumor response or function, or how precisely any such changes were estimated. A named outcome is not itself a result.
Because there is no control group, the study cannot directly compare pexidartinib with another treatment or with no treatment. General limitations of an uncontrolled study include difficulty separating changes associated with treatment from changes that might have occurred for other reasons. Open-label conduct also means treatment masking was not used; the registry record does not describe additional procedures to limit potential influence on subjective assessments.
These limitations do not erase the descriptive information the registry does contain. The record specifies the population, intervention, study structure, primary endpoint definition, and selected adverse-event counts. But it does not provide the endpoint values, detailed analysis methods, or missing-data information needed for a fuller assessment. The appropriate interpretation is therefore bounded: the registry describes how the study was designed and gives a limited adverse-event summary, while leaving the primary result and efficacy estimates unreported.
13. Why This Trial Matters Statistically
This study illustrates why design and outcome reporting matter alongside a treatment name and an enrollment figure. A single-group study can describe participants' experiences under a specified intervention, but it cannot supply a randomized comparison with another approach. Readers need to keep descriptive safety counts separate from causal claims about treatment effects.
The primary endpoint is defined as a count within a specified early treatment window, which is more interpretable than an endpoint without a time frame. Yet the registry record does not report the count or the size of the DLT Evaluable Set. This makes the distinction between a clearly defined endpoint and a reported endpoint especially important: the former tells readers what was intended to be measured, while the latter is needed to evaluate what was observed.
The adverse-event summary offers some direct descriptive information, but event counts alone cannot convey clinical detail or statistical precision. In general, denominators, event definitions, uncertainty estimates, follow-up, and missing-data handling all shape the meaning of a safety result. The record lacks several of those details for a complete assessment.
Finally, the listed secondary outcomes span response, physical function, range of motion, pain, and response duration. These domains can address different aspects of a disease, but their presence does not establish that data were analyzed or what those analyses found. With the outcome values and statistical methods not reported in the registry record, the study's possible contribution to those questions cannot be quantified from this record alone.
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 main limitation for interpreting this specific registry record is that it does not report the result for the primary dose-limiting toxicity endpoint. Although the endpoint window and named analysis population are given, the event count and DLT Evaluable Set size are not. The registry enrollment of 9 cannot be assumed to be the denominator for that endpoint.
The design is single-group and open-label, with no control arm. It can describe outcomes observed among participants, but does not provide a randomized comparison. The registry record also does not report results for the listed secondary outcomes, including tumor response, range of motion, physical function, pain, and duration of response. No estimate of efficacy or change in these measures can be drawn from the outcome names alone.
The adverse-event summary is limited to counts: 0 serious adverse events among 9 at risk, other adverse events in 9 among 9 at risk, and 0 deaths. Serious-event terms and detail about the other events are not reported. The record does not provide confidence intervals, statistical methods, missing-data procedures, or the criteria and size of the primary endpoint analysis population. It also does not report a multiplicity approach or trial-specific sample-size justification.
These limitations concern what can be interpreted from the registry record; they do not establish that unreported information was never collected. They mean that the posted record alone cannot support a detailed assessment of endpoint precision, completeness of follow-up, or comparative effects.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Study of Pexidartinib in Tenosynovial Giant Cell Tumor in Japan — NCT04703322.
- Registry record last updated 2026-06-24; status last verified 2026-05.
- Results first posted 2025-03-03.
- 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
NCT04703322 is a completed phase 2, multicenter, two-part, open-label, single-group study of oral pexidartinib in adults with symptomatic tenosynovial giant cell tumor in Japan. The registry lists an enrollment of 9 and dates of 2021-03-15 for study start and 2023-03-20 for primary completion.
The primary endpoint is the count of participants with any-grade DLT treatment-emergent adverse events during Cycle 1, Day 1 to Cycle 1, Day 28. Its result is not reported in the registry record. The adverse-event summary records 0 serious events among 9 at risk, other adverse events in 9 among 9 at risk, and 0 deaths. Results for the listed secondary outcomes and detailed statistical and missing-data methods are not reported.