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 Temozolomide,Thiotepa and Carboplatin With Autologous Stem Cell Rescue Followed by 13-cis-retinoic Acid in Patients With Recurrent/Refractory Malignant Brain Tumors (NCT00528437), a na phase 2 study. The primary outcome is Event-free Survival (EFS).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00528437 |
| Phase | Phase 2 |
| Condition | Brain Tumors |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 46 |
| Arms in the primary outcome | n/a |
| Lead sponsor | NYU Langone Health |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns children and adolescents with recurrent or refractory malignant brain tumors. The primary endpoint description narrows its stated reporting population to patients with recurrent or refractory medulloblastoma or primitive neuroectodermal tumors. The registry record does not report how many participants belonged to that endpoint population or how many were included in an endpoint analysis.
Intervention
The treatment sequence was high-dose temozolomide, thiotepa, and carboplatin with autologous stem cell rescue, followed by continuation therapy with 13-cis-retinoic acid. The brief summary also describes objectives concerning the body's handling of 13-cis-retinoic acid, including blood levels, proteins involved in its breakdown, and its penetration into spinal fluid.
Comparator
The registry describes a single-group study with allocation listed as not applicable and masking listed as none. It does not describe a concurrent control group. Consequently, the record does not set up a randomized comparison of the treatment sequence against another treatment or against no treatment.
Primary question
The primary endpoint is event-free survival, with a timeframe of Day +42. The registry says this endpoint would be reported for the specified tumor population, but it also states that no study data are available after unsuccessful efforts to contact the study team. The record therefore does not give an observed event-free survival estimate or a result that answers how participants fared on this endpoint.
3. Trial Design
This was a phase 2 study sponsored by NYU Langone Health. The registry lists an enrollment of 46 and describes the study as a single-group design, with allocation marked as not applicable and masking as none. The study status is completed. Its listed start is 2005-10, and its primary completion date is 2017-06-30. Those administrative details describe the registry record; they do not establish how many participants received the treatment, completed follow-up, or contributed to an endpoint analysis.
The treatment sequence combined high-dose temozolomide, thiotepa, and carboplatin with autologous stem cell rescue, followed by 13-cis-retinoic acid. The arm description names the myeloablative chemotherapy regimen, while the intervention listing includes all four drug names. The brief summary describes safety and effectiveness monitoring in children and adolescents with recurrent or refractory brain tumors, as well as investigation of blood levels, breakdown-related proteins, and spinal-fluid penetration of 13-cis-retinoic acid.
Because the design is single-group, the registry does not provide a concurrent randomized control for estimating a treatment contrast. Any outcome description from such a design would need to be interpreted as experience within the enrolled study population, rather than as a randomized estimate of what would have happened under another treatment. The registry record does not report a protocol-level statistical analysis plan, planned comparators, or details of the treatment allocation process beyond the single-group designation.
The registry reports that efforts to contact the principal investigator or study team were unsuccessful and that no study data are available. It lists 3 outcome measures and 0 analyses. Thus, the enrollment and design information can be described, but the available record does not support a numerical account of the participants' outcomes or the treatment's observed effects.
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 | Myeloablative Chemo-Temozolomide, Thiotepa, and Carboplatin. |
|---|---|
| STARTED | 46 |
| COMPLETED | 46 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: Efforts were made to contact the PI/study team members, but were unsuccessful. No study data are available
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 | Myeloablative Chemo-Temozolomide, Thiotepa, and Carboplatin. |
|---|---|---|
| Participants analysed | 46 | |
| Age, Categorical: <=18 years | Participants | 40 |
| Age, Categorical: Between 18 and 65 years | Participants | 6 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 15 |
| Sex: Female, Male: Male | Participants | 31 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 7 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 39 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 1 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 1 |
| Race (NIH/OMB): White | Participants | 25 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 19 |
| Region of Enrollment: United States | participants | 46 |
6. Primary Endpoint
The registry lists the primary outcome as Event-free Survival (EFS), measured over Day +42.
| 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 event-free survival (EFS), with a listed timeframe of Day +42. In general, an event-free survival endpoint measures the time until a defined event occurs; depending on the protocol, events can include disease progression, recurrence, or other specified outcomes. The registry describes EFS as the length of time after primary cancer treatment ends during which a patient remains free of certain complications or events that the treatment was intended to prevent or delay. The exact events counted for this study, the start point used for timing, and the rules for censoring or handling incomplete follow-up are not reported in the registry record.
In general, EFS can summarize disease control and other prespecified events in a time-to-event framework. It is useful when the timing of events matters, rather than only whether an event occurred by a single assessment. But interpretation depends on a clear endpoint definition, complete follow-up information, and an appropriate analysis method. The registry's Day +42 timeframe is reported as the endpoint assessment timeframe; the record does not clarify how that timing relates to the stated time origin or whether it represents a single assessment point.
No EFS estimate, event count, uncertainty interval, or analysis population is reported. The registry record explicitly states that no study data are available, so the endpoint definition should not be mistaken for an observed result.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes the study design and planned clinical questions, but it does not provide results for interpreting the primary endpoint. It identifies event-free survival as the primary outcome and gives Day +42 as its timeframe. It also specifies recurrent or refractory medulloblastoma or primitive neuroectodermal tumors as the endpoint population. However, the record states that efforts to contact the study team were unsuccessful and that no study data are available. There is therefore no posted EFS estimate to interpret, no reported event count, and no interval describing statistical uncertainty.
The enrollment entry of 46 is a registry enrollment figure. It cannot be treated as the number contributing to EFS, as the number completing the treatment sequence, or as the size of the endpoint population. The record does not report participant flow, follow-up completeness, or an analysis population. Those distinctions matter because the amount and pattern of observed follow-up determine how much information an EFS analysis contains.
The registry lists 0 analyses. It also displays adverse-event group fields with zero participants at risk and zero affected, and no top serious terms. In the context of the explicit statement that no study data are available, these entries should not be read as evidence that no adverse events occurred or that the regimen was free of toxicity. They do not provide an interpretable safety rate or a denominator of participants assessed.
The study is single-group and has no described randomized comparator. Even if outcome estimates were available, a single-group result would describe outcomes among participants in the study, not establish a causal contrast against another treatment. Differences between the study population and any external comparison could influence such a contrast. Here, the absence of posted outcome data means even a descriptive numerical assessment cannot be made.
The registry's sample-size assumptions describe a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The record does not provide the observed effect or any resulting participant-per-arm or event-count illustration. Those assumptions are not the design of this single-group study and cannot be used to infer its actual power or precision.
Accordingly, the defensible statistical reading is limited: the registry documents a completed phase 2, single-group study, its treatment sequence, and its intended endpoint, but reports no study data for evaluating outcomes. Neither benefit nor lack of benefit, and neither presence nor absence of toxicity, can be inferred from the unavailable results.
9. Statistical Methods Explained
The registry identifies a single-group phase 2 study, but it does not report the statistical methods used to analyze the clinical outcomes. The distinctions below explain how such methods generally work and why their details matter; they do not assert that any particular method was used for this trial.
How is event-free survival generally analyzed?
In general, time-to-event methods use both the time until an event and information from participants who have not had an event by their last known follow-up. Such participants are commonly treated as censored at the last time they are known to be event-free. Kaplan–Meier estimation is one common descriptive method: it estimates the probability of remaining event-free over time while accounting for differing follow-up. The estimate is most informative when event definitions, time origins, follow-up schedules, and censoring rules are clear.
The registry names EFS and gives Day +42 as the timeframe, but it does not report the event components, time origin, censoring rules, or an analysis method. It also gives no event counts or EFS estimates. It is therefore not possible to assess whether a time-to-event estimator was used, how follow-up contributed to an estimate, or how precise any estimate might have been.
What does uncertainty mean?
In general, a confidence interval describes the range of values compatible with the data under a specified statistical model and repeated-sampling procedure. A narrow interval indicates greater statistical precision than a wide interval, while neither width nor statistical significance alone determines clinical importance. For a survival estimate, uncertainty depends on the number and timing of events and on how much participants are followed. The registry does not report a confidence interval or any other uncertainty measure for EFS.
A p-value, when used, addresses compatibility between observed data and a specified null hypothesis under model assumptions. It is not the probability that a treatment works or that the null hypothesis is true. The record lists no analyses and gives no p-value. No hypothesis test can be reconstructed from the endpoint name or enrollment entry alone.
What does a single-group design allow?
In general, a single-group analysis can describe outcomes observed among participants receiving the study regimen. It does not, by itself, distinguish treatment effects from the natural course of disease, selection into the study, changes in supportive care, or other factors. A randomized comparison can help estimate a between-group treatment contrast by balancing factors on average, but the registry does not describe such a comparator for this study. The study's allocation field is not applicable, and its model is single-group.
Any statistical comparison with historical or external data would require those data and a justified approach to comparability. No such comparison or method is reported in the registry record. Thus, no comparative treatment effect can be attributed to this study from the available record.
What do the planning assumptions describe?
The record states that its sample-size assumptions are for a planning illustration computed from an observed effect, not the trial's own design. It specifies a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It also says that the effect to detect is a stated fraction of the observed effect, and that time-to-event planning gives a total event count while other planning gives participants per arm.
These are planning concepts, not observed trial outcomes. In general, a sample-size calculation estimates the amount of information needed under chosen assumptions about the effect, variability, significance level, and desired power. A planning number does not show that a study actually enrolled or analyzed that number, and it is not evidence of observed power. Here, the record does not include an observed effect or calculated planning values to interpret. The equal-allocation, two-arm illustration also does not describe the listed single-group design.
Why does over-dispersion matter in general?
Over-dispersion occurs when outcome variability is greater than a statistical model assumes. If ignored, standard errors can be too small and confidence intervals too narrow. This concept is especially relevant for certain count outcomes, but the registry does not report a count-outcome analysis or a model for which over-dispersion was assessed. No claim about its relevance to the trial's actual analyses can be made.
Overall, the registry supports a description of the intended endpoint and design, but not a reconstruction of the statistical analysis. The endpoint event definition, analysis population, missing-data handling, model, uncertainty estimates, and testing strategy are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 3 outcome measures, but the available record describes the primary endpoint as EFS and names toxicity of 13-cis-retinoic acid among the secondary outcomes. It does not provide the complete outcome-level results or explain whether outcomes were assigned a hierarchy, whether any outcome was designated exploratory, or how multiple analyses were handled. A multiplicity strategy, including any adjustment of significance levels or interpretation of secondary findings, is not reported in the registry record.
Multiplicity matters in general when several outcomes or hypotheses are examined: conducting more tests can increase the chance of at least one apparently unusual result under a null model. Prespecified outcome priorities and transparent reporting help readers distinguish the main question from secondary or exploratory analyses. No conclusions about the study's testing strategy can be drawn from the outcome count alone.
Missing-data methods and analysis populations are also not reported. The registry states that no study data are available after unsuccessful efforts to contact the study team. It does not give participant flow, the number assessed for each outcome, reasons for missing measurements, follow-up completeness, or rules for censoring. The enrollment entry of 46 does not establish which participants were included in any particular analysis.
The record lists 0 analyses. Consequently, it is not possible to determine whether the primary endpoint was analyzed according to an intention-to-treat principle, a treated-population definition, or another approach. Those analysis-population definitions, and any sensitivity analyses addressing missing data, are not reported in the registry record.
11. What the Result Does, and Does Not, Mean
The record establishes that a completed phase 2 study was registered to examine an intensive chemotherapy sequence with autologous stem cell rescue followed by 13-cis-retinoic acid in children and adolescents with recurrent or refractory brain tumors. It identifies EFS as the primary endpoint and specifies Day +42 as the timeframe. It also describes objectives concerning safety and the body's handling of 13-cis-retinoic acid.
Those details describe the study's purpose and design, not its findings. The registry record says no study data are available. It therefore does not show an observed EFS result, a safety estimate, a pharmacokinetic result, or an estimate of spinal-fluid penetration. The zero entries in adverse-event fields, alongside zero participants at risk and the statement that no study data are available, should not be interpreted as proof that no adverse events occurred.
The record also does not establish whether the treatment sequence improved outcomes relative to another option. The design is single-group and does not list a concurrent control. In general, observations within a single group cannot isolate a treatment effect from other explanations for outcomes. In this record, the lack of outcome data further prevents even a descriptive account of those outcomes.
The enrollment entry of 46 is not an outcome result and does not indicate the endpoint analysis size. No participant flow or analysis population is reported. Similarly, the sample-size assumptions are described as a planning illustration, not as the study's own design, and the effect estimate on which that illustration would depend is unavailable in the record.
The appropriate conclusion is limited to what is documented: the registry records the intended intervention, study design, and endpoint, while the results needed to judge observed outcomes and their precision are not reported. The record supports neither a claim of effectiveness nor a claim of no effect, and it does not support a conclusion about the frequency of harms.
12. Why This Trial Matters Statistically
This trial illustrates an important distinction in clinical-trial interpretation: registration details can describe a study's question and design without supplying the results needed to answer that question. The record identifies a treatment sequence, a target population, and EFS as the primary endpoint, but explicitly states that no study data are available. Statistical interpretation must stop at that boundary rather than treating a planned endpoint as an observed outcome.
It also highlights the difference between enrollment and analysis. An enrollment figure documents a registry entry, but it does not tell readers how many participants received treatment, had evaluable follow-up, or contributed information to a particular endpoint. For a time-to-event outcome, event and censoring information are essential to understanding the estimate and its precision. Those details are not reported.
The single-group design is another reason to distinguish descriptive outcomes from comparative effects. In general, a single-group study can document experience within its participants, but it does not create a randomized counterfactual. Without a comparator, causal attribution requires assumptions that the registry record does not describe. In this case, unavailable results prevent a descriptive assessment as well.
Finally, the planning assumptions are explicitly framed as an illustration rather than the study's own design. Their two-arm allocation assumption does not match the registry's single-group designation. This is a useful reminder that a sample-size illustration is conditional on its assumptions and should not be confused with observed trial information, actual power, or a result.
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 central limitation for interpreting this trial from the registry record is that no study data are available. The record says attempts to contact the principal investigator or study team were unsuccessful. Without results, there is no basis for estimating EFS, describing toxicity, assessing pharmacokinetic objectives, or judging statistical precision.
The primary endpoint is named, but its operational definition is incomplete in the available record. The description refers to freedom from certain complications or events intended to be prevented or delayed, yet the specific events are not listed. The meaning of Day +42, the time origin, follow-up schedule, and censoring rules are not reported in the registry record. These details are necessary for a reproducible interpretation of a time-to-event endpoint.
The record does not report participant flow or the endpoint analysis population. Although enrollment is listed as 46, it is not possible to establish how many participants received the regimen, belonged to the specified EFS population, completed follow-up, or contributed to any analysis. The registry lists 0 analyses, and no outcome estimates or uncertainty intervals are given.
The single-group design provides no concurrent randomized comparator. This limits the potential for a causal comparison even if descriptive outcomes were available. The record also does not report a statistical analysis plan, multiplicity handling, missing-data methods, protocol deviations, or sensitivity analyses. The adverse-event fields list zero participants at risk and zero affected; given the stated lack of study data, they cannot be treated as interpretable safety findings.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: Temozolomide,Thiotepa and Carboplatin With Autologous Stem Cell Rescue Followed by 13-cis-retinoic Acid in Patients With Recurrent/Refractory Malignant Brain Tumors — NCT00528437.
- Registry record last updated 2021-07-08; status last verified 2021-06.
- Results first posted 2021-07-08.
- 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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Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
17. Record Summary
The registry record describes a completed phase 2, single-group study sponsored by NYU Langone Health. It lists enrollment of 46, a start date of 2005-10, and a primary completion date of 2017-06-30. The intervention combined temozolomide, thiotepa, and carboplatin with autologous stem cell rescue, followed by 13-cis-retinoic acid, for children and adolescents with recurrent or refractory brain tumors.
The primary outcome is EFS for patients with recurrent or refractory medulloblastoma or primitive neuroectodermal tumors, with a timeframe of Day +42. The registry also describes safety and drug-handling objectives. It lists 3 outcome measures and 0 analyses, and states that no study data are available after unsuccessful efforts to contact the study team. As a result, the record documents the intended study question and design but does not provide outcome estimates for statistical interpretation.