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 Tretinoin and Arsenic Trioxide With or Without Idarubicin in Treating Patients With Acute Promyelocytic Leukemia (NCT00528450), a na phase 2 study. The primary outcome is Molecular Remission Rate.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00528450 |
| Phase | Phase 2 |
| Condition | Leukemia |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 1 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Memorial Sloan Kettering Cancer Center |
| Results posted | Yes |
2. Clinical Question
Population
Patients with acute promyelocytic leukemia. The registry lists the broader condition as leukemia and does not report further eligibility details or a defined analysis population.
Intervention
The study concerns tretinoin and arsenic trioxide, with or without idarubicin. The registry lists all three drugs as interventions, but the arm description refers readers to an outline for treatment details; those details are not reported in the registry record.
Comparator
No separate control group is listed. Allocation is recorded as NA, and the study model is single-group. The registry therefore does not present a like-for-like comparison between assigned treatment groups.
Primary question
The stated primary outcome is the Molecular Remission Rate at 2 years. Its description defines the measure as the number of patients with Complete Remission. The record does not report a result, so it does not show how many participants met that outcome or provide an estimate of its frequency.
The clinical question is therefore descriptive rather than comparative in the posted record: what remission outcome was recorded for participants receiving the study approach? The registry gives the study's treatment scope and names the intended outcome, but it does not provide the outcome value or an analysis. It cannot establish a difference between the listed treatment approach and another treatment, because no comparator group is reported.
3. Trial Design
This is a Phase II study registered as NCT00528450, sponsored by Memorial Sloan Kettering Cancer Center. Its title describes tretinoin and arsenic trioxide with or without idarubicin for patients with acute promyelocytic leukemia. The official title describes a study of combined all-trans retinoic acid and arsenic trioxide followed by risk-adapted postremission therapy. The registry lists tretinoin, arsenic trioxide, and idarubicin as drug interventions.
The recorded model is single-group, allocation is NA, and masking is none. No separate randomized comparator is listed. The record reports enrollment of 1 and status as terminated. The recorded study start is 2007-09 and primary completion is 2011-01. These registry entries describe the design and status; they do not explain why the study was terminated or what treatment each participant actually received.
The arm is named “Tretinoin and Arsenic Trioxide With or Without Idarubicin,” but its description says “See Outline for details.” Specific regimen, dosing, assignment, eligibility criteria, and follow-up procedures are not reported in the registry record. The official title mentions risk-adapted postremission therapy, but the registry entries available do not specify how that therapy was selected or delivered.
Although the study is designated Phase II, that label does not supply a treatment-effect estimate or establish that the primary outcome was evaluated. The record lists one outcome measure and zero analyses. Thus, the design and administrative history are identifiable, but the posted record does not provide a completed statistical account of the primary endpoint.
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 | All Patients |
|---|---|
| STARTED | 1 |
| COMPLETED | 1 |
| NOT COMPLETED | 0 |
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 | All Patients |
|---|---|---|
| Participants analysed | 1 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 1 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 1 |
| Sex: Female, Male: Male | Participants | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Molecular Remission Rate, measured over 2 years.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The named primary endpoint is “Molecular Remission Rate,” with a timeframe of 2 years and a unit of participants. However, its description is “# of patients with Complete Remission.” That wording matters: the title refers to molecular remission, while the operational description refers to complete remission. The registry record does not clarify whether these terms represent the same endpoint in this study, how remission was assessed, or what criteria were used.
As a general statistical concept, a remission endpoint records whether participants meet a defined disease-response criterion. A count of participants meeting that criterion can describe the observed outcome in a study population, while a rate ordinarily relates that count to a defined denominator. Interpretation depends on clear outcome definitions, assessment timing, and an analysis population. Those details are not reported in the registry record.
The 2 years timeframe identifies the stated assessment horizon; it does not establish when or how assessments occurred. No endpoint count, denominator for an outcome analysis, rate, uncertainty interval, or analysis result is reported. Consequently, the endpoint's intended role is clear at a high level, but its observed value and precision cannot be assessed from the posted record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central statistical limitation is that the registry names a primary outcome but does not report an analysis of it. The stated endpoint is Molecular Remission Rate at 2 years, described as the number of patients with Complete Remission. The record reports zero analyses. It gives no outcome count, analyzed denominator, estimate, confidence interval, or test result. The posted information therefore cannot quantify the endpoint or its precision.
Enrollment is recorded as 1. That is a registry enrollment figure, not an outcome result. It does not establish that the enrolled participant completed treatment, reached the stated assessment time, had an evaluable outcome, or belonged to a particular analysis population. Each of those details is not reported in the registry record. The serious and other adverse-event denominators are recorded separately and should not be substituted for an endpoint-analysis denominator.
The study is listed as single-group, with allocation NA and no masking. There is no separate control group in the record, so no comparative treatment effect can be estimated from a randomized contrast. Even if a remission count had been reported, a single-group result would describe outcomes in the observed group; it would not, by itself, distinguish treatment effects from other explanations for those outcomes.
The registry status is terminated. The record does not report the reason for termination, whether termination occurred before planned recruitment or follow-up was complete, or whether any outcome data were collected but not posted. It is therefore not appropriate to infer that termination was caused by safety, efficacy, recruitment, or administrative considerations.
The registry's adverse-event entries show 0 participants affected by serious adverse events among 1 at risk, and 1 participant affected by other adverse events among 1 at risk. These are descriptive counts in the record, not a comparative safety analysis. The death value is not reported. The entries do not identify the nature, timing, severity breakdown, or relationship of the other event to treatment.
Overall, the record supports a description of the registered design, listed outcome, status, and sparse safety counts. It does not support a numerical conclusion about remission, comparative benefit, or the magnitude of risk. Missing analysis information should not be interpreted as evidence that an outcome did or did not occur.
9. Statistical Methods Explained
The registry identifies the primary outcome as a participant count and classifies the outcome as binary. In general, a binary outcome records whether each participant did or did not meet a specified criterion. A total count can be informative only when the criterion, assessment, and relevant denominator are clear. Here, the registry's endpoint title and description use different remission terms, and the record does not provide an endpoint result or denominator for analysis.
What does a single-group design allow?
In general, a single-group study can describe outcomes among the participants observed under its study approach. It does not create a concurrent randomized comparison. Random assignment in a comparative trial helps make treatment groups comparable on average, while a single-group design lacks that between-group contrast. The registry lists a single-group model and allocation NA, so it does not report a randomized comparison of tretinoin and arsenic trioxide, with or without idarubicin, against another treatment or control.
This design distinction affects what a statistic can mean. An observed count or rate, if reported, would describe the study group under the outcome definition and follow-up used. It would not by itself estimate how outcomes would have differed under an alternative treatment. No adjusted or unadjusted treatment comparison is reported, and no analysis is listed.
How should uncertainty be understood?
In general, a confidence interval expresses the range of values reasonably compatible with data under a specified statistical method and assumptions. It communicates precision, not certainty that a particular value is true. A small or incomplete dataset often carries substantial uncertainty, but no interval can be described for this endpoint because the record provides no outcome estimate or analysis. The enrollment figure alone is not enough to reconstruct one without inventing outcome information or assumptions.
A p-value, in general, evaluates how compatible observed data are with a stated null model under specified assumptions. It is not a measure of clinical importance and is not the probability that a hypothesis is true. The registry does not report a p-value or a hypothesis test for the primary endpoint. No statistical model, test choice, or confidence-interval method for that endpoint is reported in the registry record.
What do the planning assumptions represent?
Planning illustrations are distinct from the trial's observed results. The stated illustration assumptions use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. For time-to-event illustrations, the stated quantity is total events; for other outcomes, it is participants per arm. These are planning conventions, not evidence that this single-group study used a two-arm design or achieved a particular power.
In general, a sample-size calculation asks how much information might be needed to detect a specified effect under stated assumptions. It is not observed power, and it cannot establish that a study has found an effect. The record does not report the trial's own sample-size justification or a numerical planning estimate in the registry entries. In addition, the posted record contains no primary outcome estimate from which the stated observed-effect-based illustration could be independently understood.
Why do model assumptions matter?
General statistical methods depend on assumptions about the outcome, sampling, and structure of the data. A normal approximation is a planning assumption in the stated illustration, not a reported method for analyzing the primary endpoint. Over-dispersion is a general concern when observed variability exceeds what a chosen model expects; whether it matters depends on the data and model. The registry does not report a fitted model, diagnostic checks, or enough outcome information to assess such assumptions in this study.
For a binary outcome, analysis commonly requires clarity about the event definition, the number assessed, and the handling of participants whose status is unknown. Those details are not reported. Since there is no posted endpoint analysis, there is no basis to assess model fit, precision, sensitivity to assumptions, or robustness of a result. The statistical interpretation is therefore limited by the absence of an outcome analysis, not simply by the choice between particular statistical methods.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one outcome measure and zero analyses. It does not report a multiplicity plan, a hierarchy of endpoints, or whether any additional outcomes were intended for formal testing. A single listed outcome does not establish that the study had no other planned analyses; it means only that the record available for this analysis names one outcome measure. Whether any adjustment for multiple comparisons was planned is not reported in the registry record.
Missing-data procedures are also not reported. The record does not explain how participants with missing remission assessments, incomplete follow-up, or unevaluable status would be handled. It does not state whether the primary analysis would include all enrolled participants, only treated participants, or a defined subset. Those are important distinctions because the endpoint is recorded as a participant count and its interpretation depends on the denominator and outcome ascertainment.
The enrollment figure is 1, but the record does not indicate whether that participant was included in an endpoint analysis. No analysis population, evaluability criteria, or accounting of participants through follow-up is reported. No imputation method, missingness assumption, or sensitivity analysis is reported either. Accordingly, the degree and consequences of missing outcome information cannot be assessed.
In general, multiplicity arises when several outcomes, time points, or statistical comparisons are examined; repeated testing can increase the chance of a seemingly notable finding by chance. Missing-data methods address uncertainty when some participant outcomes are unavailable. These concepts cannot be applied to produce conclusions for this study without the study's analysis plan and outcome data. The registry record does not report those details, and their absence should not be read as proof that no procedures existed.
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 |
|---|---|---|---|
| All Patients | 0 | 1 | 0.0% |
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 |
|---|---|
| All Patients | 1 of 1 |
Most frequent non-serious adverse event terms
| Event term | Organ system | All Patients |
|---|---|---|
| ALT, SGPT | Blood and lymphatic system disorders | 1 of 1 |
| AST, SGOT | Blood and lymphatic system disorders | 1 of 1 |
| Alkaline phosphatase | Metabolism and nutrition disorders | 1 of 1 |
| Bilirubin (hyperbilirubinemia) | Metabolism and nutrition disorders | 1 of 1 |
| Dizziness | Nervous system disorders | 1 of 1 |
| Glucose, high (hyperglycemia) | Metabolism and nutrition disorders | 1 of 1 |
| Hemoglobin | Blood and lymphatic system disorders | 1 of 1 |
| Infection, other | Infections and infestations | 1 of 1 |
| Leukocytes (total WBC) | Blood and lymphatic system disorders | 1 of 1 |
| Lymphopenia | Blood and lymphatic system disorders | 1 of 1 |
The registry's serious adverse-event entry lists 1 participant at risk and 0 affected. Its other adverse-event entry lists 1 participant at risk and 1 affected. These are counts, not rates calculated for a larger study population, and they do not provide a comparison with another group. The enrollment figure is also 1, but the registry does not explain the relationship between the enrollment and safety analysis populations.
The record does not report the death value. It also does not list terms among the top serious adverse events. That absence does not establish that no specific event occurred beyond what the recorded serious-event count says; the event-term detail is not reported in the registry record. The nature and timing of the reported other adverse event, its severity, duration, outcome, and relationship to study treatment are not reported.
In general, safety counts are interpreted in light of definitions, observation periods, and the number of participants assessed. A zero recorded serious-event count in this registry entry is a descriptive observation for the listed safety denominator; it cannot establish that the treatment approach carries no serious-event risk. Likewise, the other-event count does not establish causation. The sparse entries do not support a comparative or comprehensive safety assessment.
12. What the Result Does, and Does Not, Mean
The record establishes that NCT00528450 was registered as a Phase II, single-group study of tretinoin and arsenic trioxide, with or without idarubicin, for acute promyelocytic leukemia. It records enrollment of 1, a terminated status, and a primary outcome named Molecular Remission Rate at 2 years. The endpoint description says the measure is the number of patients with Complete Remission.
Those details do not amount to a reported treatment result. The registry lists zero analyses and provides no primary outcome count, rate, confidence interval, or test result. It is therefore not possible to tell from the posted record whether any participant met the endpoint, how the endpoint was assessed, or how precise an estimate would be. Enrollment is not an outcome.
The study's single-group model and allocation NA also limit interpretation. There is no reported comparator group from which to estimate a treatment contrast. An outcome observed in a single group, even if it were available, would not alone show what would have happened under another treatment. The record cannot establish a causal effect or a comparative benefit or harm.
The safety entries are likewise limited: the record lists 0 serious adverse events among 1 at risk and 1 other adverse event among 1 at risk. It does not report event descriptions or deaths. These counts should be read as registry entries, not as a complete safety profile or as proof of causation.
In general, a study designation, a registered endpoint, and an observed estimate answer different questions. Here, the design and intended outcome are recorded, but an outcome analysis is not. The reason for termination and the statistical plan are not reported in the registry record. The appropriate interpretation is that the available record is insufficient to assess remission results or comparative treatment effects.
13. Why This Trial Matters Statistically
This study is statistically notable because its registry record illustrates the difference between a registered research question and a reported analysis. It identifies a Phase II, single-group study and names a primary remission endpoint, yet records zero analyses. Without the endpoint count and denominator, even a basic descriptive estimate cannot be evaluated.
The wording of the endpoint is also important. “Molecular Remission Rate” appears as the title, while the description specifies the number of patients with “Complete Remission.” Statistical interpretation requires knowing exactly what outcome was measured, how it was assessed, and who was included. The registry does not resolve the terminology or provide those methods, so a reader cannot determine whether the two labels refer to the same operational measure in this study.
The record also makes design constraints visible. A single-group study can describe a group, but it does not provide a randomized control contrast. This matters when distinguishing an observed outcome from evidence of a treatment effect. The Phase II designation does not substitute for either a reported outcome or a comparison.
Finally, the record has sparse safety information and a terminated status, with no reported reason for termination. Those details call for restraint rather than a causal explanation. The record's value is that it documents the study's registered scope, outcome label, status, and limited event counts. Its statistical limits are equally important: the posted information does not permit assessment of the primary result, its precision, or a treatment comparison.
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 trial-specific limitation is the absence of a reported primary outcome analysis. Although the registry names a remission endpoint and a 2 years timeframe, it provides no outcome count, analyzed denominator, estimate, or uncertainty interval. The registry lists enrollment of 1, but does not report whether that participant was assessed for the primary endpoint or included in an analysis.
The endpoint description does not fully resolve what was measured: the title says “Molecular Remission Rate,” while the description says “# of patients with Complete Remission.” Criteria, assessment procedures, and the relationship between these terms are not reported in the registry record. The arm description refers to an outline for details, so the specific treatment regimen and the use of idarubicin are not specified in the record.
The single-group design and allocation NA mean that a like-for-like control comparison is not reported. The registry also records no masking. The reason for termination, the statistical analysis plan, sample-size justification, analysis populations, and missing-data procedures are not reported. No inference about why the study ended or how any unreported data were handled is warranted.
Safety interpretation is limited by the small recorded denominators and sparse event descriptions. The registry reports counts for serious and other adverse events, but does not report event terms, timing, treatment relationship, or the death value. These entries cannot characterize a full safety profile or support comparison with another group.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Tretinoin and Arsenic Trioxide With or Without Idarubicin in Treating Patients With Acute Promyelocytic Leukemia — NCT00528450.
- Registry record last updated 2016-01-29; status last verified 2015-12.
- Results first posted 2016-01-29.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT00528450 is a Phase II, single-group study sponsored by Memorial Sloan Kettering Cancer Center, with tretinoin and arsenic trioxide, with or without idarubicin, for acute promyelocytic leukemia. Allocation is recorded as NA, masking as none, enrollment as 1, and status as terminated. The recorded start is 2007-09 and primary completion is 2011-01.
The primary outcome is titled Molecular Remission Rate at 2 years, while its description specifies the number of patients with Complete Remission. The registry lists one outcome measure and zero analyses; no primary outcome result is reported. Safety entries list 0 serious adverse events among 1 at risk and 1 other adverse event among 1 at risk. The death value and reason for termination are not reported in the registry record. No randomized comparator is listed, so the record does not provide a comparative treatment-effect estimate.