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 Lenalidomide in HTLV-1 Adult T-Cell Leukemia (NCT01274533), a na phase 2 study. The primary outcome is Response Rate (CR + Cru + PR).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01274533 |
| Phase | Phase 2 |
| Condition | Adult T Cell Leukemia/Lymphoma |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 4 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Columbia University |
| Results posted | Yes |
2. Clinical Question
Population
Patients with relapsed or refractory HTLV-1-associated adult T-cell leukemia/lymphoma. The record lists enrollment as 4; other details of the enrolled population are not reported in the registry record.
Intervention
Oral lenalidomide, initiated on Day 1 of Cycle 1 and taken once daily on days 1-21 of a 28 day cycle. Participation in the treatment phase could continue for 24 months unless disease progressed or the drug was discontinued for safety reasons.
Comparator
No comparator group is listed. The study is identified as single-group, with allocation recorded as NA and masking recorded as none. It therefore does not provide a like-for-like control comparison.
Primary question
The registered primary outcome is response rate, defined by the title as CR + Cru + PR, with a 28 days timeframe and assessment by peripheral blood, CT or MRI. The response outcome was not analyzed.
The central question was whether lenalidomide could be associated with a tumor response in patients with relapsed or refractory HTLV-1-associated adult T-cell leukemia/lymphoma. The registry describes the condition as a rare and aggressive peripheral T-cell neoplasm caused by HTLV-1, and identifies lenalidomide as investigational for this condition. The study was a Phase II investigation, not a randomized comparison of lenalidomide against another treatment or a control.
The primary outcome title combines CR, Cru, and PR, but the registry record does not report definitions for those response categories, how they were combined, or the response results. It states that data would not be analyzed because the principal investigator had left the institution, attempts to contact the investigator were unsuccessful, and Columbia would not have access to the data. The only information described as available was the number of participants who started and completed the study, and that report is truncated. Consequently, the registry does not answer the response question with an estimate, nor does it support a comparison of response with another group.
3. Trial Design
This was a completed Phase II study sponsored by Columbia University. The registry lists a start date of 2010-12 and a primary completion date of 2013-01. Its design is identified as single-group, with allocation recorded as NA and masking recorded as none. Enrollment is listed as 4. These design features describe a small, nonrandomized investigation without a concurrent comparator in the registry record.
The intervention was lenalidomide. The treatment description specifies oral dosing beginning on Day 1 of Cycle 1, once daily on days 1-21 of a 28 day cycle. It says participants could continue in the treatment phase for 24 months, unless disease progression occurred or the drug was discontinued for safety reasons. The record does not report how many participants actually started treatment, completed treatment, or received particular durations of therapy. It also does not report dose modifications or adherence.
The primary outcome was response rate (CR + Cru + PR), with a 28 days timeframe and assessment described as peripheral blood, CT or MRI. Safety of lenalidomide monotherapy is listed as a secondary outcome. Although the record lists two outcome measures, it reports no analyses. For the primary outcome, the registry specifically explains that the data would not be analyzed because the principal investigator had left the institution, contact attempts had been unsuccessful, and Columbia would not have access to the data. The number of participants who started and completed the study is described as the only available information, but the record's text is truncated before those counts are given.
No protocol rationale for the enrollment target, detailed eligibility criteria, treatment allocation procedures, or statistical analysis plan is reported in the registry record. The registry status is completed, but completion status does not itself supply outcome results or establish that the planned endpoint was analyzed.
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 | Lenalidomide |
|---|---|
| STARTED | 4 |
| COMPLETED | 0 |
| NOT COMPLETED | 4 |
Reasons for not completing this period:
| Reason | Lenalidomide |
|---|---|
| Withdrawal by Subject | 1 |
| Non-compliance | 1 |
| Disease progression | 2 |
Analysis population for the primary outcome, as defined in the registry: The principal investigator has left the institution. Attempts to contact the PI have been unsuccessful. Columbia will never have access to the data. Thus, data will not be analyzed. The only information available is the number of participants who started and completed the study, which was last reported to and approved by the IRB in Aug. 2013.
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 | Lenalidomide |
|---|---|---|
| Participants analysed | 4 | |
| Age, Customized: 18 years and older | participants | 4 |
| Sex: Female, Male: Female | Participants | 0 |
| Sex: Female, Male: Male | Participants | 4 |
| Region of Enrollment: United States | participants | 4 |
6. Primary Endpoint
The registry lists the primary outcome as Response Rate (CR + Cru + PR), measured over 28 days.
| 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 titled “Response Rate (CR + Cru + PR).” In general, a response rate is the proportion of an assessed study population meeting a prespecified definition of response. Combining categories can provide a single summary of response, but its interpretation depends on the category definitions, assessment rules, and denominator. Those details, including the meanings of CR and Cru, are not reported in the registry record. The record names peripheral blood, CT or MRI as assessment sources and gives a timeframe of 28 days.
Response is used in cancer studies because it can summarize observed changes in disease status during treatment. A clearly defined response endpoint can support a descriptive estimate and, when a suitable comparator and analysis are available, help frame a treatment comparison. In general, response rate does not by itself describe how long a response lasts, whether disease control persists, or how patients fare on other outcomes. Those interpretations require additional outcome definitions and data.
For this study, no response count, denominator, response-rate estimate, or confidence interval is reported. The registry states that the data would not be analyzed. Therefore, the endpoint's title and assessment description identify what was intended to be measured, but they do not establish how many participants responded or how precisely a response rate could be estimated.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies the study as completed, single-group, and Phase II, and lists enrollment as 4. It also records lenalidomide as the intervention and response rate (CR + Cru + PR) as the primary outcome. Those details describe the intended study question and design. They are not efficacy findings. The primary response data were not analyzed, and the registry reports no response estimate, response count, denominator, or interval expressing uncertainty.
The registry's explanation is important to interpretation: the principal investigator had left the institution, attempts to contact the investigator were unsuccessful, and Columbia would not have access to the data. The only information described as available concerned the number of participants who started and completed the study; the text giving that information is truncated. A listed enrollment value is not a substitute for an analyzed primary outcome and does not show the number evaluated for response.
Because this is a single-group study, the record contains no concurrent control group for comparison. Even if an outcome estimate were available, a single-group result would describe outcomes in that study group, not isolate the effect of lenalidomide from other explanations. In general, a comparator can help distinguish treatment-associated outcomes from changes that might also occur without the treatment, although comparator design and analysis determine how informative that contrast is. No such contrast is reported.
The record also lists a safety outcome, but gives no interpretable safety analysis. The adverse-event fields list zero participants at risk and zero affected in the displayed categories, and no serious-event terms. Those entries do not provide a usable safety denominator; they cannot establish that no adverse events occurred. The registry does not report analyzed safety results or the number of participants actually exposed to treatment.
A planning illustration based on an observed effect cannot supply missing trial findings. The registry describes planning assumptions involving an observed effect and equal allocation between two arms, while the study itself is identified as single-group and no analyzed observed effect is reported. Any such illustration should therefore not be interpreted as evidence about the treatment or as a design feature of this trial. No recalculated estimate or sponsor analysis is available to compare.
Overall, the record supports a description of the intended question and design, but it does not support a numerical conclusion about response or safety. The absence of reported analysis means uncertainty cannot be quantified from the primary outcome, and it should not be mistaken for a result showing either benefit or lack of benefit.
9. Statistical Methods Explained
The trial is described as a single-group study with no masking. These are design characteristics, not analysis results. A single-group study observes outcomes in one treated group; it does not estimate a randomized between-group contrast. In general, random assignment to a comparator can reduce systematic differences between groups, while masking can reduce some influences on measurement or reporting. Neither a comparator nor masking is listed for this study. The registry does not report a more detailed statistical analysis plan.
What does the primary response measure represent?
In general, a response rate is a proportion: the number meeting a defined response criterion relative to the number assessed under the relevant rules. To interpret it, readers need both the response definition and the analysis denominator. For example, a protocol may specify which assessments count, how missing assessments are handled, and whether all enrolled or only evaluable participants form the denominator. These are general considerations; the registry record does not report those details for this endpoint.
The registered outcome title combines CR + Cru + PR, and the stated assessment sources are peripheral blood, CT or MRI. The timeframe is 28 days. The record does not provide operational definitions for the response categories or explain how differing assessment sources would be reconciled. It also provides no response counts or denominator. Consequently, there is no rate to reproduce or check against the stated endpoint.
How should uncertainty be expressed?
In general, a confidence interval describes the range of values compatible with the observed data under a specified statistical method and its assumptions. For a response proportion, an interval conveys how imprecisely that proportion is estimated. Its width depends on the available data and the method used. An interval is not a guarantee that the true value falls within its limits, and it does not repair biases in study design or missing data.
No confidence interval or response-rate estimate is reported in the registry record. Since there is no analyzed response count or denominator, the precision of the primary outcome cannot be assessed. A significance test would not address this absence of data. The record lists zero analyses, and no primary-outcome p-value is reported.
What does the single-group design allow?
In general, a single-group estimate can describe the outcomes recorded for that group, if outcome data and analysis details are available. It cannot by itself establish how those outcomes compare with what would have happened under another treatment or no treatment. Differences in patient characteristics, disease course, supportive care, assessment, or follow-up can complicate comparisons with results from other studies. These are general limits of uncontrolled comparisons, not claims that any particular factor affected this study.
The record's single-group designation means the study has no listed arm-level contrast. Its allocation is recorded as NA, and masking as none. The registry does not report a statistical model, adjustment variables, or procedures for handling repeated or incomplete assessments. As a result, no adjusted estimate or comparative analysis can be reconstructed.
How do the planning assumptions fit?
The registry describes planning illustrations that use a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. It says participant counts are per arm except for time-to-event illustrations, which use a total event count. These are planning assumptions, not a description of the trial's own statistical plan. The two-arm equal-allocation assumption does not match the registered single-group design.
Planning sample sizes are hypothetical calculations for future studies under specified assumptions. In general, they do not show how much power an already completed study had, and they are not observed outcomes. Here, the registry does not provide an analyzed observed effect on which to base an interpretation of the illustrations. Any planning values should not be read as trial findings, a justification of enrollment, or observed power.
What can be said about safety analysis?
The registry lists safety of lenalidomide monotherapy as a secondary outcome. General safety summaries require a clear population at risk, an exposure period, event definitions, and a method for collecting and classifying events. The adverse-event record lists zero at risk and zero affected in its displayed serious and other categories, with no serious-event terms; the record does not provide a usable exposure denominator or analyzed safety results. Those entries cannot be treated as evidence that no events occurred.
Overall, statistical interpretation is constrained not by a complicated reported model, but by the lack of analyzed endpoint data and missing analysis details. The registry does not report a response estimate, its uncertainty, a safety analysis, or a comparison with another group. General statistical concepts clarify what such analyses could mean, but they cannot fill these gaps.
10. Multiplicity, Missing Data and Analysis Populations
Multiplicity concerns arise when a study conducts multiple statistical tests or evaluates multiple outcomes, because repeated testing can increase the chance of at least one apparently positive finding. In general, analysis plans may prespecify a primary endpoint, distinguish confirmatory from exploratory outcomes, and describe any adjustment or hierarchy for interpreting multiple tests. The registry identifies a primary response outcome and lists safety as a secondary outcome, but the multiplicity strategy is not reported in the registry record. It lists no analyses, so there are no reported tests for which an adjustment can be evaluated.
Missing data are also central to interpretation. The registry explains that the primary data would not be analyzed because the principal investigator had left the institution, contact attempts were unsuccessful, and Columbia would not have access to the data. It says only the number of participants who started and completed the study was available, but the relevant text is truncated. It does not report missing-data procedures, outcome availability by participant, reasons for missing assessments, or an analysis population.
In general, missing outcomes can affect both the estimate and its precision, especially if missingness is related to disease status, treatment exposure, or tolerability. A complete-case analysis, imputation, or other strategy would require clear assumptions and sufficient data. None is described. The registry's enrollment listing does not establish the denominator for the response analysis, and the zero analyses listed do not permit assessment of an analysis population. These omissions prevent evaluation of how participants were included or excluded from endpoint analyses.
11. What the Result Does, and Does Not, Mean
The registry record establishes that a completed Phase II, single-group study of lenalidomide was registered for relapsed or refractory HTLV-1-associated adult T-cell leukemia/lymphoma. It identifies a response rate composed of CR + Cru + PR as the primary outcome and safety of lenalidomide monotherapy as a secondary outcome. It also describes the intended dosing schedule and the response assessment sources.
It does not establish how many participants responded, how many were assessed, or how precise any response estimate would be. The registry explicitly states that the primary data would not be analyzed. The number of participants who started and completed is described as available information, but the registry text is truncated before those counts. The record also does not provide interpretable analyzed safety results.
In general, an outcome observed in a single-group study cannot by itself show what would have happened under a different treatment or without the study treatment. Since no response result is reported, even a descriptive assessment of outcomes in this group is unavailable. The record therefore does not establish that lenalidomide improved outcomes, and it does not establish that lenalidomide failed to do so. It leaves the primary clinical question unanswered in the posted results.
The missing analysis is not equivalent to a null finding. A null finding would require an analyzed result that indicated little or no difference or response under a defined method; this registry record reports no such estimate. Nor can the enrollment listing or empty analysis count be used as evidence about efficacy or safety. The most accurate conclusion is that the registered study's outcome question cannot be assessed from the analysis information recorded.
12. Why This Trial Matters Statistically
This trial matters statistically because it illustrates the distinction between a registered question and an answer supported by analyzed data. A clearly named endpoint and a completed study status may make the intended evaluation apparent, but neither provides an outcome estimate. Here, the registry identifies a primary response measure and an assessment timeframe, yet states that the data would not be analyzed.
The record also demonstrates why denominators and analysis populations matter. A response rate requires both a response count and a defined population assessed under stated rules. Enrollment is listed as 4, but the registry does not give the analyzed response denominator or results. The text says the number who started and completed was the only available information, but does not preserve those counts. Without these elements, neither the response level nor its precision can be evaluated.
Its single-group design is another important statistical feature. In general, a single-group study can describe outcomes when data are available, but it cannot create a randomized treatment contrast. Since the primary data are not analyzed, the record offers neither a group-level response estimate nor a comparator-based estimate. This keeps both the descriptive and comparative questions unresolved.
Finally, the planning assumptions described in the record should be distinguished from trial findings and from the actual design. The stated illustration assumes equal allocation between two arms, whereas the study is registered as single-group. Planning calculations are conditional on their assumptions; they cannot replace outcome analyses or provide observed power. Careful separation of design, analysis, and planning is essential to avoid assigning meaning to information that does not answer the clinical question.
13. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The principal limitation is the absence of an analyzed primary endpoint. The registry says the data would not be analyzed because the principal investigator had left the institution, attempts to contact the investigator were unsuccessful, and Columbia would not have access to the data. It reports no response count, denominator, response estimate, or interval. This prevents evaluation of both the observed outcome and its precision.
The available description of study flow is incomplete. The record says the only available information was the number of participants who started and completed the study, but the text is truncated before those counts. Enrollment is listed as 4, but the registry does not report how many started treatment, completed it, or contributed an endpoint assessment. The analysis population and handling of missing assessments are not reported in the registry record.
The response outcome is not fully operationalized in the record. It names CR + Cru + PR, peripheral blood, CT or MRI, and a 28 days timeframe, but does not define the response categories, assessment rules, or denominator. Safety is listed as a secondary outcome, but no analyzed safety results or usable exposure denominator are reported. Zero entries in adverse-event fields do not establish absence of events.
The design is single-group, with no listed comparator and no masking. The registry does not report a detailed statistical analysis plan or a multiplicity approach. Its planning assumptions describe equal allocation between two arms, which does not match the registered single-group design. These limitations mean neither the primary clinical question nor the safety outcome can be assessed from the registry's reported analyses.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: Lenalidomide in HTLV-1 Adult T-Cell Leukemia — NCT01274533.
- Registry record last updated 2016-05-23; status last verified 2016-04.
- Results first posted 2016-04-22.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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17. Record Summary
NCT01274533 is a completed Phase II, single-group study sponsored by Columbia University, with enrollment listed as 4. The registry lists lenalidomide for relapsed or refractory HTLV-1-associated adult T-cell leukemia/lymphoma and describes oral dosing on days 1-21 of a 28 day cycle, with treatment-phase participation up to 24 months unless progression or safety discontinuation occurred.
The primary outcome is response rate (CR + Cru + PR), with a 28 days timeframe and assessment by peripheral blood, CT or MRI. Safety of lenalidomide monotherapy is listed as a secondary outcome. The registry reports no analyses and states that the primary data would not be analyzed because the investigator had left, contact attempts were unsuccessful, and Columbia would not have access to the data. It provides no interpretable response estimate, precision measure, or safety analysis.