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 Subcutaneous Recombinant Human IL-15 (s.c. rhIL-15) and Alemtuzumab for People With Refractory or Relapsed Chronic and Acute Adult T-cell Leukemia (ATL) (NCT02689453), a non-randomized phase 1 study. The primary outcome is Number of Dose-limiting Toxicities (DLTs) of Subcutaneous Recombinant Human IL-15 (s.c. rhIL-15) Administered With 3 Times Per Week Intravenous (IV) Alemtuzumab.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02689453 |
| Phase | Phase 1 |
| Condition | T-Cell Lymphoma Relapsed, Adult T-Cell Leukemia (ATL), Peripheral T-Cell Lymphoma (PTCL) |
| Allocation | Non-Randomized |
| Design model | Sequential |
| Masking | None (open label) |
| Enrollment | 11 |
| Arms in the primary outcome | n/a |
| Lead sponsor | National Cancer Institute (NCI) |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned adults with chronic or acute adult T-cell leukemia (ATL) whose disease had not been helped by other treatments. The registry also lists other T-cell conditions, including relapsed T-cell lymphoma, peripheral T-cell lymphoma, cutaneous T-cell lymphoma, and T-cell prolymphocytic leukemia. The brief summary describes eligibility as adults 18 years and older with chronic or acute ATL. The recorded enrollment is 11. The number enrolled in each dose level is listed separately in the safety record; the registry does not provide a complete account of analysis populations.
Intervention
The intervention was subcutaneous recombinant human interleukin 15 (rhIL-15) followed by intravenous alemtuzumab. The dose-level descriptions specify IL-15 for 10 doses over two weeks, followed by alemtuzumab for four weeks according to the dosing schema. The registry describes the study as assessing the combination and determining a maximum tolerated dose. It also identifies immune-system measures and clinical response among the secondary outcomes.
Comparator
There was no randomized control group. The study was non-randomized and sequential, with dose levels of IL-15 followed by alemtuzumab. The dose-level groups therefore represent stages of dose evaluation, not like-for-like treatment arms assigned to compare the combination against another treatment. No placebo, usual-care, or alternative-treatment comparator is reported in the registry record.
Primary question
The primary question was how many dose-limiting toxicities occurred during six weeks of treatment with subcutaneous rhIL-15 administered with intravenous alemtuzumab three times per week. The registry defines a DLT as a grade 3 or 4 toxicity possibly, probably, or definitely related to rhIL-15 during the first six weeks, with stated exceptions including grade 3 or 4 lymphopenia and grade 3 neutropenia. The numerical primary-endpoint result is not reported in the registry record. The study also sought to identify a safe dose and describe side effects and immune effects, but a maximum tolerated dose result is not reported in the registry record.
3. Trial Design
This was a phase I, non-randomized, unmasked, sequential study sponsored by the National Cancer Institute. The registry lists the study as completed, with a start date of 2017-01-19 and primary completion date of 2021-06-15. Recorded enrollment was 11. Participants were described as adults with refractory or relapsed chronic or acute ATL. Although other T-cell conditions appear in the registry condition list, the brief summary and eligibility description focus on ATL.
The intervention sequence began with subcutaneous rhIL-15, followed by intravenous alemtuzumab. The arm descriptions specify 10 IL-15 doses over two weeks, followed by alemtuzumab for four weeks. One arm description identifies dose finding for the maximum tolerated dose; another describes alemtuzumab given after IL-15 at the maximum tolerated dose. The registry lists three IL-15 dose levels: 0.5 mcg/kg/Dose, 1 mcg/kg/Dose, and 2 mcg/kg/Dose. This sequential dose-level structure is consistent with an early-phase safety and dose-evaluation study, not a randomized efficacy comparison. The detailed dose-escalation rules and the criteria for moving between dose levels are not reported in the registry record.
The brief summary describes screening, frequent visits during the first two weeks, and clinic-based alemtuzumab infusions during the subsequent treatment weeks. It also mentions physical examinations, vital signs, blood samples, and imaging as part of study procedures. Follow-up visits were planned after treatment, but the summary available in the registry record ends before giving the follow-up schedule. The exact follow-up duration is not reported in the registry record.
Secondary outcomes included clinical response, progression-free survival, circulating lymphocyte and T-cell subset percentages, and plasma pro-inflammatory cytokine levels. The registry lists eight outcome measures, but does not provide results for these outcomes in the registry record for this analysis. The record also lists zero analyses. An analysis plan, including planned statistical models and rules for evaluating the secondary outcomes, is not reported in the registry record.
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.
Before assignment: No participants were enrolled on Level 3 - 3 mcg/kg/dose of Interleukin 15 (IL-15) Followed by Alemtuzumab.
Overall Study
| Stage | Level 1 - 0.5 mcg/kg/Dose of Interleukin 15 (IL-15) | Level 2 - 1 mcg/kg/Dose of Interleukin-15 (IL-15) Followed by Alemtuzumab | Level 3 - 2 mcg/kg/Dose of Interleukin 15 (IL-15) Followed by Alemtuzumab |
|---|---|---|---|
| STARTED | 3 | 4 | 4 |
| COMPLETED | 3 | 3 | 3 |
| NOT COMPLETED | 0 | 1 | 1 |
Reasons for not completing this period:
| Reason | Level 1 - 0.5 mcg/kg/Dose of Interleukin 15 (IL-15) | Level 2 - 1 mcg/kg/Dose of Interleukin-15 (IL-15) Followed by Alemtuzumab | Level 3 - 2 mcg/kg/Dose of Interleukin 15 (IL-15) Followed by Alemtuzumab |
|---|---|---|---|
| Progressive disease | 0 | 1 | 1 |
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 | Level 1 - 0.5 mcg/kg/Dose of Interleukin 15 (IL-15) | Level 2 - 1 mcg/kg/Dose of Interleukin-15 (IL-15) Followed by Alemtuzumab | Level 3 - 2 mcg/kg/Dose of Interleukin 15 (IL-15) Followed by Alemtuzumab | Total |
|---|---|---|---|---|---|
| Participants analysed | 3 | 4 | 4 | 11 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 3 | 2 | 4 | 9 |
| Age, Categorical: >=65 years | Participants | 0 | 2 | 0 | 2 |
| Age, Continuous | years | 25.47 (SD 10.71) | 57.1 (SD 14.54) | 47.68 (SD 3.33) | 45.05 (SD 16.3) |
| Sex: Female, Male: Female | Participants | 1 | 1 | 0 | 2 |
| Sex: Female, Male: Male | Participants | 2 | 3 | 4 | 9 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 3 | 4 | 4 | 11 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 3 | 3 | 3 | 9 |
| Race (NIH/OMB): White | Participants | 0 | 1 | 1 | 2 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 | 0 |
| Region of Enrollment: United States | participants | 3 | 4 | 4 | 11 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Dose-limiting Toxicities (DLTs) of Subcutaneous Recombinant Human IL-15 (s.c. rhIL-15) Administered With 3 Times Per Week Intravenous (IV) Alemtuzumab, measured over 6 weeks.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | toxicities |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the number of dose-limiting toxicities (DLTs) associated with subcutaneous rhIL-15 given with intravenous alemtuzumab. The registry specifies a six-week timeframe. A DLT is defined as a grade 3 or 4 toxicity considered possibly, probably, or definitely related to rhIL-15 during the first six weeks of treatment. The definition includes exceptions, with grade 3 or 4 lymphopenia and grade 3 neutropenia given as examples. The endpoint therefore does not count every adverse event as a DLT: it applies a severity threshold, a time window, and an attribution criterion, alongside the stated exceptions.
In general, early-phase dose-finding studies use toxicity outcomes to help assess whether a dose or regimen can be given within an acceptable safety range and to guide further study. A DLT count is a safety measure, not a direct measure of tumor response or survival. The registry describes the study as seeking a safe dose and a maximum tolerated dose, but the numerical DLT result and the selected maximum tolerated dose are not reported in the registry record. The registry definition also focuses attribution on rhIL-15, while the treatment sequence includes alemtuzumab. The record does not explain how attribution was handled when a toxicity could relate to either component or to their sequence.
The outcome title refers to DLTs, while the endpoint unit is recorded as toxicities. Those terms can describe different quantities if a participant experiences multiple qualifying toxicities. The registry record does not clarify whether the reported endpoint would count events, affected participants, or both. No primary-endpoint count, uncertainty interval, or statistical comparison is reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The available record describes a small, sequential phase I dose-evaluation study, not a randomized comparison of the combination with another treatment. Its primary purpose was to assess dose-limiting toxicity while evaluating subcutaneous rhIL-15 followed by intravenous alemtuzumab. The primary endpoint is defined in terms of severity, attribution, and a six-week observation window. However, the numerical result for that endpoint is not reported in the registry record. Without that result, the posted information cannot establish how many DLTs were observed under the registry definition or how the dose levels differed on that endpoint.
The record identifies three dose levels and describes sequential evaluation, including a dose level using alemtuzumab after IL-15 at the maximum tolerated dose. It does not report the dose-escalation algorithm, the decision rules used to advance or stop, or the selected maximum tolerated dose. Those omissions prevent a reader from reconstructing how the dose-finding decisions were made from the registry record alone. The group sizes recorded in the safety data are small, and the study is not designed as a like-for-like randomized comparison. As a general statistical point, estimates from small groups are usually imprecise: a small change in observed events can materially affect the apparent pattern. That principle does not establish what happened in this study, because the primary DLT counts are not reported.
The registry does include safety figures by dose level. It lists serious adverse-event counts and other adverse-event counts, along with deaths, for each group. Those figures should be read as descriptive safety information rather than as evidence of a treatment effect. The registry does not identify a concurrent control group, and the recorded design is non-randomized. Differences between dose-level groups could reflect the sequential design, the underlying patients, or other factors; the registry record does not provide an adjusted comparative analysis. The specific serious-event percentages listed by term also lack a clearly stated denominator in the record details available for interpretation.
Clinical response, progression-free survival, immune-cell measurements, and cytokine levels are listed as secondary outcomes. Their numerical findings are not reported in the registry record. Consequently, no conclusion about the observed response pattern, time-to-event outcomes, or immune changes can be drawn from these registry entries. The registry lists zero analyses, and inferential statistics such as confidence intervals and p-values are not reported in the registry record. In general, confidence intervals convey uncertainty around an estimate, while a p-value addresses compatibility with a specified statistical null model; neither can be interpreted for outcomes without reported estimates and analysis results.
The study’s evidence is therefore principally characterized by its design and endpoint definitions, rather than by reported outcome estimates. Its recorded completion status does not substitute for results. The available record establishes that a dose-evaluation study was conducted and identifies its planned primary and secondary outcomes, but it does not provide enough outcome information to assess the observed DLT burden, clinical response, or progression-free survival.
9. Statistical Methods Explained
Statistical methods need to be interpreted in light of the question a study was designed to answer. This was a phase I, non-randomized, sequential dose-evaluation study. It was not a randomized trial comparing the intervention with a control treatment. The principal statistical focus described in the registry is a toxicity count over a defined treatment window, with the broader purpose of evaluating dose and identifying a maximum tolerated dose. Detailed statistical methods, decision rules, and analysis populations are not reported in the registry record.
What does a dose-limiting toxicity count describe?
The primary endpoint counts DLTs under a study-specific definition. Here, the definition applies to grade 3 or 4 toxicities considered possibly, probably, or definitely related to rhIL-15 during the first six weeks, subject to stated exceptions. In general, endpoint definitions determine which observations count as events and which do not. The severity threshold, attribution requirement, and observation period make the endpoint more specific than a count of all adverse events. They also mean that two safety summaries can differ without contradicting one another if they use different definitions or time windows.
The distinction between the number of events and the number of people affected is important. A person could, in principle, experience more than one toxicity, so an event count need not equal a count of participants with at least one event. The registry gives the primary endpoint unit as toxicities but does not report the result or clarify whether the intended summary is an event count, a participant count, or both. That ambiguity limits interpretation of the endpoint as described in the record.
Why use a sequential dose-evaluation design?
In general, a sequential early-phase design can evaluate dose levels in stages, using safety observations to inform decisions about subsequent dosing. It differs from random allocation: participants are not randomly assigned between concurrent treatment conditions for a like-for-like comparison. In this study, the arm descriptions distinguish dose levels and describe a later regimen using alemtuzumab after IL-15 at the maximum tolerated dose. The actual escalation and stopping rules, timing of decisions, and criteria for declaring a maximum tolerated dose are not reported in the registry record. It is therefore not possible to infer those rules from the listed doses alone.
Sequential dose studies are generally aimed at understanding tolerability and selecting a dose for further evaluation, rather than estimating comparative efficacy. Dose-level outcomes can be affected by the order in which participants enter the study and by changes in the population over time. Without randomization and a concurrent control group, group differences should not be interpreted as causal treatment contrasts. The registry provides no adjusted comparison between dose levels.
What can uncertainty measures contribute?
In general, a point estimate is a single summary of observed data, while a confidence interval describes the statistical uncertainty around an estimate under specified assumptions. A confidence interval does not remove design limitations, and it cannot correct for lack of randomization or missing outcome reporting. The registry entries available for this analysis do not include a primary DLT estimate or its confidence interval. No p-value for the primary endpoint is reported in the registry record. Because the underlying estimate and analysis are absent, there is no basis to interpret its precision or statistical significance.
For event counts, statistical approaches depend on such details as the event definition, observation time, whether multiple events per participant are possible, and the model assumptions. In general, over-dispersion occurs when variability in count data exceeds what a simple count model assumes; accounting for it can prevent uncertainty from being understated. The registry does not report a count-data model, dispersion parameter, or other primary-endpoint modeling method. It would therefore be inappropriate to attribute a particular count model to this trial.
How should the planning illustrations be understood?
In general, a sample-size planning illustration estimates the amount of information a future study might need under specified assumptions. It is not a measure of the probability that the completed study detected an effect, and it does not change what was observed. The registry’s stated illustration assumptions refer to 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. For time-to-event planning, the stated approach uses a total event count; for other outcomes, it uses participants per arm.
These are planning assumptions, not a description of this study’s allocation. The recorded trial design is non-randomized and sequential, whereas the planning illustration assumes equal allocation between two arms. The registry entries do not include the numerical planning results, and no additional sample-size value can be inferred from the assumptions alone. Such illustrations depend on the effect used as their starting point and on the assumptions chosen; they should not be read as observed power or as evidence that the actual study was sized according to those assumptions. A trial’s observed data and uncertainty are the relevant basis for interpreting its results.
What is missing from the analysis description?
The registry lists eight outcome measures and zero analyses. It does not report the primary analysis population, handling of participants who stopped treatment, missing-data rules, or analysis methods for the secondary outcomes. It also does not report whether analyses were adjusted for any baseline characteristics or how repeated measurements, such as immune-cell percentages over time, would be handled. In general, those choices matter because different analysis populations and missing-data assumptions can yield different estimates. With those details absent, the analysis cannot be reproduced or fully evaluated from the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary safety endpoint and several secondary outcomes: clinical response, progression-free survival, circulating lymphocyte and T-cell subset percentages, and plasma pro-inflammatory cytokine levels. It also lists eight outcome measures overall. The record details available for interpretation do not identify which secondary outcomes were confirmatory, how they were prioritized, or whether any formal adjustment for multiple testing was planned. Multiplicity procedures and the statistical analysis plan are not reported in the registry record.
In general, testing many outcomes can increase the chance that at least one result appears notable by chance, particularly when each is treated as a separate confirmatory test. The appropriate approach depends on the study’s aims and how the outcomes are interpreted. A descriptive early-phase study may emphasize estimation and safety characterization rather than formal hypothesis testing, but the registry record does not specify the intended inferential framework. No p-values or confidence intervals for the listed outcomes are reported in the registry record, so the effect of any multiplicity approach cannot be assessed.
Missing-data methods and analysis populations are also not reported in the registry record. The record does not describe how participants with incomplete treatment, unavailable assessments, or missing follow-up would be included in each outcome analysis. It does not identify an intention-to-treat, treated-participant, or other analysis population. In general, missing outcome data can affect estimates when the probability of being observed is related to a participant’s health or outcome. The assumptions and methods used to address that possibility are not reported in the registry record.
The registry lists zero analyses. This does not establish that no analysis was conducted; it means analysis results and details are not reported in the registry entries available for interpretation. Without a stated analysis plan or reported results, readers cannot determine how multiplicity, missing data, or analysis-population decisions were handled.
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 |
|---|---|---|---|
| Level 1 - 0.5 mcg/kg/Dose of Interleukin 15 (IL-15) Followed by Alemtuzumab | 1 | 3 | 33.3% |
| Level 2 - 1 mcg/kg/Dose of Interleukin-15 (IL-15) Followed by Alemtuzumab | 1 | 4 | 25.0% |
| Level 3 - 2 mcg/kg/Dose of Interleukin 15 (IL-15) Followed by Alemtuzumab | 1 | 4 | 25.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Level 1 - 0.5 mcg/kg/Dose of Interleukin 15 (IL-15) Followed by Alemtuzumab | 0 of 3 |
| Level 2 - 1 mcg/kg/Dose of Interleukin-15 (IL-15) Followed by Alemtuzumab | 0 of 4 |
| Level 3 - 2 mcg/kg/Dose of Interleukin 15 (IL-15) Followed by Alemtuzumab | 0 of 4 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Level 1 - 0.5 mcg/kg/Dose of Interleukin 15 (IL-15) Followed by Alemtuzumab | 3 of 3 |
| Level 2 - 1 mcg/kg/Dose of Interleukin-15 (IL-15) Followed by Alemtuzumab | 4 of 4 |
| Level 3 - 2 mcg/kg/Dose of Interleukin 15 (IL-15) Followed by Alemtuzumab | 4 of 4 |
Most frequent serious adverse event terms
| Event term | Organ system | Level 1 - 0.5 mcg/kg/Dose of Interleukin 15 (IL-15) Followed by Alemtuzumab | Level 2 - 1 mcg/kg/Dose of Interleukin-15 (IL-15) Followed by Alemtuzumab | Level 3 - 2 mcg/kg/Dose of Interleukin 15 (IL-15) Followed by Alemtuzumab |
|---|---|---|---|---|
| Thromboembolic event | Vascular disorders | 0 of 3 | 1 of 4 | 1 of 4 |
| Depression | Psychiatric disorders | 0 of 3 | 0 of 4 | 1 of 4 |
| Encephalopathy | Nervous system disorders | 1 of 3 | 0 of 4 | 0 of 4 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Level 1 - 0.5 mcg/kg/Dose of Interleukin 15 (IL-15) Followed by Alemtuzumab | Level 2 - 1 mcg/kg/Dose of Interleukin-15 (IL-15) Followed by Alemtuzumab | Level 3 - 2 mcg/kg/Dose of Interleukin 15 (IL-15) Followed by Alemtuzumab |
|---|---|---|---|---|
| Chills | General disorders | 1 of 3 | 4 of 4 | 2 of 4 |
| Fever | General disorders | 2 of 3 | 3 of 4 | 2 of 4 |
| Lymphocyte count decreased | Investigations | 2 of 3 | 3 of 4 | 1 of 4 |
| Hypophosphatemia | Metabolism and nutrition disorders | 2 of 3 | 2 of 4 | 1 of 4 |
| Neutrophil count decreased | Investigations | 2 of 3 | 2 of 4 | 1 of 4 |
| Aspartate aminotransferase increased | Investigations | 2 of 3 | 2 of 4 | 0 of 4 |
| Fatigue | General disorders | 0 of 3 | 2 of 4 | 2 of 4 |
| Infusion related reaction | Injury, poisoning and procedural complications | 0 of 3 | 3 of 4 | 1 of 4 |
| Rash maculo-papular | Skin and subcutaneous tissue disorders | 1 of 3 | 3 of 4 | 0 of 4 |
| White blood cell decreased | Investigations | 2 of 3 | 2 of 4 | 0 of 4 |
Serious events with the highest arm-level rate: encephalopathy (33.3%), depression (25.0%), thromboembolic event (25.0%).
The registry reports adverse-event figures separately for three IL-15 dose levels. For the serious adverse-event entries, Level 1 lists 3 at risk and 1 affected; Level 2 lists 4 at risk and 1 affected; Level 3 lists 4 at risk and 1 affected. The other adverse-event entries list 3 at risk and 3 affected for Level 1, 4 at risk and 4 affected for Level 2, and 4 at risk and 4 affected for Level 3. Deaths are recorded as 0 at each level. These are descriptive group-level figures, not a randomized comparison.
The registry also lists Encephalopathy at 33.3%, Depression at 25.0%, and Thromboembolic event at 25.0% among the top serious terms. The denominator and the precise basis for these percentages are not reported in the registry record. The figures should therefore be read as reported term percentages, not converted into participant counts or interpreted as comparative risks.
In general, serious adverse events, all adverse events, and dose-limiting toxicities are distinct summaries. A serious event is not automatically a DLT: the DLT definition additionally depends on grade, attribution to rhIL-15, timing, and specified exceptions. The registry does not establish that every listed event was caused by treatment. These safety figures cannot, by themselves, identify the treatment’s causal contribution or establish comparative safety.
12. What the Result Does, and Does Not, Mean
The record establishes that a completed, non-randomized phase I study evaluated sequential subcutaneous rhIL-15 and intravenous alemtuzumab in people with refractory or relapsed ATL. It specifies dose levels, describes the six-week DLT endpoint, and lists secondary clinical and immune outcomes. It also reports adverse-event summaries by dose level. These elements describe the study’s design and the kinds of evidence the registry intended to capture.
The key limitation for interpreting results is that the numerical primary DLT result is not reported in the registry record. The maximum tolerated dose is not reported in the registry record either. Numerical results for clinical response, progression-free survival, and immune outcomes are not reported in the registry record. Thus, the registry entries do not establish the observed DLT burden, the response pattern, or the results of the secondary outcomes. Completion status alone does not provide those findings.
The safety figures provide descriptive counts within dose levels, but they are not a controlled treatment comparison. Because the study was non-randomized and sequential, the groups should not be treated as equivalent populations assigned to competing treatments. The figures also do not establish that reported events were caused by the intervention. The registry’s serious-term percentages have no stated denominator in the registry record for interpretation.
In general, early-phase studies can contribute information about feasibility, tolerability, dose selection, and the design of later research. Their findings are usually not sufficient to establish comparative benefit. Here, the stated objectives include assessing safety and immune effects and evaluating clinical outcome, but results addressing those objectives are not reported in the registry record. The information therefore supports a description of what the study set out to assess, not a conclusion about whether the regimen was effective or ineffective.
The registry record also does not provide the statistical analysis plan, handling of missing observations, or analysis populations. Those omissions limit evaluation of the reliability and precision of any potential outcome estimates. Interpretation should remain within what is documented: a sequential dose-evaluation study with specified outcomes and some descriptive safety figures, but without reported primary or secondary efficacy results in the available record.
13. Why This Trial Matters Statistically
This trial matters statistically because it illustrates the distinction between a dose-evaluation study and a randomized comparative trial. The recorded design is non-randomized and sequential, with dose levels used to evaluate a regimen of subcutaneous rhIL-15 followed by intravenous alemtuzumab. That design can address early safety and dose questions, but it does not create a like-for-like control comparison for estimating a treatment contrast.
The primary endpoint also highlights why operational definitions matter. The registry does not define a DLT simply as any adverse event. It specifies a severity grade, a relationship to rhIL-15, a six-week time window, and exceptions. Each element affects which observations count toward the endpoint. The registry gives the endpoint unit as toxicities, but does not clarify whether the result is intended to count events, affected participants, or both. A clear endpoint definition and a clear reporting unit are essential for interpreting a safety count.
The record also shows why study status and outcome availability are different. The study is listed as completed, yet its primary DLT result and secondary outcome results are not reported in the registry record for interpretation. Without estimates and uncertainty measures, readers cannot assess the magnitude or precision of outcomes. In general, transparent reporting of analysis populations, missing-data rules, and decision methods is needed to judge how results were produced and what population they describe.
Finally, the planning assumptions described in the registry differ from the recorded sequential design: they refer to equal allocation between two arms, while the trial itself is non-randomized. This contrast underscores that planning illustrations are conditional calculations, not a description of the completed study’s allocation or evidence of observed power. A reader should distinguish design, analysis assumptions, and observed results rather than treating them as interchangeable.
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 most important trial-specific limitation in the available record is the absence of the numerical primary endpoint result. Although the registry defines DLT and gives a six-week timeframe, it does not report the DLT count or the maximum tolerated dose. The listed arm descriptions and adverse-event summaries do not substitute for that endpoint result because adverse events are not necessarily DLTs under the stated definition.
The study is non-randomized and sequential, so dose-level groups are not randomized comparison arms. The record does not describe the dose-escalation and stopping rules, and it does not provide an adjusted comparison between levels. The recorded enrollment is 11, and the group-level safety figures involve small recorded groups. In general, small groups yield limited precision and may not represent the range of outcomes in a broader population; no precision estimate for the primary outcome is reported in the registry record.
The definition attributes DLTs to rhIL-15, while treatment includes alemtuzumab in sequence. How investigators distinguished effects of each component, or handled uncertain attribution, is not reported in the registry record. The record also does not clarify whether the primary count refers to events or participants with events. The basis for the serious-event term percentages is not reported in the registry record.
Finally, statistical analysis methods, analysis populations, missing-data handling, and multiplicity procedures are not reported in the registry record. Numerical results for the listed secondary outcomes are also not reported in the registry record. These gaps limit assessment of outcome estimates and their uncertainty. The brief follow-up description is incomplete, and the exact follow-up duration is not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Subcutaneous Recombinant Human IL-15 (s.c. rhIL-15) and Alemtuzumab for People With Refractory or Relapsed Chronic and Acute Adult T-cell Leukemia (ATL) — NCT02689453.
- Registry record last updated 2022-04-29; status last verified 2022-04.
- Results first posted 2022-04-29.
- 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
The registry describes NCT02689453 as a completed phase I, non-randomized, sequential study sponsored by the National Cancer Institute. It evaluated subcutaneous rhIL-15 followed by intravenous alemtuzumab in people with refractory or relapsed chronic or acute ATL. Recorded enrollment was 11. The study began on 2017-01-19 and reached primary completion on 2021-06-15.
The primary endpoint was the number of DLTs over six weeks, defined by toxicity grade, attribution to rhIL-15, and stated exceptions. Three IL-15 dose levels are listed. Secondary outcomes include clinical response, progression-free survival, circulating immune-cell measures, and cytokine levels. The registry reports descriptive safety figures by dose level, including zero deaths in each group.
The numerical primary DLT result, maximum tolerated dose, and secondary outcome results are not reported in the registry record. Statistical analysis methods, analysis populations, and missing-data procedures are also not reported in the registry record. The available information therefore characterizes the trial’s design and reported safety summaries but does not provide the outcome estimates needed to assess its primary or secondary clinical findings.