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 Study of CC-5013 to Evaluate Safety, Pharmacokinetics and Effectiveness for Japanese Patients With Symptomatic Anemia Associated With Myelodysplastic Syndrome With a Del(5)(q31-33) Abnormality. (NCT00812968), a na phase 2 study. The primary outcome is Number of Participants With Adverse Events (AE).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00812968 |
| Phase | Phase 2 |
| Condition | Myelodysplastic Syndromes |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 11 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Celgene |
| Results posted | Yes |
2. Clinical Question
Population
Japanese patients with low- or intermediate-1-risk myelodysplastic syndromes associated with a deletion 5(q31-33) abnormality and symptomatic anemia were the intended population. The primary endpoint used a safety population defined as patients who received at least one dose of study drug.
Intervention
Participants received lenalidomide orally at 10mg daily on Days 1-21 of each 28-day cycle. Treatment could continue until disease progression or relapse, or permanent discontinuation for any reason, for up to 156 weeks (3 years).
Comparator
There was no comparison group. The trial was single-group, with allocation recorded as NA and masking recorded as NONE. Its results therefore describe participants treated with lenalidomide, rather than a contrast between treatment strategies.
Primary question
The primary endpoint counted participants with adverse events after the first dose through 28 days after study completion or discontinuation. The registry also describes pharmacokinetic objectives, including measures of lenalidomide concentration over time. The posted primary results are safety counts, not a controlled estimate of treatment effect.
3. Trial Design
This completed phase 2 study evaluated lenalidomide in Japanese patients with low- or intermediate-1-risk myelodysplastic syndromes associated with a deletion 5(q31-33) abnormality and symptomatic anemia. The registry describes a multicenter, single-arm design. It records enrollment of 11 and lists one intervention, lenalidomide. Because there was no control group, the design does not support a like-for-like comparison with another treatment or with no treatment.
The regimen was oral lenalidomide 10mg daily on Days 1-21 of each 28-day cycle. Treatment could continue until disease progression or relapse, or until the drug was permanently discontinued for any reason, for up to 156 weeks (3 years). The primary safety observation period began after the first dose and continued until 28 days after study completion or discontinuation; the stated maximum time on study was 155 weeks.
The study began on 2007-09-01 and reached primary completion on 2010-09-01. Its status is COMPLETED. The registry lists pharmacokinetic outcomes that include maximum observed plasma concentration, time to maximum concentration, several measures of area under the concentration-time curve, terminal half-life, apparent volume of distribution, and apparent total plasma clearance. Numerical results for these measures are not reported in the registry record used for this analysis.
Randomization was not part of the recorded design, and masking was NONE. The registry record does not report a rationale for the planned enrollment, a detailed statistical analysis plan, or an explanation of how the single-group design was selected.
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 | 11 |
| COMPLETED | 0 |
| NOT COMPLETED | 11 |
Reasons for not completing this period:
| Reason | Lenalidomide |
|---|---|
| Relapse after erythroid response | 6 |
| Disease progression | 1 |
| No further treatment required | 1 |
| Study closed due to marketing approval | 3 |
Analysis population for the primary outcome, as defined in the registry: Safety population: all patients who received at least 1 dose of study drug.
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 | 11 | |
| Age, Continuous | years | 71.8 (SD 5.95) |
| Sex: Female, Male: Female | Participants | 7 |
| Sex: Female, Male: Male | Participants | 4 |
| Region of Enrollment: Japan | participants | 11 |
| Duration of MDS | years | 2.0 (SD 1.44) |
| International Prognostic Scoring System (IPSS) Score: Low risk | participants | 2 |
| International Prognostic Scoring System (IPSS) Score: Intermediate-1 risk | participants | 9 |
| International Prognostic Scoring System (IPSS) Score: Intermediate-2 risk | participants | 0 |
| International Prognostic Scoring System (IPSS) Score: High risk | participants | 0 |
| French-American-British (FAB) classification of MDS: Refractory anemia (RA) | participants | 9 |
| French-American-British (FAB) classification of MDS: Refractory anemia with ringed sideroblasts (RARS) | participants | 0 |
| French-American-British (FAB) classification of MDS: Refractory anemia with excess blasts (RAEB) | participants | 2 |
| French-American-British (FAB) classification of MDS: Chronic myelomonocytic leukemia (CMML) | participants | 0 |
| French-American-British (FAB) classification of MDS: RAEB in transformation (RAEB-t) | participants | 0 |
| World Health Organization Classification of MDS: Refractory anemia (RA) | participants | 0 |
| World Health Organization Classification of MDS: RA with ringed sideroblasts (RARS) | participants | 0 |
| World Health Organization Classification of MDS: Refractory anemia with excess blasts-1 (RAEB-1) | participants | 2 |
| World Health Organization Classification of MDS: Refractory anemia with excess blasts-2 (RAEB-2) | participants | 0 |
| World Health Organization Classification of MDS: Refractory cytopenia multilineage dysplasia (RCMD) | participants | 1 |
| World Health Organization Classification of MDS: RCMD and ringed sideroblasts (RCMD-RS) | participants | 0 |
| World Health Organization Classification of MDS: MDS, unclassified (MDS-U) | participants | 0 |
| World Health Organization Classification of MDS: MDS associated with isolated del(5q) | participants | 8 |
| Bone Marrow Cellularity: Aplastic (0%) | participants | 0 |
| Bone Marrow Cellularity: Hypocellular (> 0% to ≤ 30%) | participants | 3 |
| Bone Marrow Cellularity: Normocellular (> 30% to ≤ 60%) | participants | 5 |
| Bone Marrow Cellularity: Hypercellular (> 60% to ≤ 90%) | participants | 2 |
| Bone Marrow Cellularity: Packed (> 90% to ≤ 100%) | participants | 0 |
| Bone Marrow Cellularity: Missing | participants | 1 |
| Transfusion Dependency: Yes | participants | 5 |
| Transfusion Dependency: No | participants | 6 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Adverse Events (AE), measured over After the first study dose until 28 days after completion of/discontinuation from the study (maximum time on study was 155 weeks)..
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with adverse events. It captures whether participants in the safety population experienced an adverse event during the specified observation period: after the first study dose through 28 days after completion of or discontinuation from the study. The registry defines the safety population as all patients who received at least one dose of study drug.
The endpoint also distinguishes serious adverse events. The registry defines an event as serious when it results in death, is life-threatening, involves inpatient hospitalization or prolongation of existing hospitalization, causes persistent or significant disability or incapacity, is a congenital anomaly or birth defect, or is another important medical event. The investigator assessed the relationship of each event to study drug using its timing and whether other drugs, interventions, or underlying conditions could explain it. Severity was assessed using NCI CTCAE Version 3.0, from Grade 1 (Mild) through Grade 5 (Death).
Counting participants with events is a way to describe observed safety experience in the treated group. It is not, by itself, an estimate of how many events would have occurred without treatment, nor does it establish that the drug caused an event. The registry record does not report a comparative safety endpoint or a controlled estimate of risk.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry reports 3 participants with serious adverse events among 11 at risk in the lenalidomide group. It reports 11 participants with other adverse events among 11 at risk. These are counts from the single treated group, not contrasts against a control group. Participants may contribute to both categories; the counts should not be added to produce a total.
The serious-event count describes the number of participants recorded as having at least one serious adverse event during the stated observation period. It does not state how many serious events occurred, whether participants experienced more than one, or how long each participant was observed. The separate count for other adverse events gives another participant-level summary, but the registry record does not provide event-level detail for all events in those counts.
The registry lists Gastric Ulcer, Cholelithiasis, Herpes Zoster, Influenza, Spinal Compression Fracture, and Liver Function Test Abnormal among the top serious terms; each is reported as 9.1%. Those entries identify listed event terms and their posted percentages. They do not establish a causal relationship to lenalidomide. The registry says investigators judged relatedness by considering timing and possible alternative explanations. The listed serious-event terms should not be treated as an exhaustive account of all safety experience.
No comparator was included, so the results do not estimate how these counts would differ under another treatment or no treatment. The small enrollment also means the observed counts describe a limited group; they cannot precisely characterize uncommon events or broader variation in safety experience. No confidence intervals, formal comparative tests, or adjusted estimates are reported in the registry record.
The primary endpoint is a safety count, not an efficacy result. Although the study’s stated purpose included effectiveness and the registry lists pharmacokinetic outcomes, numerical results for those outcomes are not reported in the registry record used. The posted safety data therefore support a description of recorded events during the study, but not a conclusion about comparative efficacy or causation.
9. Statistical Methods Explained
The posted primary endpoint is a count of participants with adverse events. The registry reports one treated group and gives the number at risk and the number affected for serious and other adverse events. These are descriptive statistics: they state what was recorded in the observed safety population. Because the design has no comparator, a treatment-versus-control effect estimate cannot be obtained from these counts.
What does a participant count describe?
A participant count records whether a person experienced an event in the defined period; it is not necessarily a count of all events. A participant with repeated events may still be counted once in a participant-level measure. The record does not provide enough event-level detail to determine the number of repeated events, their timing, or their duration. Counts in different categories can also overlap, so they should not be summed unless the registry explicitly states that the categories are mutually exclusive.
Why does the observation period matter?
Adverse-event findings depend on the interval during which events are collected. In this study, the primary safety timeframe starts after the first dose and extends through 28 days after study completion or discontinuation. Treatment duration could vary, and the registry states that the maximum time on study was 155 weeks. A participant observed for a longer period has more time in which an event could be recorded. A participant count alone does not adjust for differences in time under observation.
What do seriousness and severity mean?
Seriousness is defined by outcomes or medical importance, including hospitalization, a life-threatening event, or death. Severity is a separate rating of intensity. The registry describes severity grading under NCI CTCAE Version 3.0, from Grade 1 (Mild) to Grade 5 (Death). A serious event is not defined solely by a high severity grade, and an event’s seriousness does not establish that study drug caused it. The registry describes investigator assessment of relatedness based on timing and alternative explanations.
How should uncertainty be understood?
A confidence interval, in general, expresses a range of values compatible with data under a specified statistical method and assumptions. It can communicate uncertainty around an estimate; it does not remove limitations in study design or make a single-group result comparative. No confidence interval for the reported adverse-event counts is reported in the registry record. Nor does the record report a formal hypothesis test for these safety counts.
In general, small studies tend to provide limited information about uncommon outcomes and produce imprecise estimates. Here, the registry records 11 at risk in the lenalidomide group. The posted counts are therefore best read as an account of events in this study population, not as a precise estimate of event frequency in all patients with the described condition.
What are the planning illustrations?
Any sample-size illustrations associated with the posted results are planning calculations, not observed power. The stated calculation assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. These are hypothetical inputs for planning, not features of this single-group trial’s actual allocation. Such illustrations cannot turn a one-group study into a controlled comparison, and their values should not be interpreted as observed results. The registry record does not report that these assumptions were the trial’s original design plan.
The study also listed pharmacokinetic outcomes, including concentration and exposure measures. General pharmacokinetic summaries describe how drug concentrations change over time and can include measures such as maximum concentration, time to maximum concentration, and area under the concentration-time curve. The numerical results for the listed pharmacokinetic measures are not reported in the registry record used for this analysis. The record likewise does not report the statistical methods used to analyze those outcomes.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary safety endpoint and multiple secondary pharmacokinetic outcomes. When a study examines multiple outcomes or performs repeated statistical tests, the chance of at least one apparently notable result can increase. General methods for addressing multiplicity include prespecifying a hierarchy or adjusting inference across tests. The registry record does not report a multiplicity strategy, a testing hierarchy, or an adjustment for multiple comparisons.
The posted primary safety information is descriptive: participant counts are reported for serious and other adverse events. The registry record does not report p-values, confidence intervals, or a formal hypothesis-testing plan for these counts. Numerical results for the listed pharmacokinetic outcomes are not reported in the registry record used here, so their missing results cannot be assessed for consistency, multiplicity, or precision.
The primary endpoint population is defined as all patients who received at least one dose of study drug. The group-level safety figures list 11 at risk. The registry record does not report details about participants who may have been screened but not treated, or how missing safety observations were handled. It does not describe missing-data methods, exclusions from individual outcome analyses, or whether all participants contributed complete follow-up.
Because the primary population is defined by receipt of at least one dose, the safety results describe treated participants rather than all people who may have entered the study process. The record does not report an intention-to-treat population or a separate efficacy population. It also does not report interim analyses, a detailed statistical analysis plan, or rules for stopping the study early.
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 |
|---|---|---|---|
| Lenalidomide | 3 | 11 | 27.3% |
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 |
|---|---|
| Lenalidomide | 11 of 11 |
Most frequent serious adverse event terms
| Event term | Organ system | Lenalidomide |
|---|---|---|
| Gastric Ulcer | Gastrointestinal disorders | 1 of 11 |
| Cholelithiasis | Hepatobiliary disorders | 1 of 11 |
| Herpes Zoster | Infections and infestations | 1 of 11 |
| Influenza | Infections and infestations | 1 of 11 |
| Spinal Compression Fracture | Injury, poisoning and procedural complications | 1 of 11 |
| Liver Function Test Abnormal | Investigations | 1 of 11 |
| Anorexia | Metabolism and nutrition disorders | 1 of 11 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Lenalidomide |
|---|---|---|
| Neutropenia | Blood and lymphatic system disorders | 11 of 11 |
| Thrombocytopenia | Blood and lymphatic system disorders | 11 of 11 |
| Leukopenia | Blood and lymphatic system disorders | 10 of 11 |
| Constipation | Gastrointestinal disorders | 10 of 11 |
| Lymphopenia | Blood and lymphatic system disorders | 8 of 11 |
| Nasopharyngitis | Infections and infestations | 8 of 11 |
| Rash | Skin and subcutaneous tissue disorders | 8 of 11 |
| Eosinophilia | Blood and lymphatic system disorders | 5 of 11 |
| Pruritus | Skin and subcutaneous tissue disorders | 5 of 11 |
| Basophilia | Blood and lymphatic system disorders | 4 of 11 |
Serious events with the highest arm-level rate: gastric ulcer (9.1%), cholelithiasis (9.1%), herpes zoster (9.1%), influenza (9.1%), spinal compression fracture (9.1%).
The registry reports 3 participants with serious adverse events among 11 at risk and 11 participants with other adverse events among 11 at risk in the lenalidomide group. These are participant counts, not counts of every event. A person may have experienced more than one event, and the two categories should not be added because overlap is not ruled out in the record.
The top serious terms listed are Gastric Ulcer, Cholelithiasis, Herpes Zoster, Influenza, Spinal Compression Fracture, and Liver Function Test Abnormal, each reported as 9.1%. These terms describe events recorded in the registry; the percentages do not establish that lenalidomide caused them. The record states that investigators assessed relatedness using event timing and possible alternative explanations. It does not report the number of deaths in the adverse-event results; that information is not reported in the registry record.
Seriousness and severity are different classifications. Seriousness depends on specified outcomes or medical importance, while severity was assessed using NCI CTCAE Version 3.0. These data are descriptive of the study’s safety population and observation period. Without a comparison group, they cannot show whether event counts were higher or lower than they would have been under another treatment or no treatment.
12. What the Result Does, and Does Not, Mean
The results describe adverse events recorded in a small, single-group study of lenalidomide in Japanese patients with symptomatic anemia and low- or intermediate-1-risk myelodysplastic syndromes associated with a deletion 5(q31-33) abnormality. The registry reports participant counts for serious and other adverse events over the stated safety observation period. It also lists several serious-event terms and their posted percentages.
These results do not show whether lenalidomide caused any particular event. The registry describes investigator assessment of relatedness, but the posted counts alone do not separate effects of study drug from underlying illness, other medicines, or other explanations. They also do not establish how the observed event counts compare with what would have occurred without lenalidomide.
The single-group design has no control arm, so it cannot provide a direct comparative estimate. The study’s enrollment and safety counts give information about the participants observed, but do not precisely characterize all possible outcomes in the broader population. The registry record does not provide confidence intervals or a formal comparative statistical analysis to quantify uncertainty.
The study’s stated purpose included safety, pharmacokinetics, and effectiveness. However, the numerical pharmacokinetic results and a numerical primary efficacy result are not reported in the registry record used. The adverse-event data should not be interpreted as an efficacy finding. They address what was recorded for safety, not whether treatment improved anemia or other clinical outcomes.
In general, a result from a clinical trial is interpreted in light of the population enrolled, the design, the outcomes measured, and the completeness of reporting. This study is specific to Japanese patients meeting the described disease and anemia criteria, and its findings should be understood within that setting. The registry information supports a limited description of recorded safety events, rather than a conclusion about comparative benefit, comparative harm, or causation.
13. Why This Trial Matters Statistically
This trial is statistically informative as an example of what a single-group safety study can and cannot establish. It records adverse-event experience in participants who received lenalidomide, with a defined observation period and a registry definition of the safety population. Those features let readers understand the scope of the reported counts.
At the same time, the absence of a comparison group is central to interpretation. A one-group count can describe events observed during treatment, but it cannot estimate a difference in event frequency between treatment strategies. This remains true even when counts are clearly reported. A causal claim would require evidence that distinguishes treatment effects from other explanations; these results alone do not do that.
The small enrollment also matters. In general, small studies provide limited information about uncommon events and can yield imprecise estimates. A listed event term or participant count should therefore be read as an observation from this study, not as a stable estimate for a broader population. The registry does not report confidence intervals that would quantify uncertainty around the counts.
The record also illustrates why endpoint availability and design should be considered together. The study’s stated objectives included pharmacokinetics and effectiveness, but numerical results for those outcomes are not reported in the registry record used. The available primary results are safety counts. Statistical interpretation should remain tied to what is actually reported, rather than extending safety observations into efficacy conclusions.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The main limitation is the single-group design. With no comparator, the reported adverse-event counts cannot establish a difference from another treatment or from no treatment, and they cannot isolate the effect of lenalidomide from other possible explanations. The registry records allocation as NA and masking as NONE.
Enrollment was 11, which limits how much the study can reveal about uncommon events and the range of safety experience in a broader population. The registry reports participant counts, but does not provide confidence intervals, event rates adjusted for time at risk, or event-level details sufficient to characterize recurrence and duration. The observation period could vary with treatment duration, and the record does not report individual follow-up completeness.
The registry lists several serious-event terms but does not provide a complete event-by-event account in the information used for this analysis. It does not report a death count in the adverse-event results. It also does not report numerical results for the listed pharmacokinetic outcomes or a numerical primary efficacy result. The absence of those results in the registry record limits assessment of the study’s broader stated objectives.
Further statistical details are not reported in the registry record, including a detailed analysis plan, missing-data methods, an approach to multiplicity, interim analyses, and the rationale for enrollment. Without those details, it is not possible to assess whether analyses followed prespecified procedures or how incomplete outcome information may have been handled. These limitations constrain interpretation of the posted results; they do not change the counts that the registry reports.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study of CC-5013 to Evaluate Safety, Pharmacokinetics and Effectiveness for Japanese Patients With Symptomatic Anemia Associated With Myelodysplastic Syndrome With a Del(5)(q31-33) Abnormality. — NCT00812968.
- Registry record last updated 2019-11-19; status last verified 2019-11.
- Results first posted 2013-12-17.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
NCT00812968 is a completed phase 2, multicenter, single-group study sponsored by Celgene. It evaluated lenalidomide in Japanese patients with symptomatic anemia and low- or intermediate-1-risk myelodysplastic syndromes associated with a deletion 5(q31-33) abnormality. Enrollment was 11. The study began on 2007-09-01 and reached primary completion on 2010-09-01.
The regimen was oral lenalidomide 10mg daily on Days 1-21 of each 28-day cycle, for up to 156 weeks (3 years), subject to progression, relapse, or permanent discontinuation. The primary endpoint counted participants with adverse events from after the first dose through 28 days after completion or discontinuation. The registry reports 3 participants with serious adverse events and 11 with other adverse events among 11 at risk. No comparator was included. Numerical efficacy and pharmacokinetic results are not reported in the registry record used for this analysis.