Lenalidomide in Patients With Chronic Lymphocytic Leukemia Older Than 65 Years of Age: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Lenalidomide in Patients With Chronic Lymphocytic Leukemia Older Than 65 Years of Age (NCT01011894), a na phase 2 study. The primary outcome is Best Response.

2. Clinical Question

The study asks whether lenalidomide can control chronic lymphocytic leukemia for at least one year in patients older than 65 years of age. Its listed population is patients with intermediate- or high-risk chronic lymphocytic leukemia who are 65 years of age or older. The registry describes lenalidomide as experimental in this study and states that participants received it until disease progression or unacceptable toxicity.

The clinical question and the recorded endpoint are related but not identical. The study purpose refers to the likelihood of control for at least one year, whereas the posted primary outcome records best response using categories that include complete response, partial response, progressive disease, and stable disease. The registry does not report a time-to-loss-of-control estimate or the number of participants whose disease remained controlled for at least one year. The posted response counts therefore describe the recorded response categories, not a direct estimate of the duration-based question.

3. Trial Design

This is a phase II, single-group study sponsored by Memorial Sloan Kettering Cancer Center. The registry lists enrollment of 26 and describes the study as completed. It lists no random allocation and no masking. There is no control arm, so the study is not a randomized comparison and cannot directly contrast lenalidomide with another treatment or with no treatment within this trial.

The intervention is lenalidomide. The arm description says that patients with intermediate- or high-risk chronic lymphocytic leukemia, aged 65 years or older, received lenalidomide at the 20mg dose level until disease progression or unacceptable toxicity. It also notes that progression at this dose requires non-protocol alternate therapy. The registry's general study description identifies lenalidomide as experimental in this study. It describes possible biological actions in theory, but those statements are background rationale rather than measured clinical outcomes.

The registry gives the study start as 2009-11-06 and primary completion as 2016-02-23. Those dates describe the recorded study timeline; they do not provide details about recruitment duration, follow-up completeness, or the timing of individual assessments. The primary outcome is titled Best Response, uses participants as its unit, and has a 2 years timeframe. Its description sets out response criteria based on physical examination and examination of peripheral blood and bone marrow.

Because the design has one group, the observed counts describe outcomes among enrolled participants without an internal control estimate. They can characterize what was recorded during the study, but they do not separate treatment effects from the natural course of disease, participant characteristics, or other influences. The registry record does not report a statistical analysis plan or an analysis population definition.

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

Analysis population for the primary outcome, as defined in the registry: 20 participants had Stable Disease, 3 had Progression of Disease, 3 were not evaluable due to toxicity

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.

6. Primary Endpoint

The registry lists the primary outcome as Best Response, measured over 2 years.

The primary endpoint is Best Response, measured as a count of participants, with a stated timeframe of 2 years. Response assessment is based on physical examination and examination of peripheral blood and bone marrow. The registry describes complete response using absence of specified disease findings and symptoms together with blood-count criteria. Partial response involves reductions in lymphocyte count and disease findings. Progressive disease is defined by worsening disease findings, including changes in lymph nodes or enlargement of the liver or spleen. Stable disease is also reported as a category in the posted results.

A categorical response endpoint is used to describe the clinical status recorded under defined criteria. It can distinguish participants with evidence of improvement, progression, or neither classification, rather than reducing all observations to a single continuous measurement. The criteria matter because they determine how observations are assigned to response categories. The registry's outcome description explains several components of the criteria, although it ends during the description of progressive disease.

The primary endpoint should not be read as a direct measure of how long disease control lasted. The study purpose refers to control for at least one year, but Best Response records a category over the stated 2 years timeframe. The registry does not report counts for complete response or partial response, nor a duration-based estimate of control for at least one year. The posted counts instead report stable disease, progression, and participants not evaluable because of toxicity. Thus, the recorded endpoint helps describe response status but does not by itself answer every aspect of the study's stated purpose.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies a binary kind of outcome and describes the unit as participants with an event, expressed as counts. For Best Response, however, the posted results are categorical participant counts rather than an adjusted effect estimate. The registry lists zero analyses. No model, inferential test, confidence interval, or adjusted comparison is reported in the registry record. The following concepts explain how such information is generally interpreted; they do not imply that the trial used methods that are not documented.

What does a participant count describe?

A count reports how many participants were assigned to a stated category. It is directly interpretable as a description of the recorded group, provided that the category and the population being counted are clearly defined. A count alone does not show the uncertainty around an underlying response probability. Nor does a count by itself clarify whether every enrolled participant had an assessment, how missing assessments were handled, or whether participants could contribute to more than one category. Those details depend on the endpoint rules and analysis population.

For this study, the registry reports 20 participants with Stable Disease, 3 with Progression of Disease, and 3 not evaluable due to toxicity. These counts should be kept in their posted categories. They should not be converted into a percentage or combined into a newly calculated summary. The record does not report the endpoint analysis population, so it is not possible to determine from the registry how the not-evaluable participants were handled in any formal analysis.

Why does the design affect interpretation?

A single-group study has no internal comparator. In a randomized comparison, random allocation is intended to make treatment groups comparable in expectation, allowing a between-group contrast to estimate the effect of assignment under the study conditions. That logic does not apply to a single group. The observed outcome can be described, but there is no concurrent group in this study against which to estimate a relative treatment effect. Changes in disease status may reflect treatment, underlying disease course, participant selection, or other factors; the registry does not quantify these influences.

Allocation is listed as not applicable and masking as none. These design features do not invalidate the descriptive counts, but they matter when interpreting outcome assessment and causal claims. Response categories rely on clinical assessments. In general, masking can reduce the chance that knowledge of treatment affects an assessment, although the registry does not report a masked assessment procedure. The record does not describe a blinded independent review.

What does a confidence interval add?

In general, a confidence interval gives a range of values compatible with an estimate under a specified statistical model and sampling process. A narrow interval indicates greater statistical precision than a wide interval, while neither width nor coverage guarantees that the study population represents other populations or that the endpoint was measured without bias. The registry does not report a confidence interval for Best Response, and no interval should be inferred from the counts in explanatory text.

Likewise, a p-value addresses compatibility between observed data and a specified null hypothesis under a statistical model. It is not the probability that a treatment works, and it does not describe the size or clinical importance of an outcome. The registry reports no endpoint analysis or p-value. A p-value would not resolve the absence of a comparator in this single-group design.

How should planning illustrations be understood?

General sample-size planning asks how many participants might be needed to detect a specified effect under stated assumptions. The planning assumptions associated with this record describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect expressed as a fraction of an observed effect. Such assumptions describe a hypothetical planning calculation, not the actual single-group allocation in this study. Planning sample sizes are not observed power and do not establish that an effect was detected. The registry record does not report the trial's own sample-size justification, so it is not possible to say that the planning assumptions were part of the study's original design.

Over-dispersion is a general issue when count data vary more than a statistical model expects. If a count model assumes less variability than the data actually have, standard errors may be too small and intervals may be too narrow. The posted Best Response categories are participant counts in one group, not a reported over-dispersed event-rate model. The registry does not report a model that would allow assessment of over-dispersion, and no such conclusion should be attributed to this study.

What can be concluded from the recorded endpoint?

The endpoint supports a limited descriptive statement: the registry records participants in the listed response and evaluability categories. It does not provide a reported estimate of the chance of maintaining disease control for at least one year, an uncertainty interval, or a comparison with another group. General statistical interpretation must therefore remain separate from the actual record. The record's counts describe the categories it lists; they do not establish a causal effect or resolve missing-analysis details.

10. Multiplicity, Missing Data and Analysis Populations

Multiplicity concerns arise when a study evaluates multiple outcomes, subgroups, time points, or statistical tests. Repeated testing can increase the chance of obtaining at least one apparently notable result even when no true effect exists. General methods to address this include prespecifying a primary analysis or adjusting inference across a family of tests. The registry lists one outcome measure and zero analyses. It does not report a multiplicity strategy, a hierarchy of outcomes, or additional endpoint analyses. The absence of a reported strategy should not be taken as evidence that no analyses occurred outside the registry record; the registry record does not describe them.

The outcome description identifies a timeframe of 2 years, while the study purpose refers to disease control for at least one year. The record does not explain how assessments at different times were combined to determine Best Response, whether a response had to be confirmed, or how competing events and discontinuation were treated. It also does not report an analysis plan connecting the duration-based purpose to the categorical endpoint.

Missing-data handling is not reported in the registry record. The posted population description identifies 3 participants as not evaluable due to toxicity. That is a specific reason for non-evaluability, but the record does not say whether their data were excluded, counted in a particular category, or handled under another rule in an analysis. No general missing-data method should be assumed. In general, different approaches to missing outcome data can change the interpretation, especially when missingness is related to clinical status or tolerability.

The registry does not define an intention-to-treat, per-protocol, or safety population for the primary outcome. It also does not state whether all enrolled participants were included in each outcome assessment. The reported counts should therefore be read as the registry's posted categories, without assuming an analysis population or reconstructing a denominator for an unreported estimate. These reporting gaps limit assessment of multiplicity, missingness, and the relationship between the study purpose and the recorded endpoint.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: pneumonia (15.4%), fatigue (11.5%), lung infection (11.5%), alt, sgpt (3.8%), creatinine increased (3.8%).

The registry reports serious adverse events among 26 participants at risk, with 11 affected. It separately reports other adverse events among 26 participants at risk, with 26 affected. These are safety counts for the listed study group; they are not a comparison of risks between treatment arms. The record does not report deaths in this safety entry.

The listed serious adverse-event terms and percentages are Pneumonia, 15.4%; Fatigue, 11.5%; Lung infection, 11.5%; ALT, SGPT, 3.8%; Creatinine increased, 3.8%; and Dizziness, 3.8%. These figures describe the registry's reported terms. They should not be added together: participants may experience more than one type of event, and the record does not provide information on overlap among terms. The percentages also do not, by themselves, describe severity beyond the serious-event classification or establish that an event was caused by lenalidomide.

General safety interpretation distinguishes the number of participants affected from the number of event episodes. The posted figures are participant-based risk and affected counts; episode counts, timing, duration, and outcomes are not reported in the registry record. The available safety summary identifies events observed in this study group, but without a control group it cannot estimate comparative excess risk. These figures should be read as descriptive reporting, not as a standalone causal assessment.

12. What the Result Does, and Does Not, Mean

The result is a registry description of best-response categories and safety reporting in a single-group phase II study of lenalidomide for older patients with chronic lymphocytic leukemia. The posted primary outcome counts are 20 participants with Stable Disease, 3 with Progression of Disease, and 3 not evaluable due to toxicity. The safety entry reports 11 affected by serious adverse events among 26 at risk and 26 affected by other adverse events among 26 at risk. These findings describe what the registry records for the study group.

The results do not directly answer whether disease control lasted at least one year. Best Response is listed with a 2 years timeframe, but the registry does not provide a duration-of-control estimate or show how many participants met a one-year duration criterion. Stable disease is a response category, not a duration measure. The record also does not report counts for complete or partial response in the posted population description.

The results do not establish what would have happened under another treatment or without lenalidomide. With no comparator group, the study cannot estimate a relative treatment effect from a randomized contrast. The counts also do not establish that lenalidomide caused each observed clinical outcome or adverse event. Such conclusions would require evidence and design information beyond these descriptive summaries.

Precision is also limited by the absence of an inferential endpoint analysis in the registry record. No confidence interval, hypothesis test, or adjusted estimate is reported. The registry does not describe the primary endpoint analysis population, the handling of participants not evaluable due to toxicity, or the statistical plan. These gaps make it difficult to assess uncertainty and the exact relationship between the posted categories and the study's stated disease-control objective.

The appropriate reading is therefore bounded: the record documents response categories and adverse-event summaries for a defined older, intermediate- or high-risk CLL population treated in a single group. It does not provide a controlled estimate of benefit, a precise estimate for one-year disease control, or a complete account of analysis and missing-data methods. Statistical description is useful, but it should not be mistaken for evidence that answers questions the registry did not measure or analyze.

13. Why This Trial Matters Statistically

This trial illustrates why the match between a study objective and its endpoint matters. The stated purpose concerns the likelihood of maintaining disease control for at least one year, while the registered primary outcome is Best Response over a 2 years timeframe. A categorical response can describe clinical status, but it is not interchangeable with a duration-based outcome. A reader needs the endpoint definition, assessment timing, and analysis method to determine whether the recorded outcome answers the intended question.

It also illustrates the limits of a single-group design. Participant counts can show what was recorded in the treated group, but without a concurrent comparator they cannot estimate a treatment contrast. Inference about causation requires more than observing outcomes after treatment. The design and reporting determine which questions can be addressed, regardless of how clearly the counts are presented.

The three participants described as not evaluable due to toxicity highlight another statistical issue: tolerability can affect whether an outcome is observed or classified. The registry gives a reason for non-evaluability, but does not state how these participants were handled in an endpoint analysis. Transparent reporting of analysis populations and missing-data rules is essential because different choices can lead to different interpretations.

Finally, the record separates response reporting from safety reporting but does not provide a full inferential analysis for either. Counts and percentages are useful descriptive summaries. They do not, on their own, communicate precision, comparative risk, or causality. This study is therefore a useful example of reading registry results within the boundaries of the design, endpoint definition, and analysis details actually recorded.

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.

Several limitations are specific to the information recorded for this study. The single-group design has no concurrent comparator, and the registry lists no random allocation. Consequently, the posted outcomes do not support a within-trial estimate of how results differ from another treatment or from no treatment. The absence of masking is also recorded, while the registry does not describe independent or blinded response review.

The study purpose and endpoint do not align completely in their stated forms. The purpose refers to control for at least one year, but the primary outcome is Best Response with a 2 years timeframe. The record does not report a duration-of-control estimate or explain how the endpoint addresses the stated duration question. The outcome description provides response criteria but ends during its description of progressive disease, leaving the complete criterion wording unavailable in the registry record.

The posted response categories include participants not evaluable due to toxicity, but the record does not specify how they were handled in an analysis. The registry does not define an analysis population, report a missing-data method, or explain the timing and confirmation of response assessments. It also lists zero analyses and does not report inferential estimates or uncertainty intervals for the primary outcome.

The safety summary reports affected counts and selected serious-event terms, but the record does not provide event timing, duration, participant-level overlap, or a causal assessment. Deaths are not reported in the registry safety entry. These omissions constrain interpretation of both benefit-related outcomes and safety. The registry record also does not report the trial's sample-size justification or a full statistical analysis plan, so those design choices cannot be evaluated from the recorded information.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Lenalidomide in Patients With Chronic Lymphocytic Leukemia Older Than 65 Years of Age — NCT01011894.
• Registry record last updated 2017-05-18; status last verified 2017-04.
• Results first posted 2017-05-18.
• 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.

18. Record Summary

The registry describes a completed phase II, single-group study of lenalidomide in patients with chronic lymphocytic leukemia older than 65 years of age. Enrollment is listed as 26, with no random allocation and no masking. The arm description specifies intermediate- or high-risk disease and lenalidomide at the 20mg dose level until progression or unacceptable toxicity.

The primary outcome is Best Response, measured in participants, with a 2 years timeframe. The posted categories are 20 with Stable Disease, 3 with Progression of Disease, and 3 not evaluable due to toxicity. The safety entry reports serious adverse events in 11 of 26 participants at risk and other adverse events in 26 of 26 at risk. The registry lists no analyses and does not report an endpoint estimate for disease control lasting at least one year.

The record supports a descriptive account of response categories and safety events in the study group. It does not provide a controlled treatment comparison or enough analysis detail to quantify precision for the stated duration-based question.