A Pilot Study of CC-220 to Treat Systemic Lupus Erythematosus.: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Pilot Study of CC-220 to Treat Systemic Lupus Erythematosus. (NCT02185040), a randomized phase 2 study. The primary outcome is Number of Participants With Treatment Emergent Adverse Events (TEAEs) in Part 1 Treatment Phase.

2. Clinical Question

This distinction matters when interpreting the evidence. The registered primary endpoint is a safety measure, not a direct measure of change in lupus manifestations. The secondary outcomes include pharmacokinetic measures and measures of disease activity and joint counts, including changes from baseline and the proportion reaching a stated SELENA SLEDAI reduction during ATEP. Their presence identifies topics the study tracked; it does not establish that results or formal comparisons for those outcomes are available in the registry record.

The design includes several dose schedules and an additional ATEP period, while the placebo comparison is listed for Part 1. The posted adverse-event counts should therefore be read by their named group and period rather than as one pooled contrast between all participants assigned CC-220 and all participants assigned placebo.

3. Trial Design

The registry record describes a randomized, parallel-group, Phase 2 study with quadruple masking and placebo control. It is titled as a pilot study of CC-220 in systemic lupus erythematosus. Enrollment was 42, and the record gives the status as completed. The recorded study start was 2014-09-16 and primary completion was 2018-09-25.

Part 1 included a placebo group and four CC-220 dose schedules: 0.3 mg every other day, 0.3 mg every day, 0.6 mg/0.3 mg alternating doses each day, and 0.6 mg every day. The record also lists ATEP groups receiving 0.3 mg daily or alternating 0.6 mg/0.3 mg daily. It does not explain the ATEP abbreviation in the listed information, so its meaning and relationship to the Part 1 treatment period are not reported in the registry record.

The primary endpoint concerns treatment-emergent adverse events in Part 1. Its timeframe begins with the first dose and continues until 28 days after the last dose or study discontinuation, according to the registered description. The record reports median treatment durations of 12.0 weeks for placebo, 0.3 mg QOD and 0.3 mg QD, and 11.9 weeks for the 0.6/0.3 ALT and 0.6 cohorts.

The group counts in the posted adverse-event information are not all from the same period: Part 1 groups and ATEP groups are listed separately. This is important because these entries do not constitute a single randomized comparison with one shared comparator across both periods. Details about sequence generation, concealment, masking roles, eligibility criteria, treatment adherence, and any changes to the design are not reported in the registry record.

The record lists efficacy, safety, tolerability, pharmacokinetics, pharmacodynamics and pharmacogenetics among the study objectives. It names secondary outcomes involving iberdomide concentration measures, SELENA SLEDAI, and swollen and tender joint counts. The posted information does not establish which of these secondary outcomes were analyzed or how their results were interpreted.

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: In part 1 of the study, participants were randomly assigned to 1 of 4 dose cohorts; within each cohort participants were randomized in a 4:1 ratio to receive iberdomide or placebo. Participants who completed the Part 1 treatment phase were eligible to receive iberdomide for up to 2 years in the active treatment extension phase (ATEP).

Only the first 6 of 7 groups are shown.

Part 1 Treatment Phase

Reasons for not completing this period:

Active Treatment Extension Phase

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The safety population included all participants who were randomized and received at least 1 dose of IP. For all participants, this was the treatment group to which they were randomized.

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.

Population: Intent to Treat (ITT) includes all participants who were randomized and received at least 1 dose of investigational product (IP). Participants were included in the treatment group to which they were randomized for the ITT analyses.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Treatment Emergent Adverse Events (TEAEs) in Part 1 Treatment Phase, measured over From the start of the first dose of IP until 28 days after the last dose or study discontinuation in Part 1; median treatment duration = 12.0 weeks for the placebo, 0.3 mg QOD and 0.3 mg iberdomide QD arms, 11.9 weeks for the 0.6/0.3 ALT and 0.6 cohorts..

The primary endpoint counts participants with treatment-emergent adverse events during the Part 1 treatment phase. A treatment-emergent adverse event is defined in the registry record as an event that began or worsened on or after the start of investigational product, up to 28 days after the last dose or the investigational-product discontinuation date, whichever was later. Each participant is counted once for each applicable category.

This endpoint is used to describe the occurrence of adverse events during treatment and the specified follow-up window. Counting participants, rather than individual event episodes, gives a participant-level measure of how many people experienced an event in a category. It does not describe the number of separate event episodes, their duration, or the full clinical course for an affected participant.

The record distinguishes investigational-product-related treatment-emergent events, which were events the investigator considered suspected to be related to the product. It also describes investigator assessment of severity and defines serious adverse events by outcomes such as death, life-threatening events, hospitalization, persistent or significant disability, congenital anomaly or birth defect, or an important medical event.

The posted endpoint description does not itself establish that an event was caused by treatment. The registry record does not report a statistical comparison for the primary endpoint or a primary endpoint result by randomized group in the information available for interpretation. The separate adverse-event counts are therefore descriptive and should not be treated as a reported test of treatment effect.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The interpretation of a clinical trial depends on more than the treatment groups and the observed counts. The analysis plan determines which participants contribute to each outcome, how outcomes are summarized, which comparisons are emphasized, and how uncertainty is quantified. The registry record describes a randomized parallel-group design and a participant-count primary endpoint, but does not report the statistical plan or a primary endpoint comparison.

What does a participant count represent?

For a binary outcome, each participant is classified according to whether the event occurred within the outcome definition and observation window. A count such as participants with an event is different from a count of event episodes: one participant may have more than one episode but contributes once to a participant-level category, as the endpoint description specifies. The adverse-event listing separates serious events from other events, but the record does not fully explain the construction of every posted category. Those categories should not be combined or relabeled without that detail.

Counts are easiest to interpret alongside their group denominators. A count alone does not indicate how common an outcome was within its group. The registry’s adverse-event information includes counts at risk and counts affected, which allows the group-specific entries to be read descriptively. A formal comparison would still require a defined estimand, a statistical method and an uncertainty measure; none is reported for the primary endpoint in the registry record.

Why does randomization matter, and what does it not guarantee?

In general, random allocation is intended to make treatment groups comparable on average with respect to factors measured and unmeasured before treatment. It supports a causal interpretation when the trial is conducted and analyzed according to a suitable plan. It does not eliminate uncertainty, guarantee that small groups will be balanced, or make unadjusted group counts a substitute for a prespecified analysis. Details of the randomization procedure and any planned adjustments are not reported in the registry record.

Masking can reduce the influence of expectations on participant reporting, clinical care and outcome assessment. The record describes the study as quadruple-masked, but does not identify the masked roles or explain how masking was maintained. It is therefore possible to report the stated design without assigning specific masking procedures to participants, investigators or assessors.

How should uncertainty be understood?

In general, a confidence interval gives a range of values compatible with the data under the statistical model used, and communicates the precision of an estimate. A narrow interval indicates greater precision than a wide interval, while neither interval width nor a point estimate alone establishes clinical importance. No confidence intervals or other uncertainty estimates for the primary outcome are reported in the registry record. The small group denominators make it particularly important not to treat the observed counts as precise estimates of what would occur in a broader population.

A p-value, when used in a defined analysis, describes how unusual data at least as extreme as those observed would be under a specified null model. It does not give the probability that a treatment is effective, nor does it convey the size or importance of an effect. No p-value or corresponding primary-endpoint test is reported in the registry record. There is consequently no basis for a significance claim about the primary outcome.

What does the design say about sample size?

The registry record lists planning-illustration assumptions based on an observed effect: 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 also says that non-time-to-event illustrations are expressed as participants per arm, while time-to-event illustrations use a total event count. These are general planning assumptions, not evidence of the study’s original sample-size justification. The original justification and actual planning calculations are not reported in the registry record. The sample-size illustrations must not be interpreted as observed power or as proof that the study was adequately powered.

Power is a design-stage probability calculated under assumptions about an effect, variability, sample size and analysis. It does not describe the probability that a result is true after data have been observed. When a sample-size illustration is derived from an observed effect, it is especially sensitive to that estimate and is not an independent confirmation of the result. The registry record does not report the underlying efficacy comparison needed to assess such an illustration.

Why can variability and over-dispersion matter?

In general, an analysis model must reflect the type and distribution of the outcome. For participant-level binary outcomes, models may be used to estimate group contrasts while accounting for the chosen design and analysis population. For event counts or repeated observations, variability may exceed what a simple model assumes; this is called over-dispersion. If ignored, model-based standard errors can be too small and uncertainty can be understated. The primary endpoint is described as a count of participants, not a repeated-event rate, and the registry record does not report a model that would permit assessment of over-dispersion.

For outcomes measured repeatedly over time, the analysis must also address within-participant correlation and the handling of visits or missing measurements. The registry record lists secondary outcomes by time point, but does not report the methods used to analyze repeated measurements, define a treatment contrast, or account for missing values.

These statistical concepts explain what readers would need to evaluate a comparative result. They do not fill in absent methods. The registry record does not report an inferential analysis for the primary endpoint, its uncertainty, or a detailed plan for secondary outcomes.

10. Multiplicity, Missing Data and Analysis Populations

The study lists 17 outcome measures, including the primary safety endpoint and secondary measures of pharmacokinetics, disease activity and joint counts. When a study evaluates multiple outcomes, doses, time points or contrasts, the chance of at least one apparently notable result can increase if each is examined without accounting for multiplicity. In general, a prespecified hierarchy or multiplicity adjustment can clarify which findings are confirmatory and how to interpret related tests. The approach used for multiplicity is not reported in the registry record.

The primary endpoint is flagged as involving several categories or time points and is not reduced to one comparison in the posted statistical information. The record reports zero analyses and does not present a primary endpoint test or estimate. It is therefore not possible to determine which comparison was intended as the principal statistical contrast, whether secondary outcomes were exploratory, or whether any adjustment was applied.

Missing-data methods are also not reported in the registry record. The safety population is defined as all randomized participants who received at least one dose of investigational product, analyzed in the group to which they were randomized. That is the population definition stated for safety; it does not establish how missing measurements were handled for other outcomes or whether every randomized participant contributed to every analysis.

In general, missing observations can affect interpretation when the probability of missingness is related to health status, treatment or outcome. Different assumptions and methods can produce different estimates. The registry record does not describe missingness by group, reasons for missing data, imputation procedures, sensitivity analyses, or analysis populations for the secondary outcomes. No specific missing-data strategy should therefore be inferred.

The distinction between the defined safety population and any analysis population for efficacy or pharmacokinetic outcomes is important. The record does not report the latter populations or a complete statistical analysis plan. As a result, multiplicity and missing-data handling cannot be evaluated from the posted information.

11. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: vitreous detachment (12.5%), systemic lupus erythematosus (12.5%), seizure (12.5%), schizoaffective disorder (12.5%), pulmonary embolism (12.5%).

The adverse-event entries give counts of participants affected and counts at risk for named groups. In Part 1, the serious-event counts are 2 of 8 for placebo, 0 of 8 for 0.3 mg QOD, 0 of 8 for 0.3 mg QD, 1 of 9 for 0.6 mg/0.3 mg ALT QD, and 1 of 9 for 0.6 mg QD. The ATEP entries report 0 of 9 for 0.3 mg QD and 4 of 8 for 0.6 mg/0.3 mg ALT QD. No deaths are listed in any group.

These entries are counts, not estimates from a comparative statistical model. The groups are small, and Part 1 and ATEP are listed separately. The registry record does not report a statistical test or uncertainty interval for the serious-event counts, so they cannot establish whether the groups differ reliably. A zero count means no affected participant is listed for that group; it does not establish that the event could never occur.

The listed serious-event terms are vitreous detachment, systemic lupus erythematosus, seizure, schizoaffective disorder, pulmonary embolism and deep vein thrombosis, each with 12.5%. The registry record does not provide enough detail in this listing to assign these terms to particular groups or to determine treatment relatedness. Seriousness is a classification defined by the stated criteria, not a measure of how often an event occurred or proof that treatment caused it.

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

The posted information supports a limited descriptive account of a pilot, randomized, placebo-controlled Phase 2 study in systemic lupus erythematosus. It identifies the treatment schedules, describes a participant-count safety endpoint, and reports adverse-event counts for named Part 1 and ATEP groups. The record lists no deaths in those groups and identifies several serious adverse-event terms.

It does not establish whether CC-220 changed skin, joint or serological manifestations of systemic lupus erythematosus. Although the study purpose refers to those manifestations and the secondary outcome list includes disease-activity and joint-count measures, the registry record does not report a primary efficacy comparison or statistical results for those outcomes. No efficacy conclusion should be drawn from the listed safety counts.

The descriptive counts also do not establish that any adverse event was caused by a study regimen. The endpoint description distinguishes treatment-emergent events from events considered by an investigator to be suspected to be related to investigational product. The posted group counts do not provide a comparative causal estimate. The serious-event terms cannot be attributed to a specific treatment group from the information listed.

In general, a randomized design can support comparisons when results are analyzed with a clear plan and reported with estimates and uncertainty. The registry record does not report the primary-endpoint analysis, confidence intervals, p-values, or analysis methods needed to assess comparative safety. The small denominators also mean that the observed counts alone provide limited precision about event frequencies beyond the participants represented.

The record’s planning assumptions describe sample-size illustrations based on an observed effect, but no resulting estimates are included among the registry entries available for interpretation. Such planning illustrations are not observed power and do not substitute for a reported treatment-effect estimate. The original sample-size justification is not reported in the registry record.

Accordingly, these results can be read as a registry description of trial design and posted adverse-event counts, not as a definitive comparison of treatment benefits or risks. The distinction is between what was recorded for these groups and what a formal analysis could support about differences beyond them.

13. Why This Trial Matters Statistically

This study is statistically notable because it combines several dose schedules with a placebo group and lists an additional ATEP period, while its primary endpoint is a safety count. That structure makes it important to keep treatment groups and study periods distinct. Pooling across doses or periods would require a prespecified rationale and analysis; neither is reported in the registry record.

The endpoint also illustrates a frequent interpretive distinction: a participant-level count is not the same as a count of event episodes, an event rate, or a comparative treatment effect. The registry record defines when an event qualifies as treatment-emergent and specifies that each participant is counted once in each applicable category. Those details inform the meaning of the measure, but do not provide the missing inferential analysis.

With 42 participants enrolled and small denominators in the listed groups, descriptive counts are an important starting point but cannot by themselves provide precise comparative estimates. Randomization is a design feature, not a guarantee that observed differences are meaningful. Uncertainty intervals and a clearly specified comparison would be needed to assess precision; they are not reported for the primary endpoint in the registry record.

The record also names a broad set of outcomes, spanning safety, pharmacokinetics and disease activity. This breadth raises questions about outcome hierarchy, multiplicity, time-point selection and missing-data handling. Those are not minor technical details: they determine how individual results should be interpreted and whether a result was confirmatory or exploratory. The relevant statistical procedures are not reported in the registry record.

Finally, the listed sample-size assumptions are described as planning illustrations based on an observed effect. Such calculations can help explain how assumed effects relate to sample-size planning, but do not demonstrate actual power or validate a treatment effect. The original study justification is not reported. The case therefore highlights the need to distinguish a trial’s design, its descriptive results, and the formal evidence needed for a comparative conclusion.

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 registry record does not report the primary endpoint result as a single comparison or give a statistical test, estimate, confidence interval or p-value. The posted information therefore supports descriptive reading of the adverse-event counts but not a quantified comparative conclusion.

The group denominators are small, and the listed safety information combines distinct Part 1 and ATEP entries. The record does not explain the ATEP abbreviation or provide enough detail to establish how that period relates to the Part 1 randomized comparison. It would be inappropriate to treat all listed entries as one set of parallel randomized arms.

Although the study title and purpose include efficacy questions, the registry record does not report the results for the listed disease-activity, joint-count or pharmacokinetic outcomes. It also does not provide outcome-specific analysis populations, missing-data methods, multiplicity procedures, or the statistical plan. The original sample-size justification is not reported in the registry record.

Details needed to assess trial conduct and generalizability are also not reported in the registry record, including eligibility criteria, baseline characteristics, treatment adherence, the randomization procedure, the roles included in quadruple masking, and reasons for missing observations or discontinuation. These omissions limit assessment of group comparability, outcome completeness and the applicability of the findings beyond the enrolled participants.

The serious-event terms are listed with percentages, but their group attribution and treatment relatedness are not established in the information available. The absence of listed deaths is descriptive and does not resolve uncertainty about other safety outcomes. These limitations are reasons to avoid over-interpreting the posted counts, not evidence that an unreported analysis had a particular result.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Pilot Study of CC-220 to Treat Systemic Lupus Erythematosus. — NCT02185040.
• Registry record last updated 2020-03-19; status last verified 2020-03.
• Results first posted 2020-03-19.
• 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 record describes a completed, randomized, parallel-group, quadruple-masked, placebo-controlled Phase 2 pilot study of CC-220 in systemic lupus erythematosus, with enrollment of 42. Part 1 included placebo and four dose schedules; separate ATEP adverse-event entries are also listed.

The primary endpoint counts participants with treatment-emergent adverse events during Part 1. The registry defines the event window and the safety population. Posted adverse-event counts include serious and other events by group, and no deaths are listed. The record does not report a primary-endpoint statistical comparison, efficacy results, analysis methods, multiplicity procedures or missing-data methods. The reported counts are therefore descriptive rather than a basis for a comparative conclusion.