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 An Open Label Study of Levetiracetam in Japanese Pediatric Patients With Partial Seizures (NCT01063764), a na phase 3 study. The primary outcome is Change From Baseline in Partial Seizure Frequency Per Week Over the 14-weeks Treatment Period.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01063764 |
| Phase | Phase 3 |
| Condition | Epilepsy, Partial Seizures |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 73 |
| Arms in the primary outcome | n/a |
| Lead sponsor | UCB Japan Co. Ltd. |
| Results posted | Yes |
2. Clinical Question
Population
Japanese pediatric patients aged 4 to 16 years with partial seizures that remained uncontrolled despite treatment with 1 or 2 anti-epileptic drugs. The primary endpoint population is identified as the Full Analysis Set.
Intervention
Levetiracetam dry syrup as adjunctive therapy, at doses up to a maximum of 60 mg/kg/day or 3000 mg/day. The study was open-label and had one treatment group.
Comparator
There was no concurrent comparison group. The registry describes a single-arm study, so the primary endpoint is assessed against baseline rather than against a control treatment.
Primary question
What was the median percentage reduction in partial seizure frequency per week from baseline over the 14-weeks treatment period? The registry record names this endpoint but does not report its numerical result.
The clinical question is therefore about within-participant change in seizure frequency during treatment, not a randomized comparison of levetiracetam with another treatment or with no treatment. Baseline covers Week 0-8; the 14-weeks treatment period includes 4 weeks of up-titration from Week 8-12 and 10 weeks of evaluation from Week 12-22. The endpoint expresses the change as a percentage reduction, with positive values indicating a decrease from baseline.
This framing matters for interpretation. A before-and-after change can describe what happened during the study period among participants included in the analysis, but, without a comparison group, it does not separate treatment effects from other possible explanations for change over time. The registry record gives no numerical endpoint estimate or confidence interval, so the size and precision of the observed change cannot be assessed from the posted results described in the record.
3. Trial Design
This was a Phase 3, open-label, single-group, multicenter study of levetiracetam in Japanese pediatric patients with partial seizures. The registry lists enrollment of 73 and a completed study. The recorded start was 2010-01, and primary completion was 2011-04. Allocation is listed as not applicable, consistent with the single-arm design; masking was none.
Participants received levetiracetam as adjunctive therapy while continuing treatment with 1 or 2 anti-epileptic drugs, according to the study objective. The intervention description identifies levetiracetam dry syrup, with doses up to a maximum of 60 mg/kg/day or 3000 mg/day. The record does not describe a treatment arm receiving placebo, standard care alone, or another active drug as a concurrent control.
The primary endpoint covers change from baseline through the 14-weeks treatment period. Its timeframe identifies baseline as Week 0-8, followed by 4 weeks of up-titration during Week 8-12 and 10 weeks of evaluation during Week 12-22. Other listed outcomes include seizure frequency at different periods, 50% responder measures, seizure-free participant counts, and treatment-emergent adverse drug reactions during a second period. The second-period safety outcome is described as extending up to three years until the time of approval granted; that description does not establish that results for the period were posted.
The registry record does not report further protocol details such as the rationale for the planned enrollment, the precise treatment schedule for individual participants, or interim analyses. No randomized comparison is available, so the study design can describe treatment-period observations but cannot provide a like-for-like estimate against a separate control arm.
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: Participant Flow refers to the Full Analysis Set. First Period started after Baseline (Week 0 to Week 8).
1st Period (From Week 8 to Week 22)
| Stage | Levetiracetam |
|---|---|
| STARTED | 73 |
| COMPLETED | 62 |
| NOT COMPLETED | 11 |
Reasons for not completing this period:
| Reason | Levetiracetam |
|---|---|
| Adverse Event | 4 |
| Lack of Efficacy | 6 |
| Withdrawal by Subject | 1 |
2nd Period (Week 22 to the End of Study)
| Stage | Levetiracetam |
|---|---|
| STARTED | 55 |
| COMPLETED | 35 |
| NOT COMPLETED | 20 |
Reasons for not completing this period:
| Reason | Levetiracetam |
|---|---|
| Adverse Event | 3 |
| Lack of Efficacy | 9 |
| Withdrawal by Subject | 7 |
| Protocol Violation | 1 |
Analysis population for the primary outcome, as defined in the registry: Full Analysis Set (FAS).
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: Baseline Characteristics refer to the Full Analysis Set (FAS). FAS includes all subjects taking at least one dose of study medication.
| Characteristic | Unit | Levetiracetam |
|---|---|---|
| Participants analysed | 73 | |
| Age, Continuous | years | 10.1 (SD 3.4) |
| Sex: Female, Male: Female | Participants | 32 |
| Sex: Female, Male: Male | Participants | 41 |
| Region of Enrollment: Japan | participants | 73 |
| Age Categorical: >=4 - <8 years | participants | 22 |
| Age Categorical: >=8 - <12 years | participants | 22 |
| Age Categorical: >=12 - <16 years | participants | 29 |
| Body Weight | kilogram (kg) | 32.43 (SD 13.20) |
| Height | centimeter (cm) | 134.55 (SD 20.69) |
| Body Mass Index (BMI) | kilogram / meter^2 (kg/m^2) | 17.15 (SD 2.99) |
| Hospitalization Status: Yes | participants | 0 |
| Hospitalization Status: No | participants | 73 |
6. Primary Endpoint
The registry lists the primary outcome as Change From Baseline in Partial Seizure Frequency Per Week Over the 14-weeks Treatment Period, measured over From Baseline (Week 0-8) to the 14-weeks Treatment Period (First Period: 4 weeks Up-titration (Week 8-12) and 10 weeks Evaluation (Week 12-22)); Week 0-22.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | 95% Confidence Interval |
| Unit | Percent reduction |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the change from baseline in partial seizure frequency per week over the 14-weeks treatment period, expressed as a percent reduction. Frequency per week is defined in the registry as the total number of partial seizures during a period divided by the number of observation days in that period, then multiplied by 7. This standardizes the count to a weekly rate when observation periods differ in length.
The percent reduction is defined as (B values- T values) / B values x 100, where B is baseline and T is the treatment-period value. Positive values mean that the value decreased from baseline during the first 14-week Period. The endpoint uses the median, with a 95% Confidence Interval specified as the dispersion measure. The registry record does not report the numerical median or its interval.
Seizure frequency is used to represent seizure burden over time, while a percentage change expresses that change relative to each participant’s baseline level. The median describes the middle of the distribution and can be less influenced by unusually large values than the mean. In general, reporting a confidence interval alongside an estimate helps convey its statistical precision. In this record, however, the endpoint result and interval are not reported in the registry record, so neither the observed magnitude nor its precision can be evaluated.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies a clinically relevant question: whether partial seizure frequency per week changed from baseline during treatment with adjunctive levetiracetam. It defines the primary outcome and the direction of the percentage reduction, but it does not report the numerical primary endpoint estimate. The record also lists no analysis entries. Consequently, the posted information does not establish the observed median change, the confidence interval, or a statistical test result for the primary endpoint.
Positive values under the stated endpoint definition represent a decrease from baseline; negative values would represent an increase. This sign convention helps interpret an estimate when one is available, but it cannot substitute for the missing result. The registry specifies a median and 95% Confidence Interval. In general, the interval describes uncertainty around an estimate under the assumptions of the analysis. Without the numerical interval, readers cannot assess how precisely the change was estimated or whether a range of materially different changes remains compatible with the data.
The endpoint compares participants with their own baseline, not with a concurrent control group. In a single-arm study, a change over time cannot by itself distinguish an effect of treatment from other influences, including natural variation in seizure frequency, changes in background care, or expectations that may affect reporting. These are general interpretive limitations of uncontrolled before-and-after comparisons; the registry record does not say whether or how such influences were assessed.
Enrollment was 73, but that figure alone does not reveal how many participants contributed data to the primary analysis at each time point. The primary population is named as the Full Analysis Set, but its operational definition, the number analyzed, and handling of missing observations are not reported in the registry record. These details affect how directly the endpoint estimate would represent all enrolled participants.
The registry also lists several seizure-related outcomes and safety outcomes. Their presence indicates that the study tracked more than the primary measure, but the record does not give numerical results for those outcomes in the information available for this analysis. The list should not be read as evidence that a particular outcome changed or that a particular safety event occurred beyond the posted safety figures. Nor does the absence of a numerical primary result show that no change occurred. It means the magnitude, precision, and statistical evidence for that endpoint cannot be judged from the registry record.
Any sample-size planning illustration is distinct from an observed trial result. The stated assumptions use a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a fraction of the observed effect. Those are planning assumptions, not a description of this single-arm study’s actual design or an estimate of observed power. They cannot fill the gap left by the unreported primary endpoint result.
9. Statistical Methods Explained
What does the primary measure represent?
The endpoint starts with partial seizure frequency per week at baseline and during the treatment period. The registry defines weekly frequency by dividing the number of partial seizures in a period by observation days and multiplying by 7. This puts seizure counts on a common weekly scale. It then expresses change as a percentage reduction relative to baseline. In general, a relative change can help describe the size of a change in relation to the starting value, but it depends on having a usable baseline value.
The stated calculation is (B values- T values) / B values x 100. Under this convention, positive values indicate a reduction from baseline. The registry says the primary summary is the median, rather than the mean. In general, the median is the central observation when values are ordered and is less sensitive than the mean to very large or very small observations. It does not, by itself, show the full spread of participant-level changes. The registry’s specified 95% Confidence Interval is intended to convey uncertainty around the summary; its numerical limits are not reported in the registry record.
What does a confidence interval add?
In general, a confidence interval is a range calculated by a statistical procedure to represent uncertainty in an estimated quantity. A narrower interval indicates greater precision under the method’s assumptions, while a wider interval indicates less precision. An interval is not a measure of the importance of an effect, and it does not resolve limitations in study design. Here, the interval is named as the dispersion measure, but its endpoints and the estimate it would accompany are not reported in the registry record.
Why does the single-arm design matter?
The study has one open-label treatment group and no concurrent comparator. A within-participant comparison uses each participant’s baseline as a reference, which can be informative about change during follow-up. But baseline is not a randomized control condition. General influences such as natural fluctuation, time trends, and changes in other care can contribute to differences between baseline and treatment. Open-label conduct also means participants and study personnel were not masked to treatment assignment. The registry record does not report procedures that would quantify or remove these influences.
For that reason, the primary measure should be read as a planned or recorded change from baseline, not as a randomized estimate of the treatment’s effect relative to an alternative. The record’s designation of the trial as Phase 3 does not change the implications of its single-group design.
How should the analysis population be understood?
The primary population is identified as the Full Analysis Set. In general, an analysis population specifies which participants contribute to an endpoint and therefore how the estimate is defined. The exact membership rules for this Full Analysis Set, the number included in the primary analysis, and the number with complete observations are not reported in the registry record. Enrollment of 73 should not automatically be treated as the number analyzed at every assessment.
Repeated seizure-frequency measurements may require choices about how to summarize observations across participants and periods. Missing observations can also affect the analysis, depending on why they are missing and how they are handled. The statistical plan for the primary endpoint, including missing-data methods and any adjustment for baseline values beyond the stated percentage calculation, is not reported in the registry record.
What can planning calculations say?
The planning assumptions describe an illustration based on an observed effect, not the trial’s own design. They specify a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect to detect defined as a fraction of the observed effect. General sample-size calculations estimate how many participants might be needed for a prespecified design and assumptions. Such illustrations are not observed power and do not establish that the completed single-arm study had a particular probability of detecting an effect. The registry record does not report the protocol’s sample-size justification or a statistical plan for the study.
What is not available for interpretation?
The record lists 11 outcome measures and no analysis entries. It identifies the primary endpoint’s summary type and dispersion measure, but not a numerical estimate, interval, or test result. Without those results, statistical significance cannot be evaluated and the precision of the estimated change cannot be described. The available design and endpoint definitions explain what was intended to be measured, but they do not establish the outcome of that measurement.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary endpoint and multiple secondary outcomes. Those include seizure frequency over different treatment periods, change from baseline, 50% responder outcomes, seizure-free participant counts, and treatment-emergent adverse drug reactions. The record lists 11 outcome measures in total. When multiple outcomes are examined, the chance of at least one apparently notable result can increase; in general, prespecified testing hierarchies or multiplicity adjustments can address that issue. The registry record does not report whether any such strategy was planned or used.
The primary analysis population is named as the Full Analysis Set. The definition of that population, the number included in the primary analysis, and the number with evaluable observations are not reported in the registry record. The endpoint requires baseline and treatment-period seizure-frequency information, but the record does not describe how missing baseline values, missing follow-up, or incomplete observation periods were handled. It also does not report reasons for missing data or sensitivity analyses.
These omissions matter because the analyzed participants and the handling of incomplete observations can affect an estimate. The registry record’s listing of an analysis population is not enough to establish who contributed data or how missingness was addressed. It also lists no analysis entries, and the numerical primary result is not reported in the registry record. As a result, neither the multiplicity approach nor the robustness of the primary analysis can be assessed from the posted record.
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 |
|---|---|---|---|
| Levetiracetam | 8 | 73 | 11.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Levetiracetam | 66 of 73 |
Most frequent serious adverse event terms
| Event term | Organ system | Levetiracetam |
|---|---|---|
| Gastroenteritis | Infections and infestations | 2 of 73 |
| Convulsion | Nervous system disorders | 2 of 73 |
| Strabismus | Eye disorders | 1 of 73 |
| Abdominal pain lower | Gastrointestinal disorders | 1 of 73 |
| Acetonaemic vomiting | Gastrointestinal disorders | 1 of 73 |
| Dental caries | Gastrointestinal disorders | 1 of 73 |
| Pneumonia | Infections and infestations | 1 of 73 |
| Near drowning | Injury, poisoning and procedural complications | 1 of 73 |
| Status epilepticus | Nervous system disorders | 1 of 73 |
| Conversion disorder | Psychiatric disorders | 1 of 73 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Levetiracetam |
|---|---|---|
| Nasopharyngitis | Infections and infestations | 54 of 73 |
| Somnolence | Nervous system disorders | 34 of 73 |
| Influenza | Infections and infestations | 20 of 73 |
| Pyrexia | General disorders | 17 of 73 |
| Upper respiratory tract infection | Infections and infestations | 12 of 73 |
| Headache | Nervous system disorders | 10 of 73 |
| Diarrhoea | Gastrointestinal disorders | 9 of 73 |
| Contusion | Injury, poisoning and procedural complications | 8 of 73 |
| Gastroenteritis | Infections and infestations | 7 of 73 |
| Convulsion | Nervous system disorders | 7 of 73 |
Serious events with the highest arm-level rate: gastroenteritis (2.7%), convulsion (2.7%), strabismus (1.4%), abdominal pain lower (1.4%), acetonaemic vomiting (1.4%).
The registry’s safety figures list 73 participants at risk for serious adverse events and 8 in the serious adverse-event affected column. For other adverse events, it lists 73 at risk and 66 affected. These are separate registry categories; the figures do not indicate whether participants may appear in both categories. The record lists no death count, so deaths are not reported in the registry record.
The listed serious-event terms and percentages are gastroenteritis, 2.7%; convulsion, 2.7%; strabismus, 1.4%; abdominal pain lower, 1.4%; acetonaemic vomiting, 1.4%; and dental caries, 1.4%. These entries describe the posted terms and percentages. The record does not provide event-level details such as timing, duration, outcome, or whether the event was considered related to levetiracetam. It also does not give counts alongside these percentages in the listed terms.
These figures describe safety observations in an open-label, single-arm study. They cannot establish how the same events would compare with a control group, and the registry record does not report a comparative safety analysis. The listed affected figures should not be interpreted as a complete account of each participant’s clinical course.
12. What the Result Does, and Does Not, Mean
The registry record defines a study of adjunctive levetiracetam in Japanese children with partial seizures and identifies a primary measure of change from baseline in weekly seizure frequency. It also records enrollment of 73 and lists safety observations. These details explain the study question and some of the information collected.
The numerical primary endpoint result is not reported in the registry record. Therefore, the posted information does not show the median percentage reduction, the corresponding 95% Confidence Interval, or a primary statistical test. It is not possible to determine the direction or magnitude of the group’s primary endpoint change from the information recorded. That absence should not be mistaken for evidence that the outcome was unchanged; the result is simply not reported in the registry record.
Even if a before-and-after change were available, the single-arm design would not show how outcomes would have differed under a concurrent control treatment. Open-label conduct and the lack of random allocation to a comparison group limit causal interpretation. The trial can describe observations during treatment, but it cannot make a like-for-like estimate against another treatment from its design alone.
The posted safety figures show that the registry lists 8 participants in the serious-adverse-event affected column and 66 in the other-adverse-event affected column, among 73 at risk in each category. Those figures do not by themselves establish event causation or comparative risk. No death count is reported in the registry record, and details for the listed serious-event terms are limited to the posted percentages.
In short, the record supports a description of the trial’s design, endpoint definition, and listed safety data. It does not provide enough numerical efficacy information to assess the primary result or its precision. It also does not support a randomized comparison or a conclusion about how results would compare with other treatments.
13. Why This Trial Matters Statistically
This trial is statistically instructive because its primary endpoint is a within-participant change, while the design has no concurrent control group. The distinction between describing change over time and estimating a comparative treatment effect is central to interpreting clinical studies. A baseline reference can provide useful context, but it does not reproduce the protection against time trends and other influences that a randomized control group is designed to offer.
The endpoint also illustrates how outcome definitions shape interpretation. Seizure frequency is standardized to a weekly rate, and change is expressed as a percentage reduction relative to baseline. The registry defines positive values as decreases. Those choices clarify the scale and direction of the outcome, while the median gives a summary that is less affected by extreme observations than the mean. The accompanying confidence interval would be important for judging precision, but its numerical result is not reported in the registry record.
Another statistical lesson is that a named endpoint is not the same as a posted result. The record describes the primary measure and the Full Analysis Set, yet does not report the numerical primary estimate or its interval. A reader therefore cannot infer the size, uncertainty, or statistical evidence of the observed change from the endpoint description alone.
Finally, the range of listed secondary outcomes raises questions about multiplicity, analysis populations, and missing observations. Those are not minor technical details: they influence what each result means and how reliably it can be interpreted. The registry record does not describe the corresponding methods. The study is therefore a useful example of why interpretation depends both on the design and on sufficiently detailed reporting of estimates and analysis methods.
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 is its open-label, single-arm design. There is no concurrent control group, and allocation is listed as not applicable. As a result, the registry design cannot support a like-for-like treatment comparison. Any change from baseline may reflect influences other than treatment, and the record does not report methods to distinguish those influences.
The primary endpoint is specified, but its numerical result and 95% Confidence Interval are not reported in the registry record. The record also lists no analysis entries. This prevents assessment of the size, direction, precision, or statistical evidence of the primary endpoint result. Enrollment of 73 does not establish how many participants contributed to that analysis.
The primary analysis population is called the Full Analysis Set, but its definition and the number analyzed are not reported in the registry record. Missing-data rules, sensitivity analyses, and the handling of incomplete seizure observations are also not reported. These details are important for understanding whether the analysis reflects all enrolled participants or a subset with available measurements.
The registry lists multiple secondary outcomes, but the approach to multiplicity is not reported. The record also does not provide detailed methods for outcome ascertainment or the statistical plan. The population is specifically Japanese pediatric patients aged 4 to 16 years with partial seizures despite treatment with 1 or 2 anti-epileptic drugs, so the stated study population is narrower than all people with epilepsy. The registry’s results cannot be assumed to apply beyond the population and setting described.
Finally, listed safety terms and percentages are not accompanied by detailed event narratives or a control group comparison. The record does not report a death count. These reporting limits constrain interpretation of both efficacy and safety observations.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: An Open Label Study of Levetiracetam in Japanese Pediatric Patients With Partial Seizures — NCT01063764.
- Registry record last updated 2015-03-05; status last verified 2015-02.
- Results first posted 2012-06-19.
- 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.
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18. Record Summary
NCT01063764 is a completed Phase 3, open-label, multicenter, single-arm study of adjunctive levetiracetam in Japanese pediatric patients aged 4 to 16 years with partial seizures uncontrolled despite treatment with 1 or 2 anti-epileptic drugs. Enrollment was 73; the recorded start was 2010-01, and primary completion was 2011-04.
The primary endpoint is median percent reduction in partial seizure frequency per week from baseline through the 14-weeks treatment period, with a 95% Confidence Interval specified. The numerical primary result and interval are not reported in the registry record. The record identifies the Full Analysis Set but does not describe its membership rules, missing-data methods, or multiplicity approach.
The safety record lists 8 of 73 in the serious-adverse-event affected column and 66 of 73 in the other-adverse-event affected column. A death count is not reported in the registry record. The single-arm design allows description of treatment-period observations but does not provide a concurrent comparative estimate.