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 Extension Study of Cannabidiol (GWP42003-P) in Children and Adults With Dravet or Lennox-Gastaut Syndromes (NCT02224573), a na phase 3 study. The primary outcome is Number of Participants With Any Treatment-emergent Adverse Event (TEAE) Occurring in ≥5% of Participants in Any Treatment Group.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02224573 |
| Phase | Phase 3 |
| Condition | Epilepsy, Dravet Syndrome, Lennox-Gastaut Syndrome |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 681 |
| Arms in the primary outcome | n/a |
| Lead sponsor | GW Research Ltd |
| Results posted | Yes |
2. Clinical Question
Population
Children and adults with inadequately controlled Dravet syndrome or Lennox-Gastaut syndrome who entered an extension study after participating in a core study. The safety analysis set included participants who received at least one dose of the investigational medicinal product.
Intervention
GWP42003-P, cannabidiol (CBD), was the study drug. The registry record does not state the dose or dosing schedule in the information reported for this study.
Comparator
There was no comparator group. The study is described as single-group, open label, and without randomized allocation. The Dravet and Lennox-Gastaut cohorts are not randomized treatment and control groups.
Primary question
The primary endpoint concerns the number of participants with a treatment-emergent adverse event occurring in at least 5% of participants in any treatment group, through Week 260. The registry record does not report the overall result for this endpoint.
The study was an open-label extension focused on safety in children and adults with Dravet or Lennox-Gastaut syndrome. The record’s brief summary also refers to potential antiepileptic effects, and several secondary outcomes concern seizures, quality of life, adaptive behavior, hospitalizations, and cognitive measures. Those stated aims and outcome categories do not by themselves establish what the study found.
For the primary question, the key descriptive information would be how many participants experienced treatment-emergent adverse events and how those events were characterized. The record defines such events as events that started, or worsened in severity or seriousness, after the first dose in this study. Events that continued from a core study were counted as treatment emergent only if they worsened during the extension.
The record reports serious adverse-event counts separately for the two syndrome cohorts, along with counts in an “other” adverse-event category and deaths. It does not give a comparative treatment effect: there is no concurrent untreated or alternative-treatment group, and the cohorts differ by syndrome rather than assigned intervention. These data can describe events recorded during follow-up, but they cannot isolate the effect of cannabidiol from the course of the conditions, prior treatment, or other influences.
3. Trial Design
This was a Phase 3, open-label extension study with a single-group model and no randomized allocation. The intervention was GWP42003-P. The study record identifies children and adults with inadequately controlled Dravet or Lennox-Gastaut syndrome as its intended population, and lists epilepsy, Dravet syndrome, and Lennox-Gastaut syndrome among its conditions.
The registry reports enrollment of 681 participants. The study began on 2015-06-11, reached primary completion on 2020-09-24, and is marked completed. The primary endpoint timeframe extends up to Week 260. These registry dates describe the study record; they do not indicate how long any particular participant was followed.
Because the study was open label, participants and study personnel were not masked to treatment assignment. There was no randomized allocation and no control arm. The Dravet syndrome and Lennox-Gastaut syndrome groups are disease cohorts, not like-for-like treatment groups. Their observed event counts should therefore be read as descriptive information for each cohort, not as a randomized comparison of treatment effects.
The primary endpoint is safety-focused. It counts participants with treatment-emergent adverse events occurring in at least 5% of participants in any treatment group. The record also lists 60 outcome measures, including secondary measures on quality of life, adaptive behavior, epilepsy-related hospitalization, seizure response and duration, and executive-function tasks. Listing an outcome does not mean that its results are reported. The registry record does not provide numerical results for those secondary outcomes in the registry record.
Enrollment alone does not establish the number included in every analysis. The primary outcome’s stated analysis population is the Safety Analysis Set: participants who received at least one dose of the investigational medicinal product. The number of participants contributing to each specific outcome, and the reasons for any differences in analysis populations, are not reported in the registry record.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Before assignment: Participants who completed the double-blind, placebo-controlled, clinical studies with GWP42003-P (Core Studies: GWEP1332A \[NCT02091206\], GWEP1332B \[NCT02091375\], GWEP1424 \[NCT02224703\], GWEP1414 \[NCT02224560\], and GWEP1423 \[NCT02224690\]) were eligible for enrollment.
Treatment Phase
| Stage | Dravet Syndrome | Lennox-Gastaut Syndrome |
|---|---|---|
| STARTED | 315 | 366 |
| COMPLETED | 170 | 243 |
| NOT COMPLETED | 145 | 123 |
Reasons for not completing this period:
| Reason | Dravet Syndrome | Lennox-Gastaut Syndrome |
|---|---|---|
| Caregiver Asked to Stop Investigational Medicinal Product (IMP) | 0 | 1 |
| Started on Other IMP | 1 | 0 |
| Participant Discontinued IMP | 0 | 1 |
| Lack of Efficacy | 15 | 8 |
| Began Commercial Product | 1 | 0 |
| Lack of Efficacy per Participant/Caregiver | 3 | 3 |
| Met Withdrawal Criteria | 5 | 7 |
| Participant Did Not Return for Visits | 0 | 1 |
| Continued Compassionate Use | 1 | 0 |
| Lack of Efficiency | 2 | 1 |
| Participant with Protocol-Excluded Treatment | 0 | 1 |
| Participant Moved | 2 | 0 |
Taper Phase
| Stage | Dravet Syndrome | Lennox-Gastaut Syndrome |
|---|---|---|
| STARTED | 79 | 71 |
| COMPLETED | 76 | 67 |
| NOT COMPLETED | 3 | 4 |
Reasons for not completing this period:
| Reason | Dravet Syndrome | Lennox-Gastaut Syndrome |
|---|---|---|
| Completed Incorrect Number of Taper Days | 1 | 0 |
| Hospitalization/Dose Reduction | 1 | 0 |
| Withdrawn by participants or parent/guardian | 0 | 3 |
| Adverse Event | 1 | 1 |
Analysis population for the primary outcome, as defined in the registry: Safety Analysis Set: all participants who received at least 1 dose of investigational medicinal product (IMP).
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 | Dravet Syndrome | Lennox-Gastaut Syndrome | Total |
|---|---|---|---|---|
| Participants analysed | 315 | 366 | 681 | |
| Age, Continuous | years | 9.737 (SD 4.4434) | 15.906 (SD 9.5392) | 13.053 (SD 8.2120) |
| Age, Customized: Children (2-11 years) | Participants | 216 | 157 | 373 |
| Age, Customized: Adolescents (12-17 years) | Participants | 90 | 89 | 179 |
| Age, Customized: Adults (18-64 years) | Participants | 9 | 120 | 129 |
| Sex: Female, Male: Female | Participants | 159 | 168 | 327 |
| Sex: Female, Male: Male | Participants | 156 | 198 | 354 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 1 | 0 | 1 |
| Race (NIH/OMB): Asian | Participants | 6 | 10 | 16 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 10 | 15 | 25 |
| Race (NIH/OMB): White | Participants | 269 | 325 | 594 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 29 | 16 | 45 |
| Race: White/Caucasian | Participants | 269 | 325 | 594 |
| Race: Black/African American | Participants | 10 | 15 | 25 |
| Race: American Indian/Alaska Native | Participants | 1 | 0 | 1 |
| Race: Asian | Participants | 6 | 10 | 16 |
| Race: Not Applicable (As per country-specific data protection law. | Participants | 15 | 1 | 16 |
| Race: Caucasian/Asian | Participants | 1 | 1 | 2 |
| Race: Hispanic/Caucasian | Participants | 1 | 2 | 3 |
| Race: White and Black Caribbean | Participants | 1 | 0 | 1 |
| Race: Biracial | Participants | 2 | 1 | 3 |
| Race: Caucasian and African American | Participants | 3 | 1 | 4 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Any Treatment-emergent Adverse Event (TEAE) Occurring in ≥5% of Participants in Any Treatment Group, measured over up to Week 260.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint counts participants with any treatment-emergent adverse event occurring in at least 5% of participants in any treatment group, through Week 260. It is a participant count, rather than a measure of event severity, duration, or total number of episodes. A participant may experience more than one event, so a count of participants with an event is not the same as a count of all event occurrences.
The record defines a treatment-emergent event as one that started, or worsened in severity or seriousness, after the first dose in this study. An adverse event continuing from a core study was counted as treatment emergent only if it worsened during the extension. This definition sets a time relationship to treatment exposure; it does not establish that the study drug caused an event.
Safety endpoints of this kind are used to describe the types and frequency of events recorded during treatment and follow-up. The stated threshold focuses the primary endpoint on events that occurred with a specified frequency in a treatment group. The registry record does not report the overall primary-endpoint count or the event-specific results meeting that threshold. It therefore does not permit a numerical reading of the primary endpoint itself from the information.
The registry separately gives serious-event counts for each syndrome cohort. Those counts provide additional safety information, but they are not a substitute for the unreported primary endpoint result: serious events and events meeting a frequency threshold are distinct classifications.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry reports serious adverse events in both syndrome cohorts. In the Dravet syndrome group, 133 of 315 participants were reported as affected by a serious adverse event. In the Lennox-Gastaut syndrome group, the corresponding count was 157 of 366. The record also reports 292 of 315 participants in the Dravet group and 338 of 366 in the Lennox-Gastaut group in the “other” adverse-event category. The meaning of that category beyond its label is not further specified in the information, so it should not be assumed to mean a particular severity class.
The record lists 6 deaths in the Dravet syndrome group and 12 in the Lennox-Gastaut syndrome group. These are counts recorded for the groups; the information reported does not establish the causes of death, their timing in relation to treatment, or whether investigators considered them related to the study drug. A count alone does not answer those questions.
Among the serious adverse-event terms listed, Status epilepticus is reported at 14.9%, Convulsion at 12.0%, Pneumonia at 7.1%, Pyrexia at 5.4%, Pneumonia aspiration at 4.4%, and Vomiting at 3.6%. These are the percentages as presented in the registry information. The denominator and detailed calculation for each percentage are not reported in the registry record, so they should not be converted into participant counts or compared as if their denominators were known.
The study has no randomized comparator. Consequently, the event counts describe what was recorded among participants in an extension study, not the difference between cannabidiol and another treatment or no treatment. The two syndrome cohorts also cannot serve as one another’s controls: they represent different clinical populations and were not assigned to treatment by randomization.
The primary endpoint’s overall result is not reported in the registry record. Nor are confidence intervals, hypothesis tests, or adjusted comparisons reported in the information available. Without those results, the precision of the overall primary endpoint cannot be assessed. The event counts and listed percentages are useful descriptions, but they do not establish how much of the observed event experience is attributable to treatment rather than the underlying conditions, prior treatment, follow-up, or other factors.
The record states that 681 participants were enrolled, while the endpoint population is defined as participants who received at least one dose. The number actually included in the safety analysis is not separately stated in the information. Enrollment should not automatically be treated as the denominator for every endpoint.
9. Statistical Methods Explained
Statistical interpretation depends first on what was measured and how participants entered the study. This was a single-group, open-label extension, not a randomized comparison. The available registry information is primarily descriptive: it reports participant counts for adverse-event categories and percentages for selected serious adverse-event terms. The record lists no analysis entries for inferential results.
What a participant count describes
A count of participants with an event records how many people experienced at least one event in the defined category. It does not count repeated episodes as separate participants. If a person has more than one event, a participant-level count may still include that person once for the category. By contrast, an event count can include multiple occurrences for one participant. Those quantities answer different questions and should not be interchanged.
Counts are most informative when their analysis population and observation period are clear. The primary endpoint specifies the Safety Analysis Set, defined as participants who received at least one dose, and a timeframe up to Week 260. The record does not give the number analyzed for each outcome or participant-level follow-up duration. Thus, enrollment of 681 is not necessarily the denominator for every reported count.
What “treatment-emergent” means
In this record, treatment emergent is a timing and event-classification rule: an adverse event had to start, or worsen in severity or seriousness, after the first dose in the extension. An event that continued from a core study qualified only if it worsened in this study. This rule helps define which events are included in the endpoint. It does not, by itself, establish causation. An event occurring after treatment begins may be related to treatment, the underlying condition, another exposure, or other circumstances.
Why the design limits comparison
Randomization is a general method for allocating participants to groups so that, on average, known and unknown baseline factors are less systematically tied to treatment assignment. This study had no randomized allocation and no control group. Accordingly, it cannot provide a randomized estimate of the difference between treatment and a comparator. The two syndrome cohorts are not interchangeable control groups: cohort membership reflects syndrome, not random treatment assignment.
Open-label means treatment masking was absent. In general, knowledge of treatment can influence reporting, assessment, and decisions about care or event classification. The record does not describe procedures used to mitigate such influences, so no particular safeguard should be assumed.
Percentages and denominators
A percentage is interpretable only alongside its numerator, denominator, and definition. The registry lists percentages for selected serious adverse-event terms, but the relevant denominators and detailed calculation are not stated in the information. Those percentages should therefore be quoted as recorded, without reverse-calculating counts or treating them as directly comparable across terms.
In general, a confidence interval communicates the range of values compatible with the observed data under a specified statistical model and level of confidence. Narrower intervals indicate greater precision, while wider intervals indicate more uncertainty. No confidence intervals for the primary endpoint or the listed serious-event results are reported in the registry information. Their precision therefore cannot be evaluated from these counts alone.
Over-dispersion and count outcomes
For repeated event counts, a statistical model may need to account for over-dispersion: variability greater than a simple model assumes. Over-dispersion matters because a model that understates variability can produce overly narrow intervals or misleading tests. This is a general consideration for count data, not a method reported for this study. The primary endpoint is a count of participants with an event, not a repeated-event rate, and the registry record does not specify an over-dispersion model.
Planning calculations versus trial analysis
The record describes a planning illustration based on an observed effect, using 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. These are assumptions for an illustration, not a report of the study’s own design justification or analysis plan. In particular, equal allocation between two arms does not describe this single-group extension design. Any resulting sample-size figures are planning illustrations, not observed power, and should not be read as evidence that the extension was designed or analyzed as a two-arm trial.
In general, power is a design-stage probability tied to a specified effect, sample size, variability, and analysis. It is not a property that can be read from a result after the fact. No sample-size justification or trial-specific power calculation is reported in the registry record. The registry information also does not specify the analysis model used for the outcomes.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 60 outcome measures, including the primary safety endpoint and secondary measures involving quality of life, adaptive behavior, hospitalization, seizures, and cognitive tasks. When many outcomes are examined, multiplicity is a general statistical concern: the chance of at least one apparently unusual result can increase when many separate tests are conducted. Common approaches include defining a hierarchy of outcomes or adjusting the interpretation or significance threshold. The registry record does not report whether either approach, or another multiplicity strategy, was used.
The record does not report a statistical analysis plan, interim analyses, or the handling of missing outcome data. It also does not state whether missingness was addressed by imputation, complete-case analysis, a model using available observations, or another method. These methods can answer different questions and rely on different assumptions; none should be attributed to this study without a report.
The Safety Analysis Set is defined as participants who received at least one dose of investigational medicinal product. That definition identifies who is eligible for the primary safety analysis, but it does not explain how missing event information, withdrawal, or incomplete follow-up was handled. The number analyzed for each outcome and the amount of missing data are not reported in the registry record.
Because no inferential analysis results are reported, there are no reported p-values or confidence intervals to interpret for the listed outcomes. The absence of these details means that precision, adjustment for multiple outcomes, and sensitivity to missing data cannot be assessed from the registry information.
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 |
|---|---|---|---|
| Dravet Syndrome | 133 | 315 | 42.2% |
| Lennox-Gastaut Syndrome | 157 | 366 | 42.9% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Dravet Syndrome | 6 of 315 |
| Lennox-Gastaut Syndrome | 12 of 366 |
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 |
|---|---|
| Dravet Syndrome | 292 of 315 |
| Lennox-Gastaut Syndrome | 338 of 366 |
Most frequent serious adverse event terms
| Event term | Organ system | Dravet Syndrome | Lennox-Gastaut Syndrome |
|---|---|---|---|
| Status epilepticus | Nervous system disorders | 47 of 315 | 42 of 366 |
| Convulsion | Nervous system disorders | 34 of 315 | 44 of 366 |
| Pneumonia | Infections and infestations | 20 of 315 | 26 of 366 |
| Pyrexia | General disorders | 17 of 315 | 11 of 366 |
| Pneumonia aspiration | Respiratory, thoracic and mediastinal disorders | 4 of 315 | 16 of 366 |
| Aspartate aminotransferase increased | Investigations | 10 of 315 | 6 of 366 |
| Alanine aminotransferase increased | Investigations | 7 of 315 | 7 of 366 |
| Vomiting | Gastrointestinal disorders | 0 of 315 | 13 of 366 |
| Dehydration | Metabolism and nutrition disorders | 6 of 315 | 5 of 366 |
| Acute respiratory failure | Respiratory, thoracic and mediastinal disorders | 1 of 315 | 10 of 366 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Dravet Syndrome | Lennox-Gastaut Syndrome |
|---|---|---|---|
| Diarrhoea | Gastrointestinal disorders | 133 of 315 | 138 of 366 |
| Pyrexia | General disorders | 117 of 315 | 123 of 366 |
| Somnolence | Nervous system disorders | 86 of 315 | 106 of 366 |
| Decreased appetite | Metabolism and nutrition disorders | 99 of 315 | 92 of 366 |
| Convulsion | Nervous system disorders | 60 of 315 | 120 of 366 |
| Upper respiratory tract infection | Infections and infestations | 77 of 315 | 102 of 366 |
| Vomiting | Gastrointestinal disorders | 63 of 315 | 99 of 366 |
| Nasopharyngitis | Infections and infestations | 78 of 315 | 58 of 366 |
| Cough | Respiratory, thoracic and mediastinal disorders | 42 of 315 | 63 of 366 |
| Sinusitis | Infections and infestations | 38 of 315 | 48 of 366 |
Serious events with the highest arm-level rate: status epilepticus (14.9%), convulsion (12.0%), pneumonia (7.1%), pyrexia (5.4%), pneumonia aspiration (4.4%).
The serious adverse-event counts are reported separately by syndrome cohort. In Dravet syndrome, 133 of 315 participants had a serious adverse event; in Lennox-Gastaut syndrome, 157 of 366 did. The record also gives “other” adverse-event counts of 292 of 315 and 338 of 366, respectively. These are participant counts, not counts of every individual event episode.
The registry lists serious-event terms with percentages: Status epilepticus, 14.9%; Convulsion, 12.0%; Pneumonia, 7.1%; Pyrexia, 5.4%; Pneumonia aspiration, 4.4%; and Vomiting, 3.6%. The denominator and calculation details for these percentages are not reported in the registry record. The terms and percentages should therefore be read as reported, without inferring counts or comparing risks across cohorts.
Deaths are recorded as 6 in the Dravet cohort and 12 in the Lennox-Gastaut cohort. The information reported does not specify cause, timing, or attribution to treatment. These safety figures are descriptive observations from an open-label study without a randomized comparator; they do not by themselves estimate a treatment-caused risk.
12. What the Result Does, and Does Not, Mean
The registry record documents a long-term, open-label extension study of GWP42003-P in children and adults with Dravet or Lennox-Gastaut syndrome. It reports serious adverse-event counts by syndrome cohort, counts in another adverse-event category, deaths, and percentages for selected serious-event terms. These observations describe events recorded in the study population.
The record does not report the overall result for the primary endpoint, which concerns participants with treatment-emergent adverse events occurring in at least 5% of participants in any treatment group. It also does not report confidence intervals or inferential tests for the safety counts. Therefore, the precision of the primary endpoint and the uncertainty around the observed counts cannot be quantified from the reported information.
The absence of a control group is central to interpretation. Without random assignment to a comparator, the study cannot distinguish event experience during treatment from what might have occurred over the same period without that treatment or with another treatment. The syndrome cohorts are not substitutes for a control group, because they were not randomized and represent different conditions.
“Treatment-emergent” indicates when an event began or worsened relative to the first dose; it is not equivalent to “caused by treatment.” Likewise, a death recorded in a cohort does not establish its cause or relationship to the study drug. Those interpretations require information not reported in the registry record.
The study’s listed secondary outcomes indicate that seizure-related, quality-of-life, behavioral, and cognitive measures were of interest. Their presence in the outcome list does not show whether the measures improved, worsened, or remained unchanged. Numerical findings for those outcomes are not reported in the information. The responsible conclusion is limited to the design and safety observations actually recorded, rather than a claim about clinical benefit or harm.
13. Why This Trial Matters Statistically
This study illustrates a common statistical distinction between describing outcomes during treatment and estimating a treatment effect. An open-label extension can record longer-term experience among participants who enter and receive the study drug. Without a randomized comparator, however, those observations do not isolate what would have happened under another treatment or without treatment.
The distinction between an event’s timing and its cause is also important. The registry’s treatment-emergent definition identifies events that began or worsened after dosing began. That consistent classification can support safety description, but temporal order alone cannot establish causality. The counts of serious adverse events and deaths therefore need to be interpreted as recorded observations, not as causal effects of the intervention.
The record further shows why denominators, analysis populations, and follow-up matter. Enrollment is 681, while the stated safety population includes participants who received at least one dose. The number analyzed for each endpoint and the details of follow-up are not reported in the information. Without those details, readers should not assume that every count uses all enrolled participants or that participants had equal observation time.
Finally, the record lists many outcome measures but does not report an inferential analysis plan or results for the primary endpoint. In general, multiple outcomes raise questions about how analyses were prioritized and how uncertainty was handled. Here, those methods are not reported, so no multiplicity strategy should be presumed. These limitations do not erase the descriptive safety information; they define what it can and cannot support.
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 overall numerical result for the primary endpoint, its confidence interval, or an inferential comparison. It therefore does not provide a complete quantitative estimate of the primary safety outcome. Although serious-event counts and selected term percentages are listed, denominators for the percentages are not stated in the information.
The study is open label, single group, and nonrandomized. It has no concurrent control arm, so it cannot estimate a comparative treatment effect. The Dravet and Lennox-Gastaut cohorts should not be treated as controls for one another. Differences in their counts may reflect differences between the populations, follow-up, or other factors; the record does not provide a randomized basis for attributing differences to treatment.
The registry gives enrollment as 681 and defines the safety population as participants who received at least one dose, but the number analyzed for each endpoint is not reported. Participant-level follow-up, withdrawals, missing outcome data, and the handling of incomplete observations are also not described in the information reported. These gaps limit interpretation of denominators and precision.
The record lists 60 outcome measures but does not report a multiplicity strategy, detailed analysis methods, or interim analyses. It does not provide the trial’s sample-size justification. The planning illustration described in the record uses assumptions for a two-arm design, unlike this single-group study, and should not be treated as the trial’s own design calculation or as observed power.
Finally, the listed adverse-event counts do not establish causality, and the death counts are not accompanied by causes or attribution. Findings for the listed secondary outcomes are not reported in the information. These are limitations of what the registry record reports, not proof that unreported procedures or analyses did not occur.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: An Open Label Extension Study of Cannabidiol (GWP42003-P) in Children and Adults With Dravet or Lennox-Gastaut Syndromes — NCT02224573.
- Registry record last updated 2022-02-03; status last verified 2022-01.
- Results first posted 2022-02-03.
- 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
NCT02224573 is a completed Phase 3, open-label, single-group extension study of GWP42003-P in children and adults with Dravet or Lennox-Gastaut syndrome. Enrollment was 681. The study began on 2015-06-11, primary completion was 2020-09-24, and the primary endpoint timeframe was up to Week 260.
The primary endpoint concerns participants with treatment-emergent adverse events occurring in at least 5% of participants in any treatment group. The registry record defines the safety population as participants who received at least one dose, but does not report the overall primary endpoint result in the information.
Serious adverse-event counts, other adverse-event counts, deaths, and selected serious-event term percentages are reported by syndrome cohort. The study has no randomized comparator, and its cohorts are not treatment-control groups. Inferential results, missing-data methods, and multiplicity procedures are not reported in the registry information.