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 Safety and Efficacy of NBI-98854 in Pediatric Subjects With Tourette Syndrome (NCT03530293), a randomized phase 2 study. The primary outcome is Time to Loss of Treatment Response.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03530293 |
| Phase | Phase 2 |
| Condition | Tourette Syndrome |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 81 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Neurocrine Biosciences |
| Results posted | Yes |
2. Clinical Question
Population
Pediatric subjects with Tourette syndrome were enrolled. The registry lists 81 participants overall. For the primary endpoint, the full analysis set included randomized subjects with at least one post-randomization visit at which loss of treatment response could be assessed.
Intervention
Valbenazine was given once daily before randomization, with randomization occurring at Week 8, 10, or 12. Participants assigned to randomized valbenazine continued their optimized once-daily dose through Week 36.
Comparator
Participants assigned to randomized placebo received a matching placebo once daily from randomization through Week 36. Both randomized groups had 26 participants listed for the primary endpoint.
Primary question
The primary question was how long it took after randomization for participants to meet the study definition of loss of treatment response, comparing continued valbenazine with withdrawal to placebo. The median time and its confidence interval were not calculable because the incidence of loss-of-response events was low.
This design asks about maintenance of response during a withdrawal period, rather than comparing initial treatment with no prior treatment. All randomized participants had received valbenazine before assignment to continue valbenazine or switch to placebo. Randomization therefore distinguishes the two post-randomization strategies within this study sequence; it does not make the groups equivalent to treatment-naive populations.
The primary question was evaluated from randomization, which could occur at Week 8, 10, or 12, through Week 36. The endpoint combined symptom-scale changes with certain discontinuations. Because the central time-to-event result could not be calculated, the registry record does not establish a numerical median comparison between the randomized groups. The posted secondary results describe changes on two scales at the 8-weeks-post-randomization timepoint, but those outcomes are distinct from the primary endpoint and should not be treated as substitutes for it.
3. Trial Design
The registry describes a Phase 2, randomized, parallel-group, placebo-controlled withdrawal study. Its official title calls it double-blind; the registry's masking classification is triple. The record does not explain the masking terminology further. The study was sponsored by Neurocrine Biosciences and lists Tourette syndrome as its condition.
Participants received valbenazine once daily before randomization for up to 12 weeks, depending on if and when randomization occurred. Randomization took place at Week 8, 10, or 12. Participants then received either their optimized valbenazine dose or matching placebo once daily through Week 36. The randomized groups listed for the primary endpoint each contained 26 participants. The registry lists 81 enrolled overall; the pre-randomization valbenazine safety group includes 80 participants at risk. These counts refer to different stages or analysis groups and should not be treated as interchangeable.
The record lists the study as terminated and gives a primary completion date of 2019-07-16. The reason for termination is not reported in the registry record. Nor is a detailed account of how termination affected recruitment, follow-up, or the planned analyses reported in the registry record.
The design is a randomized withdrawal study: initial treatment preceded random assignment, after which one group continued valbenazine and the other received placebo. This setup focuses the randomized comparison on the period after assignment. It does not by itself establish why participants were randomized at different weeks, what dose each participant received, or whether any specific response threshold was required before randomization; those details are not reported in the registry record. The arm description gives dose starting rules but its stated maximum is incomplete, so the maximum dose is 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: At the end of Weeks 8, 10, or 12, treatment responders (sufficient control of tic behaviors based on investigator assessment) were randomized in a 1:1 ratio to placebo or valbenazine. Randomization was stratified based on the subject's weight group at baseline (\<50 kg versus ≥50 kg). The visit week when subjects were randomized was blinded. At Week 12 all nonresponders were discontinued.
Pre-randomization
| Stage | Pre-randomization Valbenazine | Randomized Placebo | Randomized Valbenazine |
|---|---|---|---|
| STARTED | 81 | 0 | 0 |
| Safety Analysis Set | 80 | 0 | 0 |
| COMPLETED | 57 | 0 | 0 |
| NOT COMPLETED | 24 | 0 | 0 |
Reasons for not completing this period:
| Reason | Pre-randomization Valbenazine | Randomized Placebo | Randomized Valbenazine |
|---|---|---|---|
| Adverse Event | 12 | 0 | 0 |
| Protocol Violation | 2 | 0 | 0 |
| Study Terminated by Sponsor | 5 | 0 | 0 |
| Withdrawal by Subject | 5 | 0 | 0 |
Randomized Withdrawal Period / Follow-up
| Stage | Pre-randomization Valbenazine | Randomized Placebo | Randomized Valbenazine |
|---|---|---|---|
| STARTED | 0 | 26 | 26 |
| COMPLETED | 0 | 9 | 9 |
| NOT COMPLETED | 0 | 17 | 17 |
Reasons for not completing this period:
| Reason | Pre-randomization Valbenazine | Randomized Placebo | Randomized Valbenazine |
|---|---|---|---|
| Adverse Event | 0 | 2 | 4 |
| Protocol Violation | 0 | 0 | 1 |
| Withdrawal by Subject | 0 | 3 | 2 |
| Lack of Efficacy | 0 | 2 | 0 |
| Study Terminated by Sponsor | 0 | 10 | 10 |
Analysis population for the primary outcome, as defined in the registry: The full analysis set includes all subjects who were randomized to a treatment group and had at least one post-randomization visit where loss of treatment response was able to be assessed.
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: The full analysis set includes all subjects who were randomized to a treatment group and had at least one post-randomization visit where loss of treatment response was able to be assessed.
| Characteristic | Unit | Randomized Placebo | Randomized Valbenazine | Total |
|---|---|---|---|---|
| Participants analysed | 26 | 26 | 52 | |
| Age, Continuous | years | 12.7 (SD 2.7) | 12.8 (SD 3.1) | 12.8 (SD 2.9) |
| Sex: Female, Male: Female | Participants | 5 | 2 | 7 |
| Sex: Female, Male: Male | Participants | 21 | 24 | 45 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 8 | 6 | 14 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 18 | 20 | 38 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 1 | 0 | 1 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 2 | 0 | 2 |
| Race (NIH/OMB): White | Participants | 22 | 24 | 46 |
| Race (NIH/OMB): More than one race | Participants | 0 | 1 | 1 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 1 | 1 | 2 |
6. Primary Endpoint
The registry lists the primary outcome as Time to Loss of Treatment Response, measured over Randomization (Week 8, 10 or 12) through Week 36.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | 95% Confidence Interval |
| Unit | Days |
| Endpoint classification | Time-to-Event Analysis |
The primary endpoint was time to loss of treatment response, measured in days from randomization at Week 8, 10, or 12 through Week 36. The purpose of a time-to-event endpoint is to describe not only whether a defined event occurred, but also when it occurred during follow-up. A median time can summarize the point by which half of an analysis population has experienced the event, when the data permit that estimate. A confidence interval describes uncertainty around an estimate.
Loss of response was defined using a composite rule. It required two consecutive visits with both a YGTSS Total Tic Score increase of greater than 35% or 7 points from the randomized-withdrawal baseline, and a CGI-Tics-Severity score increase of at least 2 points from that baseline. Alternatively, discontinuation because of lack of efficacy or a treatment-emergent adverse event involving worsening of tics also counted as loss of response.
The registry states that median and quartile Kaplan-Meier estimates could not be calculated because the incidence of loss-of-response events was low. Consequently, it does not provide a median time or 95% confidence interval for either randomized group. This is an absence of an estimable summary, not evidence that the event never occurred or that the groups had identical event timing. The endpoint remains clinically interpretable as the planned measure, but the posted record does not quantify its between-group contrast.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central result is that the registry could not calculate the primary endpoint's median time to loss of treatment response or its confidence interval. The stated reason is the low incidence of loss-of-response events. The randomized groups each list 26 participants for this outcome, but the record does not give an estimated median or a numerical comparison between those groups. It is therefore not possible to use the primary endpoint to describe the size or precision of a difference in time to loss of response.
This limitation matters because the primary outcome was a time-to-event measure, not a simple endpoint score at a single visit. A low event incidence can leave too little event information to estimate a median or its uncertainty, even when participants were assigned to groups and followed over time. The record does not report event counts by randomized group, so the extent of event scarcity within each group cannot be assessed from the posted results. It also does not report a hazard ratio for the primary comparison.
Two secondary outcomes have posted numerical summaries at 8 weeks after randomization. For YGTSS TTS, the least-squares mean change was 3.8 in the randomized placebo group and -1.0 in the randomized valbenazine group. The recalculated unadjusted mean difference was -4.8, with a 95% confidence interval from -9.376 to -0.224 and an unadjusted p-value of 0.04. For CGI-Tics-Severity, the least-squares mean change was 0.7 in the randomized placebo group and -0.1 in the randomized valbenazine group. The recalculated unadjusted mean difference was -0.8, with a 95% confidence interval from -1.354 to -0.246 and an unadjusted p-value of 0.005. These are secondary, unadjusted comparisons, not estimates of the primary time-to-event contrast.
The confidence intervals for these recalculated differences do not include zero, but that observation does not resolve the primary endpoint's lack of an estimable result. The p-values are unadjusted; the registry record does not report whether or how multiplicity was addressed. The posted summaries also do not describe the full analysis model or provide sponsor-reported analysis entries for these outcomes. Interpret them as limited numerical evidence from secondary outcomes, with uncertainty and analysis-plan details not fully documented in the registry record.
The trial's terminated status is relevant context, but its reason and statistical consequences are not reported in the registry record. The reported results support describing what was numerically posted and what could not be estimated. They do not support a definitive conclusion about the primary endpoint or a broad claim about treatment effect.
9. Statistical Methods Explained
What does a time-to-event endpoint describe?
In general, time-to-event methods account for the time until a defined event, rather than reducing follow-up to a single measurement at a fixed visit. The event must be defined in advance so the analysis has a consistent rule for deciding when it occurred. In this study, the event was loss of treatment response, assessed from randomization through Week 36 using symptom-scale changes or specified discontinuations. The time origin was randomization, which could occur at Week 8, 10, or 12.
Kaplan-Meier methods generally estimate the probability of remaining event-free over time and can be used to derive a median event time when enough events occur. A median is the time by which the estimated event-free proportion reaches the relevant midpoint. If events are uncommon, that point may not be reached during observed follow-up, or estimates may otherwise be too unstable to report. The registry specifically says the median and quartile Kaplan-Meier estimates could not be calculated because of the low incidence of loss-of-response events. It does not give the event counts, group-specific survival estimates, or a hazard ratio.
How should the primary result be read?
The absence of an estimable median is not the same as a median of zero, an infinite median, or proof that there was no difference. It means the registry does not provide the requested estimate. A confidence interval cannot describe precision when the underlying median estimate was not calculable. Readers should therefore distinguish a missing or non-estimable primary summary from a measured result showing no effect. The record does not provide enough primary-endpoint data to quantify the between-group time difference.
What does a confidence interval communicate?
In general, a confidence interval gives a range of values compatible with an estimate under the assumptions of the analysis. It conveys uncertainty as well as direction and magnitude; it is not a guarantee that the true value lies within the particular interval. For the two posted secondary comparisons, the intervals are attached to recalculated unadjusted mean differences. They do not represent the unavailable primary endpoint, and they do not account for any multiplicity adjustment. The registry record does not include sponsor-reported analysis entries for these secondary results.
What do the secondary mean differences represent?
The posted secondary summaries are least-squares mean changes from randomization baseline to 8 weeks after randomization. A mean difference compares the randomized valbenazine group's change with the randomized placebo group's change, with the placebo group as the reference. The displayed recalculated differences are simple unadjusted calculations from the posted group summaries. They should not be confused with a model-adjusted sponsor estimate. The record does not supply details of an analysis model that would allow an adjusted result to be described.
The standard errors attached to the least-squares means describe uncertainty in those means. They are not standard deviations of individual participant outcomes. The recalculated intervals use an approximate pooled standard deviation derived from the posted standard errors, as marked in the statistical calculation. This is a simplifying approach; it does not reconstruct the study's original analysis plan. The record does not report whether the sponsor used a different model, covariate adjustment, or missing-data procedure for these endpoints.
Why does low event incidence matter?
In general, time-to-event precision depends substantially on the number of events, not only on the number of enrolled participants. When few events occur, there is limited information to distinguish event-time patterns between groups. This can prevent calculation of a median and leave a comparison imprecise or unavailable. The record attributes the uncalculated primary summaries to low event incidence, but it does not report group-specific event counts or additional analyses intended to address that limitation.
How should the planning illustrations be understood?
The planning illustrations use observed secondary effect estimates to show participant counts per arm under stated assumptions: a two-sided significance level of 0.05, equal allocation, and a normal approximation. Rows planning for 100%, 75%, or 50% of the observed effect are hypothetical scenarios, not observed trial results. These illustrations are not the trial's original sample-size justification, and they are not observed power. The trial's own sample-size assumptions and justification are not reported in the registry record. Because the primary endpoint is time-to-event and its event incidence was low, continuous-outcome planning illustrations should not be mistaken for planning estimates for the primary endpoint.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists multiple outcomes and assessment times, while numerical results are posted for two secondary outcomes at the 8-weeks-post-randomization timepoint. Whether the study prespecified a hierarchy of outcomes, controlled the family-wise error rate, or used another multiplicity approach is not reported in the registry record. Because the secondary p-values are unadjusted, they should not be interpreted as if they were protected from the increased false-positive risk that can arise when multiple comparisons are considered.
Missing-data handling is also not reported in the registry record. The record does not describe how participants with incomplete visits were handled in the secondary analyses, whether any imputation was used, or whether sensitivity analyses assessed alternative assumptions. The primary endpoint's analysis population is described as randomized subjects with at least one post-randomization visit at which loss of response could be assessed. That definition does not by itself explain how incomplete event information was handled.
The registry states that the primary median and quartile Kaplan-Meier estimates could not be calculated because of low event incidence. It does not report group-specific event counts, censoring summaries, or a hazard ratio. The results record lists no sponsor-reported analysis entries. The full statistical analysis plan, including any interim analysis plan or decision rules, is not reported in the registry record.
The overall enrollment is 81, while the primary outcome lists 26 participants in each randomized group and the pre-randomization safety group lists 80 at risk. These figures correspond to different trial stages or outcome sets; the registry does not provide a full accounting of all participants through randomization and follow-up. The reason for termination and any effect on missingness or analysis populations are not reported in the registry record. These gaps limit assessment of whether observed secondary data represent the planned analysis populations and how robust the estimates are to incomplete follow-up.
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 |
|---|---|---|---|
| Pre-randomization Valbenazine | 1 | 80 | 1.2% |
| Randomized Placebo | 2 | 26 | 7.7% |
| Randomized Valbenazine | 2 | 26 | 7.7% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Pre-randomization Valbenazine | 0 of 80 |
| Randomized Placebo | 0 of 26 |
| Randomized Valbenazine | 0 of 26 |
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 |
|---|---|
| Pre-randomization Valbenazine | 41 of 80 |
| Randomized Placebo | 12 of 26 |
| Randomized Valbenazine | 14 of 26 |
Most frequent serious adverse event terms
| Event term | Organ system | Pre-randomization Valbenazine | Randomized Placebo | Randomized Valbenazine |
|---|---|---|---|---|
| Enterovirus infection | Infections and infestations | 1 of 80 | 0 of 26 | 0 of 26 |
| Akathisia | Nervous system disorders | 0 of 80 | 0 of 26 | 1 of 26 |
| Tic | Psychiatric disorders | 0 of 80 | 0 of 26 | 1 of 26 |
| Obsessive-compulsive disorder | Psychiatric disorders | 0 of 80 | 1 of 26 | 0 of 26 |
| Tourette's disorder | Congenital, familial and genetic disorders | 0 of 80 | 1 of 26 | 0 of 26 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Pre-randomization Valbenazine | Randomized Placebo | Randomized Valbenazine |
|---|---|---|---|---|
| Somnolence | Nervous system disorders | 20 of 80 | 0 of 26 | 1 of 26 |
| Irritability | General disorders | 6 of 80 | 4 of 26 | 4 of 26 |
| Headache | Nervous system disorders | 9 of 80 | 3 of 26 | 2 of 26 |
| Fatigue | General disorders | 10 of 80 | 1 of 26 | 0 of 26 |
| Nausea | Gastrointestinal disorders | 4 of 80 | 1 of 26 | 4 of 26 |
| Nasal congestion | Respiratory, thoracic and mediastinal disorders | 7 of 80 | 1 of 26 | 1 of 26 |
| Vomiting | Gastrointestinal disorders | 4 of 80 | 0 of 26 | 3 of 26 |
| Insomnia | Psychiatric disorders | 5 of 80 | 2 of 26 | 0 of 26 |
| Weight increased | Investigations | 6 of 80 | 0 of 26 | 0 of 26 |
| Decreased appetite | Metabolism and nutrition disorders | 2 of 80 | 2 of 26 | 1 of 26 |
Serious events with the highest arm-level rate: akathisia (3.8%), tic (3.8%), obsessive-compulsive disorder (3.8%), tourette's disorder (3.8%), enterovirus infection (1.2%).
The adverse-event record separates the pre-randomization valbenazine period from the two randomized groups. In the pre-randomization group, 80 participants were at risk for serious adverse events and 1 was affected; 80 were at risk for other adverse events and 41 were affected. In each randomized group, 26 participants were at risk for serious adverse events, with 2 affected in the placebo group and 2 in the valbenazine group. Other adverse events affected 12 of 26 participants in the placebo group and 14 of 26 in the valbenazine group. No deaths are listed in any of the three groups.
These are group-level counts from different treatment periods, not a direct randomized comparison across the entire study. The pre-randomization group includes participants before random assignment, so it should not be combined with or treated as equivalent to either randomized arm. The record lists several serious-event terms and percentages, including Akathisia, Tic, Obsessive-compulsive disorder, Tourette's disorder, and Enterovirus infection. Those terms and percentages describe the posted serious-event listings; they do not establish causation or comparative risk.
Adverse-event counts alone do not show severity, duration, relatedness, or the timing of events. Further detail on those aspects is not reported in the registry record. The figures are descriptive and should be read alongside the study's different treatment periods and group definitions.
12. What the Result Does, and Does Not, Mean
The primary endpoint was intended to quantify the time from randomization to loss of treatment response. The registry does not provide an estimable median or confidence interval for either randomized group because loss-of-response events were infrequent. As a result, the posted record does not establish a numerical primary comparison. It does not demonstrate that the groups had equal event times, nor does it demonstrate a difference in those times.
The secondary summaries describe changes at 8 weeks after randomization on two scales. Their recalculated unadjusted mean differences and confidence intervals are numerical findings for those outcomes and timepoint only. They do not replace the primary endpoint. Since adjustment for multiple comparisons and the sponsor's detailed analysis methods are not reported in the registry record, the secondary comparisons should be interpreted cautiously rather than as definitive evidence.
The randomized withdrawal structure means the randomized comparison concerns participants who had already received valbenazine before assignment to continued valbenazine or placebo. The results should not be generalized automatically to people who have not received prior treatment, to different treatment durations, or to other populations. The registry identifies pediatric subjects with Tourette syndrome, but it does not report enough detail to characterize how broadly the enrolled participants represent that population.
The terminated status, incomplete numeric reporting across listed secondary outcomes, and missing details on missing-data handling and multiplicity further constrain interpretation. The reason for termination and its consequences for the analysis are not reported in the registry record. Taken together, the record supports a narrow description: the primary time-to-event summary was not calculable, while selected 8-week secondary summaries were posted. It does not support a broad conclusion about treatment benefit, lack of benefit, or safety beyond the descriptive adverse-event counts.
13. Why This Trial Matters Statistically
This trial illustrates an important distinction in clinical-trial interpretation: the number of participants is not the only determinant of whether a time-to-event endpoint can be estimated. The primary endpoint depended on loss-of-response events. The registry reports low event incidence and says the Kaplan-Meier median and quartiles could not be calculated. Without enough events, a planned endpoint may yield no usable median comparison even when the trial enrolled participants and randomized groups.
It also shows why endpoint definitions matter. Loss of response was not a single score threshold alone: the rule included consecutive visits with changes on both YGTSS TTS and CGI-Tics-Severity, or specified reasons for discontinuation. Such a composite definition affects which observations count as events. Understanding the rule is necessary to understand what the time-to-event summary was intended to represent.
The study further illustrates the difference between primary and secondary evidence. The 8-week secondary outcomes have posted numerical summaries, but they do not answer the same question as time to loss of treatment response. Their unadjusted status and the absence of reported multiplicity procedures limit how strongly they can be interpreted. The Week 36 secondary results are not reported in the registry record, making the outcome pattern over follow-up difficult to evaluate.
Finally, the record's randomized-withdrawal structure is relevant to the comparison being made. Both randomized groups received valbenazine before assignment, so the comparison concerns continuing treatment versus switching to placebo after that shared period. Recognizing this design, alongside the incomplete primary estimate and limited secondary reporting, helps keep statistical conclusions aligned with what the record actually quantifies.
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 primary endpoint lacks its central numerical summaries: the median time and confidence interval could not be calculated. The registry attributes this to low event incidence but does not report event counts by randomized group, group-specific event curves, or a hazard ratio. That prevents assessment of the magnitude, direction, and precision of the primary comparison.
The trial is listed as terminated, but the reason for termination and its effect on recruitment, follow-up, or analysis are not reported in the registry record. Overall enrollment is listed as 81, while safety and randomized outcome groups reflect different counts and stages. A full participant flow from enrollment through randomization and each analysis is not reported in the registry record.
Four secondary outcomes are listed, but numerical results are posted for only two, both at the 8-week timepoint. Week 36 secondary results are not reported in the registry record. The two available comparisons are recalculated and unadjusted; the registry does not supply sponsor-reported analysis entries or enough model detail to verify whether the calculations match a planned analysis. Multiplicity procedures, missing-data methods, sensitivity analyses, and the statistical analysis plan are not reported in the registry record.
The adverse-event figures are descriptive and span a pre-randomization period as well as randomized groups. The record does not provide all details needed to compare event timing, severity, or relatedness. The pre-randomization arm description also ends before stating the maximum dose; that maximum is not reported in the registry record. These limitations restrict both statistical interpretation and the completeness of the clinical record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety and Efficacy of NBI-98854 in Pediatric Subjects With Tourette Syndrome — NCT03530293.
- Registry record last updated 2022-05-17; status last verified 2022-04.
- Results first posted 2022-05-17.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT03530293 is a Phase 2 randomized, parallel-group, placebo-controlled withdrawal study in pediatric subjects with Tourette syndrome. It lists 81 participants overall and compares continued once-daily valbenazine with matching placebo after a pre-randomization valbenazine period. The study is listed as terminated, with primary completion dated 2019-07-16.
The primary endpoint was time to loss of treatment response from randomization through Week 36. Its median and quartile Kaplan-Meier estimates could not be calculated because of low event incidence. Numerical secondary summaries are posted for two 8-week outcomes; results for the listed Week 36 secondary outcomes are not reported in the registry record. The record does not report the reason for termination, multiplicity procedures, or missing-data methods.