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 Study in Stabilized Schizophrenic Patients to Evaluate the Pharmacokinetics of Risperidone and 9-Hydroxy (OH)-Risperidone When Risperidone is Administered From a Polyurethane Implant (NCT02658357), a non-randomized phase 2 study. The primary outcome is Area Under the Curve (AUC) for Active Moiety, 9-hydroxy-risperidone and Risperidone.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02658357 |
| Phase | Phase 2 |
| Condition | Schizophrenia, Schizo-affective Disorder |
| Allocation | Non-Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 66 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Braeburn Pharmaceuticals |
| Results posted | Yes |
2. Clinical Question
Population
Stable participants diagnosed with schizophrenia or schizoaffective disorder. The brief summary describes approximately 50 subjects; the registry lists enrollment as 66.
Intervention
Risperidone delivered through polyurethane implants, using either two or three 300 mg implants.
Comparator
The record describes parallel 600 mg and 900 mg groups. Allocation was non-randomized, and the record does not describe a like-for-like control comparison.
Primary question
What is the area under the curve (AUC) for active moiety, 9-hydroxy-risperidone and risperidone over 6 months after implantation?
This is principally a pharmacokinetic question: it concerns drug exposure over time after risperidone is administered from an implant. The registry also lists safety and tolerability as study aims, and identifies safety and efficacy assessed by the Positive and Negative Syndrome Scale (PANSS) as a secondary outcome. However, the registry record states that results are unavailable because the product was sold to another company before data analysis and that company closed before the results were completed. Consequently, it does not report observed AUC values, a comparison between the implant groups, or findings for the secondary outcome. The planned question can be described, but the posted record cannot answer it with estimates of exposure or clinical outcomes.
3. Trial Design
The registry identifies this as a Phase 2 study with a parallel model and non-randomized allocation. Masking is listed as none, and the brief summary calls the study open-label. It was described as a 6-month, multicenter study in stable subjects diagnosed with schizophrenia or schizoaffective disorder. The registry lists enrollment as 66, while the brief summary describes approximately 50 subjects as the intended study population.
The intervention was a risperidone implant. The 600 mg group was described as receiving two 300 mg implants, and the 900 mg group as receiving three 300 mg implants. Because assignment was non-randomized, these groups should not be treated as randomized treatment arms or as a controlled comparison. The registry does not report how participants were assigned to the dose groups or whether other aspects of care differed between them.
The record lists the study as completed. Its start is recorded as 2015-10 and its primary completion as 2017-08. The primary outcome was AUC for active moiety, 9-hydroxy-risperidone and risperidone, with a timeframe of 6 months. Although the registry lists a secondary PANSS outcome, it contains no completed analyses. The record explains that results were not completed after the product was sold and the new company closed. Details of the analysis plan, participant flow, and outcome data 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: The product was sold to another company prior to data analysis. The new company closed before the results were completed, so no results are available for this study
Overall Study
| Stage | 600 mg | 900 mg |
|---|---|---|
| STARTED | 0 | 0 |
| COMPLETED | 0 | 0 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: The product was sold to another company prior to data analysis. The new company closed before the results were completed, so no results are available for this study.
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 product was sold to another company prior to data analysis. The new company closed before the results were completed, so no results are available for this study.
| Characteristic | Unit | 600 mg | 900 mg | Total |
|---|---|---|---|---|
| Participants analysed | 0 | 0 | 0 | |
| Age, Categorical: <=18 years | — | — | — | |
| Age, Categorical: Between 18 and 65 years | — | — | — | |
| Age, Categorical: >=65 years | — | — | — | |
| Sex: Female, Male: Female | — | — | — | |
| Sex: Female, Male: Male | — | — | — | |
| Race (NIH/OMB): American Indian or Alaska Native | — | — | — | |
| Race (NIH/OMB): Asian | — | — | — | |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | — | — | — | |
| Race (NIH/OMB): Black or African American | — | — | — | |
| Race (NIH/OMB): White | — | — | — | |
| Race (NIH/OMB): More than one race | — | — | — | |
| Race (NIH/OMB): Unknown or Not Reported | — | — | — | |
| Region of Enrollment: United States | participants | — | — | — |
6. Primary Endpoint
The registry lists the primary outcome as Area Under the Curve (AUC) for Active Moiety, 9-hydroxy-risperidone and Risperidone, measured over 6 months.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the area under the curve (AUC) for active moiety, 9-hydroxy-risperidone and risperidone, assessed over 6 months. AUC is a measure of drug exposure across a period of time: in general, it represents the accumulated concentration over the measurement interval. Pharmacokinetic studies use measures such as AUC to characterize how much drug is present in the body over time, rather than relying on a single concentration measurement.
The registry does not specify a unit, parameter definition, dispersion measure, or further description for this endpoint. It also provides no reported AUC values, participant-level measurements, or analysis. Therefore, the endpoint’s intended measurement can be explained, but its observed magnitude and precision cannot be assessed from the registry record.
The record names active moiety, 9-hydroxy-risperidone and risperidone in the endpoint title. It does not give further details about how these quantities were combined or analyzed. Such details matter when interpreting a pharmacokinetic endpoint, since the definition of the measured quantity and the timing of measurements determine what an estimate represents. Those specifications are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central interpretive fact is that no primary outcome results are available. The registry explains that the product was sold to another company before data analysis, and that the new company closed before the results were completed. There are no posted AUC estimates for active moiety, 9-hydroxy-risperidone or risperidone. Accordingly, the registry does not show the amount of exposure observed in either implant group, nor the precision of any such estimate.
Without estimates and uncertainty measures, no conclusion can be drawn from this record about differences between the 600 mg and 900 mg groups. The allocation was non-randomized, so even if group results were available, a difference would not automatically represent an effect caused by dose. Participant characteristics or other factors related to assignment could also contribute. The registry does not describe the assignment process or report an adjusted analysis that could address such factors.
The study is described as assessing safety and tolerability, and it lists PANSS as a secondary outcome. However, the record does not report outcome findings for these aims. Its adverse-event entries list zero counts in the displayed categories for both groups; these entries do not supply a complete account of safety results, event definitions, observation time, or participant-level follow-up. They should not be interpreted as evidence that no adverse events occurred.
The registry’s status of completed describes the study status, not the availability or completeness of its results. The available record supports describing the design, intended endpoints and stated reason results are unavailable. It does not support an estimate of treatment effect, a claim about clinical benefit or harm, or an assessment of how precisely the study answered its primary question.
9. Statistical Methods Explained
The record identifies a parallel, non-randomized study with no masking. In a parallel design, participants are assigned to one of the study groups and followed in that group rather than crossing between interventions. This is a general description of the design; the registry does not report the participant-level sequence or the details of follow-up. Non-randomized allocation means that the record does not establish assignment by chance. As a general statistical principle, this can leave group comparisons open to confounding: characteristics connected with group assignment may also be associated with the outcome.
What would an AUC estimate represent?
In general, the area under a concentration-time curve summarizes drug exposure across a defined interval. It depends on measurements taken over time and on how those measurements are combined. AUC is not a direct measure of symptom change or safety. In this study, the named endpoint concerns active moiety, 9-hydroxy-risperidone and risperidone over 6 months. The registry does not give the concentration units, collection schedule, calculation method, or a more detailed definition of the endpoint. It reports no resulting estimates.
How should a group comparison be interpreted?
For a randomized study, random assignment can help balance measured and unmeasured characteristics on average. That protection is not established by this record, which labels allocation non-randomized. In general, a comparison between non-randomized groups should be interpreted with attention to how group membership was determined and whether relevant baseline differences were measured and addressed. The registry does not report the assignment procedure, baseline characteristics, or a statistical adjustment strategy. No causal interpretation of a difference between the implant groups is available from the posted record.
What does uncertainty add?
In general, a confidence interval describes the range of values reasonably compatible with an estimate under the statistical model used. A narrow interval indicates greater precision than a wide interval, while neither one alone resolves design limitations such as confounding. The registry reports no primary estimate or confidence interval. Thus, there is no numerical precision assessment to interpret. A p-value, even if one were reported, would not replace an effect estimate and its uncertainty; no primary analysis or p-value is reported.
What is the role of sample-size calculations?
Sample-size planning generally asks how many participants would be needed to detect a specified effect under stated assumptions about variability, significance level, allocation and statistical model. Such calculations are planning illustrations, not evidence that an effect was observed, and they are not observed power. The registry record does not report the trial’s own sample-size justification or design assumptions. Because outcome estimates are unavailable, there is no observed effect in the record on which to base a recalculation. The record’s sample-size assumptions do not provide a substitute for those missing results or establish that the study was adequately powered.
What can be inferred from the listed analysis information?
The registry lists three outcome measures and no analyses. That absence is consistent with the record’s explanation that results were not completed, but it does not reveal what analyses might have been planned or performed. The statistical plan, including any model, covariate adjustment, handling of repeated measurements, or approach to missing observations, is not reported in the registry record. Without those details and the underlying results, neither the analysis nor its assumptions can be evaluated.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary pharmacokinetic outcome and a secondary outcome assessing safety and efficacy with PANSS. It also names active moiety, 9-hydroxy-risperidone and risperidone in the primary endpoint. The record does not explain whether these were treated as separate endpoints, combined measures, or components of one analysis. It does not report a multiplicity strategy, such as how inference across multiple outcomes or comparisons would be controlled. These statistical-plan details are not reported in the registry record.
Missing-data methods and analysis populations are also not described. The record does not state how many participants contributed measurements to each outcome, whether all enrolled participants were included in any analysis, how incomplete follow-up was handled, or whether measurements were excluded. No imputation method or sensitivity analysis is reported. These omissions are particularly relevant to a longitudinal pharmacokinetic endpoint, for which the timing and completeness of measurements can affect the estimate.
The record lists enrollment as 66, but does not provide participant flow or outcome-specific denominators. It would therefore be inappropriate to infer how many participants completed follow-up or contributed to an analysis. Since no outcome analyses are posted, the effects of missing observations and multiplicity on estimates cannot be assessed. The registry states that results were not completed after the product was sold and the new company closed; further detail about whether any analyses were attempted is not reported in the registry record.
11. What the Result Does, and Does Not, Mean
The registry record establishes that a Phase 2 study was designed to examine risperidone exposure after implantation in stable participants with schizophrenia or schizoaffective disorder. It specifies two implant-dose groups, a 6-month primary timeframe, and a secondary PANSS outcome. It also states that the study was completed and explains why results were not completed for posting.
These registry entries describe the study’s question and design; they do not provide evidence about the observed pharmacokinetic profile, symptoms, safety, or comparative effects of the two implant regimens. No AUC estimates, uncertainty intervals, or completed outcome analyses are available. The registry’s zero entries in adverse-event categories cannot establish that no events occurred or that safety was assessed comprehensively.
More generally, a study’s completion status is distinct from having interpretable outcome results. Likewise, enrollment information alone does not show whether an endpoint was measured successfully or with adequate precision. Since allocation was non-randomized, any eventual group difference would also require cautious interpretation regarding confounding; the posted record does not provide data or methods with which to evaluate that issue.
The appropriate reading is therefore limited: the record describes intended pharmacokinetic and secondary clinical assessments, but it does not report the findings needed to answer them. It cannot support a conclusion that either dose produced a particular exposure, that one group differed from the other, or that the implant did or did not affect clinical outcomes.
12. Why This Trial Matters Statistically
This trial is statistically informative as an example of the distinction between a registered research question and an answerable result. The record gives a defined pharmacokinetic objective and a parallel comparison of two implant doses, yet it provides no outcome estimates. Without those estimates, readers cannot judge either the magnitude of exposure or its precision. A completed study status does not fill that evidentiary gap.
The non-randomized allocation is also important. In general, comparing groups that were not assigned at random requires information about how participants entered each group and how potential confounders were handled. The registry does not report these details. Thus, even a reported difference would need design-aware interpretation; the available record does not reach that stage because the results are absent.
The record additionally illustrates why endpoint definitions and analysis details matter. AUC summarizes exposure over time, but measurement schedules, calculation choices, and handling of incomplete observations affect interpretation. Those methodological details are not reported. The PANSS secondary outcome is named, but no findings or analyses are available for it.
For clinical researchers and biostatisticians, the practical lesson is that registration details can clarify what a trial intended to study while leaving its empirical question unanswered. Transparent reporting of estimates, uncertainty, participant flow, and analysis methods is necessary to assess what the data show. In this case, those results were not completed in the registry record.
13. 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 consequential limitation is the absence of completed results. The registry explicitly states that no results are available because the product was sold before data analysis and the new company closed before results were completed. There are no primary AUC values, uncertainty estimates, or analyses for the secondary PANSS outcome. This prevents assessment of the endpoint’s observed magnitude and precision.
The design information also limits interpretation. Allocation was non-randomized and masking was none; the brief summary describes an open-label study. The registry does not report how participants entered the 600 mg or 900 mg groups, nor does it provide baseline characteristics or adjustment methods. It is therefore not possible to assess comparability between groups or the potential influence of confounding.
Further endpoint and analysis details are not reported in the registry record. These include measurement units and schedule, the detailed AUC calculation, analysis populations, missing-data procedures, and the statistical plan. Participant flow and outcome-specific denominators are also absent, so enrollment cannot be equated with the number contributing to any endpoint.
The adverse-event entries list zeros for the displayed categories, but no fuller safety account or event definitions are reported. Those entries do not resolve the lack of completed safety results. The record also gives no sample-size justification or interim-analysis information. Consequently, the study’s planned precision and any monitoring or analysis decisions cannot be evaluated.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: Study in Stabilized Schizophrenic Patients to Evaluate the Pharmacokinetics of Risperidone and 9-Hydroxy (OH)-Risperidone When Risperidone is Administered From a Polyurethane Implant — NCT02658357.
- Registry record last updated 2020-02-19; status last verified 2020-02.
- Results first posted 2020-02-19.
- 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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17. Record Summary
NCT02658357 is a completed Phase 2, multicenter study of risperidone implants in stable participants with schizophrenia or schizoaffective disorder. The brief summary describes an open-label study lasting 6 months. The registry lists enrollment as 66 and describes two parallel, non-randomized groups: 600 mg as two 300 mg implants, and 900 mg as three 300 mg implants.
The primary outcome was AUC for active moiety, 9-hydroxy-risperidone and risperidone over 6 months. A secondary outcome assessed safety and efficacy using PANSS. The record reports no completed analyses or outcome results. It explains that the product was sold before data analysis and the new company closed before results were completed. As a result, the registry describes the study design and objectives but does not provide estimates with which to assess the primary or secondary outcomes.