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 A Study to Evaluate the Efficacy and Safety of X0002 Spray in Subjects With Osteoarthritis (NCT02067611), a randomized phase 2 study. The primary outcome is To Evaluate the Efficacy of X0002 Spray Compared to Placebo for Relief of Knee Pain in Subjects With Osteoarthritis (OA) of the Knee.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02067611 |
| Phase | Phase 2 |
| Condition | Osteoarthritis of the Knee |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 216 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Lina Xu |
| Results posted | Yes |
2. Clinical Question
The study asked whether X0002 spray, at low, middle, or high dose, could reduce knee pain compared with placebo in adults with clinically symptomatic mild to moderate osteoarthritis of the knee. It also aimed to assess safety and tolerability. The record describes a phase 2, multicenter, randomized, placebo-controlled study, with treatment over 4 weeks.
Population
Adults with clinically symptomatic mild to moderate osteoarthritis of the knee. The registry records an enrollment of 216, but does not report the allocation of participants among the treatment groups.
Intervention
X0002 topical spray, assigned as low dose, middle dose, or high dose, each described as BID. The record does not give the dose amounts.
Comparator
Placebo spray. The primary comparisons were each active dose group against combined placebo.
Primary question
What was the change from baseline in target-knee WOMAC (VAS) pain subscale score after 4 weeks of treatment, and how did that change compare between each X0002 dose group and combined placebo?
The primary question is defined in the registry, but the record does not report a numerical estimate of change or a comparison result. It also records that the X0002 and placebo labels were mixed up and that the data were mixed up totally. This makes it especially important not to interpret any treatment-specific result as established by this record. The study's stated objectives, endpoint definition, and planned analysis describe what investigators intended to assess; they do not establish what the results were.
3. Trial Design
This was a phase 2, multicenter, randomized, parallel-group study comparing X0002 spray with placebo. The registry lists quadruple masking. Its brief description also calls the study double blind, with dose masking. These are the descriptions in the record; it does not explain how the masking labels relate to one another. The trial status is completed, with enrollment of 216. The record does not report how participants were distributed among the groups.
The active treatment was described in low, middle, and high dose groups, each administered BID. Placebo was also described at low, middle, and high dose labels, each BID. The primary comparisons were active Group A, identified as low dose, active Group B, identified as middle dose, and active Group C, identified as high dose, each versus combined placebo. The amounts of the doses, the treatment assignment ratio, and the group-specific enrollment are not reported in the registry record.
The study was intended to evaluate efficacy, safety, tolerability, and pharmacokinetics. The primary efficacy timeframe was 4 weeks of treatment. Listed secondary objectives included joint stiffness, difficulty performing daily activities, safety and tolerability, and pharmacokinetics. The registry records 11 outcome measures but does not give numerical results for the primary endpoint in the information available in the record.
The record contains a material data-quality warning: it states that the X0002 and placebo labels were mixed up and that the data were mixed up totally. It does not explain the scope of the mix-up, identify which entries were affected, or describe a correction. Consequently, design features can be described, but treatment-specific outcome findings cannot be confidently assigned using this record alone.
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.
Overall Study
| Stage | Group A | Group B | Group C |
|---|---|---|---|
| STARTED | 72 | 72 | 72 |
| COMPLETED | 66 | 66 | 68 |
| NOT COMPLETED | 6 | 6 | 4 |
Analysis population for the primary outcome, as defined in the registry: The labels for X0002 and placebo were mixed up, and the data was mixed up totally.
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: In the study, the active drug and placebo were mixed up and we did not have safety and efficacy data and no report at all.
| Characteristic | Unit | X0002+Placebo |
|---|---|---|
| Participants analysed | 216 | |
| Age, Continuous | years | — |
| Sex: Female, Male: Female | Participants | — |
| Sex: Female, Male: Male | Participants | — |
6. Primary Endpoint
The registry lists the primary outcome as To Evaluate the Efficacy of X0002 Spray Compared to Placebo for Relief of Knee Pain in Subjects With Osteoarthritis (OA) of the Knee, measured over 4 weeks of treatment.
| 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 was change from baseline in the WOMAC (VAS) pain subscale score for the target knee at 4 weeks of treatment. WOMAC is the named measure in the registry; the record does not supply the unit, scoring range, or a numerical definition of what constitutes a clinically important change. It also does not report baseline or follow-up scores.
Change from baseline expresses how a participant's measured pain score differs from their starting score over the specified treatment period. Comparing changes between randomized groups is intended to distinguish the pattern in the active-dose groups from the pattern under placebo, while accounting for the baseline pain score in the planned analysis. The registry specifies three primary comparisons: each of the low-, middle-, and high-dose groups against combined placebo.
In general, a patient-reported pain measure can capture symptoms that may not be represented by a laboratory or imaging measure. A prespecified target-knee endpoint also makes clear which joint is being assessed. These are general reasons such measures may be used; they are not evidence that the endpoint changed in this trial.
The record gives the endpoint definition and timeframe, but no treatment estimates, uncertainty intervals, or significance tests. It also warns that treatment labels and data were mixed up. Thus the endpoint's intended meaning is clear, while the size, precision, and treatment attribution of any observed effect are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes the intended question and analysis framework, not the trial's numerical efficacy result. It names change from baseline in target-knee WOMAC (VAS) pain subscale score at 4 weeks as the primary endpoint and describes an ANCOVA model. It does not report group-level changes, between-group estimates, confidence intervals, or p-values. Without those results, the magnitude and precision of any difference cannot be assessed from the record.
The planned contrasts were low-dose X0002 versus combined placebo, middle-dose X0002 versus combined placebo, and high-dose X0002 versus combined placebo. Those are three separate comparisons, not one overall treatment estimate. A result for one contrast would not by itself describe the other dose comparisons. No numerical results for any of these contrasts are reported in the registry record.
The record's data warning is central to interpretation. It states that the X0002 and placebo labels were mixed up and that the data were mixed up totally. The record does not explain whether this refers to treatment assignments, outcome data, or both, nor does it provide a corrected analysis. Accordingly, even a treatment-labeled result elsewhere would require clarification of its provenance before it could be attributed to X0002 or placebo. The present record does not resolve that concern.
In general, an estimate describes the observed difference between groups, while a confidence interval indicates the range of values reasonably compatible with the data and model. A p-value addresses compatibility with a specified null hypothesis under the analysis assumptions; it does not give the size or clinical importance of an effect. These general interpretations cannot be applied to this trial's results because the registry record does not report those statistics.
The registry lists 216 enrolled participants, but does not report group-specific counts or how many contributed to the primary analysis. It also records no analysis entries. These omissions prevent assessment of the amount of information underlying any comparison. The completed status indicates that the study is recorded as completed; it does not substitute for outcome results.
The adverse-event record lists a combined X0002/Placebo group with zero participants at risk and zero reported event counts. Those entries do not establish that no adverse events occurred among trial participants: a group with zero listed at risk does not provide an interpretable safety denominator. The record's stated safety approach was descriptive, and no formal safety analyses were planned. Overall, the posted record supports a description of the design and intended analysis, but not a conclusion about treatment effects or safety outcomes.
9. Statistical Methods Explained
The registry describes an analysis of covariance (ANCOVA) for the primary endpoint. The outcome was change from baseline in target-knee WOMAC (VAS) pain subscale score at 4 weeks of treatment. Treatment was to be included as a fixed class effect, and baseline WOMAC pain subscale score as a covariate. The stated comparisons were each active dose group against combined placebo.
What does ANCOVA do?
In general, ANCOVA models an outcome while accounting for one or more covariates. Here, the recorded plan identifies baseline pain score as a covariate. Adjusting for a baseline measure can account for differences in starting scores when estimating treatment-group comparisons. The model does not turn an observational association into a randomized comparison; randomization is the design feature intended to support comparison of assigned groups. The registry does not report model estimates, standard errors, confidence intervals, or p-values, so the fitted model's results cannot be evaluated from this record.
What does a fixed treatment effect mean?
In general, treating intervention as a fixed class effect means that the model represents the specified treatment categories as distinct groups, rather than treating them as a random sample from a larger set of treatments. The plan names active low-, middle-, and high-dose groups and combined placebo as the comparison group. The record does not state additional model terms, such as site effects, or describe how any other covariates were handled. Those details are not reported in the registry record and should not be inferred.
Why are the contrasts important?
The stated primary comparisons were low-dose X0002 against combined placebo, middle-dose X0002 against combined placebo, and high-dose X0002 against combined placebo. Each contrast answers a dose-specific question. In general, an estimated contrast is a model-based difference between the groups being compared, conditional on the covariates in the model. The record does not report the estimates or clarify whether any adjustment was planned for making multiple comparisons. A plan for three contrasts is not, by itself, evidence that the contrasts were statistically significant or that they had similar results.
What does baseline adjustment add?
In general, including a baseline value as a covariate can improve precision when baseline and follow-up measurements are related, and can account for baseline imbalance. The adjustment depends on the specified model and the available data. The registry identifies the baseline pain score as a covariate but does not provide its distribution, the relationship between baseline and change, or diagnostics for the model. It is therefore possible to explain the role of the planned adjustment, but not to judge whether it worked well in this study.
What is known about safety analysis?
The registry states that safety analyses would be conducted on the SAS and that safety parameters would be listed and summarized using standard descriptive statistics, as appropriate. It also says no formal statistical analyses were planned for safety. The meaning and definition of “SAS” are not reported in the registry record. In general, descriptive summaries characterize recorded events; without a clear analysis population and interpretable denominators, they cannot establish comparative safety. The adverse-event entry lists zero at risk in the combined X0002/Placebo group, so its zero event counts should not be read as evidence of zero events among participants.
What can the registry results support?
The record lists 11 outcome measures but no analysis entries. It does not report a numerical estimate for the primary endpoint, an uncertainty interval, a test result, or the number of participants included in the primary analysis. Therefore, the ANCOVA description is a planned-method description rather than a report of an estimated effect. The record also warns that treatment labels and data were mixed up totally. General statistical interpretation depends on knowing which observations belong to which treatment groups, so this warning prevents confident attribution of results to X0002 or placebo.
In general, a confidence interval conveys uncertainty around an estimated quantity, and wider intervals indicate less precision than narrower intervals. Over-dispersion is a general concern when observed variation exceeds what a statistical model assumes; it can make model-based uncertainty estimates unreliable if not handled appropriately. The registry does not report a confidence interval or dispersion measure for this endpoint, and it does not report a model assessment addressing over-dispersion. These concepts explain what analysts would examine, not what occurred in this trial.
No interim analysis plan, missing-data method, or detailed statistical analysis plan is reported in the registry record. The absence of those details does not show that investigators did or did not use additional procedures outside the information recorded. It limits what can be independently assessed from the registry entry.
10. Multiplicity, Missing Data and Analysis Populations
The primary objective included three comparisons: each X0002 dose group against combined placebo. Whenever several hypotheses are assessed, multiplicity is a statistical consideration. In general, repeated testing can increase the chance of at least one false-positive finding if each test is interpreted without accounting for the family of comparisons. Possible approaches include defining a testing hierarchy or adjusting inference, but the registry record does not state whether any multiplicity procedure was planned. No p-values or estimates are reported, so the practical impact of this omission cannot be evaluated.
The registry does not report how missing primary endpoint measurements were handled. It does not describe imputation, a repeated-measures model, a complete-case analysis, or sensitivity analyses. These are examples of general approaches, not claims about what investigators used. Without the number of participants with endpoint data in each group and the reasons for missingness, the potential influence of missing data cannot be assessed.
The record identifies a safety analysis population using the abbreviation “SAS,” but does not define it. The primary efficacy analysis population is not reported in the registry record. Enrollment is listed as 216, but group allocation and analysis denominators are not given. It is therefore not possible to determine how many enrolled participants contributed to each planned comparison or safety summary.
The record also states that the X0002 and placebo labels were mixed up and that the data were mixed up totally. It does not describe a correction or provide an analysis that resolves the labeling concern. This is a limitation beyond ordinary multiplicity or missing-data uncertainty: treatment attribution itself is unclear in the registry record.
11. What the Result Does, and Does Not, Mean
The record describes a completed phase 2 study designed to compare three X0002 dose groups with placebo for knee pain, with change in WOMAC (VAS) pain subscale score at 4 weeks as the primary endpoint. It identifies ANCOVA as the planned primary analysis and baseline pain score as a covariate. These details explain the question investigators intended to answer.
They do not show whether pain scores changed, how the groups compared, or how precisely any difference was estimated. No numerical primary outcome results, confidence intervals, or p-values are reported in the registry record. The record's count of 11 outcome measures and its completed status do not fill that gap. Without group-specific results and analysis denominators, neither the direction nor the magnitude of a treatment comparison can be described.
The registry's statement that treatment labels and data were mixed up totally further limits interpretation. It does not specify the affected data or document a resolution. Therefore, this record cannot support reliable attribution of any treatment-labeled finding to X0002 or placebo.
The adverse-event entry also needs cautious reading. It lists zero participants at risk and zero event counts for a combined X0002/Placebo group. Because no participants are listed at risk, those entries do not establish that the trial had no adverse events. The registry says safety summaries were to be descriptive and that no formal safety analyses were planned, but it does not provide interpretable group denominators or safety results.
In general, absence of a reported result is not evidence of no effect, and an imprecise estimate is not evidence of equivalence. Neither principle can be applied to infer a trial outcome because the numerical estimates and uncertainty are not reported. The record supports a description of the planned research question and its data-quality limitations, not a conclusion about efficacy or safety.
12. Why This Trial Matters Statistically
This study is statistically notable because its primary question involved multiple dose-specific comparisons against a combined placebo group. That structure makes the interpretation of each contrast and the handling of multiplicity important. The registry identifies the planned contrasts but does not report whether their inference was adjusted or how the results compared across doses.
The planned ANCOVA also illustrates the distinction between a method description and an analysis result. The record names the outcome, treatment effect, baseline covariate, and analysis timeframe. Without estimates, uncertainty measures, analysis denominators, and the fitted-model results, readers cannot assess the size or precision of the comparisons. A detailed analysis plan does not replace reporting of the analysis itself.
Most importantly, the registry explicitly warns that the treatment labels and data were mixed up totally. Sound statistical inference relies not only on an appropriate model but also on correctly identified observations and groups. If treatment attribution is unclear, a treatment contrast cannot be interpreted confidently, regardless of the planned model. The registry does not document how this issue was resolved.
The entry also illustrates why safety counts need denominators. Zero event counts alongside zero participants at risk cannot be interpreted as evidence of no events in the trial. The safety approach was described as descriptive, with no formal statistical analyses planned, and the record does not provide a usable group-specific safety summary.
These points matter for reading a registry record: design, endpoint, and methods can be informative even when results are absent, but they do not establish what the trial found. Here, the design is described in some detail, while the primary efficacy estimates and interpretable safety outcomes are not reported.
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 main trial-specific limitation is the registry's explicit warning that the X0002 and placebo labels were mixed up and that the data were mixed up totally. The record does not clarify which data were affected, whether the problem was corrected, or whether any analysis used corrected assignments. This prevents confident treatment attribution from the registry record.
Numerical results for the primary endpoint are not reported. There are no group-level changes, treatment contrasts, confidence intervals, p-values, or reported analysis denominators. Although the record defines the endpoint and planned ANCOVA, it does not permit assessment of the magnitude or precision of the primary comparison.
Group-specific enrollment is not reported, despite the total enrollment listing of 216. The registry does not define the primary efficacy analysis population or explain the “SAS” designation for safety. It also does not report how missing endpoint data were handled. These omissions limit assessment of the populations underlying the planned efficacy and safety analyses.
The plan identifies three primary comparisons, but a multiplicity strategy is not reported. The registry also does not give the dose amounts, the randomization ratio, or a detailed statistical analysis plan. These details should not be inferred from the study's phase, design, or stated objectives.
For safety, the record lists zero participants at risk and zero event counts in a combined X0002/Placebo group. Those entries do not form an interpretable safety result for the enrolled trial. The registry describes descriptive safety summaries and says no formal statistical analyses were planned, but no usable event summary by treatment group is reported. Taken together, the record supports discussion of intended methods and limitations, but not a reliable estimate of efficacy or safety.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: A Study to Evaluate the Efficacy and Safety of X0002 Spray in Subjects With Osteoarthritis — NCT02067611.
- Registry record last updated 2018-02-07; status last verified 2018-02.
- Results first posted 2018-02-07.
- 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
The registry describes a completed phase 2, multicenter, randomized, parallel-group, placebo-controlled study of X0002 spray in adults with clinically symptomatic mild to moderate knee osteoarthritis. Enrollment is listed as 216. Active treatment groups were low, middle, and high dose, each described as BID; placebo was described at corresponding dose labels.
The primary endpoint was change from baseline in target-knee WOMAC (VAS) pain subscale score after 4 weeks of treatment. ANCOVA was planned, with treatment as a fixed class effect and baseline pain score as a covariate. The planned primary comparisons were each active dose group against combined placebo.
The record does not report numerical primary efficacy results, analysis denominators, or a defined efficacy analysis population. It states that treatment labels and data were mixed up totally. Safety was to be summarized descriptively, with no formal statistical analyses planned, but the recorded adverse-event group has zero participants at risk and is not interpretable as evidence of no events.