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 Tocilizumab for the Treatment of Behcet's Syndrome (NCT01693653), a randomized phase 2 study. The primary outcome is Primary Outcome.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01693653 |
| Phase | Phase 2 |
| Condition | Behcet Syndrome |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 1 |
| Arms in the primary outcome | n/a |
| Lead sponsor | NYU Langone Health |
| Results posted | Yes |
2. Clinical Question
Population
The planned population was people with active Behcet's syndrome and oral ulcers that had not responded after 4 weeks of conventional treatment. The registry summary specifies a maximum allowable colchicine dose of 0.6mg twice a day, stable for 4 weeks before enrollment. Prednisone or an equivalent treatment at less than 10mg/day was permitted if the dose had been stable for 6 weeks before enrollment. The record does not report the characteristics of any enrolled participant.
Intervention
The intervention was tocilizumab infusion every 4 weeks over 3 months, in addition to participants' current treatments. The summary describes Actemra IV at 8mg/kg every 4 weeks for 3 doses. The record does not report whether any participant received an infusion.
Comparator
The comparator was placebo infusion, described as 0.9% sodium chloride, every 4 weeks over 3 months, also added to current treatments. The registry record does not report a participant-level allocation or whether placebo was administered.
Primary question
The study was intended to investigate the safety and efficacy of tocilizumab for Behcet's syndrome. However, the primary outcome is named only “Primary Outcome”; the record does not describe what it measured. It states that the trial was terminated and no data were collected for this outcome, so the record cannot answer a comparative question about that endpoint.
3. Trial Design
The registry identifies this as a phase 2, randomized, parallel-group trial with an enrollment of 1. Its status is terminated. The planned sample size in the study summary was 30 participants per arm, for a total of 60 participants. The difference between that planned enrollment and the recorded enrollment describes the scale of the trial as registered; it does not establish why recruitment stopped or what happened to any individual participant. The reason for termination is not reported in the registry record.
The planned comparison was tocilizumab added to participants' existing treatment versus placebo added to existing treatment. The summary describes infusions every 4 weeks for 3 months. It also describes a safety follow-up at 2 months after study termination. The primary outcome timeframe is separately listed as 9 months. The registry record does not explain how that timeframe relates to the treatment period and follow-up described in the summary.
The masking classification is “triple,” while the brief summary calls the study double-blind. The registry record does not identify which roles were masked or explain the difference between those descriptions. Allocation is listed as randomized, but details such as the sequence-generation method, concealment procedures, and stratification are not reported in the registry record. These omissions do not show that such procedures were absent; they mean the record does not describe them.
Although the study planned to assess safety as well as efficacy, the trial's termination and the statement that no primary outcome data were collected mean that the intended randomized comparison is not available for interpretation from this record. The record lists secondary outcomes but reports no analyses for them.
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 | Tocilizumab | Placebo |
|---|---|---|
| STARTED | 1 | 0 |
| COMPLETED | 1 | 0 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: The study was terminated. No data were collected for this Outcome Measure.
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 | Tocilizumab | Placebo | Total |
|---|---|---|---|---|
| Participants analysed | 1 | 0 | 1 | |
| Age, Categorical: <=18 years | Participants | 0 | — | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 1 | — | 1 |
| Age, Categorical: >=65 years | Participants | 0 | — | 0 |
| Sex/Gender, Customized | participants | 1 | — | 1 |
| Race/Ethnicity, Customized | particpants | 1 | — | 1 |
| Region of Enrollment: United States | participants | 1 | — | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Primary Outcome, measured over 9 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 registry names the primary endpoint only as “Primary Outcome.” It gives a timeframe of 9 months, but does not state the outcome's definition, unit, measurement method, scoring rules, or the direction considered favorable. It therefore is not possible to explain from the registry record what clinical event, symptom, or measurement the primary endpoint was intended to capture.
General: A primary endpoint is the main outcome used to frame the central question of a trial. A clearly specified endpoint helps readers understand what treatment groups are being compared, when the outcome is assessed, and what a difference would mean. Its definition also matters for choosing an appropriate analysis and interpreting uncertainty. Those general principles cannot fill in the missing endpoint details in this record.
The registry states that the study was terminated and that no data were collected for the primary outcome. Consequently, there is no reported endpoint estimate or group comparison to interpret. The stated timeframe alone does not indicate that assessments occurred at that time, and the record does not provide a substitute measure or an explanation for why the endpoint data were not collected.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central statistical fact is that the planned primary outcome was not collected. The registry explicitly says the study was terminated and no data were collected for that outcome. It reports no analyses, so there is no primary-outcome estimate, treatment contrast, confidence interval, or significance test in the record to evaluate. This is not evidence that the treatment groups had similar outcomes: without the outcome observations, a comparison cannot be made.
The trial was randomized and parallel-group according to the registry, and its summary describes a planned comparison of tocilizumab with placebo while participants remained on current treatment. The intended enrollment was 30 participants per arm, but the recorded enrollment is 1. With the primary data absent and the recorded enrollment far below the stated plan, the registry record does not provide a basis for assessing the planned comparative effect. The reason for termination and the disposition of the recorded enrollment are not reported.
The record also lists secondary outcomes, including genital ulcers, oral ulcers, treatment failures, oral ulcer pain, genital ulcer pain, BSAS, MDHAQ, and BDCAF. It lists 10 outcome measures but no analyses. The presence of outcome names in a registration record does not establish that they were measured or analyzed. Their definitions, assessment results, and any between-group estimates are not reported in the registry record.
Safety information is sparse and should be read as counts of participants listed as at risk and affected, not as a comparative safety analysis. The tocilizumab group lists 1 participant at risk for serious adverse events and 0 affected; the placebo group lists 0 at risk and 0 affected. The groups also list 0 deaths. Because no placebo participants are listed as at risk and the record provides no further safety analysis, these entries cannot support a meaningful comparison between arms. The record does not describe the safety observation period for these counts.
General: Estimates from small or incomplete datasets can be imprecise, and missing outcome data prevent estimation altogether when no outcome values are available. Confidence intervals express uncertainty around an estimated quantity; none can be interpreted for the primary outcome in this record because no estimate is reported. The registry information therefore documents a planned randomized study and its termination, not evidence for or against a treatment effect.
9. Statistical Methods Explained
General: Randomization is intended to make treatment assignment independent of participants' measured and unmeasured characteristics, on average across repeated trials. A parallel-group design assigns participants to one of the groups and compares outcomes between those groups. Those design labels describe the intended structure; they do not guarantee that a completed comparison is available. In this trial record, no primary outcome data were collected, so randomization cannot produce an interpretable estimate of the primary treatment contrast.
What can the design labels tell us?
The record labels allocation as randomized, masking as triple, and the model as parallel. These labels provide a high-level description but not the operational details. The randomization sequence method, allocation concealment, and any stratification are not reported in the registry record. The record also does not say which people were masked. Its triple-masking label differs from the brief summary's description of a double-blind study, and the record does not reconcile those terms. Readers should not infer the identity of masked roles from the label alone.
General: Masking is used to reduce the influence of expectations on care, outcome assessment, or reporting. The roles masked can vary, so the label by itself is not enough to determine how masking was implemented. Likewise, knowing that allocation was randomized does not reveal whether allocation could be anticipated before assignment. Those details are not reported for this study.
Why are there no treatment-effect statistics?
The primary outcome has no collected data according to the registry, and the record lists 0 analyses. An effect estimate requires outcome information from the compared groups. A standard error and confidence interval require information about the estimate's variability as well. Without primary outcome observations, none of these quantities can be obtained from the record. A p-value would not resolve the problem: it is a test statistic calculated from data under a specified analysis, not a substitute for missing observations.
General: A confidence interval describes a range of values compatible with the data and analysis, under the method's assumptions. Its width reflects statistical uncertainty, but it does not capture every source of uncertainty, such as biased measurement or unrepresentative participants. When no endpoint data are collected, there is no endpoint estimate around which to form an interval. The registry therefore supports no conclusion about the size or precision of the intended primary comparison.
What does the planned enrollment mean?
The summary planned 30 participants per arm, 60 in total. The recorded enrollment is 1. These are different quantities: the first is the planned recruitment target, and the second is the enrollment recorded for the trial. Neither establishes how many participants completed treatment or had safety follow-up. Those details are not reported in the registry record.
General: Sample-size planning depends on design choices and assumptions about the outcome, the effect worth detecting, variability, significance level, power, and allocation. An achieved enrollment below a plan can leave an analysis less precise than intended, but it does not by itself tell readers what effect occurred. Power is a property of a design under assumptions, not a retrospective measure of whether a result is true. The record does not report a justification for the planned enrollment, and no trial-specific sample-size rationale should be inferred.
The registry includes a general description of planning illustrations based on an observed effect and specified assumptions. However, no numerical planning-illustration results are included in the record. In any event, the primary outcome was not collected, so the record contains no observed primary effect from which to interpret such an illustration. A planning exercise is not evidence of an observed treatment effect and is not observed power.
Why do outcome definitions matter?
The primary outcome is labeled only “Primary Outcome,” with a 9-month timeframe. The record does not state how it was measured or scored. Without an operational definition, readers cannot judge whether it is a symptom measure, a clinical event, a composite, or another type of outcome. They also cannot assess whether the chosen statistical method would match the data type or whether the timing corresponds to the treatment and follow-up schedule in the summary.
The record names several secondary outcomes and reports 10 outcome measures, but outcome names alone do not explain their measurement scales, assessment schedules, or analysis populations. No analyses are reported. Thus, there is no basis to infer a change in ulcers, pain, treatment failure, or any listed instrument score.
General: Over-dispersion occurs when observed variability is greater than a statistical model expects. If present, it can make standard errors from an unsuitable model too small and confidence intervals too narrow. Whether over-dispersion is relevant depends on the outcome and the model. Since the primary outcome's nature and analysis are not described and no outcome data were collected, it cannot be assessed for this trial from the registry record.
In sum, the design labels and planned regimen describe what the study intended to do, while the termination status and absence of primary outcome data determine what can be learned statistically. The registry does not report the analysis plan, endpoint details, or outcome results needed to reproduce or evaluate a treatment-effect analysis.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists several secondary outcomes: genital ulcers, oral ulcers, treatment failures, oral ulcer pain, genital ulcer pain, BSAS, MDHAQ, and BDCAF. It reports 10 outcome measures and 0 analyses. The individual outcome definitions, assessment times, and results are not reported in the registry record. The names alone do not establish that all listed outcomes were collected.
Multiplicity arises when several outcomes, time points, subgroups, or statistical tests are examined. General: The more comparisons considered, the greater the chance that at least one result may appear notable by chance if no adjustment or prespecified interpretation strategy is used. Methods such as adjusted testing or a hierarchy of outcomes can address some multiplicity concerns, but the registry record does not report a statistical analysis plan or a multiplicity strategy. No correction or testing sequence should be assumed.
The record says no data were collected for the primary outcome, but does not describe whether secondary outcome data were collected. It does not report reasons for missingness, the amount of missing data for any secondary measure, or any method for handling missing values. The number of participants analyzed for each outcome is also not reported. These gaps prevent assessment of whether missingness could affect an estimate or the representativeness of any analyzed group.
The registry does not identify an analysis population, such as all randomized participants or participants who received treatment. It also does not report participant flow, treatment adherence, withdrawals, or exclusions. General: Analysis populations answer different questions, and conclusions can depend on how participants are included. Without these details and without reported analyses, no claim about an intention-to-treat, per-protocol, or other analysis can be made.
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 |
|---|---|---|---|
| Tocilizumab | 0 | 1 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Tocilizumab | 0 of 1 |
| Placebo | 0 of 0 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Tocilizumab | 0 of 1 |
| Placebo | 0 of 0 |
The serious adverse event entries list the tocilizumab group as having 1 participant at risk and 0 affected. The placebo group lists 0 participants at risk and 0 affected. The record lists 0 deaths in each group. It reports no top serious adverse event terms.
These are registry counts, not a treatment comparison. In particular, the placebo group has no participants listed as at risk, so its zero affected count is not evidence that no serious adverse events occurred among a comparable group of exposed participants. The record does not explain why no placebo participants are listed as at risk, whether the participant listed in the tocilizumab group received treatment, or what observation period applies to the safety counts.
The summary describes safety as an objective and planned follow-up at 2 months after study termination, but the registry does not connect that plan to the reported at-risk counts. It also does not provide event-level details, exposure duration, or a safety analysis. The counts should therefore be read narrowly as recorded entries, not as evidence that the study established a comparative safety profile.
12. What the Result Does, and Does Not, Mean
The registry record documents a randomized phase 2 study intended to compare tocilizumab infusion with placebo infusion as additions to ongoing treatment for Behcet's syndrome. It records a planned enrollment of 30 participants per arm and an actual enrollment of 1, and it marks the trial as terminated. Most importantly for interpretation, it states that no data were collected for the primary outcome and reports no analyses.
Those details mean the registry cannot show whether the treatment groups differed on the intended primary outcome. They also mean the record cannot establish the magnitude, direction, or precision of a primary effect. The absence of a result is not a finding of no difference, and it is not evidence that the groups had equivalent outcomes. No equivalence or non-inferiority conclusion is reported.
The record also cannot establish that tocilizumab did or did not affect any of the listed secondary outcomes. Outcome names and a planned treatment regimen do not substitute for observed measurements. The safety entries are limited counts with no placebo participants listed at risk; they cannot establish that the treatments had similar or different safety profiles.
General: A randomized design can support a causal comparison when outcomes are collected and the analysis is appropriate, but the design label alone does not provide a result. Interpretation also depends on endpoint definition, follow-up, analysis population, missing data, and uncertainty estimates. Key information on these points is absent or incomplete in this record.
The defensible reading is therefore descriptive: the registry records the intended study question, planned design and regimen, termination status, enrollment, and absence of primary outcome data. It does not provide efficacy or comparative safety evidence. The reason for termination and the circumstances surrounding the recorded enrollment are not reported in the registry record.
13. Why This Trial Matters Statistically
This trial matters statistically because it illustrates the distinction between a registered research plan and an analyzable clinical comparison. The record describes randomization, a parallel-group design, a placebo comparator, and a planned enrollment target. Those features set out an intended framework for comparing groups, but no primary outcome observations were collected. Without outcome data, the central treatment contrast cannot be estimated.
The recorded enrollment of 1 alongside a planned total of 60 is also important context. A planned target describes the intended scale of recruitment; it is not evidence that the target was reached or that the resulting trial could answer its question. In this case, the registry explicitly reports termination and no primary outcome data, so readers should not treat the registration as a completed efficacy analysis.
The record highlights why precise endpoint reporting matters. “Primary Outcome” and a 9-month timeframe do not explain what was to be measured, how it was to be assessed, or how results would be analyzed. The summary's planned 3-month treatment period and safety follow-up at 2 months after study termination are not reconciled with that timeframe in the record. Clear definitions and a transparent analysis plan are necessary for interpreting a result if one is reported.
Finally, the limited safety counts illustrate why denominators matter. A zero affected count in a group with zero participants listed at risk cannot serve as a useful comparative estimate. Statistical interpretation depends not only on event counts but also on who was observed, for how long, and under what exposure. Those details are not reported. Taken together, the record is informative about what was intended and what was not collected, while offering no estimate of a treatment effect.
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.
Several trial-specific omissions limit interpretation. The primary outcome is not defined beyond its label, and its measurement method, scoring, unit, and assessment details are not reported. Although the listed timeframe is 9 months, the registry does not explain its relationship to the summary's planned 3-month study period and safety follow-up at 2 months after study termination.
The record states that the study was terminated and that no primary outcome data were collected, but it does not report the reason for termination. The recorded enrollment is 1, compared with the planned total of 60, yet participant flow, allocation, treatment receipt, completion, and follow-up are not described. The record therefore does not show what happened to the recorded enrollment or whether any secondary outcome or safety information was collected beyond the listed entries.
The registry's design descriptions are incomplete for detailed appraisal. It labels masking as triple, while the summary calls the study double-blind, without explaining the difference. Randomization procedures and allocation concealment are not reported. The statistical analysis plan, analysis population, handling of missing data, and approach to multiple outcomes are also not reported.
The safety counts have a limited denominator: 1 participant is listed at risk in the tocilizumab group and 0 in the placebo group. The record does not provide exposure or observation details that would permit a comparative safety interpretation. These limitations are specific to the information recorded and do not establish what procedures or data may have existed outside the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Tocilizumab for the Treatment of Behcet's Syndrome — NCT01693653.
- Registry record last updated 2019-02-15; status last verified 2019-02.
- Results first posted 2016-06-02.
- 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
The registry describes a phase 2 randomized, parallel-group study of tocilizumab versus placebo, added to participants' current treatment for Behcet's syndrome. The planned regimen was infusion every 4 weeks over 3 months; planned enrollment was 30 participants per arm, 60 total. The record lists enrollment of 1 and status as terminated.
The primary outcome is named only “Primary Outcome,” with a 9-month timeframe. The registry states that no data were collected for it and lists 0 analyses. The reason for termination and the relationship between the outcome timeframe and the planned treatment and follow-up schedule are not reported in the registry record. Safety entries list 1 participant at risk in the tocilizumab group and 0 in the placebo group, with 0 affected and 0 deaths in both groups. These entries do not establish a comparative safety result.