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 Neuromyelitis Optica (NMO) & Cetirizine (NCT02865018), a na phase 1, phase 2 study. The primary outcome is Annualized Relapse Rate Before Cetirizine.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02865018 |
| Phase | Phase 1, Phase 2 |
| Condition | Neuromyelitis Optica |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 16 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Icahn School of Medicine at Mount Sinai |
| Results posted | Yes |
2. Clinical Question
Population
People with neuromyelitis optica (NMO). The registry record lists NMO as the condition and describes patients with the disease as the intended population. It does not report further eligibility details or a breakdown of participant characteristics in the posted results.
Intervention
Add-on cetirizine, listed as 10mg orally each day. The study is described as open label, meaning masking was not used. The record does not report how long each participant received treatment beyond identifying the primary outcome timeframe as baseline and 1 year.
Comparator
No separate comparator group is listed. The trial is recorded as a single-group study, with allocation listed as not applicable. The annualized relapse rate before cetirizine is named in the primary outcome, but the registry record does not provide a randomized or concurrent control comparison.
Primary question
The primary outcome concerns annualized relapse rate before cetirizine, with the record also defining an on-study annualized relapse rate based on relapses during the study and time in the study. The registry record does not report the observed primary outcome values or an estimate comparing periods. It therefore does not establish the size or precision of any change in relapse rate.
In practical statistical terms, this is a question about relapse frequency over time in a treated group, rather than a direct estimate of the difference between treatment and control groups. Such a design can describe what was observed among participants in the study, but a before-and-after comparison can be influenced by factors other than treatment. Without a concurrent comparator and a reported outcome estimate, the record does not allow those influences to be separated from a treatment-associated change.
3. Trial Design
The registry record describes an open-label, add-on trial of cetirizine in patients with neuromyelitis optica. It lists the study as phase 1 and phase 2, with a single-group model, no masking and allocation recorded as not applicable. The intervention is cetirizine 10mg orally each day. The named sponsor is Icahn School of Medicine at Mount Sinai. The record lists the study as completed, with a start date of 2014-04 and primary completion date of 2016-02.
The registry lists enrollment as 16. That is a registry enrollment figure; the posted results do not provide an outcome-specific analysis count or explain whether all enrolled participants contributed to each outcome. The record also does not report participant flow, withdrawals, or the number of participants completing each measurement.
A single-group design has no concurrent control arm for separating changes associated with treatment from changes that could occur over time for other reasons. Open-label conduct means participants and study personnel were not masked to the intervention, according to the registry entry. The record does not report whether outcome assessment was blinded or how relapse reports were reviewed.
The primary outcome is titled “Annualized Relapse Rate Before Cetirizine” and has a timeframe of baseline and 1 year. Its description defines relapses and states how the on-study annualized relapse rate was calculated. These details point to an interest in relapse frequency around the treatment period, but the registry record does not report an actual before-and-after estimate or an analysis method for comparing the periods.
The record lists Epworth Sleepiness Scale, Expanded Disability Status Scale (EDSS), and Eotaxin Plasma Levels as secondary outcomes. It does not provide results for these measures in the posted results described by this record. Other design details, including eligibility criteria, the treatment schedule beyond the daily dose, and any planned statistical analysis, 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.
Overall Study
| Stage | Cetirizine |
|---|---|
| STARTED | 16 |
| COMPLETED | 15 |
| NOT COMPLETED | 1 |
Reasons for not completing this period:
| Reason | Cetirizine |
|---|---|
| Withdrawal by Subject | 1 |
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 | Cetirizine |
|---|---|---|
| Participants analysed | 16 | |
| Age, Continuous | years | 36.5 (27.1 to 51.0) |
| Age, Customized: Age at Symptom onset | years | 31.0 (22.5 to 41.7) |
| Sex: Female, Male: Female | Participants | 15 |
| Sex: Female, Male: Male | Participants | 1 |
| Positive NMO antibody in serum | Participants | 13 |
| Type of NMO Preventative Treatment at Enrollment: Rituximab | Participants | 8 |
| Type of NMO Preventative Treatment at Enrollment: Azathioprine | Participants | 1 |
| Type of NMO Preventative Treatment at Enrollment: Mycophenolate | Participants | 7 |
| Duration of Current Treatment | months | 18.3 (7.8 to 40.1) |
| Number of Previous Preventative NMO treatment types: 0 | Participants | 10 |
| Number of Previous Preventative NMO treatment types: 1 | Participants | 5 |
| Number of Previous Preventative NMO treatment types: 2 | Participants | 1 |
| Oral Prednisone use at Enrollment | Participants | 1 |
| Total pre-study relapses | relapses | 3.0 (1.5 to 5.0) |
| Total pre-study relapses while on current preventative treatment | relapses | 0.0 (0.0 to 1.0) |
| Annualized Relapse Rate | relapses per treatment year | 0.0 (0.0 to 0.7) |
6. Primary Endpoint
The registry lists the primary outcome as Annualized Relapse Rate Before Cetirizine, measured over Baseline and 1 year.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | relapses per year |
| Endpoint classification | Continuous Endpoint |
The primary outcome is named “Annualized Relapse Rate Before Cetirizine,” with the unit relapses per year and a mean as the measure of central tendency. Standard deviation is listed as the dispersion measure. The timeframe is baseline and 1 year. The outcome description defines a relapse as patient-reported symptoms or objectively observed signs typical of an acute inflammatory demyelinating event in the central nervous system, lasting at least 24 hours, without fever or infection. It states that on-study annualized relapse rate was calculated as the number of relapses during the study divided by the length of time in the study.
Annualizing a count expresses event frequency relative to time observed. This is useful when people have differing observation periods, because the raw number of events alone does not account for how long each person was followed. A group mean can describe the average annualized rate, while the standard deviation describes variability among the values contributing to that mean. Neither measure alone indicates how precisely the group mean is estimated.
The outcome title refers to the rate before cetirizine, while its description also defines an on-study rate. The registry record does not report the corresponding outcome values, a difference between periods, or a confidence interval. It is therefore not possible to describe the observed rate or the precision of a treatment-period comparison from the posted results.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a clinically relevant outcome—relapse frequency over time—and gives a definition intended to distinguish qualifying relapses from symptoms associated with fever or infection. It also specifies the unit, the mean and standard deviation, and the timeframe. These details help explain what the outcome was intended to capture. They do not, on their own, show what participants experienced or how much uncertainty surrounds an estimate.
No primary outcome values are reported in the registry record. In particular, the record does not give the mean annualized relapse rate before cetirizine, an on-study mean, a difference between these values, or a confidence interval. It also does not report a statistical test or a p-value for the primary outcome. The posted results therefore do not support a quantitative interpretation of the primary endpoint, including the direction, size, or precision of a change.
The design is single group and open label, with allocation listed as not applicable. A within-group comparison over time, if reported, would not be equivalent to a randomized comparison. As a general statistical point, a before-and-after change can reflect treatment as well as changes in observation, patient circumstances, disease course, or other influences. Without a concurrent comparator, those explanations are difficult to distinguish. The registry record does not report an adjusted analysis that addresses such potential influences.
The registry lists enrollment as 16, but does not report how many participants contributed to the primary outcome analysis or whether the analysis included all enrolled participants. The outcome is a rate, so the time observed matters as well as the number of relapses. Although the description specifies a calculation using study duration, the posted results do not show individual follow-up times, the distribution of observed counts, or the approach used to handle incomplete observation.
Standard deviation describes variation among observations; it is not the same as uncertainty in the estimated mean. A confidence interval, if reported, would help communicate the range of values reasonably compatible with the data under the analysis assumptions. No such interval is reported for the primary outcome. The absence of an estimate and interval means that neither the magnitude of the outcome nor its statistical precision can be assessed from this record.
The registry also lists secondary measures of sleepiness, disability and plasma eotaxin levels. Their names indicate additional outcomes of interest, but no numerical results for them are reported in the registry record. The adverse-event entry reports zero serious adverse events among 15 listed at risk, three other adverse events among 15 listed at risk, and zero deaths. These are descriptive counts, not comparative estimates. The record does not provide event details or a control group for interpreting differences in safety outcomes.
Overall, the record documents the study question, intervention, design and selected safety counts, but not the primary efficacy result. Statistical interpretation should therefore remain at the level of what was planned and how the endpoint was defined. A conclusion about the observed relapse-rate result, its uncertainty, or its relation to cetirizine is not reported in the registry record.
9. Statistical Methods Explained
Several statistical ideas help clarify what the registry entry does and does not establish. The discussion below describes general concepts and applies them only where the record supplies relevant details.
What does annualized relapse rate represent?
An annualized rate relates a count of events to the time during which events could be observed. This can make rates more interpretable when observation periods differ, since equal counts over unequal follow-up periods do not represent equal event frequency. The record defines the on-study calculation as the number of relapses during the study divided by the length of time in the study. It does not report the observed counts, follow-up distribution, or resulting rates.
The endpoint description uses a specific clinical definition of relapse: patient-reported symptoms or objectively observed signs typical of an acute inflammatory demyelinating event in the central nervous system, lasting at least 24 hours and occurring without fever or infection. A definition supports consistent classification, but does not by itself show how consistently events were identified or adjudicated. Those operational details are not reported in the registry record.
What do the mean and standard deviation tell us?
The registry lists the mean as the summary measure and standard deviation as the dispersion measure for the continuous outcome. The mean describes the average of the analyzed values. The standard deviation describes how spread out those values are around their average. It reflects variation in the data, not the precision of the estimated mean.
Precision is commonly communicated with a confidence interval. In general, a confidence interval reflects both the observed data and assumptions of the statistical method, and gives a range of estimates compatible with those data under that method. A narrow interval indicates greater precision than a wide interval, but neither width nor location can be assessed without a reported interval. The registry record does not report one for the primary outcome.
Why does the study design matter?
This trial is listed as single group, open label, with allocation not applicable. In a single-group study, the observed outcome describes participants who received the intervention, but there is no concurrent control group to represent what might have happened over the same period without it. If outcomes are compared before and during treatment, general statistical reasoning cautions that time trends and other changes can also contribute to the observed difference.
Random allocation in a controlled trial is one way to support a fair comparison by distributing measured and unmeasured influences across groups in expectation. This record does not describe randomized allocation or a control group. It should therefore not be read as a randomized treatment-effect estimate. The registry record does not report an alternative design feature or analysis that would make a causal comparison possible.
How should a rate comparison be assessed?
A comparison of rates should make clear which periods or groups are being contrasted, how observation time is accounted for, and what estimate and uncertainty accompany the contrast. If individual event counts vary more than a simple statistical model expects, over-dispersion can make standard errors too small when ignored. This is a general concern in count data, not a finding about this study. The registry record does not report the distribution of relapse counts or the model used, so it is not possible to assess whether over-dispersion was considered.
Rates may also be affected by unequal follow-up or incomplete outcome observation. General statistical approaches can account for time at risk or missing observations, but their appropriateness depends on the data and assumptions. The record gives a rate definition based on study duration but does not describe how missing observations, varying follow-up, or incomplete records were handled.
What can sample-size planning illustrations show?
Sample-size calculations are planning tools: they estimate how many participants might be needed under specified assumptions to detect a target effect with a chosen statistical procedure. They are not observed results and do not indicate what the trial found. The assumptions recorded for the planning illustration are a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect specified as a fraction of the observed effect. Time-to-event illustrations use a total event count; other illustrations are expressed as participants per arm for 80% power or another listed power level.
The registry record does not report the resulting planning values or a trial-specific sample-size justification. Those illustrations should not be interpreted as the study's original design rationale or as observed power. In general, post hoc calculations based on an observed effect can be unstable, particularly when the effect estimate is uncertain. A trial's observed estimate and its confidence interval are more informative about the result than a retrospective power calculation.
What does a significance test add?
A significance test evaluates how compatible data are with a specified statistical model and null hypothesis. A p-value is not the probability that a treatment has no effect, and it does not describe the size or clinical relevance of an estimate. It is most useful when read alongside the effect estimate, its confidence interval, the analysis plan and the study design. No primary-outcome test result or p-value is reported in the registry record.
For this study, the missing outcome estimate is central: design details and endpoint definitions cannot substitute for observed results. The methods that were actually used for the primary analysis, including any model assumptions or adjustment, are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one primary outcome and three secondary outcomes: Epworth Sleepiness Scale, Expanded Disability Status Scale (EDSS), and Eotaxin Plasma Levels. Testing several outcomes can raise a multiplicity issue: when many hypotheses are examined, the chance of at least one apparently unusual result can increase if each is assessed without adjustment. This is a general statistical concern, not evidence that any particular result in this study is misleading.
The registry record does not report a multiplicity strategy, a hierarchy among outcomes, or which analyses were considered confirmatory. It also does not report the secondary outcome results or the primary outcome analysis result. It is therefore not possible to determine how any multiple comparisons were handled or to assess their effect on interpretation.
Missing-data methods and analysis populations are also not described. The record lists enrollment as 16, but does not give outcome-specific denominators, participant flow, reasons for missing measurements, or whether an intention-to-treat or other analysis population was used. It does not report how missing relapse information or incomplete follow-up was handled. These details matter because the people contributing data to an analysis can differ from those who entered the study, and the reasons for missing data can influence how representative an estimate is.
The registry record does not report a statistical analysis plan, imputation method, sensitivity analysis, or analysis-specific inclusion criteria. These items should be treated as not reported in the registry record rather than assumed to have been absent from the conduct of the study. Without them, readers cannot assess the robustness of outcome estimates to missingness, analytic choices, or multiple testing.
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 |
|---|---|---|---|
| Cetirizine | 0 | 15 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Cetirizine | 0 of 15 |
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 |
|---|---|
| Cetirizine | 3 of 15 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Cetirizine |
|---|---|---|
| Neuro episode | Nervous system disorders | 2 of 15 |
| Unilateral eye pain with movement | Eye disorders | 1 of 15 |
| Blurry vision with difficulty distinguishing colors | Eye disorders | 1 of 15 |
The registry lists zero serious adverse events among 15 participants at risk in the cetirizine group. It lists three other adverse events among 15 participants at risk and zero deaths. These are descriptive counts from the single-group record. The registry does not list serious adverse event terms.
The counts do not provide a comparison with an untreated or alternative-treatment group. They should not be interpreted as estimating whether cetirizine changes the risk of an event. The record also does not report the types, timing, severity or attribution of the three other adverse events, or explain how adverse events were collected. The number listed at risk for safety is not the same as evidence that every participant had complete safety follow-up.
In general, small safety datasets can describe events recorded during a study but may be imprecise for uncommon outcomes. A count of zero does not establish that an event cannot occur. The registry record does not provide confidence intervals or other uncertainty estimates for these safety counts, so their precision cannot be assessed from the posted results.
12. What the Result Does, and Does Not, Mean
The record establishes that an open-label, single-group add-on trial of cetirizine was registered for patients with neuromyelitis optica. It identifies the daily oral dose, names annualized relapse rate as the primary outcome, provides a relapse definition and lists several secondary measures. It also records selected adverse-event counts and marks the study as completed.
These details explain the study's subject and the kind of outcome it set out to measure. They do not provide the primary outcome result. Without the mean rate, a comparison estimate, or a measure of uncertainty, the posted results do not show the magnitude or precision of any change in relapse frequency. The record does not report results for the named secondary outcomes either.
The design also limits what can be inferred from any within-group change. In general, a change from baseline in a single group cannot by itself distinguish the intervention's contribution from other influences over time. The absence of a concurrent control group means the record cannot provide a like-for-like comparison with an alternative or with no add-on treatment.
The safety counts describe events recorded in the cetirizine group; they are not a comparative safety analysis. They do not establish the absence of risk, and the record does not supply the event details or uncertainty estimates needed for a fuller assessment.
In short, the registry record documents a study design and outcome framework, but its posted results do not include the primary outcome estimate needed for statistical interpretation. No conclusion about the effect of cetirizine on relapse rate, or a treatment recommendation, follows from the record as reported.
13. Why This Trial Matters Statistically
This trial is statistically notable for the relationship between its stated clinical question and its design. Relapse frequency is expressed as an annualized rate, which accounts for time observed rather than relying only on raw event counts. The record also defines what qualifies as a relapse and identifies both a mean and standard deviation as the intended summary. These choices make the intended outcome more specific than a simple, undefined count.
At the same time, the study is recorded as open label and single group, with no separate comparator. This distinction matters because a change over time is not automatically a treatment effect. General statistical reasoning requires readers to separate descriptive evidence about participants in a study from a causal comparison between treatment options. A concurrent control group and a reported effect estimate can support a different kind of inference than a single-group observation.
The registry record also illustrates why endpoint definitions and design details are not enough to evaluate results. The primary outcome estimate, its precision and the method used to analyze it are not reported. Without those elements, readers cannot assess whether the data are compatible with a small or large change, or how uncertain an estimate might be.
Finally, the gap between the registry's listed enrollment and the lack of outcome-specific denominators highlights the importance of participant flow and missing-data reporting. In general, readers need to know who contributed to each analysis and how incomplete observations were handled to judge how representative an outcome estimate may be. Those details are not reported in the registry record.
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 limitations arise from the information recorded for this specific trial. The design is single group and open label, and no concurrent comparator is listed. As a result, the record does not support a direct randomized comparison, and any before-and-after change would require caution because changes over time may have other explanations.
The primary outcome title refers to annualized relapse rate before cetirizine, while the outcome description also defines an on-study rate. The record provides the timeframe as baseline and 1 year but does not report the observed values or explain how the pre-treatment and on-study periods were compared. This leaves the intended contrast and its statistical implementation unclear.
Although the registry lists enrollment as 16, it does not report outcome-specific analysis counts, participant flow, follow-up completeness, or how missing relapse information was addressed. The adverse-event counts use 15 participants at risk, but the record does not explain the relationship between that safety denominator and the enrollment figure.
The registry does not report the primary outcome estimate, confidence interval, test result, or analysis method. It also does not report the results for the named secondary outcomes, the statistical analysis plan, multiplicity handling, or the approach to missing data. These absences prevent assessment of effect size, precision, robustness and the role of analytic choices. They are limitations of what can be learned from the registry record, not proof that related procedures were not undertaken.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Neuromyelitis Optica (NMO) & Cetirizine — NCT02865018.
- Registry record last updated 2023-06-07; status last verified 2023-05.
- Results first posted 2023-06-07.
- 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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18. Record Summary
The registry record describes NCT02865018, an open-label, phase 1 and phase 2, single-group add-on trial of cetirizine in neuromyelitis optica. The listed dose is 10mg orally each day. The sponsor is Icahn School of Medicine at Mount Sinai. The record lists enrollment as 16, a start date of 2014-04, a primary completion date of 2016-02, and status as completed.
The primary outcome is titled “Annualized Relapse Rate Before Cetirizine,” with a relapse definition and an on-study rate calculation described. Secondary outcomes listed are the Epworth Sleepiness Scale, EDSS and plasma eotaxin levels. The registry reports zero serious adverse events, three other adverse events and zero deaths in the cetirizine group, with 15 participants listed at risk for each adverse-event category.
The primary and secondary outcome results, analysis methods, outcome-specific denominators, missing-data procedures and statistical analysis plan are not reported in the registry record. The posted information therefore describes the study framework but does not provide a numerical estimate of the primary outcome.