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 Apremilast for Erythema Multiforme (NCT05875714), a na phase 2 study. The primary outcome is Erythema Multiforme Flares on Medication.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05875714 |
| Phase | Phase 2 |
| Condition | Erythema Multiforme |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 6 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Robert Micheletti |
| Results posted | Yes |
2. Clinical Question
Population
Patients with chronic, treatment-resistant erythema multiforme. The registry record lists an enrollment of 6; the primary-outcome population is described as three patients who completed the study.
Intervention
Open-label apremilast treatment for 6 months. The primary outcome description focuses on the 24 weeks on medication.
Comparator
Each patient's preceding 24 weeks, before apremilast treatment. There was no randomized control group or concurrent comparator.
Primary question
How many erythema multiforme flares occurred during 24 weeks on apremilast compared with the preceding 24 weeks?
The clinical question is framed as a within-person comparison: flare counts during treatment are set against counts from the same patients' pretreatment period. This can describe whether the recorded counts differed across those periods, but it does not by itself establish that treatment caused any difference. Without a concurrent control group, changes over time could also reflect the natural course of the condition, other care, or differences in how flares were recorded.
The study also lists secondary measures concerning pain, flares after the primary period, quality of life, and investigator assessment. The registry record does not report numerical results for the primary endpoint or those secondary outcomes. Thus, the question is clear, but the posted information does not show the size or direction of any change in flare frequency.
3. Trial Design
This is a phase 2, single-group, open-label study of apremilast for erythema multiforme. The registry record gives enrollment as 6 and status as completed. It lists the study start as 2022-01-13 and primary completion as 2024-12-31. No allocation to different treatment groups is described; the record identifies allocation as not applicable.
Participants received apremilast, and the primary outcome description compares the number of flares during 24 weeks on medication with the preceding 24 weeks. The study summary describes a 6-month treatment period. The primary-outcome population is described as three patients who completed the study. The registry record does not report further details about the analysis population or how the within-person comparison was conducted.
Because the study was open label and had a single group, participants and investigators were not masked to treatment, and there was no randomized, concurrent control group. The pretreatment period serves as a historical reference for the on-treatment period, not as a separately randomized arm. That design makes the observed change potentially informative as a description of these participants' experiences, while limiting attribution of any difference specifically to apremilast.
The registry record lists secondary outcomes involving pain on medication, flare counts and flare-associated pain in weeks 24-36, quality of life, and investigator global assessment. It does not report a statistical analysis plan or analyses of these outcomes. Details such as eligibility criteria beyond the summary, treatment adherence, and concomitant care 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 | Open Label Intervention |
|---|---|
| STARTED | 6 |
| COMPLETED | 3 |
| NOT COMPLETED | 3 |
Reasons for not completing this period:
| Reason | Open Label Intervention |
|---|---|
| Adverse Event | 1 |
| Withdrawal by Subject | 1 |
| Lost to Follow-up | 1 |
Analysis population for the primary outcome, as defined in the registry: Three patients completed the 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.
| Characteristic | Unit | Open Label Intervention |
|---|---|---|
| Participants analysed | 6 | |
| Age, Continuous | years | 28.7 (23 to 40) |
| Sex: Female, Male: Female | Participants | 3 |
| Sex: Female, Male: Male | Participants | 3 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 3 |
| Race (NIH/OMB): White | Participants | 3 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 6 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Number of Erythema Multiforme Flares in Preceding 6 months | number of flares | 6.3 (2 to 12) |
| Average Duration of Erythema Multiforme Flares in Preceding 6 Months | days | 8 (6 to 10) |
| Pain (units on a 0-10 scale; maximum = 10) with Flares of Erythema Multiforme in Preceding 6 Months | units on a 0-10 scale; max pain = 10 | 7.5 (5 to 10) |
| Autoimmune Bullous Disease Quality of Life Scale | Units on a 0-51 scale; higher is worse | 24.5 (12 to 44) |
| Investigator Global Assessment of Disease Severity | units on a 0-10 scale; max severity = 10 | 6.5 (5 to 8) |
6. Primary Endpoint
The registry lists the primary outcome as Erythema Multiforme Flares on Medication, measured over 24 weeks.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Full Range |
| Unit | Number of flares |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the number of erythema multiforme flares occurring during 24 weeks on apremilast, compared with the number in the preceding 24 weeks. It is a count outcome: it records how often flares occurred rather than their duration or severity. The registry describes the summary measure as a mean with full-range dispersion and identifies the primary-outcome population as three study completers.
Flare frequency is relevant to the stated clinical question because it directly describes recurrence over time. Comparing each participant's on-treatment period with their own pretreatment period can account for stable differences between participants, such as a generally higher or lower tendency to experience flares. It does not, however, control for time-varying influences or the natural fluctuation of the condition.
For count outcomes, the mean conveys an average frequency, while the full range conveys the spread from the lowest to the highest recorded value. In general, a range is particularly sensitive to extreme observations, and a mean can be influenced by participants with higher counts. The registry record does not report the actual flare counts, mean, or range, so the magnitude and variability of the primary outcome cannot be assessed from the posted results.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record defines a within-person comparison of flare counts over the 24 weeks on apremilast and the preceding 24 weeks. It identifies three study completers as the primary-outcome population, but it does not report the flare counts for either period, a mean, a full range, an estimated difference, or an inferential analysis. Consequently, the posted information does not establish whether flare frequency increased, decreased, or stayed similar during treatment.
That absence matters for interpretation. A design description and an endpoint definition are not outcome results. The record's primary endpoint title indicates what was intended to be measured, but it cannot substitute for a numerical result. The registry record also lists no analyses, so there is no reported estimate or uncertainty measure to evaluate. No confidence interval or p-value for the primary comparison is reported in the registry record.
Even if a numerical before-and-during difference were available, the single-group design would call for caution. A within-person comparison avoids some differences between individuals, but the pretreatment period is not a concurrent control. General statistical interpretation of such a comparison must allow for changes over time unrelated to treatment, natural variation in flare occurrence, differences in observation or recording, and other care. The open-label design also means expectations could influence subjective measures such as pain or investigator assessment.
The small enrollment and the primary-outcome population described in the record further limit how much can be inferred about a broader population. The record does not report a precision estimate for the primary outcome, and the number of completers alone cannot indicate how consistently a result might apply to other patients. The reason that the primary population includes three completers, and how missing observations were handled, are not reported in the registry record.
The safety record reports no serious adverse events among six at risk, one under the other adverse-event measure among six at risk, and no deaths. These counts describe the registry's recorded safety data; they do not resolve the missing efficacy result, and they should not be taken as evidence that uncommon harms are absent. Overall, the registry record identifies the question and some safety counts, but it does not provide enough primary-outcome information to characterize the treatment-period change or its precision.
9. Statistical Methods Explained
A within-person comparison evaluates measurements from the same participants across different periods. In general, this can reduce the influence of characteristics that remain stable within a person, because those characteristics are shared by the periods being compared. Here, the planned contrast is flare counts during 24 weeks on apremilast versus counts in the preceding 24 weeks. It is not equivalent to comparing randomized treatment groups: the periods occur at different times, and treatment is not assigned independently of time.
What does a count outcome represent?
A flare count is a nonnegative count of events over a defined observation period. Count data often have a skewed distribution, particularly when many observations have low counts and a small number have higher counts. In general, the mean describes average event frequency, but the mean alone may not show whether most participants had similar counts or whether a few high counts drove the average. The full range reports the minimum and maximum, but it does not show the distribution of observations between those extremes. The registry identifies the endpoint summary as a mean with full range; the numerical summary itself is not reported in the registry record.
Over-dispersion is a general feature of count data in which variability is greater than a simple model would expect. If present, it can make standard errors from an overly restrictive model too small and confidence intervals too narrow. Analysts may use models that allow extra variability, or methods suited to paired count data, depending on the data and study design. The registry record does not report a model, test, variance assumption, or other method used for the primary comparison, so it is not possible to determine how count variability was handled.
How should a confidence interval be read?
In general, a confidence interval expresses the uncertainty around an estimated effect under the assumptions of the analysis. A narrower interval indicates greater statistical precision, while a wider interval indicates less precision. Its interpretation depends on the estimate being evaluated, the model, and the data. No confidence interval or primary-effect estimate is reported in the registry record, so precision for the flare comparison cannot be assessed.
A p-value, when reported, describes how compatible the observed data are with a specified null hypothesis under the statistical model; it does not give the probability that the treatment is effective, nor does it measure clinical importance. The registry record reports no primary p-value. Without an estimate and its uncertainty, a statistical-significance interpretation would not be possible in any event.
What do the planning assumptions describe?
The registry's sample-size assumptions describe planning illustrations rather than the study's reported analysis. They specify a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of an observed effect. The assumptions also distinguish participant-per-arm quantities from total event quantities for time-to-event illustrations. These are general planning conventions, not evidence that the completed study had two randomized arms; the actual trial is registered as single group.
Planning sample sizes are conditional on the assumptions used, including the effect size chosen and the statistical method. They do not represent observed power, and they do not show the precision achieved in this study. The record does not report calculated planning sample sizes or the observed effect used for those illustrations. Since the primary result is also absent, a reader cannot evaluate whether the assumptions match the observed data.
For a within-person count comparison, an analysis might focus on each participant's change between periods or model the counts while accounting for their paired structure. The choice would affect the estimate and its uncertainty. The registry record does not report which approach was used, whether any adjustment was made, or whether the comparison was treated as exploratory or confirmatory. These methodological details are not reported in the registry record and should not be inferred from the endpoint wording alone.
Finally, statistical precision and clinical relevance are different questions. Precision concerns uncertainty around an estimate; clinical relevance concerns whether the size and nature of a change matter in context. Neither can be evaluated from an endpoint definition alone. Here, the registry does not give the primary counts, estimated change, or uncertainty interval, so both remain unresolved by the posted results.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists secondary outcomes spanning pain, flare frequency and flare-associated pain in weeks 24-36, quality of life, and investigator global assessment. It also records eight outcome measures. When a study assesses multiple outcomes or time points, general statistical practice considers whether the number of comparisons could increase the chance of a nominally unusual finding. A prespecified hierarchy, adjustment, or other multiplicity strategy can help explain how results were to be interpreted. Such a strategy is not reported in the registry record.
The record lists no analyses. It therefore does not report which outcomes were analyzed, whether all registered outcomes were available, how results were selected for presentation, or whether multiple comparisons were addressed. This does not establish that an analysis was or was not performed; it means the analysis details are not reported in the registry record.
The primary population is described as three patients who completed the study, while enrollment is listed as 6. The registry does not explain the difference between these figures, identify the analysis population beyond the primary-outcome description, or state how incomplete observations were handled. Reasons for noncompletion, missing-data methods, and any sensitivity analyses are not reported in the registry record. Missingness can matter when observations are unavailable, because the people or periods with missing data may differ systematically from those observed. Without the relevant details, the direction or impact of any missing data cannot be assessed.
The record also does not report whether outcomes were analyzed according to an intention-to-treat principle, among completers only, or under another population definition. No imputation or other missing-data procedure should be assumed.
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 |
|---|---|---|---|
| Open Label Intervention | 0 | 6 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Open Label Intervention | 0 of 6 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Open Label Intervention | 1 of 6 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Open Label Intervention |
|---|---|---|
| headache | Nervous system disorders | 1 of 6 |
The registry reports six participants at risk for the serious adverse-event measure, with zero affected, and six at risk for the other adverse-event measure, with one affected. It also reports zero deaths. No serious adverse-event terms are listed.
These are descriptive counts for the registered open-label intervention group. They do not provide a comparison with an untreated or randomized control group, and the record does not report details such as event type for the other adverse-event measure, timing, severity, relationship to treatment, or the method used to collect events. The registry record also does not clarify the observation period for these safety counts in the information listed.
A recorded count of zero serious adverse events does not demonstrate that serious events cannot occur. In general, safety estimates based on small groups are imprecise, especially for uncommon outcomes. The counts should therefore be read as the events recorded in this study, not as a complete characterization of safety or a basis for comparison with other treatments.
12. What the Result Does, and Does Not, Mean
The registry record establishes that this completed phase 2 study asked whether flare frequency differed during apremilast treatment and the preceding period in patients with refractory erythema multiforme. It also identifies a small primary-outcome population and reports safety counts. However, the primary flare results are not reported in the registry record. There is no posted numerical result from which to describe the direction, size, or precision of a change.
The registry record therefore does not support a conclusion about whether flare counts were lower or higher on medication. It also does not allow an assessment of how much participants' flare counts varied, whether any difference was statistically distinguishable from chance under an analysis model, or whether a difference was meaningful to patients. The outcome definition alone is not evidence of a treatment effect.
More generally, a before-and-during comparison in a single group can describe a temporal pattern, but a difference between periods would not isolate the effect of apremilast. Changes could reflect the natural course of disease, other influences that changed over time, or observation and reporting differences. Without a concurrent randomized comparator, those explanations cannot be separated through the design described in the registry.
The record's secondary-outcome list indicates interest in pain, quality of life, and investigator assessment, but numerical results for these outcomes are not reported in the registry record. The safety counts should likewise be interpreted descriptively and in light of the limited study size and lack of a comparator. They do not establish that no additional risks exist.
In short, the posted information documents the study question, design, and some safety counts, but leaves the central efficacy result unavailable. Any stronger conclusion would require outcome estimates and analysis details that are not reported in the registry record.
13. Why This Trial Matters Statistically
This study illustrates why a clear endpoint and a completed status are not sufficient to interpret a clinical trial statistically. The registry specifies a clinically understandable outcome—flare frequency over a defined treatment period relative to a pretreatment period—but does not provide the observed counts or an estimate of their change. Without those data, the central comparison cannot be quantified or assessed for precision.
The design also highlights the distinction between a historical within-person comparison and a randomized control comparison. Repeated measurements in the same people can be useful, but period differences may reflect factors other than treatment. Statistical analysis can describe the comparison and quantify uncertainty, yet it cannot remove design limitations that arise when there is no concurrent control group.
There is an additional lesson about transparency: the record lists secondary outcomes and planning assumptions, while detailed analysis methods and outcome results are not reported. Prespecified analysis methods, clear analysis populations, and transparent handling of incomplete data help readers understand what an estimate represents and how much confidence to place in it. Their absence from the registry record limits evaluation.
Finally, the reported safety counts demonstrate why event counts need context. Zero recorded serious adverse events in a small group does not rule out uncommon harms, and a count without event details cannot fully characterize safety. Statistical interpretation depends not only on a number, but also on its denominator, observation period, outcome definition, and comparison structure. Here, those considerations reinforce a cautious reading of the 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 are specific to the information recorded for this study. The primary endpoint is described, but its numerical results are not reported in the registry record. The mean and full range are named as summary measures, yet neither the summaries nor the underlying period-specific counts are available. This prevents evaluation of the direction, magnitude, variability, and precision of the primary comparison.
The design is single group and open label, with the preceding period used as the reference. There is no randomized concurrent control group. Consequently, any difference across periods, if one were reported, could not be attributed to treatment alone using this design. The registry record does not report the method used to analyze the paired periods or how potential differences in observation and recording were addressed.
Enrollment is listed as 6, whereas the primary-outcome population is described as three completers. The record does not explain why the primary population is limited to completers, give reasons for incomplete participation, or state how missing measurements were handled. It also does not report a detailed analysis population definition.
Although several secondary outcomes are listed, their results and the approach to multiplicity are not reported. The registry record does not give a statistical analysis plan, primary-effect estimate, confidence interval, or p-value. Safety information is limited to aggregate counts and does not include listed serious-event terms or details for the other adverse-event measure. These limitations concern what can be assessed from the registry record; they do not establish what analyses or additional information may exist outside it.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Apremilast for Erythema Multiforme — NCT05875714.
- Registry record last updated 2026-06-03; status last verified 2026-05.
- Results first posted 2026-06-03.
- 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
NCT05875714 is a completed phase 2, open-label, single-group study of apremilast for refractory erythema multiforme. Enrollment is listed as 6. The primary endpoint compares flare counts during 24 weeks on medication with the preceding 24 weeks; the primary population is described as three completers.
The registry record does not report the primary flare counts, summary results, or statistical analysis. It lists secondary outcomes related to pain, flares, quality of life, and investigator assessment, but their numerical results are not reported in the registry record. Safety counts include zero serious adverse events among six at risk, one under the other adverse-event measure among six at risk, and zero deaths.
The single-group, open-label design and the absence of posted primary results limit conclusions about treatment-period changes and their precision.