A Phase 3, Open-label, Crossover Study to Evaluate Self-administration of Rozanolixizumab by Study Participants With Generalized Myasthenia Gravis (gMG): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Phase 3, Open-label, Crossover Study to Evaluate Self-administration of Rozanolixizumab by Study Participants With Generalized Myasthenia Gravis (gMG) (NCT05681715), a randomized phase 3 study. The primary outcome is Percentage of Participants With Successful Self-administration of Rozanolixizumab (With Correct Use of Syringe Driver and Manual Push, Respectively) During the Self-administration Period at Visit 13 (Week 12).

2. Clinical Question

3. Trial Design

This was a Phase 3, randomized, open-label crossover study of rozanolixizumab self-administration in generalized myasthenia gravis. The registry reports enrollment of 62 and a completed study. The listed study start was 2023-04-17 and the primary completion date was 2024-04-23.

The crossover design used two sequences: syringe driver followed by manual push, and manual push followed by syringe driver. Each sequence description states that participants received predefined weekly doses for 18 weeks. The primary endpoint was assessed at Visit 13 (Week 12), described as the last dose of Self-administration Period 1. The record also identifies a self-administration period after training and gives safety observation timeframes extending to the end-of-study visit at Visit 21 (Week 26).

Because participants were assigned to sequences rather than to a single method for the entire study, the order of administration is part of the design. A crossover can permit within-participant comparison when outcomes are collected under both methods, but interpretation may depend on period, sequence, and other design features. The registry record does not report the statistical handling of period or sequence effects, or whether a paired comparison was planned for the primary endpoint.

The study was not masked. Participants and study personnel therefore knew the method being used. That is relevant when interpreting a performance outcome that includes participant actions. The record identifies UCB Biopharma SRL as sponsor and lists rozanolixizumab as the intervention. Detailed procedural information beyond the descriptions in the registry record is not reported there.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: Participant Flow refers to Safety Set (SS) for Training Period and Randomized Safety Set (RSS) for Self-administration Periods 1 and 2.

Training Period (6-weeks)

Reasons for not completing this period:

Self-administration Period 1 (6 Weeks)

Reasons for not completing this period:

Self-administration Period 2 (6 Weeks)

Analysis population for the primary outcome, as defined in the registry: The Full Analysis Set (FAS) consisted of all participants who were included in SS, were randomized, and completed both self-administration periods in accordance with the randomization scheme.

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: Baseline characteristics refers to the Safety set which included all study participants who received at least 1 dose of investigational medicinal product (IMP) (partial or full).

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants With Successful Self-administration of Rozanolixizumab (With Correct Use of Syringe Driver and Manual Push, Respectively) During the Self-administration Period at Visit 13 (Week 12), measured over Week 12 (last dose of Self-administration Period 1).

The primary endpoint is the percentage of participants with successful self-administration of rozanolixizumab, assessed at Week 12 during the self-administration period. The record specifies success as meeting all three conditions: choosing the correct infusion site, administering the medication subcutaneously, and delivering the intended dose. This definition makes the endpoint a measure of whether the participant completed the specified administration tasks correctly, rather than a measure of clinical change in myasthenia gravis.

Such a performance endpoint is relevant to a study evaluating self-administration because it directly addresses whether participants can carry out the defined procedure after training. It is expressed as a percentage, so the reported result describes the proportion meeting the endpoint in each displayed group. It does not, by itself, describe the quality of symptom control, the duration of successful use, or clinical benefit.

The registry lists the primary timeframe as Week 12, the last dose of Self-administration Period 1. The outcome title refers to correct use of the syringe driver and manual push, respectively. The record does not report a more detailed endpoint adjudication process, whether success was assessed by an independent evaluator, or how incomplete or unevaluable administrations were handled.

7. Results Posted in the Registry

• Period 1: RLZ MP: 100.0% (23/23) versus 100.0% (18/18) on control; risk difference 0.0 percentage points (95% CI 0.0 to 0.0), risk ratio 1.00 (1.00–1.00); unadjusted two-proportion z-test p = n/a.

8. Statistical Interpretation

9. Statistical Methods Explained

The outcome is binary at the participant level: each participant either meets the stated definition of successful self-administration or does not. A percentage summarizes how common success was in a group. This is a direct and understandable way to report a performance endpoint, but it does not convey all the information about uncertainty or how participants contributed to the comparison.

What does a percentage describe?

In general, a percentage is the number of participants meeting an outcome divided by the number assessed in the relevant group, expressed on a percentage scale. For the primary outcome, the registry reports 100.0% in each displayed group and lists n=18 for Period 1: RLZ SRD and n=23 for Period 1: RLZ MP. The registry does not provide a separate narrative description of the numerator and denominator, though the group sizes and percentages are posted. No additional counts should be inferred beyond what is reported.

The endpoint definition requires correct site selection, subcutaneous administration, and delivery of the intended dose. These are distinct procedural criteria combined into an overall success outcome. A participant who does not meet the full definition would not meet the endpoint as written, but the registry record does not report how partial completion, a failed attempt, or missing assessment information was classified.

How does randomization fit the comparison?

Randomization assigns participants to an order of methods, which can help make sequence groups comparable on average. In a crossover study, sequence assignment determines which method comes first. Here, the registry identifies Period 1: RLZ SRD and Period 1: RLZ MP. Randomization supports interpretation of a comparison between those sequence groups, but it does not remove the need to account for the crossover structure when both periods are analyzed.

In general, a crossover analysis may use information from the same participant under each method, and may account for period and sequence. Such an analysis is different from simply comparing independent group percentages. The registry record does not report whether the primary analysis used participant-level pairing, an adjustment for period or sequence, or another statistical model. The comparison displayed should therefore be treated as the comparison reported, not as evidence of a particular analytical method.

What does a risk difference mean?

In general, a risk difference is the difference between the proportions with an outcome in two groups. A value of zero represents no difference between the proportions as represented by that estimate. The registry comparison reports a risk difference of 0.0 and interval endpoints of 0.0 and 0.0. The record does not explain the calculation method or whether the interval incorporates the randomization and crossover design. It is therefore important not to read the reported interval as a fully documented uncertainty analysis.

General statistical inference uses uncertainty intervals to indicate a range of values compatible with the data under the assumptions of the method. An interval can depend on the selected model, the outcome distribution, and the study design. When the underlying method is not described, the interval cannot be assessed for those assumptions. The record does not report an explicit statistical test for this primary comparison.

What is not described?

The registry record lists no analyses. It does not report the primary analysis method, a model specification, covariates, handling of repeated observations, missing-data assumptions, or a method for confidence intervals. It also does not report whether any interim analysis occurred. These omissions do not establish that such procedures were absent from the conduct of the study; they mean they are not reported in the registry record.

The record includes sample-size assumptions for planning illustrations: a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. Those are illustrations based on the observed effect, not a statement of the trial's original design assumptions. The trial's own sample-size justification is not reported in the registry record. Any sample-size illustration should not be interpreted as observed power.

In general, power is a property of a planned analysis under specified assumptions; it is not a retrospective measure of whether the observed results are reliable. The observed group percentages remain descriptive regardless of a planning illustration. A full assessment would require details of the prespecified estimand, analysis population, treatment of missing outcomes, and statistical model, which are not reported in the registry record.

10. Confidence Intervals and Precision

Precision concerns how much uncertainty surrounds an estimated result. The registry reports 100.0% for Period 1: RLZ SRD and 100.0% for Period 1: RLZ MP, with group sizes of n=18 and n=23, respectively. The comparison is recorded as a risk difference of 0.0, with interval endpoints of 0.0 and 0.0. These are the reported values and should be quoted as such.

In general, a confidence interval is an interval calculated using a specified method to represent uncertainty around an estimate. Its interpretation depends on the statistical procedure and the assumptions used. The registry record does not describe the interval method, its confidence level, or whether the crossover design was reflected in its calculation. The reported endpoints therefore cannot be evaluated as a fully documented confidence interval from the record alone.

Equal observed percentages do not establish exact equality in the populations from which the study participants came. A finite set of observations can yield identical group summaries while leaving uncertainty about differences in other participants or settings. The endpoint percentages are bounded, and observed values at the upper boundary also limit what a simple point estimate can communicate about uncertainty.

The registry does not report an interval separately for each group percentage, nor a detailed precision analysis for the primary outcome. The stated interval belongs to the posted risk-difference comparison. The trial's enrollment is reported as 62, but the primary analysis population is defined by completion of both self-administration periods and inclusion in SS. The group sizes shown for the primary outcome are not the same as the enrollment figure, and the record does not explain all reasons for that distinction. The observed results should therefore be described with the posted group sizes and without assuming that all enrolled participants contributed to this primary analysis.

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome and three secondary outcomes. The secondary outcomes concern treatment-emergent adverse events after syringe driver or manual push self-administration, local site reactions, and medication errors associated with adverse reactions. Their listing indicates planned outcome areas, but the registry record does not provide their results in the information.

When multiple outcomes or comparisons are assessed, multiplicity can increase the chance of obtaining apparently notable findings by chance. In general, a study may address this through a prespecified hierarchy or adjustment procedure. The registry record does not report a multiplicity strategy, an outcome hierarchy beyond identifying the primary endpoint, or adjusted significance thresholds. No conclusions about multiplicity adjustment should be drawn from the outcome listings alone.

The primary analysis population is described as the Full Analysis Set: participants included in SS, randomized, and completing both self-administration periods in accordance with the randomization scheme. The record does not provide a participant flow accounting or explain how participants who did not complete both periods were handled in other analyses. The primary result group sizes are reported, but reasons for exclusion from that endpoint population are not reported in the registry record.

The registry does not describe how missing primary endpoint data were handled, whether observations were imputed, or what assumptions were used for incomplete assessments. It also does not report sensitivity analyses addressing missingness. These details matter because an analysis limited to participants with observed outcomes can differ from an analysis that makes assumptions about unobserved outcomes.

The record lists no analyses. It does not report a statistical analysis plan, a primary hypothesis test, or a prespecified approach to the crossover structure. Absence of these details from the registry record should not be interpreted as evidence that no procedures were planned or conducted; it means that the relevant information is not reported in the registry record.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: myasthenia gravis (3.2%), myocardial infarction (1.9%), lung cancer metastatic (1.9%), transient ischaemic attack (1.9%), dyspnoea (1.9%).

The registry reports serious adverse events and other adverse events for the training period, the two self-administration periods by method, and the RLZ total. During the training period, the record lists 1 participant affected by a serious adverse event among 62 at risk, and 19 affected by other adverse events among 62 at risk. For Self-Administration Period 1 and 2: RLZ SRD, the corresponding figures are 3 among 54 for serious adverse events and 6 among 54 for other adverse events. For Self-Administration Period 1 and 2: RLZ MP, they are 1 among 53 and 6 among 53. The RLZ total lists 7 among 62 for serious adverse events and 24 among 62 for other adverse events. The registry reports zero deaths in each listed group.

These are descriptive safety counts with the listed at-risk denominators. The record does not establish that an event was caused by rozanolixizumab or by a particular administration method. The listed serious-event terms include Myasthenia gravis (3.2%), Myocardial infarction (1.9%), Lung cancer metastatic (1.9%), Transient ischaemic attack (1.9%), Dyspnoea (1.9%), and Urinary tract infection (1.6%). The registry record does not provide enough detail to interpret the relationship, timing, or clinical course of each event.

13. What the Result Does, and Does Not, Mean

The primary results show that 100.0% of participants in each displayed Period 1 group met the registry's definition of successful self-administration at the specified assessment. The outcome requires correct infusion-site selection, subcutaneous administration, and delivery of the intended dose. The result is therefore evidence about performance on those stated tasks among the analyzed groups.

It does not establish that every participant enrolled in the study successfully self-administered, because the primary endpoint population was restricted to the defined Full Analysis Set and the displayed groups have their own reported sizes. It does not establish that success will be identical in people outside the study or under circumstances not described in the registry. The record does not report enough detail about assessment procedures, missing outcomes, or exclusions to extend the result beyond the stated analysis groups.

The identical percentages do not establish equivalence or noninferiority between the methods. Those conclusions ordinarily require a prespecified margin and an analysis designed to evaluate it; such information is not reported in the registry record. The record reports a risk difference of 0.0 and interval endpoints of 0.0 and 0.0, but does not explain the method behind that comparison. Its statistical meaning cannot be fully assessed from the registry information alone.

The endpoint is not a measure of clinical efficacy. It does not show whether rozanolixizumab changes symptoms, disease course, or quality of life. The study is described as evaluating self-administration after training, rather than comparing clinical outcomes against a different drug or no treatment. The listed safety outcomes provide descriptive event counts, but do not establish causality.

Accordingly, the clearest reading is narrow: in the recorded Period 1 analysis groups, the posted percentage meeting the defined administration-success criteria was 100.0% for each method. Broader claims about comparative performance, long-term use, or clinical outcomes are not established by these figures.

14. Why This Trial Matters Statistically

This trial is statistically informative because the primary outcome is closely tied to the practical task under evaluation: whether participants can correctly self-administer using the assigned method after training. A clearly defined procedural endpoint can make the target of measurement concrete. The reported criteria specify site selection, route of administration, and intended dose delivery rather than relying on a broad or subjective description of success.

The crossover structure also raises important analytical questions. Participants were assigned to a sequence involving both methods, so the order of exposure is integral to the design. A comparison based only on the first period answers a different question from a model using repeated observations from both periods. Period, sequence, and possible within-participant correlation may be relevant in general, but the statistical handling of these features is not reported in the registry record.

The identical posted percentages illustrate why a point estimate alone is not enough to establish comparative equivalence. Interpretation depends on uncertainty, analysis choices, and the study's intended hypothesis. The registry record does not report the relevant inferential plan, and the risk-difference interval is not accompanied by a method description. The data are therefore most useful when kept close to their descriptive meaning.

The safety information also demonstrates the distinction between describing events and attributing them to a treatment or method. Counts and at-risk denominators provide a useful account of what was recorded, but causal interpretation requires additional context not reported in the registry record. For statisticians and clinical researchers, this record underscores the value of transparent endpoint definitions, analysis populations, missing-data procedures, and methods for crossover comparisons.

15. 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.
• Participant counts were reconstructed from posted percentages and arm sizes, so small rounding differences are possible.

The registry record gives limited detail for evaluating the primary analysis. It defines the Full Analysis Set and reports group results, but does not provide a participant flow accounting or explain exclusions and missing assessments. The reasons that the primary analysis group sizes differ from the enrollment figure are not reported in the registry record.

The study is open-label, and the outcome depends on participants carrying out administration tasks. The record does not report whether assessment was independently adjudicated, whether assessors were masked, or how any uncertain or partially completed administration was classified. These omissions limit evaluation of outcome measurement.

Although the design is crossover, the primary results are displayed for Period 1 groups. The record does not report a paired analysis across methods, adjustment for period or sequence, or testing for carryover. It also does not explain the calculation of the reported risk-difference interval. The registry lists no analyses, so the analysis approach cannot be reconstructed from the record.

The trial's sample-size justification, any interim analyses, the statistical analysis plan, and a multiplicity strategy are not reported in the registry record. Results for the three listed secondary outcomes are also not included in the information. Finally, the endpoint addresses defined administration success at Week 12; the registry results do not establish performance beyond that assessment or clinical effects on gMG.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Phase 3, Open-label, Crossover Study to Evaluate Self-administration of Rozanolixizumab by Study Participants With Generalized Myasthenia Gravis (gMG) — NCT05681715.
• Registry record last updated 2025-11-06; status last verified 2025-11.
• Results first posted 2025-05-07.
• 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.

19. Record Summary

NCT05681715 is a completed Phase 3 randomized, open-label crossover study sponsored by UCB Biopharma SRL. It enrolled 62 participants with generalized myasthenia gravis and evaluated self-administration of rozanolixizumab using a syringe driver and manual push, in opposite sequences.

The primary endpoint was successful self-administration at Week 12, defined by correct site selection, subcutaneous administration, and delivery of the intended dose. The posted Period 1 results are 100.0% for RLZ SRD (n=18) and 100.0% for RLZ MP (n=23). The registry comparison reports a risk difference of 0.0, with interval endpoints of 0.0 and 0.0, but does not report the method used to calculate it.

The record lists three secondary outcomes and safety summaries. Detailed primary analysis methods, missing-data procedures, crossover modeling, and the trial's sample-size justification are not reported in the registry record.