Front Line Ibrutinib Without Corticosteroids for Newly Diagnosed Chronic Graft-versus-Host Disease: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Front Line Ibrutinib Without Corticosteroids for Newly Diagnosed Chronic Graft-versus-Host Disease (NCT04294641), a na phase 2 study. The primary outcome is Fraction of Participants With an Overall Response Rate (Complete Response [CR] + Partial Response [PR]) Reported With an 80% Confidence Interval at 6 Months.

2. Clinical Question

The study asks whether first-line ibrutinib is associated with an overall response in people with newly diagnosed chronic graft-versus-host disease (cGVHD). The primary endpoint combines complete response (CR) and partial response (PR), assessed at 6 months using the 2014 National Institutes of Health consensus criteria. The registry record describes the planned question and endpoint but does not report the numerical response result or its 80% confidence interval.

This is a response-assessment question within one treated group, not a randomized comparison of ibrutinib against another treatment or against no treatment. The posted information therefore describes what the study set out to measure, but it does not establish a comparative treatment effect. The absence of a reported endpoint estimate also means that the response frequency and its precision cannot be interpreted from the registry record.

3. Trial Design

This completed phase 2 study enrolled 10 participants and used a single-group design. The registry lists allocation as not applicable and masking as none. Participants were screened for eligibility, and the primary endpoint population is described as six participants, because four were screen failures. The record does not describe a separate control group or a random assignment procedure.

The intervention was daily oral ibrutinib, described as first-line treatment without corticosteroids. The study summary says participants would take it once daily during 28-day cycles, for up to 2 years. Visits were scheduled every 2 weeks for the first 2 months and every 4 weeks thereafter. Planned assessments included medical history, physical examinations, vital signs, electrocardiograms, blood and urine tests, daily-activity assessment, well-being assessment, lung-function testing, and symptom and quality-of-life questionnaires. Chest computed tomography scans and additional blood tests or skin biopsies could be used. These are descriptions of the study procedures, not reported results.

The registry lists ECG, pulmonary function tests, CT, a steroid pulse (prednisone), voriconazole, posaconazole, and azithromycin among interventions. It does not explain how each listed item relates to treatment assignment, whether or when each was used, or whether these items were used by every participant. In particular, the presence of prednisone in the intervention list does not resolve the context of the study title’s “without corticosteroids” description.

The primary endpoint was assessed at 6 months. Secondary outcomes listed include the fraction of participants with grade 3 and grade 4 serious and/or non-serious adverse events, failure-free survival, and the fraction alive at 24 months of follow-up post-treatment. The registry record does not report numerical results for these outcomes in the information available for interpretation. Start and primary-completion dates are 2021-05-10 and 2024-06-24, and the status is completed.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Six out of ten participants were analyzed because 4 participants were screen failures.

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: 4/10 participants were screen failures.

6. Primary Endpoint

The registry lists the primary outcome as Fraction of Participants With an Overall Response Rate (Complete Response [CR] + Partial Response [PR]) Reported With an 80% Confidence Interval at 6 Months, measured over At 6 months.

The primary endpoint is the fraction of participants with an overall response at 6 months, defined as complete response (CR) or partial response (PR). Under the stated 2014 National Institutes of Health consensus criteria, CR means complete resolution of signs and symptoms in all affected organs or tissues. PR means improvement in at least one organ or tissue, with no progression in any other affected organ or tissue.

Combining CR and PR gives a binary endpoint: each participant either meets the overall-response definition or does not. A fraction is useful for describing how often a defined response criterion was met in the analyzed group. It is more interpretable than a change in an individual symptom alone when the study’s aim is to classify response across affected organs or tissues. It does not, by itself, show how much each participant improved, how durable a response was, or whether the result differs from what would have occurred under another treatment.

The registry specifies an 80% confidence interval for this endpoint. A confidence interval expresses uncertainty around an estimate; its width reflects the precision supported by the data and the analysis method. The numerical response estimate and confidence-interval bounds are not reported in the registry record, so the endpoint’s observed value and precision cannot be assessed from the posted information.

The primary population description says six of the 10 enrolled participants were analyzed because four were screen failures. This defines the reported analysis group, but the record does not give participant-level endpoint status or further details about endpoint availability, missing observations, or the handling of any participants who did not complete follow-up.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical description centers on a binary response endpoint: each analyzed participant is classified according to whether they met the combined CR-or-PR definition at 6 months. The registry says this fraction was to be reported with an 80% confidence interval. However, it does not report the numerical fraction or interval limits. As a result, readers cannot assess the observed response frequency or how precisely it was estimated.

What does a confidence interval express?

In general, a confidence interval is a range calculated from study data using a specified method, intended to express uncertainty around an estimate. A narrower interval indicates greater statistical precision under that method; a wider interval indicates less precision. The interval does not guarantee that the true value lies within its particular bounds, and it does not correct design limitations such as the lack of a comparison group. The stated 80% confidence level is part of the endpoint description, but the method used to calculate the interval is not reported in the registry record.

For a binary endpoint, the estimate is based on the number meeting the response definition relative to the analyzed participants. The registry identifies six participants in the primary analysis population, but does not report how many met the response criteria. It is therefore not possible to reconstruct the fraction or interval without inventing data, and no such reconstruction is appropriate.

Why does the study design matter?

A single-group design estimates outcomes within the treated group. It does not directly compare that outcome with a control group. In a randomized comparison, treatment groups can be compared under the trial’s allocation procedure; this registry record instead lists a single group, allocation as not applicable, and no masking. General statistical interpretation of a single-group response fraction is descriptive: it reports the frequency of the outcome in that group, not a treatment-versus-control contrast.

Masking can reduce some forms of influence on assessment or reporting, depending on the study procedures. The registry records no masking. It does not report further details about endpoint assessor procedures, whether response assessment was independent, or whether the outcome criteria were applied by reviewers unaware of other clinical information. These assessment details should not be inferred.

What can the planning illustration tell readers?

The registry includes sample-size planning assumptions based on the observed effect, but describes these as a planning illustration rather than the study’s own design. The stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the target effect is described as a stated fraction of the observed effect. For time-to-event illustrations, the quantity is total events; for other illustrations, it is participants per arm. These assumptions do not make the completed single-group trial a two-arm study, and the resulting planning values are not observed power. The registry record does not report the trial’s own sample-size justification.

In general, over-dispersion occurs when variability is greater than a model assumes. It can make standard errors too small and confidence intervals too narrow if the extra variability is ignored. This is a general statistical consideration, not a method reported for this trial. The registry does not identify a model for the primary endpoint, a dispersion adjustment, a confidence-interval calculation method, or a hypothesis-testing procedure.

How should the safety counts be interpreted statistically?

The safety figures are counts of participants at risk and participants affected, with serious and other adverse events reported separately. These are descriptive summaries. A serious adverse-event proportion can be affected by the size and composition of the safety population, the observation period, how events are coded, and whether one participant can experience more than one event. The registry does not explain those details or report an inferential comparison. The listed term percentages should therefore be read as reported event summaries, not as evidence of causation or comparative risk.

For the serious-event terms, the record lists atrial fibrillation, dyspnea, myalgia, and upper respiratory infection, each at 16.7%. The registry does not state whether participants experienced multiple listed terms, whether the same participant contributed to more than one term, or the timing and duration of the events. No additional rates or participant-level patterns should be inferred from the term list.

More broadly, the registry record includes six outcome measures and lists zero analyses. It does not report a full statistical analysis plan, the selected analysis method for each outcome, handling of censoring for failure-free survival, or methods for uncertainty estimation beyond the primary endpoint’s stated 80% confidence interval. These missing details limit reproducibility and prevent a fuller assessment of the reported analysis choices.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists six outcome measures, including the primary overall-response endpoint and secondary outcomes covering adverse events, failure-free survival, and survival at 24 months of follow-up post-treatment. It lists no analyses. The record does not describe a hierarchy among outcomes, an adjustment for testing multiple outcomes, or whether any outcome was treated as exploratory. Without those details, the chance of false-positive findings across multiple statistical tests cannot be assessed. This is a general issue when several outcomes are considered; it is not evidence that a particular testing procedure was used.

The primary endpoint is described with an 80% confidence interval, but the numerical estimate and interval are not reported in the registry record. The calculation method and the treatment of missing primary-endpoint observations are also not reported. The population description says six participants were analyzed because four were screen failures. It does not explain whether any additional endpoint measurements were missing or how incomplete follow-up was handled.

For failure-free survival, the registry record does not report the event definition, censoring rules, analysis method, or numerical result. For the fraction alive at 24 months post-treatment, the record does not state how participants without complete follow-up were handled. These details are important because outcome definitions and missing-data procedures can influence estimates, particularly when follow-up is incomplete.

In general, missing-data methods describe how an analysis accounts for information that was not observed. Different assumptions can lead to different estimates, so transparent reporting is needed to understand the analysis. No imputation method, sensitivity analysis, or missing-data assumption is reported in the registry record. The record also does not state whether the primary analysis followed an intention-to-treat principle or another prespecified analysis population. The available population description should not be expanded into an assumption about those methods.

11. 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 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: atrial fibrillation (16.7%), dyspnea (16.7%), myalgia (16.7%), upper respiratory infection (16.7%).

The safety group is described as Dose Level 1, with an ibrutinib dose of 420 mg (3 x 140 mg Capsules) daily. Six participants were at risk for serious adverse events, and three were affected. Six were at risk for other adverse events, and six were affected. Three deaths are recorded. These are descriptive counts from the registry, not a comparison between treatment groups.

The serious adverse-event terms listed are atrial fibrillation, dyspnea, myalgia, and upper respiratory infection, each reported as 16.7%. The registry does not clarify whether these terms occurred in separate participants or whether a participant could contribute to more than one term. The percentages should be interpreted as the posted term-level summaries, not added together or treated as a count of distinct participants.

Serious adverse events, other adverse events, and deaths are different summaries. The record does not state whether the deaths were related to an adverse event, whether any event was judged related to ibrutinib, or how events were attributed. It also does not provide event timing, duration, recurrence, or a comparison group. These figures therefore describe reported safety observations but do not establish that treatment caused an event or death, or quantify risk relative to another option.

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

The registry record documents a phase 2, single-group study of first-line ibrutinib for newly diagnosed cGVHD and defines an overall-response endpoint at 6 months. It also describes a primary analysis population of six participants, with four screen failures among the 10 enrolled. These registry entries establish the study context and the scale of the primary analysis, but the record does not report the numerical response fraction or its 80% confidence interval.

Without the primary estimate, the posted record cannot show how frequently participants met the combined CR-or-PR definition or how precisely that frequency was estimated. The response criteria are defined, but the outcome itself is not numerically available. The stated confidence level alone is not enough to determine the interval’s width or interpret the estimate.

The single-group design also limits what any response fraction could establish. A response observed in one treated group would not, by itself, show what would have happened under a different treatment or without the study intervention. The design does not provide a randomized, like-for-like comparison, and no comparator outcome is reported. Accordingly, the registry information cannot establish a comparative treatment effect.

The safety counts add descriptive information: the record reports participants affected by serious and other adverse events, three deaths, and four serious-event terms with their reported percentages. Those summaries do not establish causation. The record does not describe event attribution or provide a control group against which to compare event frequencies.

These limits do not mean that the study produced no useful information. It defines a clinical question, a response framework, and several follow-up and safety outcomes. But the record as posted leaves the central efficacy result and many analysis details unreported. Statistical interpretation should distinguish the existence of a planned measure from a numerical finding, and distinguish a description of events from evidence that an intervention caused them.

13. Why This Trial Matters Statistically

This trial is statistically notable for the gap between a clearly defined primary endpoint and the absence of its numerical result in the registry record. The endpoint specifies a response definition, a time point of 6 months, and an 80% confidence interval. Yet without the response fraction and interval limits, readers cannot assess either the observed result or its precision.

The difference between enrollment and the primary analysis population is also important. The study enrolled 10 participants, while six were analyzed because four were screen failures. A reader needs the analysis denominator to interpret a fraction, and the registry does identify that denominator. However, it does not provide the response count or describe any other missing endpoint data. Transparent reporting of both numerator and denominator would be needed to understand the endpoint fully.

The single-group design is central to interpretation. It can describe outcomes within a treated cohort, but it does not provide a concurrent control against which to assess differences. That distinction helps prevent a within-group observation from being mistaken for a comparative treatment effect. In this record, the response result is not reported, so even a descriptive response estimate cannot be assessed.

Safety reporting illustrates another statistical distinction: counts and percentages describe what was recorded in a group, but do not by themselves establish causation or comparative risk. The listed adverse-event terms, affected-participant counts, and deaths are useful descriptive information, while missing event-level details and the absence of a comparison group constrain interpretation.

Finally, the registry includes planning illustrations based on stated assumptions, but those are not the trial’s own design justification and are not observed power. Keeping planning calculations separate from results is essential: a hypothetical sample-size requirement cannot substitute for an observed outcome or resolve uncertainty about a completed study.

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.

The primary response result is not reported in the registry record. Although the endpoint is defined and its confidence level is stated, the response fraction and 80% confidence-interval limits are absent. This prevents assessment of the observed response and its statistical precision.

The study is single-group, has no masking, and lists allocation as not applicable. Without a concurrent control group, the design cannot support a direct comparison with another treatment. The enrolled group contained 10 participants, while six were analyzed for the primary endpoint because four were screen failures. The registry does not give further details about the reasons for screen failure or other possible gaps in endpoint follow-up.

The record does not report the method used to calculate the primary confidence interval, the statistical test or model, a trial-specific sample-size justification, or a full statistical analysis plan. It lists six outcome measures and zero analyses, but does not explain multiplicity handling or the analysis methods for secondary outcomes. Definitions and methods for failure-free survival and the 24-month survival fraction are not described in the information available for interpretation.

Safety reporting is limited to summary counts and serious-event terms. The record does not state whether events were considered treatment-related, clarify overlap among listed terms, or provide event timing and duration. Three deaths are recorded, but their causes and relationship to adverse events or treatment are not reported. The intervention list includes a steroid pulse and other drugs, while the registry does not explain their use or context relative to the study’s “without corticosteroids” description.

These limitations are specific to the information recorded and do not establish what analyses or assessments may have occurred outside the registry entry. The appropriate conclusion is that the posted record does not report those details.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Front Line Ibrutinib Without Corticosteroids for Newly Diagnosed Chronic Graft-versus-Host Disease — NCT04294641.
• Registry record last updated 2026-01-23; status last verified 2026-01.
• Results first posted 2025-01-22.
• 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.

18. Record Summary

NCT04294641 is a completed phase 2, single-group study titled “Front Line Ibrutinib Without Corticosteroids for Newly Diagnosed Chronic Graft-versus-Host Disease.” It enrolled 10 participants and lists six participants in the primary analysis population because four were screen failures. The primary endpoint is the fraction with complete or partial response at 6 months, assessed using the 2014 National Institutes of Health consensus criteria and described with an 80% confidence interval.

The registry record does not report the numerical primary response estimate or confidence interval. It lists secondary outcomes involving adverse events, failure-free survival, and survival at 24 months post-treatment, but numerical results and detailed analysis methods are not reported in the registry record. Safety summaries include three participants affected by serious adverse events, six affected by other adverse events, three deaths, and four serious-event terms each reported at 16.7%. The single-group design does not provide a concurrent treatment comparison, and the posted safety counts do not establish causation.