Efficacy and Safety Trial of RPC1063 for Moderate to Severe Crohn's Disease: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Efficacy and Safety Trial of RPC1063 for Moderate to Severe Crohn's Disease (NCT02531113), a na phase 2 study. The primary outcome is Change in Simple Endoscopic Score for Crohn's Disease (SES-CD) (Paired Segments) From Baseline at Week 12 as Determined by a Blinded Central Reader..

2. Clinical Question

In plain terms, the main question was whether endoscopic disease-severity scores changed over the induction period among participants who received RPC1063. SES-CD evaluates ulcer size, ulcerated surface, affected surface, and narrowing across intestinal segments. Larger scores indicate greater disease severity. The record also lists treatment-emergent adverse events during the induction and extension periods as a secondary outcome, alongside other outcome measures.

Because this was a single-group, open-label study, the primary question is about change over time within the treated group. The design does not provide a randomized untreated or active-treatment comparison that could distinguish changes associated with treatment from changes due to other influences. The central reader was blinded for the primary endoscopic assessment, but the registry does not report additional details about that process.

3. Trial Design

This was a phase 2, multi-center, open-label induction trial with an extension period. The intervention was oral RPC1063, also identified as ozanimod in the arm description. The registry classifies the study as single-group, lists allocation as not applicable, and records masking as none. Enrollment was 69 participants, and the study status is completed.

The registry gives a study start date of 2015-10-09 and a primary completion date of 2019-09-12. The official title describes an induction period and an extension period intended to access endoscopic improvement and changes in intestinal and serum biomarkers. The record also lists treatment-emergent adverse events during both periods as a secondary outcome. It lists 31 outcome measures, while the number of analyses is recorded as 0.

The primary endpoint was change in SES-CD from baseline to Week 12, based on paired segments and determined by a blinded central reader. The registry describes the intent-to-treat population as all enrolled participants who received at least one dose of ozanimod. For the change-from-baseline analysis, participants needed baseline data and available data for the analysis; the remainder of the population description is not reported in the registry record.

A single-group design can describe changes observed among participants over time, but it cannot estimate a randomized between-group treatment contrast. The open-label designation means masking was not used for the trial overall. The registry does not report a detailed protocol, dose schedule, site count, enrollment rationale, or further information about the extension design. Those details should not be inferred from the trial title or its completion status.

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: Eligible participants must have had a Crohn's Disease Activity Index (CDAI) score of 220 to 450 inclusive with an Simple Endoscopic Score for Crohn's Disease (SES-CD) score of ≥ 6 and an average daily stool score ≥ 4 points and/or an average daily abdominal pain score of ≥ 2 points.

Induction Period: Week 0 to 12

Reasons for not completing this period:

Extension Period: Week 12 up to Week 160

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The intent to treat population = all enrolled participants who received at least one dose of ozanimod. For paired segment scores, any missing segment scores, were imputed by non-missing score used in previous visit. Analysis for change from baseline includes those with data available at baseline and visit.

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: The intent to treat population included all enrolled participants who received at least one dose of investigational product (IP).

6. Primary Endpoint

The registry lists the primary outcome as Change in Simple Endoscopic Score for Crohn's Disease (SES-CD) (Paired Segments) From Baseline at Week 12 as Determined by a Blinded Central Reader., measured over Baseline to Week 12.

The primary endpoint was change in the Simple Endoscopic Score for Crohn's Disease (SES-CD) from baseline to Week 12, using paired segments. The score assesses four features: size of ulcers, ulcerated surface, affected surface, and presence of narrowing. Each feature is assessed across five segments of the ileum and colon. Larger scores indicate greater disease severity.

Endoscopy provides a direct assessment of the intestinal features included in the score, rather than relying only on symptoms or blood measurements. A change score compares a participant's measurement at follow-up with their baseline measurement, so the analysis concerns within-participant change over the induction period. The primary endpoint is described as a mean, with standard deviation as its dispersion measure. The central reader was blinded for the primary assessment, as stated in the endpoint title.

The registry record does not report a numerical mean change, standard deviation, confidence interval, or statistical test result for this endpoint. It also does not give a complete account of which participants contributed to the final paired-segment analysis. Without the numerical estimate and its uncertainty, the direction, size, and precision of the observed endpoint change cannot be assessed from the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is a continuous outcome: change in SES-CD from baseline to Week 12. The registry identifies the summary measure as a mean and the measure of dispersion as a standard deviation. These are descriptive statistical summaries of the endpoint. The registry record does not report a numerical mean, standard deviation, confidence interval, p-value, or other primary analysis result.

What a mean change describes

General statistical explanation: for a continuous measure, a mean change summarizes the average within-participant difference between the follow-up and baseline measurements. It compresses individual changes into one group-level value. Participants may have changes above or below that mean, so the mean alone does not describe the full distribution or the experiences of every participant. The registry states that larger SES-CD scores indicate greater disease severity, but does not give the direction or size of the observed mean change.

The standard deviation describes the spread of participant-level measurements around the mean. It is not the same as a standard error or a confidence interval. General statistical explanation: a confidence interval conveys uncertainty around an estimated quantity, whereas a standard deviation primarily describes variability among observations. No confidence interval for the primary endpoint is reported in the registry record, so its precision cannot be assessed from a reported interval.

Why paired measurements matter

The endpoint is defined as change from baseline, so it relies on measurements linked within participants. The registry describes paired segments and identifies a blinded central reader for the primary endoscopic assessment. General statistical explanation: pairing can account for the fact that baseline and follow-up measurements come from the same participant. The analysis population still depends on which participants have usable baseline and follow-up information; the record says the change analysis includes those with data available at baseline and then ends its description. Further details about eligibility for analysis are not reported in the registry record.

The SES-CD combines assessments of ulcer size, ulcerated surface, affected surface, and narrowing across intestinal segments. The endpoint description states that each component is scored on a scale of 0 to 3 and provides ranges for segment-level and overall scores. These details explain the construction and interpretation of the measure; they do not provide the trial's observed endpoint result.

How missing segment scores were handled

The record says that, for paired segment scores, a missing segment score was imputed using a non-missing score from the previous visit. General statistical explanation: imputation replaces missing information with an assumed value so that an analysis can proceed. A previous-visit value may not equal the score that would have been observed at the current visit. The consequences depend on the pattern of missingness and on whether the imputation assumption is reasonable. The registry record does not report how many scores were imputed, why they were missing, or whether alternative methods were examined.

Missing-data methods are part of the estimand's practical interpretation: a reported estimate would reflect both observed measurements and the stated imputation rule. Without counts of missing measurements or sensitivity analyses, readers cannot assess how dependent a result would be on that rule. No detailed statistical analysis plan is reported in the registry record.

Reading planning calculations

General statistical explanation: sample-size calculations describe how many participants might be needed under specified assumptions to target a chosen level of power for a planned comparison. They are planning illustrations, not evidence that a study achieved a particular probability of detecting an effect after it was conducted. The planning assumptions recorded for the accompanying calculations include a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect expressed as a stated fraction of the observed effect. The record describes these as illustrations based on the observed effect, not as the trial's own design.

Those assumptions do not turn this single-group study into a randomized two-arm comparison. Nor do planning calculations replace a reported estimate and uncertainty interval. The registry record does not report the numerical primary-outcome result needed to evaluate the observed effect or its precision in the clinical trial.

Multiplicity and interpretation

The record lists 31 outcome measures and 0 analyses. It does not report whether or how statistical testing across multiple outcomes was controlled, whether a hierarchy of outcomes was used, or whether interim analyses were conducted. General statistical explanation: when many outcomes or hypotheses are examined, the chance of at least one apparently unusual result can increase if no multiplicity strategy is used. The registry record does not provide enough information to characterize such a strategy, so no claim about adjustment or its absence should be inferred.

In summary, the endpoint and a rule for handling missing segment scores are described, but the primary numerical analysis and important details of the analysis plan are not reported in the registry record. The posted design information supports explanation of the intended measure and general statistical principles, not reconstruction of an unreported result.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Ozanimod Hydrochloride (HCl) 1 mg")
n   <- c(56)
m   <- c(-2.3)
sp  <- c(6.2)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Ozanimod Hydrochloride (HCl) 1 mg  56  -2.300  6.200  -3.960  -0.640

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 31 outcome measures and 0 analyses. It does not report a statistical analysis plan explaining how the primary endpoint was prioritized relative to secondary outcomes, whether testing across outcomes was adjusted for multiplicity, or whether interim analyses were planned or performed. General statistical explanation: multiplicity matters because examining many outcomes can increase the chance of an apparently noteworthy result when each is considered separately. The record does not permit a judgment about whether that issue was addressed.

The primary endpoint description identifies an intent-to-treat population as enrolled participants who received at least one dose of ozanimod. It also says that change-from-baseline analysis includes participants with baseline data and ends without completing the population definition. Therefore, the full analysis-population criteria are not reported in the registry record.

For paired segment scores, missing segment values were imputed using a non-missing score from the previous visit. The registry does not report how many participants or segments were affected, the extent of missing endpoint data, the reasons for missingness, or sensitivity analyses using other assumptions. These omissions limit assessment of how missing data could influence an endpoint estimate.

No numerical primary analysis is reported, so there is no posted endpoint estimate to evaluate for sensitivity to missing-data handling or multiplicity. The absence of these details should not be read as evidence that a particular procedure was or was not used; 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: crohn's disease (8.7%), small intestinal obstruction (2.9%), abdominal abscess (2.9%), abdominal pain upper (1.4%), anal fistula (1.4%).

The registry safety summary records 18 participants with serious adverse events among 69 at risk, 47 participants with other adverse events among 69 at risk, and 1 death. These are descriptive figures for the ozanimod group. The registry also lists serious adverse-event terms and their percentages: Crohn's disease, 8.7%; small intestinal obstruction, 2.9%; abdominal abscess, 2.9%; abdominal pain upper, 1.4%; anal fistula, 1.4%; and enterocolonic fistula, 1.4%.

These counts and listed percentages describe events recorded in this group. They do not, by themselves, show whether an event was caused by the intervention. Because the study has no randomized comparator, the safety summary does not provide a controlled estimate of how event occurrence differed from another treatment or from no study intervention. The registry record does not report further details in this summary about event timing, individual participants with multiple events, or causal attribution.

Treatment-emergent adverse events during the induction and extension periods are listed as a secondary outcome. The specific result for that outcome is not reported in the registry record. Serious-event counts and the listed event terms should therefore be interpreted as descriptive safety information, not as a comparative conclusion.

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

This record documents a completed phase 2, open-label, single-group trial in 69 participants with moderately to severely active Crohn's disease. It identifies a primary endoscopic endpoint: change in SES-CD from baseline to Week 12, using paired segments and a blinded central reader. It also describes how some missing segment scores were handled and reports descriptive adverse-event figures.

The central interpretive limitation is that the registry record does not report a numerical primary-outcome result. There is no reported mean change, measure of uncertainty, or statistical test result with which to assess the size or precision of the endoscopic change. The absence of a numerical result does not mean that no change occurred; it means that the primary estimate cannot be evaluated from the registry record.

The study's single-group design also limits causal interpretation. General statistical explanation: a change between baseline and follow-up in a treated group is not equivalent to a randomized comparison. Without a concurrent control group, changes over time cannot be separated from other possible influences using this design alone. The open-label design is another feature readers should keep in mind, although the primary endoscopic assessment is described as determined by a blinded central reader.

The safety figures show adverse events recorded among participants in the intervention group, including serious adverse events and 1 death. They do not establish causality or permit a comparative safety conclusion. The record's secondary-outcome listing does not substitute for the missing primary endpoint estimate, and the number of listed outcome measures does not reveal which analyses were conducted.

Accordingly, the trial record is useful for understanding the intended question, outcome definition, and basic design. It does not support a quantitative conclusion about the primary endoscopic result, nor does it support a controlled estimate of treatment effect or comparative safety.

14. Why This Trial Matters Statistically

This trial is statistically notable as an example of why design and reporting must be read together. The primary endpoint concerns change in an endoscopic severity measure over time, but the study is single-group and open-label. That design can describe within-group trajectories, yet it does not create a randomized comparison for separating intervention-associated change from other changes over the same period.

The primary assessment was determined by a blinded central reader, while masking for the trial overall is recorded as none. These statements describe different features: the trial was open-label, but the endpoint title specifies blinding for the central reader. The record does not provide further details about reader procedures, so the scope and implementation of that blinding cannot be assessed.

The endpoint also illustrates how an outcome can depend on measurement rules. SES-CD combines several endoscopic features across intestinal segments, and the record describes a previous-visit imputation rule for missing paired-segment scores. The interpretation of any estimate would therefore depend on both the score definition and how missing observations were treated. Counts of imputed scores and sensitivity analyses are not reported in the registry record.

Finally, the record lists 31 outcome measures but 0 analyses and does not report a numerical primary result. That makes transparent reporting especially important: a clearly stated estimate and its uncertainty are needed to interpret the magnitude and precision of the main outcome. The registry record provides useful design and measurement information, but not the primary numerical evidence needed for that assessment.

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.

The most important limitation of interpretation is that the registry record does not report the numerical primary-endpoint result. Without a mean change and an uncertainty measure, the direction, magnitude, and precision of the Week 12 change cannot be assessed. The record lists 31 outcome measures and 0 analyses, and does not provide a detailed statistical analysis plan.

The study is recorded as single-group, with allocation not applicable and masking none. There is no randomized comparator in the record. Consequently, the design does not support a randomized between-group estimate, and observed changes over time cannot by themselves establish what caused them. The primary endpoint's blinded central reader is a design feature, but details of the reading process are not reported in the registry record.

The primary-outcome population description is incomplete. It states that the intent-to-treat population includes enrolled participants who received at least one dose and that change analysis includes participants with baseline data, but the description ends before giving the full criteria. The record does not report the number of participants contributing to the primary analysis or the amount of missing endpoint data.

For paired segment scores, missing values were imputed using a non-missing score from the previous visit. The number of imputed scores, reasons for missingness, and sensitivity analyses are not reported in the registry record. These details would be needed to understand the robustness of an endpoint estimate to missing-data assumptions.

The safety summary is descriptive and has no randomized comparator. The registry does not report causal attribution details or a comparative safety estimate in this record. These limitations constrain interpretation; they do not establish that the intervention had a particular benefit or harm.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Efficacy and Safety Trial of RPC1063 for Moderate to Severe Crohn's Disease — NCT02531113.
• Registry record last updated 2021-01-22; status last verified 2020-12.
• Results first posted 2020-10-08.
• 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

The registry record describes NCT02531113, a completed phase 2, multi-center, open-label, single-group trial of oral RPC1063, also identified as ozanimod, in moderately to severely active Crohn's disease. Enrollment was 69. The study start date was 2015-10-09, and the primary completion date was 2019-09-12.

The primary endpoint was change in SES-CD from baseline to Week 12, using paired segments and a blinded central reader. The record describes imputation of missing segment scores using a non-missing score from the previous visit. A numerical primary-outcome result is not reported in the registry record.

The safety summary records serious adverse events in 18 of 69 participants, other adverse events in 47 of 69 participants, and 1 death. The record lists 31 outcome measures and 0 analyses. It does not report a detailed analysis plan or a randomized comparison.