Ability to Maintain or Achieve Clinical and Endoscopic Remission With MMX Mesalamine Once Daily in Adults With Ulcerative Colitis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Ability to Maintain or Achieve Clinical and Endoscopic Remission With MMX Mesalamine Once Daily in Adults With Ulcerative Colitis (NCT01124149), a na phase 4 study. The primary outcome is Percentage of Subjects in Complete Remission at Month 12 of Maintenance Phase.

2. Clinical Question

3. Trial Design

This was a Phase 4, open-label, multicenter, prospective study with a single-group model and no masking. Allocation is recorded as not applicable. The registry lists enrollment of 759 and a completed status. The study began on 2010-06-29, with primary completion on 2012-12-07.

The study plan described an acute phase in which subjects received MMX mesalamine/mesalazine 4.8g/day once daily for 8 weeks. Subjects achieving either complete or partial remission were to enter a 12-month maintenance phase and receive 2.4g/day once daily. The study aimed to evaluate maintenance outcomes according to remission status after acute therapy. The registry does not report how many subjects achieved each remission status or entered the maintenance phase.

The primary outcome was the percentage of subjects in complete remission at month 12 of maintenance. Its stated analysis population included subjects who took at least 1 dose of investigational product during maintenance and had at least 1 post-dose efficacy assessment. That definition means the primary outcome population was not necessarily all enrolled subjects. The registry record does not report the number analyzed for the primary outcome.

Because there was no separate control arm, the study design does not support a randomized comparison of MMX mesalamine with another treatment or with no treatment. The remission-status comparison described in the study summary is observational within the study: remission status follows the acute phase rather than being assigned at random. The registry does not report further details about group definitions, analysis methods, or adjustment for differences between those groups.

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: Although 639 subjects completed the Acute Phase, 167 were not eligible to enter the Maintenance Phase due to lack of efficacy and 2 others withdrew prior to entering the maintenance Phase and 1 was withdrawn per IVRS prior to entering the Mainenance Phase. Therefore, 469 subjects entered the Maintenance Phase.

Acute Phase

Reasons for not completing this period:

Maintenance Phase

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Maintenance Phase Efficacy Population included all subjects who, during the Maintenance Phase, took at least 1 dose of investigational product and had at least 1 post-dose efficacy assessment.

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 Safety Population was used. Safety Population defined as all subjects who took at least 1 dose of investigational product during the Acute or Maintenance Phase (n=717).

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Subjects in Complete Remission at Month 12 of Maintenance Phase, measured over 12 months.

The primary endpoint was the percentage of subjects in complete remission at month 12 of the maintenance phase. It measures the proportion of the defined maintenance-phase efficacy population meeting a combined clinical and endoscopic remission criterion at that timepoint. The endpoint is not a measure of change in symptoms alone.

Complete remission was defined as a modified UC-DAI score <=1, a score of 0 for rectal bleeding and stool frequency, and at least a 1-point reduction in endoscopy score from baseline. The modified UC-DAI combines stool frequency, rectal bleeding, endoscopy score, and physician global assessment. Each parameter scores between 0 and 3, and 12 is the worst total score. The endpoint therefore combines symptoms, an endoscopic assessment, and a physician assessment within the overall score, with additional requirements for bleeding, stool frequency, and endoscopy.

Composite endpoints can capture more than one dimension of disease activity, but their interpretation depends on the exact criteria and the population assessed. Here, a subject had to meet the specified combined threshold to count as in complete remission. The registry does not report the number or percentage meeting that definition at month 12, or a confidence interval describing its precision.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods should be read in relation to the study design and the exact population being analyzed. In this study, the registry describes a prospective, open-label, single-group design. That design can describe outcomes during the study regimen, and the planned remission-status comparison can describe outcomes across groups defined by response after acute treatment. It does not create a randomized control comparison.

What does a percentage endpoint represent?

The primary endpoint is a percentage of subjects meeting the complete-remission definition at month 12. For a binary endpoint, each eligible subject is classified as meeting or not meeting the criterion. The resulting proportion summarizes the observed frequency in the analyzed population. Its meaning depends on the endpoint definition, the denominator, and the completeness of assessment. The registry states the primary analysis population criteria but does not report the number analyzed or the resulting percentage.

General statistical explanation: a confidence interval expresses uncertainty around an estimated quantity under specified assumptions. A narrow interval generally indicates greater precision than a wide interval, while neither guarantees that the study design avoids bias. The registry does not report a confidence interval for the primary endpoint, so its precision cannot be evaluated from the registry results.

Why does the study design matter?

Random assignment helps make treatment groups comparable on average at the start of a trial. Here, allocation is listed as not applicable and the study is single-group. The planned comparison concerns subjects categorized by remission status following acute therapy. Since that status was an outcome of the acute phase rather than a randomized assignment, groups could differ in ways related to both their initial remission and later outcomes. General statistical methods can sometimes adjust for measured differences, but adjustment cannot automatically remove unmeasured differences. The registry record does not report whether adjusted analyses were performed or what variables they used.

The open-label design means masking was absent. For outcomes involving clinical assessments, knowledge of treatment or clinical status can potentially affect assessment or reporting. The endpoint includes an endoscopic component as well as symptoms and physician global assessment. The registry does not report procedures used to standardize or mask those assessments, so their potential influence cannot be characterized from this record.

How should planning calculations be understood?

General statistical explanation: a sample-size calculation asks how much information might be needed to detect a specified effect under assumptions about variability, significance level, allocation, and analysis. It is a planning exercise, not an observed result. The registry record does not report the study's own sample-size justification or a power calculation for its planned analysis.

Any planning illustrations associated with this analysis are explicitly based on an observed effect and use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the assumed effect is a stated fraction of the observed effect. Those are illustration assumptions, not evidence that the original single-group study was designed with that allocation or analysis. Such calculations should not be called observed power. Because the primary outcome estimate is not reported in the registry record, the basis and interpretation of an effect-based illustration cannot be independently assessed from the registry results alone.

What is the role of the remission definition?

The modified UC-DAI combines several components that measure symptoms, endoscopic appearance, and physician assessment. A composite definition requires careful attention to each criterion: meeting the total-score threshold alone is not sufficient if the additional bleeding, stool-frequency, and endoscopy requirements are not met. The specific threshold and component scoring are stated in the registry, but the subject-level data and the count meeting each component are not reported. Readers therefore cannot determine which component most often limited classification as complete remission.

Why do denominators and missing observations matter?

For a proportion, the denominator determines which subjects contribute information. The primary endpoint population includes subjects who received at least 1 maintenance dose and had at least 1 post-dose efficacy assessment. Subjects outside that definition do not contribute to the stated efficacy population, but the registry does not report their number or reasons for exclusion. General statistical explanation: if subjects with missing assessments differ systematically from those with observed assessments, a complete-case estimate may not represent the broader enrolled group. The registry record does not report missing-data methods or sensitivity analyses, so the impact of missing observations is unknown.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("MMX Mesalamine/ Mesalazine (Complete Remission Acu", "MMX Mesalamine/ Mesalazine (Partial Remission Acut")
n      <- c(182, 277)
events <- c(87, 72)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  MMX Mesalamine/ Mesalazine (Complete Remission Acu  182  87  47.8  40.4  55.3  40.7  55.0  40.7  55.0
ARM  MMX Mesalamine/ Mesalazine (Partial Remission Acut  277  72  26.0  20.9  31.6  21.2  31.5  21.2  31.5

11. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary endpoint and several secondary outcomes covering clinical remission, relapse, mucosal healing, symptom changes, and remission status after acute therapy. When a study evaluates multiple outcomes, the chance of at least one apparently unusual result can increase if each is tested separately without accounting for the number of tests. General statistical methods can address this through prespecified testing sequences or other multiplicity procedures. The registry record does not report whether any such approach was planned or used.

The registry record does not report p-values, confidence intervals, or results for the primary or secondary outcomes. It also does not report whether analyses were prespecified, how the remission-status groups were compared, or whether covariate adjustment was used. The analysis plan and sample-size justification are not reported in the registry record, so the intended inferential framework cannot be reconstructed.

The primary outcome population was defined as maintenance-phase subjects who took at least 1 dose and had at least 1 post-dose efficacy assessment. This is an analysis-population rule, but the record does not report its size, the number excluded from it, or the reasons for missing assessments. It does not report imputation, censoring, or sensitivity-analysis methods. Those omissions prevent assessment of how incomplete follow-up might affect the estimated percentage. The overall enrollment of 759 should not be treated as the primary endpoint denominator.

12. Safety Results

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

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: diarrhea (0.7%), anemia (0.4%), abdominal pain (0.4%), road traffic accident (0.4%), colitis ulcerative (0.3%).

The registry reports serious adverse events for the acute and maintenance phases separately. In the acute phase, 13 of 717 subjects were recorded as affected by serious adverse events; in the maintenance phase, 14 of 461 were recorded as affected. Other adverse events were recorded for 60 of 717 subjects in the acute phase and 65 of 461 in the maintenance phase. These are phase-specific counts and denominators, not a randomized comparison.

The listed serious-event terms include diarrhea at 0.7%, anemia at 0.4%, abdominal pain at 0.4%, road traffic accident at 0.4%, colitis ulcerative at 0.3%, and dehydration at 0.2%. These percentages describe the entries listed in the registry and do not, by themselves, establish whether an event was caused by treatment. The record does not report deaths; a null death entry should not be interpreted as confirming that there were none.

General statistical explanation: safety counts depend on the population observed, the duration of observation, and how events are defined and collected. Since subjects could contribute to different phases and the record does not provide a randomized control group, comparing phase counts does not estimate a treatment-related risk difference. The registry record does not report further details needed to evaluate event timing, exposure-adjusted rates, or causal attribution.

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

The study addresses an important distinction in its stated question: whether subjects who achieve complete remission after acute therapy have different later outcomes from subjects who achieve partial remission. It also specifies a combined clinical and endoscopic definition for complete remission during maintenance. These features clarify what the investigators intended to evaluate.

However, the registry record does not report the primary month-12 complete-remission percentage, its denominator, or an uncertainty interval. It also does not report the group-specific results needed to assess the comparison between subjects with complete and partial remission after acute treatment. As a result, the registry record cannot establish the frequency of the primary outcome or the magnitude and precision of any difference between those groups.

Even if such a difference were reported, the design would matter to its interpretation. The remission groups were defined by status after acute therapy rather than assigned at random. Their later outcomes could reflect differences associated with initial disease activity, response, or other factors. The registry does not report adjusted comparisons, so it is not possible to determine how such factors were handled.

The study also has no separate control arm. Its results, even if fully reported, would describe outcomes within the studied regimen and population; they would not by themselves establish what would have happened under an alternative treatment or without treatment. The listing of adverse events likewise describes events recorded in the study, not proof of causation.

General statistical explanation: an estimate answers a question about the analyzed population under the stated definitions; it does not automatically generalize to every patient or setting. The primary efficacy population excluded subjects without both maintenance dosing and a post-dose assessment, and the size and representativeness of that population are not reported in the registry record. These limitations should shape any conclusions drawn from the study description.

14. Why This Trial Matters Statistically

Statistically, the study illustrates how a remission-based comparison differs from a randomized treatment comparison. Its stated objective is to compare later outcomes by remission status following acute therapy. This can be useful for describing prognosis within the study, but the groups are formed by their response rather than by random allocation. The distinction is central to interpreting any eventual association.

The primary endpoint also combines clinical and endoscopic criteria. A binary composite can provide a clear classification, but the result depends on all parts of its definition and on who has the assessments needed for classification. The modified UC-DAI threshold, required scores for rectal bleeding and stool frequency, and required improvement in endoscopy score make the endpoint more specific than a symptom-only measure.

The record’s analysis-population definition highlights another statistical issue: enrollment and endpoint denominator are not necessarily the same. Eligibility for the primary efficacy population required maintenance dosing and a post-dose efficacy assessment. Without reporting that population’s size, the precision and representativeness of its outcome cannot be assessed.

Finally, the absence of posted efficacy results limits statistical interpretation. The registry describes the design and endpoint in detail, but does not report the primary estimate, its uncertainty, or the remission-group outcomes central to the study question. This means readers can evaluate the intended framework and identify its limitations, but cannot determine the observed outcome from the registry record.

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 study is open-label and has no separate control arm. Accordingly, the design does not provide a randomized comparison with another treatment or a control condition. The planned comparison between complete and partial remission groups is based on status after acute therapy, so group differences may reflect factors associated with that status as well as any relationship with later outcomes.

The primary efficacy population requires at least 1 maintenance-phase dose and at least 1 post-dose efficacy assessment. The registry does not report the number meeting these criteria, the number excluded, or the reasons for non-entry or missing assessment. The effect of these exclusions on the endpoint estimate cannot be assessed.

The registry record does not report the primary endpoint result, secondary outcome results, analysis methods, statistical plan, missing-data procedures, or sample-size justification. It also does not report whether group comparisons were adjusted for baseline or post-acute differences. These omissions limit evaluation of precision, bias, and the robustness of any comparison.

The study summary describes a 12-month maintenance phase, but the registry record does not report adherence, exposure duration for individual subjects, or detailed follow-up completeness. The safety listings provide phase-specific counts but do not establish causality or support a randomized risk comparison. Finally, the record’s completed status and enrollment count do not substitute for outcome results or an analysis denominator.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Ability to Maintain or Achieve Clinical and Endoscopic Remission With MMX Mesalamine Once Daily in Adults With Ulcerative Colitis — NCT01124149.
• Registry record last updated 2021-06-09; status last verified 2021-05.
• Results first posted 2013-12-02.
• 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

This completed Phase 4, open-label, multicenter, prospective study enrolled 759 adults with ulcerative colitis and used a single-group design. Its plan described acute MMX mesalamine/mesalazine at 4.8g/day once daily for 8 weeks, followed by maintenance at 2.4g/day once daily for 12 months among subjects achieving complete or partial remission.

The primary endpoint was the percentage in complete remission at month 12 among maintenance-phase subjects with at least 1 dose and at least 1 post-dose efficacy assessment. The registry describes comparing outcomes by remission status after acute therapy, but reports no primary endpoint percentage, group-specific results, confidence intervals, or p-values. It also does not report the primary analysis denominator or the statistical plan. The posted safety data list serious and other adverse-event counts by phase, without a separate control group.