This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Vedolizumab Monotherapy Vs Combination Therapy With Tacrolimus in UC (NCT02954159), a randomized phase 3 study. The primary outcome is Clinical Response.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02954159 |
| Phase | Phase 3 |
| Condition | Ulcerative Colitis |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 4 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Medical College of Wisconsin |
| Results posted | Yes |
2. Clinical Question
Population
Patients with moderately to severely active ulcerative colitis. The primary-outcome population is described as “Data not collected,” so the record does not report response results for participants.
Intervention
Vedolizumab at its standard regimen with concomitant induction treatment of tacrolimus, starting at 0.05 mg per Kg twice daily.
Comparator
Vedolizumab at its standard regimen with placebo. The registry describes this as the placebo arm.
Primary question
Whether adding tacrolimus to vedolizumab improves steroid-free clinical response at week 6 compared with vedolizumab with placebo. The registry also describes an aim to assess safety and longer- and shorter-term outcomes, including colectomy rate.
The study was designed to compare two treatment strategies during induction in moderately to severely active ulcerative colitis. One strategy combined vedolizumab with tacrolimus; the other used vedolizumab with placebo. The primary question concerns a defined clinical response while off steroids, rather than a broad judgment about treatment benefit.
The registry lists four participants enrolled, but says primary-outcome data were not collected. Consequently, it does not show how many participants in either arm met the response definition, nor does it provide an estimated difference between the strategies. The stated aim is therefore distinct from an answer to the question: the posted record describes what investigators intended to assess, but contains no primary-outcome comparison from which to assess that aim.
The record also states that the study was terminated. It does not report why it ended or provide a completed efficacy analysis. The clinical question remains identifiable from the design and endpoint description, but the posted results do not resolve it.
3. Trial Design
The registry describes a phase 3, randomized, double-masked, parallel-group study sponsored by the Medical College of Wisconsin. Enrollment was four. The study began on 2017-05-18, had a primary completion date of 2019-01-31, and is listed as terminated. The registry record does not report why the study was terminated.
In a parallel-group design, participants are assigned to one of the treatment strategies and followed in that group. Here, the recorded arms were vedolizumab with tacrolimus and vedolizumab with placebo. Randomization is intended, in general, to reduce systematic differences between groups at the point of assignment. With enrollment of four, however, the registry’s design label alone cannot establish that the groups were comparable in their characteristics. Baseline characteristics and details of the allocation procedure are not reported in the registry record.
The double-masked designation indicates that the registry classifies the study as double-masked, but it does not say which parties were masked or describe how masking was implemented. The description of the comparator identifies placebo alongside vedolizumab; further details about preparation, administration, or the standard vedolizumab regimen are not reported in the registry record.
The brief summary names induction response and remission as the main focus, with interest in short- and long-term outcomes, including colectomy rate. It also names safety of tacrolimus as an induction agent as a secondary aim. The primary endpoint description specifies steroid-free clinical response at week 6. The record lists clinical response among secondary outcomes as well, but does not report results for that outcome or for remission, colectomy, or other longer-term outcomes.
There are four outcome measures recorded and no analyses listed. The registry record does not report a statistical analysis plan, sample-size justification, planned interim analyses, or a detailed account of the study’s follow-up and analysis populations. The posted sample-size section, where displayed, is described as a planning illustration based on an observed effect, not as the trial’s design calculation.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Treatment Arm | Placebo Arm |
|---|---|---|
| STARTED | 2 | 2 |
| COMPLETED | 1 | 1 |
| NOT COMPLETED | 1 | 1 |
Reasons for not completing this period:
| Reason | Treatment Arm | Placebo Arm |
|---|---|---|
| Study ended prematurely due to low enrol | 1 | 0 |
| Withdrawal by Subject | 0 | 1 |
Analysis population for the primary outcome, as defined in the registry: Data not collected
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | Treatment Arm | Placebo Arm | Total |
|---|---|---|---|---|
| Participants analysed | 2 | 2 | 4 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 2 | 2 | 4 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 1 | 2 | 3 |
| Sex: Female, Male: Male | Participants | 1 | 0 | 1 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 | 1 | 1 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 2 | 1 | 3 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): White | Participants | 2 | 2 | 4 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | Participants | 2 | 2 | 4 |
6. Primary Endpoint
The registry lists the primary outcome as Clinical Response, measured over week 6.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is steroid-free clinical response at week 6 after starting vedolizumab. The registry defines response using the Mayo Clinic score: a reduction of at least 3 points and a decrease of at least 30% from the baseline score, together with either a decrease of at least 1 point on the rectal bleeding subscale or an absolute rectal bleeding score of 0 or 1 while off steroids.
In general, a prespecified endpoint turns a broad clinical question into a rule for classifying outcomes. This definition combines a change in the overall score with a condition involving rectal bleeding and being off steroids. That makes the endpoint more specific than a simple report of symptom improvement. The week 6 time point also anchors the assessment to a particular stage after treatment begins.
The registry record states “Data not collected” for the primary-outcome population. It therefore supplies the endpoint definition but no response counts, group estimates, uncertainty intervals, or test of the treatment comparison. The record does not report how baseline values or endpoint status were handled for participants without an assessment. It is not possible from this entry to determine whether the response definition was applied to any participant.
The endpoint should be read as the outcome the study intended to measure, not as evidence that either strategy achieved or failed to achieve it. The registry’s definition supports a clear understanding of the planned clinical measure, but the posted record contains no primary endpoint result with which to compare the arms.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The most important interpretive fact is that the registry reports four participants enrolled and says primary-outcome data were not collected. Although the primary endpoint is defined in detail, no response result is posted. There is no reported number of responders in either arm, no estimated contrast between arms, and no confidence interval or p-value for the primary comparison. The registry also lists no analyses.
Accordingly, the record does not establish whether steroid-free clinical response at week 6 differed between vedolizumab with tacrolimus and vedolizumab with placebo. It also cannot show whether a difference, if one had been estimated, was large or small, or how precisely it was estimated. This is not a null result: a null result would require an analysis of collected outcome data that found little evidence of a difference. Here, the primary outcome was not collected according to the registry entry, so there is no efficacy comparison to interpret.
The safety section contains counts for serious adverse events, other adverse events, and deaths by arm. These figures are descriptive and should be read in light of the very small enrollment. The record lists two participants at risk for serious adverse events in each arm, with one affected in the treatment arm and none in the placebo arm. For other adverse events, it lists two at risk and two affected in each arm. Deaths are listed as zero in both arms. These counts do not provide a reliable basis for broad comparative safety conclusions; they describe the events recorded among the small groups listed.
The registry identifies “Increase in severity of UC symptoms” as the top serious term and reports 50.0%. That entry should be read as a registry-listed summary, not as a complete safety narrative. The record does not provide additional context about timing, duration, severity grading, relationship to study treatment, or participant-level event histories.
Some posted sections may include planning illustrations based on an observed effect. Such illustrations are not observed power and do not restore the missing primary-outcome comparison. The record describes the illustration assumptions as a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the target effect set as a stated fraction of the observed effect. No trial-specific sample-size justification is reported in the registry record.
Overall, the record documents a randomized study design and limited safety counts, but it does not supply a primary efficacy result. The appropriate interpretation is that the intended clinical comparison is unanswered in the posted results, rather than that one strategy performed better, worse, or equally well.
9. Statistical Methods Explained
The following explains statistical ideas relevant to the design and the information that would ordinarily be used to interpret a randomized comparison. It does not describe unreported procedures as if they were used in this study.
What randomization contributes
In general, random assignment uses chance to allocate participants to study groups. Its purpose is to reduce systematic differences in prognosis and other measured or unmeasured characteristics between groups. Randomization does not guarantee that two groups will look alike in a small study. With four participants enrolled, chance imbalances are possible, and the registry record does not report participant characteristics or allocation details that would allow readers to assess the groups’ balance.
A parallel-group study follows participants in the group to which they are assigned. The registry records a parallel design and two arms: vedolizumab with tacrolimus, and vedolizumab with placebo. The record identifies the study as double-masked, but does not report which people were masked or the practical procedures used to maintain masking. In general, masking can reduce the influence of expectations on care, outcome assessment, and reporting; the degree to which it was achieved in this study is not described in the registry record.
How a binary response endpoint is usually compared
The primary endpoint defines a participant as having or not having steroid-free clinical response at week 6. In general, a binary endpoint can be summarized by the number or proportion meeting the definition in each group, followed by a between-group contrast. Depending on the analysis plan, that contrast might be expressed using a difference, ratio, or another effect measure. Each measure answers a slightly different question, and an uncertainty interval helps show which values remain compatible with the data.
A confidence interval is a range of estimates generated by a statistical procedure. In general, it communicates the precision of an estimate: a narrower interval indicates greater precision under the method’s assumptions, while a wider interval indicates more uncertainty. A p-value, when used, summarizes how incompatible the observed data are with a specified null hypothesis under the chosen model. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of an effect. No primary-outcome estimate, confidence interval, or p-value appears in this registry record, so these interpretive tools cannot be applied to the intended response comparison.
With very few participants, estimates from a binary outcome can be highly unstable. A small change in the number of participants classified as responders can substantially alter a group summary. Statistical methods may also behave differently when there are very few observations or when outcome counts are sparse. That is a general consideration, not a claim about a particular analysis in this trial: no primary analysis is listed.
What the safety counts can and cannot show
The registry gives numbers at risk and numbers affected for serious and other adverse events, plus deaths, by arm. These are descriptive counts. In general, an event count does not by itself establish that treatment caused the event. Assessment of a treatment relationship typically requires details about timing, clinical context, exposure, and how investigators classified the event. Those details are not reported in the registry record.
When groups are very small, a comparison of event counts has substantial uncertainty. A count of zero in a group does not prove that the underlying risk is zero. Similarly, observing an event in one group does not by itself establish a difference between treatment strategies. The safety figures can be accurately quoted as recorded, but they should not be treated as a stable estimate of comparative risk.
How to read planning illustrations
The registry’s sample-size assumptions describe a planning illustration computed from an observed effect, rather than the trial’s own design. The stated assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation; the effect to detect is the stated fraction of the observed effect. In general, a sample-size calculation estimates the number of participants needed to achieve a chosen probability of detecting an effect under specified assumptions. It is a planning tool, not an observed outcome and not a measure of whether this study had “observed power.”
The record says time-to-event illustrations give the total number of events, while other illustrations give participants per arm. Such results depend on the chosen target effect and assumptions. They do not explain why the study enrolled four participants or establish that its original design was adequately sized. The trial’s own sample-size justification is not reported in the registry record.
No detailed statistical analysis plan is reported. In particular, the registry record does not report the model used for the primary endpoint, covariate adjustment, handling of missing outcome values, multiplicity procedures, analysis populations, or interim analyses. These details matter because they define how outcomes are converted into estimates and how uncertainty is quantified. Their absence means readers should not infer a particular method from the randomized, double-masked, or phase 3 labels alone.
In general, an analysis plan can specify which outcome is primary, how participants are included, how missing values are handled, and how multiple questions are addressed. These choices can affect interpretation, especially when several endpoints or time points are considered. Here, the registry provides the primary endpoint definition and lists outcome measures, but does not show an analysis of the primary outcome or document how those statistical choices were made.
10. Multiplicity, Missing Data and Analysis Populations
The registry describes a primary endpoint and also names response, remission, safety, short- and long-term outcomes, and colectomy rate among the study’s aims or outcome areas. It lists four outcome measures, but does not report analyses. The record does not describe a multiplicity adjustment or a hierarchy for testing several endpoints. It is therefore not possible to tell whether any procedure was planned to address the risk of false-positive findings when multiple outcomes are tested. No efficacy results are posted for which such adjustment could be assessed.
For the primary endpoint, the registry says “Data not collected.” This means the posted record has no primary response result to interpret; it does not explain why the data were unavailable, whether measurements were attempted, or what happened to individual participants. The reasons for the absence of primary-outcome data are not reported in the registry record. The record also does not describe how missing observations would have been handled in an analysis.
Analysis populations are not reported in the registry record. The entry does not specify whether analyses were intended to include all randomized participants, participants who received treatment, or another defined group. It also does not describe exclusions, adherence criteria, or how participants who discontinued treatment would be treated analytically.
The registry lists four participants enrolled and no analyses. Without a reported analysis population, endpoint data, and statistical plan, readers cannot reconstruct an efficacy analysis or assess its robustness. These omissions do not show that any particular method was or was not used outside the posted record; they mean the method is not documented in the registry record.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Treatment Arm | 1 | 2 | 50.0% |
| Placebo Arm | 0 | 2 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Treatment Arm | 0 of 2 |
| Placebo Arm | 0 of 2 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Treatment Arm | 2 of 2 |
| Placebo Arm | 2 of 2 |
Most frequent serious adverse event terms
| Event term | Organ system | Treatment Arm | Placebo Arm |
|---|---|---|---|
| Increase in severity of UC symptoms | Gastrointestinal disorders | 1 of 2 | 0 of 2 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Treatment Arm | Placebo Arm |
|---|---|---|---|
| Intermittent tremor | Nervous system disorders | 0 of 2 | 1 of 2 |
| clinically significant elevated creatinine | Renal and urinary disorders | 1 of 2 | 0 of 2 |
| clinically significant low phosphorus | Endocrine disorders | 1 of 2 | 0 of 2 |
| clinically significant low magnesium | Endocrine disorders | 1 of 2 | 0 of 2 |
| Nausea | Gastrointestinal disorders | 0 of 2 | 1 of 2 |
| Emesis | Gastrointestinal disorders | 0 of 2 | 1 of 2 |
| increased pain | General disorders | 1 of 2 | 0 of 2 |
| increased diarrhea | Gastrointestinal disorders | 1 of 2 | 0 of 2 |
| increase in severity of UC symptoms | Gastrointestinal disorders | 1 of 2 | 0 of 2 |
| rash | Skin and subcutaneous tissue disorders | 0 of 2 | 0 of 2 |
Serious events with the highest arm-level rate: increase in severity of uc symptoms (50.0%).
The safety table reports counts separately for the treatment arm and placebo arm. For serious adverse events, two participants were listed at risk in each arm; one was affected in the treatment arm and none in the placebo arm. For other adverse events, two participants were listed at risk in each arm and two were affected in each arm. Deaths were listed as zero in both arms.
These are small-group descriptive counts, not precise estimates of comparative safety. In general, event counts can help identify what was recorded, but a count alone cannot establish causation or show how likely an event would be in a wider population. A zero count does not establish that an event cannot occur, and an observed event does not by itself show that treatment caused it.
The registry lists “Increase in severity of UC symptoms” as the top serious term, at 50.0%. That is the reported summary; the record does not provide further context about the event’s timing, clinical course, seriousness criteria, or relationship to treatment. The safety figures should therefore be read as a limited record of events among the participants listed, not as a complete account or a definitive comparison of risks.
12. What the Result Does, and Does Not, Mean
This record documents a randomized, double-masked, parallel-group study intended to compare vedolizumab with tacrolimus against vedolizumab with placebo in moderately to severely active ulcerative colitis. It identifies steroid-free clinical response at week 6 as the primary endpoint and defines how response was to be classified. It also records a total enrollment of four and a terminated study status.
What the record does not provide is the primary outcome result. It states that primary-outcome data were not collected and lists no analyses. There are no response counts or comparative estimates in the posted results. Therefore, the record cannot establish that adding tacrolimus improved response, reduced response, or produced a result similar to vedolizumab with placebo. It also cannot establish that the strategies were equivalent; showing equivalence would require an appropriate design and analysis, neither of which is reported as a completed result.
The safety counts are similarly limited. They describe serious and other adverse events and deaths among the small groups recorded, but they do not provide enough information for a robust assessment of comparative risk. The top serious term is identified in the registry, but the clinical context and treatment relationship are not reported.
The registry’s statement that the study was terminated is a status, not an explanation. The reason for termination is not reported in the registry record. Nor does the record report a trial-specific sample-size justification, detailed statistical analysis plan, or analysis populations. Those gaps prevent readers from assessing why enrollment was four or how investigators intended to analyze the endpoints.
The clearest conclusion is about the evidence available in this entry: it records the planned clinical comparison and some safety counts, but it does not contain a primary efficacy analysis. This is an absence of a reported outcome comparison, not evidence of no treatment effect. The statistical summaries and planning illustrations should be interpreted within that boundary.
13. Why This Trial Matters Statistically
This trial illustrates an important distinction between a clearly stated research question and an answer supported by outcome data. The registry defines a specific comparison, population, and week 6 response endpoint. Yet it also reports four participants enrolled, a terminated status, and no collected primary-outcome data. The design description is informative about intent, but it cannot substitute for an endpoint result.
For readers assessing clinical trials, this distinction matters because a result is more than a registered aim or a completed endpoint definition. A comparative conclusion requires outcome observations and an analysis that reports the size and precision of the contrast. Without those, readers cannot tell whether the groups differed, how uncertain any difference would be, or whether the evidence would support a particular interpretation.
The record also demonstrates why small safety counts require restraint. The listed events are useful for describing what appears in the record, but they are not a stable basis for broad comparisons. Interpreting them requires attention to group size and to the event details that are not reported.
Finally, sample-size illustrations should be kept separate from trial results and from a trial’s original design justification. The registry describes its illustrations as based on an observed effect and specified assumptions. They can show how planning calculations depend on assumptions, but they cannot recover the missing efficacy data or explain the enrollment reported for this study.
Statistically, the central lesson is that transparency about what is and is not recorded is essential. Here, the intended question is clear; the primary comparison remains unanswered in the registry record.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The central limitation is that primary-outcome data are recorded as not collected. This leaves no reported response counts or estimates for the week 6 comparison. The registry also lists no analyses, so there is no posted inferential result to evaluate.
Enrollment was four, and the study is listed as terminated. The registry record does not report the reason for termination, the circumstances leading to the enrollment total, or whether the planned recruitment target changed. A trial-specific sample-size justification is not reported in the registry record. These gaps limit interpretation of the study’s scale and completion, without explaining why the study ended.
Important design and analysis details are not reported in the registry record. These include participant characteristics, the randomization procedure, who was masked, the exact standard vedolizumab regimen, the follow-up procedures, the analysis populations, and the handling of missing values. The record also does not describe multiplicity control, covariate adjustment, interim analyses, or a detailed statistical analysis plan.
The safety information is limited to counts by arm and a listed top serious term. It does not include event narratives, timing, severity grading beyond the serious classification, treatment attribution, or details that would support a fuller comparative assessment. With only the small groups recorded, the counts should be treated as descriptive.
The registry lists four outcome measures but does not provide results for the primary endpoint or the other stated clinical aims. Consequently, the limitations extend beyond precision: the posted efficacy comparison is unavailable. These are limitations of what is documented in the registry record and should not be taken to establish what may exist outside that record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Vedolizumab Monotherapy Vs Combination Therapy With Tacrolimus in UC — NCT02954159.
- Registry record last updated 2020-09-03; status last verified 2020-08.
- Results first posted 2020-09-03.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
The registry describes a phase 3, randomized, double-masked, parallel-group study of vedolizumab with tacrolimus versus vedolizumab with placebo for moderately to severely active ulcerative colitis. The sponsor is the Medical College of Wisconsin. Enrollment was four; the study began on 2017-05-18, had a primary completion date of 2019-01-31, and is listed as terminated.
The primary endpoint was steroid-free clinical response at week 6, defined using changes in the Mayo Clinic score and rectal bleeding while off steroids. The registry states that primary-outcome data were not collected and lists no analyses. Safety counts are reported for serious and other adverse events and deaths, but the small groups and limited context restrict interpretation. The reason for termination, detailed statistical plan, and trial-specific sample-size justification are not reported in the registry record.