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 Investigating Effects of BOTOX on Weight Loss and Glucose Tolerance in Obese, Type 2 Diabetic Subjects (NCT03991299), a na phase 1, phase 2 study. The primary outcome is Change in Body Weight at 6 Months.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03991299 |
| Phase | Phase 1, Phase 2 |
| Condition | Obese, Diabetes Mellitus, Type 2 |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 4 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Vanderbilt University Medical Center |
| Results posted | Yes |
2. Clinical Question
Population
Obese subjects with pre-diabetes or type 2 diabetes were the intended population. The registry record lists obesity and type 2 diabetes among the conditions studied; the study summary describes recruitment of people with pre-diabetes or type 2 diabetes.
Intervention
Botox was to be injected into the duodenal wall by upper endoscopy. The intervention is named Botox 200 UNT Injection in the registry record.
Comparator
No concurrent comparator group is reported. The study is described as a single-group study, with allocation recorded as NA. Its participants therefore do not provide a like-for-like control comparison.
Primary question
The planned primary question was how body weight changed between baseline and 6 months after Botox injection. The primary outcome description says the analysis could not be completed because zero participants remained enrolled for 30 days or more.
The investigators proposed assessing weight and glucose-related measures over 6 months. The study summary describes repeated study visits, with body weight and body composition recorded and an oral glucose tolerance test performed at each visit. A nutrient sensing test was planned at baseline and at a later visit. The investigators anticipated that duodenal Botox injection would be followed by weight loss and changes in glucose tolerance and duodenal nutrient sensitivity. That expectation describes the study rationale, not a reported result.
Because there was no concurrent control group, the central question was a within-group change over time, rather than a comparison of outcomes between assigned treatments. Even if measurements had been available, a change after treatment would not by itself separate a treatment effect from other explanations for change over time. In this record, the primary outcome analysis was not completed, so it does not report an estimated change in weight or the precision of such an estimate.
3. Trial Design
The registry record describes a Phase 1 and Phase 2 study with a single-group model. Allocation is recorded as NA, masking as none, and enrollment as 4. The study status is terminated. The recorded study start is 2021-04-29, and the primary completion date is 2022-02-11. The registry record does not report why the study was terminated.
The intervention was Botox 200 UNT Injection, delivered into the duodenum by endoscopy. The study summary describes five visits over 6 months. At the first visit, participants were to have an oral glucose tolerance test. At the second, an esophagogastroduodenoscopy procedure was planned to deliver Botox to the duodenal wall. Later visits were planned at 1, 3, and 6 months. Body weight and body composition were to be recorded, and oral glucose tolerance testing was to be performed at each visit. Nutrient sensing testing was planned at the first and third visits.
This design planned repeated measurements in the same group, rather than random assignment to Botox and a control treatment. It can describe change over time if follow-up measurements and an appropriate analysis are available. It cannot provide a direct randomized comparison with an untreated or alternative-treatment group. The registry record does not report a masking procedure, and the masking field is recorded as none.
The primary outcome was change in body weight from baseline to 6 months. Its description states that analysis could not be completed because zero participants remained enrolled in the study for 30 days or more. The registry record lists three outcome measures and zero analyses. It does not give a reason for termination, a completed primary outcome estimate, or a detailed statistical analysis plan.
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 | Botox Arm |
|---|---|
| STARTED | 4 |
| COMPLETED | 0 |
| NOT COMPLETED | 4 |
Reasons for not completing this period:
| Reason | Botox Arm |
|---|---|
| Study closed, sponsor decision | 3 |
| Withdrawal by Subject | 1 |
Analysis population for the primary outcome, as defined in the registry: Data analysis could not be completed as zero participants remained enrolled in the study for 30 days or more
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: Participants analysis not done.
| Characteristic | Unit | BOTOX Arm |
|---|---|---|
| Participants analysed | 4 | |
| Age, Continuous | years | 43.7 (21.7 to 56.1) |
| Sex: Female, Male: Female | Participants | 3 |
| Sex: Female, Male: Male | Participants | 1 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 1 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 3 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 1 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 1 |
| Race (NIH/OMB): White | Participants | 2 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Change in Body Weight at 6 Months, measured over Baseline - 6 months.
| 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 was change in body weight from baseline to 6 months after Botox injection. The record describes body weight as measured at both time points. The outcome is a change measure: it is intended to represent how a participant's weight at follow-up differs from that participant's baseline weight.
General statistical context: a change endpoint can account for the starting value when describing follow-up, and repeated measurements can help characterize the course of an outcome over time. The endpoint does not, by itself, establish that an observed change was caused by the intervention. In a single-group study, changes may also reflect factors unrelated to treatment, including time-related changes or other influences not controlled by the design.
Weight is relevant to the study's stated focus on weight loss in obese subjects with pre-diabetes or type 2 diabetes. The summary also describes measurements related to body composition, glucose tolerance, and nutrient sensing, but these do not replace the stated primary endpoint. The registry record reports no completed estimate of body-weight change, and no confidence interval or other measure of its precision. It states that analysis could not be completed because zero participants remained enrolled for 30 days or more. Consequently, the primary endpoint is specified, but its observed result is not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The key interpretive fact is that the planned primary outcome analysis was not completed. The registry record says zero participants remained enrolled for 30 days or more, and the outcome description says that data analysis could not be completed. No primary body-weight change estimate is reported. The record also lists zero analyses. There is therefore no reported treatment-associated weight change to interpret, and no confidence interval or other precision measure for that outcome.
This absence of a completed analysis is not evidence that body weight did or did not change. It means the registry record does not establish the size or direction of any change. It also does not support a conclusion about glucose tolerance, body composition, or nutrient sensitivity. The study summary describes plans to measure these outcomes, but planned measurements and investigators' expectations are not observed findings.
The design further limits what could be concluded from any within-group change. A single-group study has no concurrent comparator, so a before-and-after difference cannot be separated from changes that might have occurred without the intervention. Masking is recorded as none. These design features do not create a completed result where none is reported, and they would need to be considered even if follow-up estimates were available.
The registry record reports enrollment of 4 and a terminated status. It does not report why the study ended or provide an explanation for the lack of an analyzable primary outcome. The reported safety counts are separate from the efficacy endpoint: they describe adverse-event counts for the Botox Arm, not evidence of weight change or glucose response.
Overall, the record specifies a clinical question and planned outcome measures, but it does not provide an analyzed primary result. The study's stated expectation of weight loss and improved glucose tolerance should not be read as an observed finding. Any interpretation beyond the descriptive record would require outcome data and analysis that are not reported in the registry record.
9. Statistical Methods Explained
General statistical explanation: a clinical study's methods determine what quantities can be estimated and how much confidence readers can place in those estimates. The registry record gives some design characteristics, but it does not report a detailed statistical plan. The concepts below explain how the stated design and missing primary result affect interpretation; they are not claims about analyses actually conducted.
What does a single-group design estimate?
In a single-group study, participants receive the intervention and are measured over time. A before-and-after analysis can describe the average change among participants with usable measurements. It does not directly estimate what would have happened to those same participants without the intervention. A concurrent comparison group can help estimate that counterfactual by showing how outcomes change under another assigned condition. No such group is reported for this study.
Repeated measurements can describe whether an outcome changes across planned visits, but they do not automatically solve the problem of causal attribution. Changes may reflect factors other than treatment, and the absence of a comparator means those influences cannot be distinguished by a treatment-versus-control contrast. In this study, the primary outcome description is specifically a baseline-to-6-month body-weight change. The record does not report the estimate or a completed analysis of that change.
What does precision mean?
General statistical explanation: an estimate describes a quantity in the observed data, while a confidence interval describes uncertainty around that estimate under the assumptions of the analysis. A narrow interval indicates greater precision than a wide interval, but neither an estimate nor an interval answers questions that the design cannot address. In particular, an interval around a single-group change would not by itself remove the lack of a concurrent comparator.
No primary estimate or confidence interval is reported in the registry record. It is therefore not possible to assess the magnitude, direction, or precision of the primary outcome from this record. The fact that enrollment is reported as 4 does not substitute for an outcome estimate, and the record's statement that zero participants remained enrolled for 30 days or more explains why the planned analysis could not be completed.
Why do assumptions matter?
General statistical explanation: many methods rely on assumptions about the distribution of outcomes, the relationship between repeated observations, or the way missing measurements arise. If assumptions are poorly matched to the data, an estimate or its uncertainty can be misleading. Small or incomplete datasets can make assumptions difficult to evaluate, but the registry record does not provide enough analyzed outcome information to assess any particular model.
The record's sample-size assumptions describe a planning illustration: two-sided significance level 0.05, equal allocation between two arms, and a normal approximation, with the target effect described as a stated fraction of the observed effect. The record says that time-to-event illustrations give total events and other illustrations give participants per arm. These are planning conventions, not evidence that this trial enrolled two arms or conducted a randomized comparison. The study itself is recorded as single-group, and the sample-size description says such values are illustrations rather than the trial's own design. They should not be interpreted as observed power. The registry record does not report a sample-size justification for the actual study design.
How should repeated outcomes be viewed?
General statistical explanation: measuring an outcome at multiple visits can provide information about its trajectory, but the analysis must account for the fact that measurements from the same participant are related. Treating repeated observations as if they came from unrelated people can misstate uncertainty. A prespecified approach can also clarify which time point and summary are primary, and how incomplete follow-up is handled. The registry record describes planned visits and measurements, but it does not report a detailed model or a completed analysis of repeated measurements.
The listed primary endpoint focuses on baseline and 6 months. Other planned measurements include body composition, oral glucose tolerance testing, and nutrient sensing. The record does not establish how these outcomes would be combined, compared, or interpreted statistically. No adjustment method, covariance structure, or outcome transformation is reported in the registry record.
What can planning calculations tell readers?
General statistical explanation: sample-size calculations are conditional on assumptions about the effect to detect, variability, significance level, allocation, and analysis method. They describe planning requirements under those assumptions; they do not demonstrate that an effect was observed. Power is a design property under a specified model and effect, not a retrospective measure of whether a study's result is true. The registry record's planning illustration refers to an observed effect, but it does not report a completed primary effect estimate that can be examined alongside that illustration.
Because the primary analysis was not completed, the record does not support recalculation of an unadjusted effect from outcome summaries. There are no posted primary outcome summary statistics from which to assess such a calculation. The record also does not report the statistical plan, interim analyses, or a sample-size justification for the enrolled study. Those details should not be inferred from the planning illustration or from the study's phase designation.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists three outcome measures and zero analyses. It identifies change in body weight at 6 months as the primary outcome, with body weight measured at baseline and 6 months. The study summary also describes measurements of body composition, oral glucose tolerance, and nutrient sensing. The registry record does not report completed inferential analyses for these measures.
General statistical explanation: multiplicity arises when several outcomes, time points, or statistical comparisons are examined. The more opportunities there are to identify a result as noteworthy, the more important it is to prespecify which analyses are primary and how other analyses will be treated. The record identifies a primary endpoint, but does not report a multiplicity adjustment or a detailed plan for the other outcomes. It is not possible to determine from the registry record whether additional analyses were planned or how their results would have been interpreted.
Missing data are central to interpreting the primary outcome. The record states that analysis could not be completed because zero participants remained enrolled for 30 days or more. It does not provide participant-level follow-up, reasons for withdrawal, or a missing-data method. No assumptions about why participants did not remain enrolled, or about what their unobserved outcomes might have been, can be justified from the record.
The analysis population is also not described in detail. The registry record does not report an intention-to-treat population, a per-protocol population, or rules for including participants with incomplete follow-up. Since no primary analysis is reported, there is no analysis population whose definition can be evaluated. The available record therefore leaves multiplicity handling, missing-data assumptions, and analysis-population rules not reported 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 |
|---|---|---|---|
| Botox Arm | 0 | 4 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Botox Arm | 0 of 4 |
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 |
|---|---|
| Botox Arm | 1 of 4 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Botox Arm |
|---|---|---|
| Abdominal Pain | Gastrointestinal disorders | 1 of 4 |
| Joint pain | Musculoskeletal and connective tissue disorders | 1 of 4 |
The safety record lists the Botox Arm with 4 participants at risk for serious adverse events and 0 affected. For other adverse events, it lists 4 at risk and 1 affected. Deaths are listed as 0. No serious adverse-event terms are listed.
These figures are counts recorded for the study group; they are not estimates of comparative risk. There is no concurrent control group, and the registry record does not provide a detailed account of event types, timing, severity beyond the serious-versus-other distinction, or participant-level follow-up. The counts therefore cannot show whether the intervention caused an event or how its safety compares with another treatment.
General statistical context: a count of zero events in a small study does not establish that an event cannot occur. The amount of information in a safety count depends on the number followed, the length and completeness of follow-up, and how events were defined and collected. The registry record reports enrollment as 4, but the primary outcome description also says zero participants remained enrolled for 30 days or more. The safety counts should be read as registry-reported counts, not as proof of comprehensive follow-up or as a basis for a precise safety estimate.
12. What the Result Does, and Does Not, Mean
The record establishes that investigators planned a study of duodenal Botox injection in obese subjects with pre-diabetes or type 2 diabetes. The intended primary measure was body-weight change from baseline to 6 months. It also documents planned measurements related to body composition, glucose tolerance, and nutrient sensing. These details explain the research question and the outcomes the investigators intended to assess.
The record does not establish whether the intervention changed body weight or any of the other planned outcomes. The primary analysis could not be completed because zero participants remained enrolled for 30 days or more. No primary estimate, confidence interval, or completed outcome analysis is reported. The investigators' stated expectation of weight loss and improvements in glucose tolerance and nutrient sensitivity is a rationale, not a result.
The single-group design also means that a before-and-after change, if it had been reported, would not provide a randomized comparison with a control group. Without such a comparator, a change over time could not be attributed to the intervention solely on the basis of this design. The registry record reports no masking and gives no detailed statistical analysis plan.
The safety counts are limited descriptive information: 0 serious adverse events among 4 at risk, 1 other adverse event among 4 at risk, and 0 deaths. They do not establish comparative safety, particularly without a control group and fuller event details.
In short, the registry record documents a planned clinical question and a terminated study, but not an analyzed answer to that question. It neither demonstrates benefit nor demonstrates absence of benefit. It does not provide enough completed outcome information to quantify the primary endpoint or its uncertainty.
13. Why This Trial Matters Statistically
This study matters statistically because it illustrates the difference between a clearly stated research question and an answer supported by analyzed data. The primary outcome is identifiable: change in body weight from baseline to 6 months. But the record says the analysis could not be completed, so there is no estimate to interpret. Naming an endpoint and planning repeated measurements are not substitutes for reporting an analyzed result.
It also illustrates the limits of a single-group design. Such a study can describe what happened among participants who were measured, but without a concurrent comparator it cannot distinguish intervention-associated change from other changes over time. That distinction is important whenever the research question is framed in terms of an intervention's effect.
The record further shows why follow-up and analysis populations matter. The stated reason the primary analysis could not be completed is that zero participants remained enrolled for 30 days or more. The record does not describe the reasons, missing-data assumptions, or an alternative analysis. Readers cannot assess whether any planned longitudinal comparison could be supported by the available observations.
Finally, the study's planning illustration should be kept separate from its observed evidence. Planning calculations depend on assumptions and are not observed power or proof of an outcome. With no completed primary estimate reported, the record offers no quantitative result against which to judge the illustration. These distinctions help readers separate research intent, design, safety counts, and analyzed clinical findings.
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 most direct limitation is that the primary outcome analysis was not completed. The registry record states that zero participants remained enrolled for 30 days or more, and it reports no primary outcome estimate or analysis. The reason for this follow-up status and the reason the study was terminated are not reported in the registry record.
Enrollment is recorded as 4, but the record does not provide an analyzed body-weight summary, a measure of variability, or a confidence interval. It also does not describe participant-level follow-up or explain how missing measurements were handled. As a result, the amount and pattern of outcome information available for any intended analysis cannot be assessed.
The single-group design provides no concurrent control comparison. Masking is recorded as none. These features constrain causal interpretation even when outcomes are measured, and the absence of a completed outcome analysis further prevents assessment of the planned primary question.
The registry record lists three outcome measures and zero analyses, but does not give a detailed statistical plan, analysis-population definitions, missing-data methods, or multiplicity approach. It also does not report a sample-size justification for the actual study design. The sample-size description is explicitly a planning illustration and assumes two-arm equal allocation, which does not describe the listed single-group trial design.
Safety information is also limited to registry counts without listed serious-event terms or detailed event descriptions. The record does not provide enough detail to assess event timing, follow-up completeness, or comparative safety. These limitations mean the registry record supports a description of the planned study and recorded counts, not an efficacy or comparative safety conclusion.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Investigating Effects of BOTOX on Weight Loss and Glucose Tolerance in Obese, Type 2 Diabetic Subjects — NCT03991299.
- Registry record last updated 2023-02-28; status last verified 2023-02.
- Results first posted 2023-02-28.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT03991299 is a terminated Phase 1 and Phase 2 single-group study sponsored by Vanderbilt University Medical Center. Enrollment is recorded as 4. The study began on 2021-04-29, and its primary completion date is recorded as 2022-02-11. Allocation is NA, and masking is none.
The intervention was Botox 200 UNT Injection into the duodenal wall by endoscopy. The planned primary endpoint was change in body weight from baseline to 6 months. The primary outcome description states that data analysis could not be completed because zero participants remained enrolled for 30 days or more. The record lists three outcome measures and zero analyses.
For the Botox Arm, the registry record lists 0 serious adverse events among 4 at risk, 1 other adverse event among 4 at risk, and 0 deaths. The reason for termination and a completed primary outcome result are not reported in the registry record.