Safety and Efficacy of Dexlansoprazole Delayed-Release Capsules in Treating Symptomatic Non-Erosive Gastroesophageal Reflux Disease in Adolescents: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Safety and Efficacy of Dexlansoprazole Delayed-Release Capsules in Treating Symptomatic Non-Erosive Gastroesophageal Reflux Disease in Adolescents (NCT01642602), a na phase 2 study. The primary outcome is Percent of Participants Who Experience Each Treatment Emergent Adverse Event Experienced by ≥5% of Participants While Receiving Dexlansoprazole During the 4 Week Treatment Period.

2. Clinical Question

3. Trial Design

This was a Phase 2, open-label, multicenter study of once-daily oral dexlansoprazole in adolescents with symptomatic non-erosive GERD. The study is listed as completed. Its official title describes a 4-week assessment of safety and effectiveness for relief of heartburn among subjects aged 12 to 17 years. The treatment regimen was dexlansoprazole 30 mg delayed-release capsules once daily for up to 4 weeks.

The registry describes a single-group model and no allocation to comparison groups. This means the posted study design supplies safety and symptom information for participants receiving dexlansoprazole, but does not provide a concurrent randomized control group. Open-label treatment also means the treatment was known rather than masked. The registry record does not report a comparator or a masking procedure.

Enrollment was 104. The safety analysis set includes all participants who received at least 1 dose of study drug, and the adverse-event figures list 104 participants at risk. The registry record does not give further details on participant flow, such as the number who completed treatment or the number with complete symptom assessments.

The primary outcome concerns treatment-emergent adverse events during the 4-week treatment period. The secondary outcome concerns the percentage of days without either daytime or nighttime heartburn over those 4 weeks. The registry lists 2 outcome measures and 0 analyses. A detailed statistical analysis plan, including the intended handling of the secondary outcome, is not reported in the registry record. The study began in 2012-07 and had a primary completion date of 2014-01.

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: Adolescent participants (male or female), aged 12 to 17 years (inclusive) with symptomatic non-erosive gastrointestinal reflux disease were enrolled in 1 group and received dexlansoprazole 30 mg orally once daily for up to 4 weeks.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Safety analysis set: All participants who received at least 1 dose of study drug.

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: Full analysis set: All participants who received at least 1 dose of study drug and had post-baseline data (and baseline data if applicable) for the appropriate efficacy variable.

6. Primary Endpoint

The registry lists the primary outcome as Percent of Participants Who Experience Each Treatment Emergent Adverse Event Experienced by ≥5% of Participants While Receiving Dexlansoprazole During the 4 Week Treatment Period, measured over 4 weeks.

The primary endpoint is the percentage of participants who experienced each treatment-emergent adverse event occurring in at least >=5% of participants during the 4-week treatment period. The registry defines a treatment-emergent event as one that started or worsened on or after Study Day 1, the first dose day, and no more than 30 days after the last dose. The safety analysis set includes participants who received at least 1 dose of study drug.

This endpoint describes how commonly reported events occurred among the treated participants. A participant-based percentage is useful for a safety summary because it indicates the share of the safety population with an event, rather than the total number of event episodes. The registry’s event-specific presentation threshold focuses attention on events reported relatively often in this study; it does not imply that less frequent events did not occur or were unimportant.

The endpoint is descriptive in this single-group study. Without a comparison group, it cannot by itself establish how frequently the same events would have occurred without dexlansoprazole or with another treatment. The registry record does not report event-specific estimates beyond the available adverse-event summary, nor does it report confidence intervals or an inferential analysis for this endpoint.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a participant percentage describe?

For a binary safety outcome, the basic descriptive quantity is the proportion of participants who experienced the event among those included in the relevant analysis population. Here, the registry defines the safety analysis set as participants who received at least 1 dose of study drug, and the adverse-event summary lists 104 participants at risk. A participant-based count answers whether a person experienced an event; it is distinct from an event count, which could count repeated episodes in the same person.

The registry identifies the primary outcome as a percentage of participants experiencing each treatment-emergent adverse event reported in at least >=5% of participants. The available event summary gives counts for serious and other adverse events, but does not report individual event terms or corresponding event-specific percentages. No percentage should be inferred from the counts when the registry’s posted result is a count and the requested interpretation is limited to reported results.

Why is the single-group design important?

A descriptive proportion in one treated group can summarize what was observed among those participants. It cannot distinguish treatment-related events from events that might also arise from the underlying condition, background risk, or other circumstances. A concurrent comparison group can support a between-group estimate, subject to the design and analysis assumptions. No comparison group is reported for this study, so a treatment contrast, relative effect, or comparative confidence interval is not available.

General statistical explanation: estimates from a sample have uncertainty because they are based on a finite set of participants. A confidence interval is a range calculated using a statistical method to express uncertainty around an estimate. Its interpretation depends on the model and assumptions used. The registry record does not report confidence intervals or a method for calculating them for the primary outcome, so the posted counts cannot be accompanied by a registry-reported interval in this interpretation.

What does the event definition contribute?

The treatment-emergent definition specifies a time relationship: an event must start or worsen on or after Study Day 1, the first dose day, and no more than 30 days after the last dose. Such a definition makes the observation window explicit. It does not establish that the drug caused the event. Causal attribution requires more than timing, and the single-group design does not offer a concurrent treatment contrast.

The outcome is limited to events that meet the registry’s treatment-emergent definition and the stated reporting threshold. That threshold helps structure which events are summarized in the primary outcome, but an event falling below the threshold may still have occurred. The record does not provide a complete event-term listing in the available summary, so the range and frequency of specific event types cannot be assessed from these figures.

What analysis details are missing?

The registry lists 0 analyses. It does not report a statistical analysis plan, a method for calculating outcome estimates, a procedure for handling repeated events, an adjustment strategy, or an inferential test for the safety outcome. It also does not report how missing event information would be handled. These omissions matter because analysis choices can affect the definition of the analysis population and the uncertainty attached to an estimate. The safety population is defined, but further details on data completeness and participant flow are not reported in the registry record.

General statistical explanation: over-dispersion is a concern when count data vary more than a chosen statistical model expects, and it can make uncertainty estimates too small if ignored. It is most relevant to particular count-data models. The posted primary outcome is a participant-based event measure, and the registry record does not report a model or any assessment of over-dispersion. It would therefore be inappropriate to assume that such a model was used or to attribute a specific method to this study.

How should planning illustrations be read?

The planning illustrations use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect defined as a stated fraction of the observed effect. These assumptions describe planning illustrations, not the study’s single-group design. The illustrations are not evidence that the completed study had a particular power, and they are not observed power. Their hypothetical allocation and comparison structure should not be mistaken for the design used in the registry record.

General statistical explanation: sample-size planning asks how many participants a proposed design may need under specified assumptions. It is conditional on the target effect, variability, analysis method, and design features. A planning output cannot validate those assumptions after the fact, and it does not replace a report of the study’s prespecified design rationale. The registry record does not report a sample-size justification or a statistical analysis plan.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 2 outcome measures: the primary adverse-event outcome and the secondary outcome of the percentage of days with neither daytime nor nighttime heartburn over the 4 weeks of treatment. It lists 0 analyses. No procedure for controlling multiplicity, prioritizing analyses, or interpreting multiple outcome tests is reported in the registry record.

Multiplicity arises when several outcomes, comparisons, or analyses are considered. General statistical explanation: evaluating multiple results can increase the chance of finding an apparently notable result by chance, depending on how the analyses are conducted. Prespecified priorities or adjustment methods can address this concern, but the registry record does not describe such methods. The primary outcome is framed as a descriptive percentage, and no inferential test results are reported.

Missing-data procedures are also not reported. The safety analysis set is defined as everyone who received at least 1 dose, and the adverse-event summary lists 104 participants at risk. However, the record does not describe completeness of event reporting, treatment discontinuation, missing symptom diaries, or how unavailable symptom measurements were treated. The secondary heartburn outcome result is not reported in the registry record, so its analysis population and missing-data handling cannot be assessed.

The definition of the safety analysis set is useful, but it does not supply all details needed to evaluate completeness or potential bias. Participant flow, reasons for missing data, and sensitivity analyses are not reported in the registry record. These limitations constrain interpretation of both safety and symptom outcomes.

11. 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 non-serious adverse event terms

The adverse-event summary lists 104 participants at risk in the dexlansoprazole 30 mg group. It reports 0 participants with serious adverse events and 14 participants with other adverse events. These are counts of participants, not counts of event episodes. The record does not identify the terms of the other adverse events in the available summary.

A serious adverse event is a distinct category from an event being treatment-emergent. The registry defines treatment-emergent events by when they began or worsened relative to the first dose and the period after the last dose. The available summary does not give additional criteria or event-level detail for the serious-event category. The zero count means no serious adverse events were recorded in the posted summary for this group; it is not proof that such events cannot occur.

The counts should be read as descriptive observations, not as a comparison with another treatment. The single-group study has no listed control arm, and the registry does not report event-specific uncertainty estimates. It also does not report seriousness, severity, relatedness, or outcomes for the other adverse events in the available figures.

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

The results describe a completed, open-label, single-group study of dexlansoprazole 30 mg delayed-release capsules taken orally once daily for up to 4 weeks by adolescents aged 12 to 17 years with symptomatic non-erosive GERD. The safety summary records 0 participants with serious adverse events and 14 with other adverse events among 104 participants at risk. The study’s primary outcome is framed around participant percentages for treatment-emergent events meeting the stated threshold.

Those findings do not establish a comparative treatment effect. There is no separate control group in the registry record, so the observed counts cannot be contrasted with what would have happened under placebo, usual care, or another treatment. The event timing definition also does not establish that an event was caused by treatment. The registry record does not report event-specific terms for the other adverse events in the available summary, so the types of events represented by that count remain unclear.

The information does not establish the absence of risk. A zero count for serious events in this study is an observation in the enrolled safety population and over the study’s defined observation period. It does not rule out uncommon events or events that might appear with longer observation. Nor does the count of other adverse events describe their severity, duration, consequences, or relationship to treatment.

The registry lists a secondary heartburn outcome, but its result is not reported in the registry record. Thus, the posted information does not support a conclusion about symptom benefit. It also does not report confidence intervals, inferential tests, or a detailed analysis plan for the primary endpoint. The results are best understood as a limited descriptive account of recorded safety events, rather than as a definitive estimate of comparative safety or effectiveness.

13. Why This Trial Matters Statistically

This trial illustrates an important distinction between describing outcomes in treated participants and estimating a treatment effect. A single-group study can record how many participants experienced events during treatment, but it cannot provide a concurrent comparison for judging whether those events occurred more or less often because of treatment. That distinction is central when interpreting safety summaries from uncontrolled studies.

The registry’s primary outcome uses a participant-based measure and defines a treatment-emergent time window. Those features help specify what is counted and when an event qualifies for consideration. At the same time, the reporting threshold and the absence of individual event terms limit what can be learned about the pattern of specific events. A count alone is not a complete account of event type, severity, or causal attribution.

The study also demonstrates why analysis details matter. A stated safety population gives readers a denominator, but further information on missing data, participant flow, uncertainty estimates, and event-specific analyses would help readers judge precision and completeness. Those details are not reported in the registry record. The registry also lists a secondary symptom outcome without reporting its result, leaving the effectiveness question unresolved in the posted data.

Finally, planning illustrations must be kept separate from the completed study design. Illustrations based on assumptions about allocation between two arms do not turn a single-group study into a comparative trial, and they do not establish observed power. Interpreting design, endpoint, and analysis together prevents descriptive safety counts from being mistaken for evidence of a controlled treatment contrast.

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 single-group, open-label design is a central limitation for interpretation. No comparator is reported, so there is no concurrent reference for separating events observed during treatment from events that might otherwise occur. Knowledge of treatment assignment may also affect reporting or assessment, although the registry record does not describe how adverse events were elicited or assessed.

The registry reports an enrollment of 104 and lists 104 participants at risk for the adverse-event figures, but it does not describe participant flow, treatment completion, or withdrawals. The safety analysis set is defined as participants who received at least 1 dose; additional details on follow-up completeness and missing information are not reported in the registry record.

The available summary gives 0 serious adverse events and 14 participants with other adverse events, but it does not list the individual event terms, severity, relatedness, duration, or consequences for those events. It therefore does not allow a detailed assessment of event patterns. No confidence intervals or inferential analyses are reported, and the registry lists 0 analyses.

The study’s treatment period was 4 weeks, with treatment-emergent events defined through no more than 30 days after the last dose. This provides a stated observation window, but the registry record does not report longer-term safety follow-up. The secondary heartburn outcome is listed, but its result and missing-data handling are not reported. A sample-size justification and detailed statistical analysis plan are also not reported in the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Safety and Efficacy of Dexlansoprazole Delayed-Release Capsules in Treating Symptomatic Non-Erosive Gastroesophageal Reflux Disease in Adolescents — NCT01642602.
• Registry record last updated 2014-08-06; status last verified 2014-07.
• Results first posted 2014-08-06.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

NCT01642602 is a completed Phase 2, open-label, multicenter, single-group study sponsored by Takeda. It enrolled 104 adolescents aged 12 to 17 years with symptomatic non-erosive GERD. Participants received dexlansoprazole 30 mg delayed-release capsules orally once daily for up to 4 weeks.

The primary outcome concerns the percentage of participants experiencing each treatment-emergent adverse event reported in at least >=5% of participants. The safety analysis set includes participants who received at least 1 dose. The adverse-event summary lists 104 participants at risk, 0 with serious adverse events, and 14 with other adverse events. The registry also lists a secondary outcome concerning days without daytime or nighttime heartburn, but its result is not reported in the registry record.

No comparator, inferential analyses, confidence intervals, missing-data procedures, or detailed statistical analysis plan are reported in the registry record.