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 Open-label Safety and Pharmacokinetic Study of DUEXIS® (Ibuprofen and Famotidine) Tablets in Juvenile Idiopathic Arthritis (NCT01563185), a na phase 4 study. The primary outcome is Number of Participants Reporting Treatment Emergent Adverse Events (TEAEs).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01563185 |
| Phase | Phase 4 |
| Condition | Juvenile Idiopathic Arthritis |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 12 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Amgen |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned patients with juvenile idiopathic arthritis (JIA) aged 10 years to 16 years, 11 months. The registry records enrollment of 12 participants. It does not report further participant characteristics in the information available for this analysis, so the enrolled group cannot be described in greater demographic or clinical detail.
Intervention
Participants received DUEXIS, recorded as 800 mg ibuprofen/26.6 mg famotidine. The brief summary describes treatment for up to 24 weeks. The record characterizes the study as open-label, meaning treatment was not masked from participants or study personnel.
Comparator
No separate comparator group is recorded. The study is classified as single-group, with allocation listed as not applicable. Its results therefore do not provide a randomized, like-for-like comparison with another treatment or with no treatment.
Primary question
The primary objective was to evaluate safety and tolerability in the study population. The listed primary endpoint counts participants reporting treatment-emergent adverse events (TEAEs), with adverse-event data collected from Day 0 through Week 26/ET, including at telephone visits. Secondary objectives included pharmacokinetic characteristics and signs and symptoms of JIA. The primary endpoint’s numerical result is not reported in the registry record analyzed here, so the extent of TEAEs cannot be described from that endpoint.
This question is descriptive rather than comparative: it asks what was recorded during DUEXIS treatment in this enrolled group, not whether DUEXIS performed better than a control. The registry record does not establish that any observed event was caused by treatment. Nor does the absence of a comparator allow treatment-related changes to be separated from the course of JIA or other influences. The study’s stated objectives and endpoint identify what investigators intended to assess; they do not by themselves establish what the results were.
3. Trial Design
This was a Phase 4, multicenter, open-label, single-group study of DUEXIS in patients with JIA. The registry lists enrollment of 12 and identifies Amgen as the sponsor. The study status is completed. The registry records a start date of 2012-04 and a primary completion date of 2015-03.
Single-group means the record describes one treatment group rather than distinct intervention and control groups. Allocation is listed as not applicable, and masking is listed as none. Participants and study personnel therefore were not blinded to the treatment, according to the registry classification. The study was not a randomized comparison; the registry record itself cautions that any arms are not a like-for-like control comparison. Consequently, the design is suited to describing observations made during treatment but does not support a randomized estimate of how outcomes compare with an alternative.
The intervention is recorded as 800 mg ibuprofen/26.6 mg famotidine. The brief summary says participants were treated for up to 24 weeks. The primary endpoint’s stated observation timeframe is Day 0 through Week 26/ET, with adverse-event data collected at every visit, including telephone visits. These are distinct descriptions in the record: the treatment duration is stated as up to 24 weeks, while the safety endpoint timeframe extends through Week 26/ET.
The study’s primary objective was safety and tolerability. Secondary objectives were to characterize pharmacokinetics and evaluate JIA signs and symptoms. Secondary measures listed include the Childhood Health Questionnaire Parent Form 50, physician and parent assessments, disability, joint counts, serum C Reactive Protein, and single-dose pharmacokinetic measures. The registry record does not report the protocol details, eligibility criteria beyond the age range and condition stated in the summary, treatment adherence, or the rationale for the enrollment target.
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 | DUEXIS |
|---|---|
| STARTED | 12 |
| COMPLETED | 10 |
| NOT COMPLETED | 2 |
Reasons for not completing this period:
| Reason | DUEXIS |
|---|---|
| Withdrawal by Subject | 1 |
| Non-Compliance with study drug | 1 |
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 | DUEXIS |
|---|---|---|
| Participants analysed | 12 | |
| Age, Categorical: <=18 years | Participants | 12 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 |
| Age, Categorical: >=65 years | Participants | 0 |
| Age, Continuous | years | 13.8 (SD 1.71) |
| Sex: Female, Male: Female | Participants | 5 |
| Sex: Female, Male: Male | Participants | 7 |
| Region of Enrollment: United States | participants | 12 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants Reporting Treatment Emergent Adverse Events (TEAEs), measured over Day 0 through Week 26/ET (adverse event data was collected at every visit, including telephone visits).
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants reporting treatment-emergent adverse events (TEAEs). It is a count of participants with at least one event, rather than a count of all event episodes. The registry lists the unit as participants and the parameter as number. The endpoint description says safety assessments included adverse-event monitoring, review of concomitant medications, physical examinations including vital signs and weight, and clinical laboratory assessments, including pregnancy testing for female patients.
The stated observation window is Day 0 through Week 26/ET. Adverse-event data were collected at every visit, including telephone visits. The brief summary describes treatment for up to 24 weeks; this treatment-duration statement does not replace the endpoint’s stated follow-up window.
Counting participants with TEAEs is a way to describe how many people experienced an event during the defined observation period. It does not, on its own, convey event severity, duration, recurrence, or causal attribution. A participant count also does not say whether the reported event was serious. Those distinctions require separate event details and definitions. The primary endpoint’s numerical result is not reported in the registry record analyzed. As a result, its stated purpose and measurement can be described, but the number of participants with TEAEs cannot be characterized from the primary outcome result.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a small, completed, open-label study in one treatment group. Enrollment was 12. The primary question concerned safety and tolerability during DUEXIS treatment, but the numerical result for the primary TEAE endpoint is not reported in the registry record analyzed. The design and endpoint therefore establish what was intended to be evaluated, but do not supply a reported primary-endpoint estimate for interpretation.
The adverse-event summary records 0 of 12 participants at risk as affected for serious adverse events. It also records 12 of 12 as affected in the other adverse-event category. These categories should be kept distinct. The registry record does not list serious adverse-event terms, and the death count is not reported in the record analyzed. The figures do not identify the specific non-serious events, their severity, their duration, or whether investigators considered them related to DUEXIS. The other-category count should not be treated as a substitute for the missing numerical result on the primary TEAE endpoint.
The lack of a control group is central to interpretation. A single-group observation can describe events occurring during the study, but it cannot show how those observations compare with an alternative treatment or with the expected course without the study intervention. Open-label conduct may also influence reporting or assessment. These design features do not invalidate a descriptive safety objective, but they limit what causal or comparative conclusions can be drawn.
The registry lists secondary objectives and measures related to JIA symptoms, function, laboratory assessment and pharmacokinetics. Numerical secondary outcome analyses are not reported in the registry record analyzed. Listing an outcome indicates that it was planned or recorded as an outcome measure; it does not establish that a result was posted or what that result was. The record therefore does not support interpretation of the direction or magnitude of change in JIA measures or pharmacokinetic estimates.
Any confidence interval, in general, represents a range of values compatible with the data and the specified statistical procedure, and its width reflects precision. No primary-endpoint confidence interval is reported in the registry record analyzed. With a study enrolling 12 participants, estimates could be imprecise, but no precision estimate for the primary endpoint is available to quantify that concern. No treatment effect estimate against a comparator is available, because the study has no recorded comparator group.
These results should be read as a registry description of a single-group safety and pharmacokinetic study, not as evidence from a randomized comparison. The serious-event count is a specific descriptive result, but it does not characterize all TEAEs or resolve questions about causality. The missing primary and secondary numerical analyses prevent fuller assessment of what was observed across the stated objectives.
9. Statistical Methods Explained
What does a participant count describe?
General: A participant count for an event endpoint records how many people meet the endpoint definition during a stated observation period. It differs from an event count, which may count repeated episodes in the same person. The primary endpoint in this study is explicitly expressed as the number of participants reporting TEAEs. Interpreting such a count depends on the event definition, the observation window, and whether participants had comparable opportunities for events to be detected. The record states that adverse-event data were collected at every visit, including telephone visits, and gives the timeframe as Day 0 through Week 26/ET.
A count alone does not describe how often each event occurred, how severe it was, how long it lasted, or whether it was considered related to treatment. Those are separate features of safety data. The record describes safety assessments and identifies the primary endpoint, but its numerical TEAE result is not reported in the registry record analyzed.
Why does the single-group design matter?
General: In a single-group study, outcomes can be described among participants receiving the study intervention. Without a concurrent comparator, the observed outcomes cannot establish what would have happened to similar participants under another treatment or no treatment. Randomization, when used, helps create groups that can be compared without deliberately assigning participants according to prognostic features. This study is recorded as single-group, with allocation not applicable and no masking. It is not a randomized comparison.
For that reason, an event recorded during treatment is not automatically an event caused by treatment. JIA, other health conditions, concomitant medications, and chance can all be relevant to clinical interpretation, but the record does not quantify their contributions. The study can contribute descriptive information within its enrolled group; it cannot provide a controlled estimate of a treatment contrast.
How should a confidence interval be understood?
General: A confidence interval expresses uncertainty around an estimate under a specified statistical model and procedure. A narrow interval indicates greater precision than a wide interval, while an interval spanning a broad range leaves more uncertainty about the underlying value. It does not correct for limitations such as lack of a comparator, incomplete outcome reporting, or possible bias in an open-label study. No confidence interval for the primary TEAE endpoint is reported in the registry record analyzed.
What can the serious-event summary tell readers?
The registry’s adverse-event summary reports 0 of 12 participants at risk as affected for serious adverse events. This is a descriptive count in the enrolled group, not a comparison against another group. General: A zero count in a study does not demonstrate that an event is impossible or that the risk is zero in a broader population. The amount of information depends on the number observed, follow-up, event ascertainment, and the population studied. No uncertainty interval for this serious-event count is reported in the registry record analyzed. The record also lists 12 of 12 affected in the other adverse-event category, but does not supply event terms or further detail in the summary being interpreted.
What do planning illustrations mean?
General: A sample-size calculation describes how many participants a hypothetical study might need under stated assumptions to detect a specified effect with a chosen statistical approach. It is a planning exercise, not an observed result and not a measure of the probability that a completed study has established a treatment effect. Any planning illustrations associated with the posted material are not the trial’s own design or an observed-power result. Their stated assumptions include a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a fraction of the observed effect. Those assumptions describe an illustration and do not change this registry record’s single-group design. The record does not report a sample-size justification or the rationale for enrolling 12 participants.
General: Over-dispersion occurs when outcome variability exceeds what a statistical model assumes. If present, it can make standard errors and confidence intervals too small under an unsuitable model. The registry record analyzed does not report an analysis model for the primary endpoint, so no claim about whether over-dispersion was assessed or relevant can be made.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists a primary safety endpoint and secondary outcome measures covering JIA assessments, laboratory measures and pharmacokinetic characteristics. It does not report a multiplicity adjustment, a hierarchy for testing outcomes, or a statistical plan specifying which results would be considered confirmatory. Without that information, the number and relationship of planned comparisons cannot be used to determine how the chance of false-positive findings was managed. The registry record also does not report numerical analyses for the primary endpoint or the secondary outcomes analyzed.
Missing-data methods are not reported in the registry record. The endpoint description states that adverse-event data were collected at every visit, including telephone visits, but does not say how incomplete visits, withdrawal, missed assessments, or unavailable outcome values were handled. Collection at visits does not establish that every participant contributed complete data throughout the observation period.
The analysis populations are not reported in the registry record. It is therefore not possible to determine whether the posted safety summaries include all enrolled participants, only those who received treatment, or another defined group. The registry lists 12 participants enrolled, and the serious-adverse-event summary lists 12 at risk, but this does not supply a general definition of the analysis population for all outcomes.
These gaps matter because outcome definitions, missing-data handling and analysis populations affect how estimates are interpreted and how results can be compared across studies. No protocol-level details, interim-analysis plans, or statistical-analysis plan are reported in the registry record analyzed. Their absence should be treated as unreported information, not as evidence that a particular method was or was not used.
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 |
|---|---|---|---|
| DUEXIS | 0 | 12 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| DUEXIS | 12 of 12 |
Most frequent non-serious adverse event terms
| Event term | Organ system | DUEXIS |
|---|---|---|
| Diarrhoea | Gastrointestinal disorders | 2 of 12 |
| Ingrowing nail | Skin and subcutaneous tissue disorders | 2 of 12 |
| Abdominal pain upper | Gastrointestinal disorders | 1 of 12 |
| Constipation | Gastrointestinal disorders | 1 of 12 |
| Gastrooesophageal reflux disease | Gastrointestinal disorders | 1 of 12 |
| Haematochezia | Gastrointestinal disorders | 1 of 12 |
| Nausea | Gastrointestinal disorders | 1 of 12 |
| Tooth impacted | Gastrointestinal disorders | 1 of 12 |
| Fatigue | General disorders | 1 of 12 |
| Gait disturbance | General disorders | 1 of 12 |
The registry’s serious-adverse-event summary records 0 affected participants among 12 at risk. The separate other adverse-event category records 12 affected among 12 at risk. These are counts within the study group, not treatment-versus-control comparisons. The record does not list serious-event terms, and a death count is not reported in the registry record analyzed.
Serious adverse events are not interchangeable with all treatment-emergent adverse events. A serious event is a distinct safety classification; a TEAE endpoint may include events that are not serious. The reported serious-event count therefore cannot be used as the missing primary TEAE result. The other-category count does not identify which events were recorded or whether they were mild, severe, related to treatment, or recurrent. The record also does not provide detail on the timing or duration of those events in the information analyzed.
General: Safety counts describe observations under the study’s event definitions and follow-up conditions. They do not, by themselves, establish causality or exclude events that were not observed during a study. In this single-group study, there is no control group against which to compare event counts. The counts should therefore be read narrowly as the recorded adverse-event summary for this enrolled group, rather than as a comparative risk estimate.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a completed, open-label, single-group Phase 4 study evaluated DUEXIS in patients with JIA. The stated primary objective was safety and tolerability, and the primary endpoint was the number of participants reporting TEAEs. The study also had secondary objectives involving pharmacokinetics and JIA signs and symptoms. The serious-adverse-event summary records 0 of 12 participants at risk as affected, while the other adverse-event category records 12 of 12 as affected.
Those details do not provide a complete account of the study’s safety findings. The primary endpoint’s numerical result is not reported in the registry record analyzed. Event terms for the other category are not reported, and the serious-event terms are not listed. A serious-event count cannot stand in for a count of all TEAEs, and the other category does not reveal the nature or clinical importance of the events. The death count is also not reported in the registry record analyzed.
The study does not establish a comparative treatment effect. It has no recorded control group and was not randomized. Events during treatment cannot be attributed to DUEXIS solely because they occurred during the study. Similarly, the record does not report numerical secondary analyses that would support conclusions about changes in symptoms, function, laboratory measures, or pharmacokinetic characteristics.
General: A completed study is not necessarily a study with every planned result posted in the registry. The absence of a result from the registry record means that the result cannot be interpreted from that record; it does not establish that no data were collected or that a particular outcome did not occur. Readers should distinguish the stated objectives, the reported adverse-event counts and the results that are not reported. No conclusion about clinical benefit or lack of benefit follows from this registry information alone.
13. Why This Trial Matters Statistically
This study illustrates the distinction between a research question and a result. Its primary endpoint is clearly framed as a participant count for TEAEs, and the registry describes the safety assessments and observation period. However, the primary endpoint’s numerical result is not reported in the registry record analyzed. A clearly defined endpoint does not substitute for a reported estimate, and a result cannot be reconstructed from the study description.
The design also matters statistically. A single-group, open-label study can describe what was observed among participants receiving the intervention, but cannot make a randomized comparison with an alternative. This distinction is important when reading safety counts: the study records 0 of 12 participants at risk affected by serious adverse events and 12 of 12 affected in the other category, but these counts do not estimate a contrast between treatments and do not resolve causality.
Outcome breadth is another consideration. The registry identifies safety, pharmacokinetic, and JIA-related outcomes, yet numerical analyses for those outcomes are not reported in the registry record analyzed. Listing several domains without their estimates leaves uncertainty about the results and about how the outcomes were analyzed. Missing analysis details, including multiplicity handling and analysis populations, further limit statistical assessment.
General: Transparent reporting supports evaluation of estimates, uncertainty, and analysis choices. When estimates and methods are absent, the appropriate statistical conclusion is limited: describe what the record does report, identify what is not reported, and avoid filling gaps with assumptions. This discipline is especially important in a small, uncontrolled study, where precision and comparative interpretation are already constrained by design.
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.
Several limitations follow directly from the registry record. Enrollment was 12, and the study used a single-group, open-label design with no recorded comparator. The data can describe the enrolled group but cannot provide a like-for-like comparison or isolate the effect of treatment from other influences. Open-label conduct also means participants and study personnel were not masked, according to the registry classification.
The primary numerical result for TEAEs is not reported in the registry record analyzed. The adverse-event summary supplies a serious-event count and a separate other-category count, but does not give the event terms for the latter or further information about severity, duration, recurrence, or attribution. Serious-event terms are not listed, and the death count is not reported. These omissions limit the clinical detail that can be drawn from the safety summary.
Numerical analyses for the listed secondary outcomes are also not reported in the registry record analyzed. The statistical analysis plan, sample-size justification, missing-data approach, analysis populations, and multiplicity procedures are not reported. It is not possible to assess the handling of incomplete observations, the precision of outcome estimates, or which analyses were intended to support confirmatory conclusions.
The record gives an age range in the brief summary, the condition, intervention, and treatment duration, but it does not report further participant characteristics in the information analyzed. Generalizability beyond the enrolled group is therefore difficult to assess. The registry’s completion status indicates that the study was recorded as completed; it does not resolve the gaps in posted outcomes and methods.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Open-label Safety and Pharmacokinetic Study of DUEXIS® (Ibuprofen and Famotidine) Tablets in Juvenile Idiopathic Arthritis — NCT01563185.
- Registry record last updated 2024-12-16; status last verified 2024-11.
- Results first posted 2015-12-23.
- 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
NCT01563185 is a completed Phase 4, multicenter, open-label, single-group study sponsored by Amgen. It enrolled 12 participants with JIA and evaluated DUEXIS, recorded as 800 mg ibuprofen/26.6 mg famotidine. The brief summary describes treatment for up to 24 weeks.
The primary objective was safety and tolerability. The primary endpoint counted participants reporting TEAEs during Day 0 through Week 26/ET, with adverse-event data collected at every visit, including telephone visits. Secondary objectives concerned pharmacokinetic characteristics and JIA signs and symptoms.
The registry’s serious-adverse-event summary records 0 of 12 participants at risk as affected; the other adverse-event category records 12 of 12 as affected. The primary TEAE result, numerical secondary analyses, analysis populations, and statistical-analysis details are not reported in the registry record analyzed. The single-group design does not provide a randomized comparison.