Alogliptin Tablets Special Drug Use Surveillance Type 2 Diabetes Mellitus: Combination Therapy With Biguanides: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Alogliptin Tablets Special Drug Use Surveillance Type 2 Diabetes Mellitus: Combination Therapy With Biguanides (NCT01964976), a registered phase not stated study. The primary outcome is Number of Participants Reporting One or More Adverse Drug Reactions.

2. Clinical Question

The registry record concerns long-term alogliptin use in people with type 2 diabetes mellitus whose response to biguanide treatment, alongside diet and exercise therapy, was inadequate. Its stated purpose was to examine safety and efficacy during combination therapy in routine clinical practice. The primary endpoint concerns the number of participants with one or more adverse drug reactions during follow-up, while listed secondary outcomes concern glycemic measures.

This is a descriptive surveillance question rather than a randomized treatment comparison. It can characterize what was recorded in the observed groups, but the record does not establish that group differences, if any, were caused by alogliptin or by a particular combination regimen. The registry record does not report the primary endpoint result. It also does not report numerical results for the glycemic outcomes listed as secondary measures.

3. Trial Design

This was a completed special drug use surveillance study of alogliptin, also identified in the record by the product name Nesina, in type 2 diabetes mellitus. Takeda is listed as the sponsor. The enrollment was 1096. The record gives a study start of 2011-07 and a primary completion of 2014-12.

The treatment description is based on routine clinical practice. Participants received alogliptin 25 milligram tablets orally once daily for up to 12 months. The record describes use with biguanides, or without biguanides within 3 months from the start of alogliptin administration and during the alogliptin treatment period. The stated study purpose was to examine long-term safety and efficacy among people whose diabetes had responded inadequately to biguanides alongside diet and exercise therapy.

Two groups are listed: alogliptin plus biguanides and alogliptin plus other. The safety populations reported for these groups are 954 and 109 participants, respectively. The registry record does not state how participants were allocated. It does not describe a randomized allocation or a like-for-like control comparison; the groups should therefore be read as observed treatment groups, not as randomized arms designed to isolate a treatment effect.

The primary outcome was the number of participants reporting one or more adverse drug reactions from baseline up to 12 months. Listed secondary outcomes include change from baseline in HbA1c, the percentage achieving objective glycemic control, change from baseline in fasting blood glucose, and change from baseline in fasting insulin level. The registry record does not report a detailed protocol, the rationale for the enrollment target, or further design details beyond the surveillance description.

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: Participants with type 2 diabetes mellitus started treatment with alogliptin as per routine clinical practice were observed. As per protocol, participants were enrolled in 1 observational group at the start and were divided into 2 groups based on biguanide use for analysis of safety endpoints. Participant flow data was collected for overall arm.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The safety analysis set was defined as all participants who completed the study and had safety data available.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

Population: The safety analysis set was defined as all participants who completed the study and had safety data available.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants Reporting One or More Adverse Drug Reactions, measured over Baseline up to 12 months.

The primary endpoint counts participants who reported one or more adverse drug reactions during the period from baseline up to 12 months. The registry record defines an adverse drug reaction as an adverse event that, in the investigator’s opinion, was causally related to study treatment. It defines adverse events as unfavorable and unintended signs, symptoms, or diseases temporally associated with use of a medicinal product, reported from the first dose to the last dose.

This endpoint is used to describe treatment-related safety experience. Counting participants with at least one qualifying reaction gives a participant-level summary: a participant is counted if one or more qualifying reactions occur, rather than each reaction being counted as a separate participant. The count can be informative for surveillance because it indicates how many people in the analyzed set were recorded as having a suspected treatment-related event. It does not, on its own, describe the event’s severity, duration, clinical importance, or certainty of causal attribution.

The planned safety assessment was to be conducted separately for the alogliptin plus biguanides group and the alogliptin plus other group. The safety analysis set was defined as participants who completed the study and had safety data available. The registry record does not report the primary endpoint counts, estimates of uncertainty, or a comparison between groups. Consequently, the endpoint definition is available, but its observed result cannot be interpreted from this registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical interpretation starts with identifying what was counted, in whom, and over what period. The primary endpoint is a participant count: people with one or more investigator-attributed adverse drug reactions from baseline up to 12 months. The record defines the safety analysis set as participants who completed the study and had safety data available. That population definition matters because it specifies whose records contribute to the planned safety assessment; it does not mean that every enrolled participant necessarily contributes to that analysis.

What does a participant count represent?

In general, a participant count records whether each person met an outcome definition. A person with multiple qualifying events still contributes one person to an endpoint defined as participants with one or more events. This differs from counting every event, which may count repeated events in the same person. The primary endpoint title uses the participant-level formulation. The registry record does not report its observed counts, so the planned measure cannot be translated into an observed frequency from the information recorded.

How should the groups be understood?

The record lists alogliptin plus biguanides and alogliptin plus other. It describes treatment in routine clinical practice and does not state allocation. In general, a randomized comparison aims to make treatment groups comparable through the allocation process, supporting a causal interpretation under additional assumptions. For a nonrandomized or allocation-unclear comparison, group membership can reflect clinical decisions or participant characteristics. A difference between group outcomes could therefore have explanations other than treatment. The record itself flags that the arms are not a like-for-like control comparison.

Accordingly, the group-specific serious and other adverse-event counts should be read descriptively. They indicate recorded events in the stated at-risk groups, not an adjusted comparison. The registry record does not report adjustment methods, a model for group comparisons, confidence intervals, or hypothesis tests. It also lists zero analyses. No inferential conclusion about a difference between groups is supported by the posted analyses.

What would uncertainty measures add?

In general, a confidence interval describes uncertainty around an estimate under the method used to construct it. For a count or event frequency, an interval can show how imprecisely the underlying frequency is estimated from the observed sample. It does not account automatically for selection bias, confounding, incomplete follow-up, or errors in outcome classification. No confidence interval for the primary endpoint is reported in the registry record, and no interval should be inferred from the counts in the separate adverse-event categories.

A p-value, in general, measures how compatible data are with a specified null hypothesis and statistical model. It does not measure the probability that the null hypothesis is true, and it does not establish clinical importance. The registry record does not report a primary endpoint p-value or a statistical test for the group figures. With no stated analysis plan or posted inferential result, a formal hypothesis-testing interpretation is unavailable.

What do the planning illustrations mean?

Planning illustrations based on an observed effect are not observed power. The stated planning 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 a stated fraction of the observed effect. For non-time-to-event outcomes, such illustrations are expressed as participants per arm. They describe hypothetical planning under the stated assumptions, not the number actually analyzed or evidence that a study had a particular probability of detecting an effect. The registry record does not report its own sample-size justification or design rationale, so these planning assumptions should not be attributed to the original surveillance design.

For a binary outcome, general sample-size methods depend on assumptions about event probabilities, the effect to be detected, the allocation structure, and the testing procedure. A normal approximation is one way to approximate the sampling distribution under specified conditions. Where event counts are sparse, approximation quality may be limited; the registry record does not report enough information to assess the model or any alternative methods used for its primary endpoint. The event-count illustrations, if consulted, remain planning calculations rather than observed study findings.

General statistical methods also distinguish a prespecified primary outcome from secondary outcomes. The primary endpoint ordinarily anchors the main study question, while secondary outcomes address additional questions. Their interpretation depends on the protocol’s definitions and analysis plan. The registry record lists one primary outcome and several secondary measures, but does not report a detailed analysis plan, endpoint hierarchy, or multiplicity procedure. Those details cannot be reconstructed from outcome names alone.

10. Exact Estimates for Each Arm

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

R code and output

arm    <- c("Alogliptin + Biguanides", "Alogliptin + Other")
n      <- c(954, 109)
events <- c(26, 2)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Alogliptin + Biguanides  954  26  2.7  1.8  4.0  1.9  4.0  1.9  4.0
ARM  Alogliptin + Other  109  2  1.8  0.2  6.5  0.5  6.4  0.6  6.4

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists one primary outcome and several secondary outcomes, including HbA1c, objective glycemic control, fasting blood glucose, and fasting insulin. It reports six outcome measures overall and zero analyses. The posted record does not give a complete statistical analysis plan, explain whether all outcomes were analyzed, or describe how multiple outcome testing was handled.

In general, testing many outcomes can increase the chance of finding at least one apparently notable result by chance. Methods for addressing multiplicity can include adjustment procedures or a prespecified hierarchy of outcomes, but the record does not say whether any such approach was planned or used. Without that information, any hypothetical collection of results could not be interpreted as though the multiplicity strategy were known. No adjustment should be assumed.

The primary endpoint’s analysis population is defined as participants who completed the study and had safety data available. The record does not report how many participants lacked data, reasons for missingness, or methods for handling missing endpoint information. It also does not describe whether missing outcome data were imputed, excluded, or otherwise handled. In general, missingness can affect both the precision and representativeness of an estimate, particularly if the likelihood of missing data is related to treatment or outcome. The direction and extent of any such effect cannot be assessed from this record.

The enrollment was 1096, while the reported group safety populations are 954 and 109. The record does not explain the participant flow from enrollment to the safety analysis set or give a detailed accounting of exclusions. The safety-set definition makes completion and availability of safety data relevant to inclusion, but the reasons participants may not have contributed are not reported in the registry record. These omissions limit assessment of missing data and analysis-population selection.

12. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: renal cancer (0.1%), prostate cancer (0.1%), diabetes mellitus (0.1%), hypoglycaemia (0.1%), fall (0.1%).

The adverse-event summary distinguishes a serious-event category from other adverse events. For alogliptin plus biguanides, the serious category records 4 affected participants among 954 at risk, and the other category records 24 among 954. For alogliptin plus other, the serious category records 0 affected participants among 109 at risk, and the other category records 2 among 109. The record does not report deaths.

These are descriptive participant counts. They should not be confused with the primary endpoint, which counts participants with one or more adverse drug reactions judged by the investigator to be causally related to treatment. The record does not establish that every event in the serious or other categories was judged treatment-related, nor does it provide a causal comparison between groups. The group allocation is not stated, and the registry record cautions that the groups are not a like-for-like control comparison.

The serious terms listed are renal cancer, prostate cancer, diabetes mellitus, hypoglycaemia, and fall, each reported as 0.1%. These entries describe terms in the registry record; they do not supply a complete clinical account of each event or establish causality. The posted record does not report event timing, duration, outcomes, or participant-level detail. Small or absent counts in a surveillance group should therefore be read as recorded observations, not as proof that an event cannot occur.

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

The record supports a limited description of the surveillance study: alogliptin was used in routine clinical practice, two treatment groups are listed, and the stated primary safety measure concerns participants with one or more investigator-attributed adverse drug reactions. The record also reports selected serious and other adverse-event counts. These registry entries describe what the registry records about the study and its outcome definitions.

The record does not report the result for the primary endpoint. It also does not report numerical results for the named glycemic outcomes. As a result, the central safety and efficacy questions cannot be answered quantitatively from the posted registry information. The adverse-event counts are not a substitute for the primary adverse drug reaction endpoint, because that endpoint has a specific investigator-attributed causal definition.

The figures do not establish whether alogliptin caused an event, whether one group had a higher underlying risk, or whether outcomes differed because of treatment. Allocation is not stated, and the arms are not a like-for-like control comparison. In general, observational group differences can reflect differences in participants, treatment choices, follow-up, or measurement as well as treatment itself. The record does not report adjusted analyses that might address such factors.

Nor do the available counts establish that an event is absent from the broader population. A count of zero in a recorded group describes the observed record, not the certainty of future outcomes. Precision cannot be evaluated without suitable estimates of uncertainty, which are not reported for the primary outcome. General statistical reasoning also cautions that completeness of follow-up and outcome recording affects how representative observed counts may be; relevant missing-data details are not reported.

The most defensible conclusion is that the registry record documents the surveillance objectives and selected safety counts but leaves the primary endpoint result, secondary outcome results, and inferential analysis unreported. Any interpretation beyond that would require results and methods not reported in the registry record.

14. Why This Trial Matters Statistically

This study is statistically relevant because it illustrates the distinction between a surveillance objective and a randomized comparative trial. The record focuses on safety and efficacy of long-term alogliptin use in routine clinical practice, with a participant-level adverse drug reaction endpoint and listed glycemic outcomes. Such a design can document outcomes observed during treatment in clinical settings, while its group comparisons require caution when allocation is not stated.

The two recorded treatment groups are unequal in their reported safety populations: 954 participants for alogliptin plus biguanides and 109 for alogliptin plus other. Those sizes are useful context for reading the event counts, but do not make the groups directly comparable. In general, unequal group sizes can lead to different precision, and nonrandom allocation can also introduce systematic differences that simple counts do not address.

The record also shows why endpoint definitions matter. The primary endpoint is not simply any adverse event: it requires investigator judgment that an event is causally related to study treatment. The event-count summaries are reported in serious and other categories, which are not interchangeable with that defined primary endpoint. Keeping these measures distinct prevents a descriptive safety summary from being mistaken for the primary outcome result.

Finally, the registry record lists outcomes but does not report the primary result, numerical secondary results, or analyses. Statistical interpretation depends not only on a study question and sample size but also on outcome data, analysis methods, and uncertainty estimates. Without those elements, the record offers useful design and safety context but does not permit a quantitative assessment of the stated primary question or treatment effects.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

A major limitation specific to this record is that the primary endpoint is defined but its observed result is not reported. The registry record therefore does not show how many participants met the primary definition in either group. Numerical results for the named secondary outcomes are also not reported, preventing assessment of changes in HbA1c, objective glycemic control, fasting blood glucose, or fasting insulin.

The study is described as surveillance in routine clinical practice, and allocation is not stated. The record explicitly indicates that the arms are not a like-for-like control comparison. This limits causal interpretation of differences between the alogliptin plus biguanides and alogliptin plus other groups. The record does not describe adjustment for differences between participants or treatment settings.

There is limited information about participant flow. Enrollment was 1096, while the reported safety populations are 954 and 109. The safety analysis set is defined by study completion and available safety data, but reasons for non-inclusion and missing-data handling are not reported in the registry record. The record also does not report the protocol’s sample-size justification, a detailed statistical analysis plan, interim analyses, multiplicity handling, or inferential analyses.

The adverse-event figures provide counts but not a full account of event timing, duration, severity detail, or outcomes. The serious terms are listed with percentages, but the record does not provide participant-level narratives or additional details supporting causal interpretation. These limitations mean that the safety summaries should be treated as reported surveillance observations, not as comprehensive estimates of treatment effects or population risks.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Alogliptin Tablets Special Drug Use Surveillance Type 2 Diabetes Mellitus: Combination Therapy With Biguanides — NCT01964976.
• Registry record last updated 2017-04-13; status last verified 2017-02.
• Results first posted 2017-04-13.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

This completed Takeda-sponsored surveillance study examined alogliptin use in type 2 diabetes mellitus, with enrollment of 1096. The record gives a study start of 2011-07 and primary completion of 2014-12. Treatment was described as alogliptin 25 milligram tablets once daily for up to 12 months in routine clinical practice.

The primary outcome was the number of participants reporting one or more investigator-attributed adverse drug reactions from baseline up to 12 months. The record lists alogliptin plus biguanides and alogliptin plus other groups, with safety populations of 954 and 109. Allocation is not stated, and the groups are not a like-for-like control comparison.

Selected adverse-event counts are reported, but the primary endpoint result and numerical secondary outcome results are not reported in the registry record. The record lists zero analyses and does not report a detailed statistical analysis plan, missing-data methods, or multiplicity approach. Its findings therefore support descriptive reading of the recorded safety figures, not a causal or inferential treatment comparison.