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 Study To Understand Efficacy And Safety Of Investigational Agent (PF-04937319) Compared To Approved Agent (Glimepiride) In Patients With Diabetes On Metformin (NCT01517373), a randomized phase 2 study. The primary outcome is Change From Baseline in Glycosylated Hemoglobin (HbA1C) at Week 12.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01517373 |
| Phase | Phase 2 |
| Condition | Diabetes Mellitus, Type 2 |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 304 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Pfizer |
| Results posted | Yes |
2. Clinical Question
Population
Adults with type 2 diabetes whose condition was inadequately controlled on metformin. The primary endpoint population was the full analysis set: randomized participants who received at least 1 dose of study treatment. The registry record distinguishes the number analyzed for a measure from the number evaluable at a given time point.
Intervention
PF-04937319 was studied at 10 mg, 50 mg and 100 mg. The study also included a placebo described as matching PF-04937319 and glimepiride.
Comparator
The active comparator was glimepiride. The randomized parallel-group study also included placebo, allowing the study to examine several assigned groups. The registry record does not give the numerical allocation to each group in the primary endpoint description.
Primary question
The primary endpoint was change from baseline in glycosylated hemoglobin (HbA1c) at Week 12. The question was whether the mean change differed across the PF-04937319 dose groups, placebo and glimepiride. Numerical estimates for those changes and comparisons are not reported in the registry record, so the direction, size and precision of the primary endpoint findings cannot be described from this record.
HbA1c is used as a measure of average glycemic control over a prolonged period, according to the endpoint description. The study also listed outcomes concerning earlier HbA1c measurements, fasting plasma glucose, HbA1c thresholds, safety events and hypoglycemic episodes. Those secondary outcomes broaden the questions addressed, but do not substitute for the primary endpoint results. The registry record names the interventions and endpoint; it does not report the numerical results needed to assess how the groups compared.
3. Trial Design
This was a phase 2, randomized, double-blinded, placebo-controlled, dose-ranging, parallel-group study in adults with type 2 diabetes inadequately controlled on metformin. The registry record lists an enrollment of 304 and identifies Pfizer as the sponsor. The study is marked completed. Its recorded start was 2012-02, and its primary completion was 2013-01.
Participants were assigned to placebo, PF-04937319 10 mg, PF-04937319 50 mg, PF-04937319 100 mg or glimepiride. A parallel-group design assigns participants to a group for comparison rather than describing a crossover between treatments. Random allocation is intended, in general, to reduce systematic differences between groups at entry; it does not guarantee that groups will be identical, particularly in a study of limited size. The registry record does not state the allocation ratio or the number randomized to each primary-outcome group.
The record calls the study double-blinded in its official title and lists masking as triple. Which parties were masked, and the procedures used to maintain masking, are not reported in the registry record. The placebo is described as matching PF-04937319 and glimepiride.
The primary endpoint was mean change from baseline in HbA1c at Week 12. Listed secondary outcomes include changes in HbA1c and fasting plasma glucose at earlier time points, proportions reaching specified HbA1c thresholds, ECG and vital-sign changes, treatment-emergent adverse events, serious adverse events, and hypoglycemic episodes. The registry record identifies the planned outcome categories and time points, but numerical efficacy findings and detailed statistical procedures are not reported. A sample-size justification and the trial's own design calculations are also not reported in the registry record.
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: A total of 628 participants were consented. Of these, 361 participants transitioned to the run-in period and received sponsor provided background therapy of Metformin. Participants completed the run-in period were then randomized to receive either placebo, PF-04937319 (10, 50 or 100 milligram \[mg\]) or Glimepiride in treatment period.
Run-in Period
| Stage | Metformin 500 mg | Placebo | PF-04937319 10 mg | PF-04937319 50 mg | PF-04937319 100 mg | Glimepiride |
|---|---|---|---|---|---|---|
| STARTED | 361 | 0 | 0 | 0 | 0 | 0 |
| COMPLETED | 304 | 0 | 0 | 0 | 0 | 0 |
| NOT COMPLETED | 57 | 0 | 0 | 0 | 0 | 0 |
Reasons for not completing this period:
| Reason | Metformin 500 mg | Placebo | PF-04937319 10 mg | PF-04937319 50 mg | PF-04937319 100 mg | Glimepiride |
|---|---|---|---|---|---|---|
| Death | 1 | 0 | 0 | 0 | 0 | 0 |
| Adverse Event | 5 | 0 | 0 | 0 | 0 | 0 |
| Did not meet eligibility criteria | 34 | 0 | 0 | 0 | 0 | 0 |
| Lost to Follow-up | 1 | 0 | 0 | 0 | 0 | 0 |
| Withdrawal by Subject | 12 | 0 | 0 | 0 | 0 | 0 |
| Sponsor Decision | 3 | 0 | 0 | 0 | 0 | 0 |
| Other | 1 | 0 | 0 | 0 | 0 | 0 |
Treatment Period
| Stage | Metformin 500 mg | Placebo | PF-04937319 10 mg | PF-04937319 50 mg | PF-04937319 100 mg | Glimepiride |
|---|---|---|---|---|---|---|
| STARTED | 0 | 61 | 60 | 61 | 61 | 61 |
| COMPLETED | 0 | 57 | 54 | 54 | 55 | 54 |
| NOT COMPLETED | 0 | 4 | 6 | 7 | 6 | 7 |
Reasons for not completing this period:
| Reason | Metformin 500 mg | Placebo | PF-04937319 10 mg | PF-04937319 50 mg | PF-04937319 100 mg | Glimepiride |
|---|---|---|---|---|---|---|
| Adverse Event | 0 | 0 | 0 | 0 | 0 | 2 |
| Lost to Follow-up | 0 | 0 | 1 | 1 | 0 | 0 |
| Withdrawal by Subject | 0 | 3 | 2 | 2 | 2 | 3 |
| Other | 0 | 0 | 0 | 0 | 1 | 0 |
| Protocol Violation | 0 | 0 | 0 | 0 | 1 | 0 |
| Lack of Efficacy | 0 | 1 | 1 | 3 | 2 | 0 |
| Medication error without AEs | 0 | 0 | 2 | 1 | 0 | 2 |
Analysis population for the primary outcome, as defined in the registry: Full analysis set (FAS) included all randomized participants who received at least 1 dose of study treatment. Here, 'N' (number of participants analyzed) signifies participants for whom data was summarized for this measure and 'n' signifies participants evaluable at given time points for each group.
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: Baseline analysis population included all randomized participants who received at least 1 dose of study treatment.
| Characteristic | Unit | Placebo | PF-04937319 10 mg | PF-04937319 50 mg | PF-04937319 100 mg | Glimepiride | Total |
|---|---|---|---|---|---|---|---|
| Participants analysed | 61 | 60 | 61 | 61 | 61 | 304 | |
| Age, Customized: >=18 to =<44 years | participants | 8 | 4 | 8 | 11 | 7 | 38 |
| Age, Customized: >=45 to =<64 years | participants | 45 | 48 | 40 | 35 | 48 | 216 |
| Age, Customized: >64 years | participants | 8 | 8 | 13 | 15 | 6 | 50 |
| Gender: Female | Participants | 27 | 26 | 24 | 32 | 22 | 131 |
| Gender: Male | Participants | 34 | 34 | 37 | 29 | 39 | 173 |
6. Primary Endpoint
The registry lists the primary outcome as Change From Baseline in Glycosylated Hemoglobin (HbA1C) at Week 12, measured over Baseline (Day 1), Week 12.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | percentage of hemoglobin |
| Endpoint classification | Continuous Endpoint |
The primary endpoint measures change from baseline in glycosylated hemoglobin (HbA1c) at Week 12, expressed as a percentage of hemoglobin. HbA1c is a form of hemoglobin used to assess average glycemic control over prolonged periods, as described in the registry record. A change-from-baseline endpoint compares a participant's value at follow-up with that participant's starting value, then summarizes those changes within groups.
The endpoint is reported as a mean with standard deviation. The mean describes the average change in the analyzed group; the standard deviation describes variation among the measured changes. These are different summaries: a standard deviation is not a confidence interval and does not by itself quantify the precision of the group mean or a between-group contrast.
The study-specific central laboratory identified the normal range for the HbA1c test as less than 6.5 percent. That context does not turn the primary endpoint into a threshold outcome: the primary endpoint is change in HbA1c, while the registry separately lists the percentage of participants below HbA1c thresholds as a secondary outcome. The numerical primary endpoint estimates, their variability and between-group comparisons are not reported in the registry record. Consequently, the magnitude and precision of the observed changes cannot be evaluated from the record's stated primary endpoint information.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes the study question and identifies the primary endpoint, but it does not report the numerical primary endpoint results. There are no posted group means for change from baseline, standard deviations, between-group estimates, confidence intervals or p-values in the record summarized for this analysis. It is therefore not possible to describe which group had a larger or smaller mean change, how large any contrast was, or how precisely it was estimated. No conclusion about the direction or statistical compatibility of the primary findings can be drawn from the endpoint title alone.
The study enrolled 304 participants across placebo, three PF-04937319 dose groups and glimepiride. That total does not establish how many participants contributed to each group or to the Week 12 endpoint. The primary population is described as the full analysis set, defined as randomized participants who received at least 1 dose of study treatment. The record also says that N denotes participants whose data were summarized for a measure, while n denotes participants evaluable at a given time point. Group-specific counts for the primary endpoint are not reported in the registry record.
The listed outcome inventory includes 12 outcome measures and 60 analyses. Those counts signal that the record covers multiple outcomes and analyses, but they do not identify which comparisons were prespecified as primary analyses, how comparisons were prioritized, or how multiplicity was handled. The record lists several secondary outcomes at multiple time points, including HbA1c and fasting plasma glucose. Without results and an analysis plan, the number of possible comparisons cannot be translated into a claim about statistical significance.
The registry record includes adverse-event counts by listed group, but those are safety summaries, not substitutes for the primary efficacy endpoint. Their interpretation also requires attention to the denominators and group labels as recorded. The primary results are not reported in the registry record, and the statistical plan, missing-data procedures and multiplicity adjustments are not reported there either. The appropriate reading is therefore descriptive: the record documents a randomized phase 2 study and its endpoints, while leaving the numerical evidence needed to assess the primary comparison unavailable.
9. Statistical Methods Explained
The endpoint is a continuous measure summarized by its mean and standard deviation. In general, a mean gives the central average of observed values, while a standard deviation describes how dispersed those values are around the mean. The mean change from baseline is useful for describing the average within-group shift, but a within-group change alone does not answer whether randomized groups differ. The relevant comparative quantity would ordinarily be a between-group contrast in change, interpreted with its uncertainty. Such numerical contrasts are not reported in the registry record.
What does a confidence interval convey?
In general, a confidence interval describes the uncertainty around an estimated quantity under the statistical model used. A narrow interval indicates greater precision than a wide interval, while the location of the interval helps readers assess which values are compatible with the data and model. A confidence interval for a treatment contrast would be needed to understand the precision of that contrast; it is not interchangeable with a standard deviation among participants. No confidence interval for the primary endpoint is reported in the registry record, so the precision of any primary comparison cannot be assessed.
Why distinguish change from baseline from a group comparison?
Each participant's change is calculated relative to that participant's baseline value, and a group mean can summarize those changes. However, the mean change in one group does not, by itself, establish how that group compares with another. Randomized comparisons focus on differences between assigned groups and account for uncertainty in those differences. Baseline values, group-specific follow-up counts, adjusted or unadjusted estimates, and the model used for the primary analysis are not reported in the registry record. It would therefore be inappropriate to reconstruct a primary comparison from the endpoint description.
How should the analysis population be read?
The full analysis set is defined as all randomized participants who received at least 1 dose of study treatment. The registry record explains that N refers to participants whose data were summarized for a measure and n refers to participants evaluable at a given time point for each group. These definitions matter because the number contributing to a summary can differ from enrollment, and evaluability can vary by time point. The exact primary endpoint counts by group and the handling of participants without Week 12 data are not reported in the registry record.
What can sample-size illustrations tell readers?
In general, a sample-size calculation estimates how many participants would be needed under specified assumptions to detect an effect with a chosen error rate and power. The sample-size illustrations associated with this analysis are described as based on a fraction of the observed effect, a two-sided significance level of 0.05, equal allocation between two arms and a normal approximation. They are planning illustrations, not the trial's own design justification and not observed power. The actual effect used, the listed fractions and resulting sample-size values are not reported in the registry record summarized for this analysis. The record does not report the trial's sample-size justification.
General statistical context is important when reading any such illustration: its result depends on assumptions about the effect to detect, variability, allocation and analysis. Changing an assumption can change the required sample size. A planning illustration does not show that a study had a particular probability of success after data collection, and it does not replace the observed estimate and its uncertainty. No observed primary effect or primary endpoint variance is available in the registry record to support a numerical assessment of precision.
Why might count outcomes need a different model?
In general, event counts are often analyzed using models for count data. A basic Poisson model assumes that the mean and variance of the counts are linked in a particular way. Over-dispersion means that the observed variability exceeds what that model allows; if not addressed, uncertainty can be understated. Other count models may account for additional variability. This general issue is relevant to outcomes such as numbers of hypoglycemic episodes, but the model used for that outcome is not reported in the registry record. The primary endpoint is continuous, not an event count.
Likewise, the registry record does not identify the test or model used for the primary endpoint, whether baseline adjustment was applied, whether any interim analyses were planned or performed, or how multiplicity was addressed. These methods should not be inferred from the fact that the study was randomized, masked or dose-ranging. The record's endpoint and design descriptions are informative, but they do not supply the analysis details or estimates needed for a full statistical appraisal.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists 12 outcome measures and 60 analyses. The outcomes include HbA1c at several time points, fasting plasma glucose at several time points, threshold-based HbA1c outcomes, safety measures and hypoglycemic events. Multiple outcomes, time points, dose groups and pairwise comparisons can create multiplicity: when many statistical questions are examined, the chance of at least one apparently notable result can increase. In general, a prespecified analysis hierarchy or adjustment procedure can help manage that issue. Whether this study used such procedures is not reported in the registry record.
The record names change from baseline in HbA1c at Week 12 as the primary endpoint and describes the full analysis set as randomized participants who received at least 1 dose of study treatment. It distinguishes the number summarized for a measure from the number evaluable at a time point. The counts analyzed for each primary comparison, the treatment of missing Week 12 observations, and whether the analysis population differed for any outcome are not reported in the registry record.
Missing data can affect an estimate when the availability of measurements is related to participants' outcomes or characteristics. In general, methods for handling missing measurements rely on assumptions; different assumptions can lead to different estimates. The record does not state whether missing values were imputed, whether a repeated-measures model or another approach was used, or what sensitivity analyses were conducted. The statistical analysis plan and the trial's interim-analysis procedures are not reported in the registry record. As a result, the available endpoint description does not establish how missing observations or the many listed analyses were handled.
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 |
|---|---|---|---|
| Metformin 500 mg | 4 | 361 | 1.1% |
| Placebo | 0 | 61 | 0.0% |
| PF-04937319 10 mg | 1 | 60 | 1.7% |
| PF-04937319 50 mg | 2 | 61 | 3.3% |
| PF-04937319 100 mg | 1 | 61 | 1.6% |
| Glimepiride | 1 | 61 | 1.6% |
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 |
|---|---|
| Metformin 500 mg | 63 of 361 |
| Placebo | 26 of 61 |
| PF-04937319 10 mg | 28 of 60 |
| PF-04937319 50 mg | 31 of 61 |
| PF-04937319 100 mg | 29 of 61 |
| Glimepiride | 36 of 61 |
Most frequent serious adverse event terms
| Event term | Organ system | Metformin 500 mg | Placebo | PF-04937319 10 mg | PF-04937319 50 mg | PF-04937319 100 mg | Glimepiride |
|---|---|---|---|---|---|---|---|
| Aortic valve incompetence | Cardiac disorders | 0 of 361 | 0 of 61 | 1 of 60 | 0 of 61 | 0 of 61 | 0 of 61 |
| Cardiac failure congestive | Cardiac disorders | 0 of 361 | 0 of 61 | 0 of 60 | 0 of 61 | 0 of 61 | 1 of 61 |
| Death | General disorders | 1 of 361 | 0 of 61 | 0 of 60 | 0 of 61 | 0 of 61 | 0 of 61 |
| Cellulitis | Infections and infestations | 0 of 361 | 0 of 61 | 1 of 60 | 0 of 61 | 0 of 61 | 0 of 61 |
| Pneumonia | Infections and infestations | 1 of 361 | 0 of 61 | 0 of 60 | 0 of 61 | 0 of 61 | 0 of 61 |
| Sepsis syndrome | Infections and infestations | 0 of 361 | 0 of 61 | 1 of 60 | 0 of 61 | 0 of 61 | 0 of 61 |
| Ankle fracture | Injury, poisoning and procedural complications | 0 of 361 | 0 of 61 | 0 of 60 | 1 of 61 | 0 of 61 | 0 of 61 |
| Dehydration | Metabolism and nutrition disorders | 1 of 361 | 0 of 61 | 0 of 60 | 0 of 61 | 0 of 61 | 0 of 61 |
| Hyperglycaemia | Metabolism and nutrition disorders | 1 of 361 | 0 of 61 | 0 of 60 | 0 of 61 | 0 of 61 | 0 of 61 |
| Pain in extremity | Musculoskeletal and connective tissue disorders | 1 of 361 | 0 of 61 | 0 of 60 | 0 of 61 | 0 of 61 | 0 of 61 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Metformin 500 mg | Placebo | PF-04937319 10 mg | PF-04937319 50 mg | PF-04937319 100 mg | Glimepiride |
|---|---|---|---|---|---|---|---|
| Hypoglycaemia | Metabolism and nutrition disorders | 3 of 361 | 3 of 61 | 2 of 60 | 3 of 61 | 5 of 61 | 21 of 61 |
| Diarrhoea | Gastrointestinal disorders | 6 of 361 | 2 of 61 | 4 of 60 | 2 of 61 | 2 of 61 | 4 of 61 |
| Upper respiratory tract infection | Infections and infestations | 4 of 361 | 1 of 61 | 3 of 60 | 0 of 61 | 2 of 61 | 3 of 61 |
| Nasopharyngitis | Infections and infestations | 3 of 361 | 2 of 61 | 3 of 60 | 2 of 61 | 1 of 61 | 0 of 61 |
| Headache | Nervous system disorders | 3 of 361 | 2 of 61 | 1 of 60 | 2 of 61 | 2 of 61 | 0 of 61 |
| Nausea | Gastrointestinal disorders | 2 of 361 | 2 of 61 | 2 of 60 | 0 of 61 | 1 of 61 | 1 of 61 |
| Fatigue | General disorders | 2 of 361 | 1 of 61 | 1 of 60 | 1 of 61 | 1 of 61 | 1 of 61 |
| Urinary tract infection | Infections and infestations | 1 of 361 | 1 of 61 | 1 of 60 | 2 of 61 | 1 of 61 | 1 of 61 |
| Dizziness | Nervous system disorders | 2 of 361 | 1 of 61 | 2 of 60 | 1 of 61 | 0 of 61 | 1 of 61 |
| Hyperglycaemia | Metabolism and nutrition disorders | 5 of 361 | 0 of 61 | 0 of 60 | 1 of 61 | 0 of 61 | 0 of 61 |
Serious events with the highest arm-level rate: aortic valve incompetence (1.7%), cellulitis (1.7%), sepsis syndrome (1.7%), aortic aneurysm (1.7%), cardiac failure congestive (1.6%).
The registry record reports serious adverse events for six listed groups. For Metformin 500 mg, 4 participants were affected among 361 at risk. For placebo, 0 were affected among 61 at risk. For PF-04937319 10 mg, 1 was affected among 60 at risk; for 50 mg, 2 among 61; for 100 mg, 1 among 61; and for glimepiride, 1 among 61. These are registry counts and denominators; they should be read as reported rather than as evidence of a causal difference between groups.
The Metformin 500 mg group has a denominator of 361, which differs from the study enrollment of 304. The record does not explain the relation between that group label and the randomized study groups, so the counts should not be reconciled by assumption. Death counts are not reported in the registry record. The record also lists counts for other adverse events, but those are distinct from serious adverse events.
Serious adverse-event counts are descriptive. They do not, on their own, establish whether an event was caused by treatment, and interpretation depends on definitions, observation time and complete follow-up. Those details are not reported in the registry record. The listed serious-event terms and percentages are not a substitute for a complete comparative safety analysis.
12. What the Result Does, and Does Not, Mean
The registry record supports a description of the study's design and question: a randomized, double-blinded, placebo-controlled phase 2 dose-ranging study in adults with type 2 diabetes inadequately controlled on metformin, with PF-04937319 dose groups, placebo and glimepiride. It identifies change from baseline in HbA1c at Week 12 as the primary endpoint and defines the full analysis set. It also documents a set of secondary efficacy and safety outcomes.
What it does not support is a conclusion about the size or direction of the primary endpoint result. Numerical changes, between-group estimates, confidence intervals and p-values are not reported in the registry record. Accordingly, the record does not establish whether the primary endpoint differed among groups, how precise any difference was, or how the findings compare across PF-04937319 doses, placebo and glimepiride. The endpoint definition and study design are not outcome findings.
The adverse-event counts provide limited descriptive information, but they do not establish causation or a comparative safety profile. Group denominators and labels should be read as recorded, especially because the Metformin 500 mg denominator is 361 while overall enrollment is 304, and the registry record does not explain that relationship. The record does not report death counts.
In general, a clinical trial result is most interpretable when the estimated group contrast, its uncertainty, the analysis population, missing-data approach and multiplicity procedures are available together. Several of these elements are not reported in the registry record. The record therefore documents what was studied and which measures were planned, but leaves the numerical evidence and key analysis details needed for a full assessment unavailable.
13. Why This Trial Matters Statistically
This study is statistically informative as an example of a dose-ranging, parallel-group design with both placebo and active-comparator groups. The presence of several doses creates a question about how estimates should be compared and whether a pattern across doses was prespecified. The registry record identifies the groups and the primary endpoint, but does not report the analysis plan or numerical estimates needed to evaluate such a pattern.
The endpoint also illustrates the distinction between a continuous outcome and threshold outcomes. Mean change in HbA1c at Week 12 is the primary measure, while the registry separately lists the percentage of participants reaching HbA1c thresholds as a secondary outcome. A group average and the proportion crossing a threshold answer different questions, and one cannot be inferred from the other without participant-level information.
The breadth of listed outcomes—12 outcome measures and 60 analyses—makes multiplicity and transparent reporting relevant statistical concerns. A reader needs to know which comparisons were prioritized, how repeated time points were handled, and whether any adjustment was used. Those details are not reported in the registry record. The registry's definition of the full analysis set and distinction between participants summarized and those evaluable at a time point also highlight the importance of transparent denominators.
Finally, the record demonstrates why design information alone is not enough to evaluate evidence. Randomization and masking describe important features of conduct, but interpretation still depends on observed estimates, their precision, and the analysis methods. Since the primary numerical results are not reported in the registry record, the statistical value of the record lies chiefly in identifying the question and documenting the limits of what can be assessed.
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 main limitation for interpreting this study is that numerical results for the primary endpoint are not reported in the registry record. Group means, standard deviations, between-group contrasts, confidence intervals and p-values are absent from the record summarized for this analysis. This prevents assessment of effect direction, magnitude and precision.
The registry record does not report the number of participants contributing to the primary endpoint in each group, or the handling of participants without evaluable Week 12 data. Although it defines the full analysis set and explains the distinction between N and n, those definitions do not supply group-specific endpoint denominators. The missing-data method and any sensitivity analyses are not reported.
The study lists multiple outcomes and analyses, but the procedures for controlling multiplicity and prioritizing comparisons are not reported. The primary statistical model, baseline adjustment, interim analyses and trial-specific sample-size justification are also not reported in the registry record. Therefore, the listed design features cannot establish how the primary comparison was estimated or how its uncertainty was evaluated.
Safety interpretation has its own limitation: the Metformin 500 mg group is reported with 361 participants at risk, while overall enrollment is 304, and the registry record does not explain the relationship. Death counts are not reported. These gaps should be kept distinct from the trial's design and endpoint descriptions rather than resolved by assumption.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study To Understand Efficacy And Safety Of Investigational Agent (PF-04937319) Compared To Approved Agent (Glimepiride) In Patients With Diabetes On Metformin — NCT01517373.
- Registry record last updated 2017-01-31; status last verified 2016-12.
- Results first posted 2017-01-31.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
The registry record describes a completed phase 2 randomized, double-blinded, placebo-controlled, dose-ranging, parallel-group study sponsored by Pfizer. It enrolled 304 adults with type 2 diabetes inadequately controlled on metformin. The listed groups were placebo, PF-04937319 10 mg, PF-04937319 50 mg, PF-04937319 100 mg and glimepiride. The recorded start was 2012-02, and primary completion was 2013-01.
The primary endpoint was mean change from baseline in HbA1c at Week 12, in the full analysis set of randomized participants who received at least 1 dose of study treatment. The record also lists secondary glucose, threshold, safety and hypoglycemia outcomes. Numerical primary endpoint results, the primary analysis method, missing-data procedures and multiplicity procedures are not reported in the registry record. Serious adverse-event counts are reported by listed group, but the relationship between the Metformin 500 mg group denominator and overall enrollment is not explained.