Study Of Safety And Efficacy Of Ertugliflozin (PF-04971729, MK-8835) In Participants With Type 2 Diabetes (MK-8835-016): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study Of Safety And Efficacy Of Ertugliflozin (PF-04971729, MK-8835) In Participants With Type 2 Diabetes (MK-8835-016) (NCT01059825), a randomized phase 2 study. The primary outcome is Baseline Hemoglobin A1c (HbA1c).

2. Clinical Question

The study’s title and summary describe an evaluation of safety and efficacy over 12 weeks, with glycemic control and body weight among the interests. However, the primary result posted for this analysis is a baseline characteristic, not an efficacy outcome. The registry record also lists changes in HbA1c at several follow-up weeks as secondary outcomes, but numerical follow-up results are not included in the registry record. Accordingly, the mean differences and confidence intervals should be read as comparisons of groups’ initial HbA1c values. They cannot establish what happened to HbA1c after treatment began.

3. Trial Design

This was a phase 2, randomized, double-blind, parallel-group study with a placebo-controlled, dose-ranging design. The registry reports enrollment of 375 participants and a 12-week treatment period. Randomization allocates participants to study groups, while double blinding is intended to keep participants and relevant study personnel unaware of assigned treatment. The record identifies both features but does not report the detailed procedures used to implement them.

The listed treatment groups were placebo, ertugliflozin 1 mg, ertugliflozin 5 mg, ertugliflozin 10 mg, ertugliflozin 25 mg, and sitagliptin 100 mg. The arm descriptions specify once-daily oral treatment for 84 days and describe placebo matching for the study drugs. The official title describes study of participants inadequately controlled on metformin. The safety results additionally list a metformin run-in group; the registry record does not provide enough information to reconstruct the run-in procedures or how those participants relate to the randomized treatment groups.

There are 54 or 55 participants in each of the six posted baseline HbA1c groups. These group counts are the denominators for the reported baseline summaries and comparisons, not a substitute for a participant flow account. The registry record does not report reasons for withdrawals, the number completing follow-up, adherence, or how missing observations were handled.

The stated study start was 2010-02-24, and primary completion was 2011-01-20; status is completed. These record details describe the study’s administrative timeline, not the timing of individual participants’ visits. The protocol’s original sample-size justification, the planned statistical analysis, and any interim-analysis procedures are 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: Of the 375 enrolled participants included in the metformin run-in period, 328 participants were randomized to 1 of 6 treatment groups.

Only the first 6 of 7 groups are shown.

Enrolled, Run-in Period

Reasons for not completing this period:

Treatment Period

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All randomized participants.

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: Of the 375 enrolled participants included in the metformin run-in period, 328 participants were randomized to 1 of 6 treatment groups.

Only the first 6 of 7 groups are shown.

6. Primary Endpoint

The registry lists the primary outcome as Baseline Hemoglobin A1c (HbA1c), measured over Baseline.

The primary measure is baseline hemoglobin A1c, or HbA1c, recorded as a percentage. HbA1c reflects glucose exposure over time and is commonly used in diabetes research as a measure of glycemic control. As a baseline measure, it also helps describe the study groups before the treatment period and can show whether starting values were broadly similar or varied across randomized groups.

The registry reports a mean and standard error for each group, with all randomized participants named as the population. The comparisons express the mean difference between each treatment group and placebo, alongside confidence intervals and unadjusted p-values. A confidence interval communicates the range of values compatible with the data under the statistical model; the standard error describes uncertainty around a group mean.

The distinction between baseline level and treatment response is essential. Baseline HbA1c is measured before the treatment period; it does not capture a change caused by treatment. Although changes in HbA1c at follow-up weeks are listed as secondary outcomes, numerical estimates for those outcomes are not reported in the registry record as analyzed. Therefore, this primary measure is useful for describing initial group characteristics, but by itself it cannot show whether HbA1c improved, worsened, or differed between groups during the study.

7. Results Posted in the Registry

• Ertugliflozin 1 mg: mean 8.01 versus 8.08 on control; difference -0.07 (95% CI -0.50 to 0.36), standardized effect d = -0.06; z-test p = 0.751.
• Ertugliflozin 5 mg: mean 7.88 versus 8.08 on control; difference -0.20 (95% CI -0.57 to 0.17), standardized effect d = -0.20; z-test p = 0.295.
• Ertugliflozin 10 mg: mean 8.13 versus 8.08 on control; difference 0.05 (95% CI -0.38 to 0.48), standardized effect d = 0.04; z-test p = 0.820.
• Ertugliflozin 25 mg: mean 8.30 versus 8.08 on control; difference 0.22 (95% CI -0.20 to 0.64), standardized effect d = 0.20; z-test p = 0.301.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Baseline Body Weight

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard errors.
• Result:
  • Ertugliflozin 1 mg: mean 83.44 versus 83.78 on control; difference -0.34 (95% CI -7.19 to 6.51), standardized effect d = -0.02; z-test p = 0.923.
  • Ertugliflozin 5 mg: mean 85.74 versus 83.78 on control; difference 1.96 (95% CI -5.26 to 9.18), standardized effect d = 0.10; z-test p = 0.595.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Ertugliflozin 1 mg and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Ertugliflozin 5 mg and the control. The interval gives the range of effects that remain compatible with the data.

Baseline Systolic Blood Pressure

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard errors.
• Result:
  • Ertugliflozin 1 mg: mean 126.50 versus 126.70 on control; difference -0.20 (95% CI -5.63 to 5.23), standardized effect d = -0.01; z-test p = 0.942.
  • Ertugliflozin 5 mg: mean 127.90 versus 126.70 on control; difference 1.20 (95% CI -4.43 to 6.83), standardized effect d = 0.08; z-test p = 0.676.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Ertugliflozin 1 mg and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Ertugliflozin 5 mg and the control. The interval gives the range of effects that remain compatible with the data.

Baseline Diastolic Blood Pressure

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard errors.
• Result:
  • Ertugliflozin 1 mg: mean 78.95 versus 79.14 on control; difference -0.19 (95% CI -3.49 to 3.11), standardized effect d = -0.02; z-test p = 0.910.
  • Ertugliflozin 5 mg: mean 78.19 versus 79.14 on control; difference -0.95 (95% CI -4.56 to 2.66), standardized effect d = -0.10; z-test p = 0.606.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Ertugliflozin 1 mg and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Ertugliflozin 5 mg and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists secondary outcomes spanning HbA1c measurements at follow-up weeks and body weight, including percent change in body weight at several time points. The registry entries also include baseline body weight and baseline blood-pressure summaries. These measures cover different aspects of the study: HbA1c and body weight are included in the stated efficacy interests, while baseline blood pressure and baseline weight describe participant characteristics. However, the numerical follow-up change results are not reported in the registry record among the results analyzed.

The secondary information therefore cannot be used to fill the main gap in the primary result. The primary measure is baseline HbA1c, and the available secondary baseline summaries likewise describe starting values rather than treatment response. Where a change-from-baseline outcome is named, the outcome title alone does not give an estimate, uncertainty interval, or comparison result. A listed endpoint should not be treated as a finding unless its analyzed result is reported.

Unadjusted secondary results generally carry less weight when many outcomes and comparisons are examined. The more questions tested, the greater the chance that some apparent findings arise from random variation. Adjustment for multiplicity or a prespecified hierarchy can help control that concern, but whether such procedures were planned or applied is not reported in the registry record. This is a general statistical consideration, not a conclusion that any particular secondary analysis was invalid.

In practical reading, the overall secondary-outcome pattern is incomplete: outcomes are named, but a set of follow-up estimates is not available in the registry record. The baseline measures can help characterize the groups, but they do not establish how the groups changed. Consequently, the secondary information does not provide independent confirmation of a treatment effect on the primary measure.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Change From Baseline in HbA1C at Week 2
• Change From Baseline in HbA1c at Week 4
• Change From Baseline in HbA1c at Week 8
• Baseline Body Weight
• Percent Change From Baseline in Body Weight at Week 12
• Percent Change From Baseline in Body Weight at Week 2
• Percent Change From Baseline in Body Weight at Week 4
• Percent Change From Baseline in Body Weight at Week 8

9. Statistical Interpretation

10. Statistical Methods Explained

The statistical summaries concern a continuous outcome: HbA1c measured as a percentage. For a continuous measure, a mean gives the group’s average observed value. The registry also reports a standard error. Standard error describes how much uncertainty surrounds an estimated mean; it is not the spread of individual participants’ values. A larger standard error generally means a less precise estimate of the group mean, while the standard deviation describes participant-to-participant variability.

What does the mean difference represent?

Each comparison uses placebo as the reference and reports the treatment-group mean minus the placebo mean. A negative estimate means the treatment group’s baseline mean was lower; a positive estimate means it was higher. For example, the ertugliflozin 5 mg estimate is -0.20, while the ertugliflozin 25 mg estimate is 0.22. These estimates summarize differences between group averages at baseline. They do not adjust for other characteristics in the registry record, and the registry record does not report whether the sponsor used an adjusted analysis for this measure.

How should a confidence interval be understood?

A confidence interval gives a range of values that are reasonably compatible with the observed data and the method’s assumptions. It reflects uncertainty in the estimated difference, rather than a range containing a specified proportion of individual participants. When an interval includes zero, the data do not rule out no mean difference at the stated confidence level. Here, every listed interval includes zero. The intervals also extend to both negative and positive values, meaning that the direction of a baseline difference is uncertain in each comparison.

What does an unadjusted p-value tell us?

A p-value measures how unusual data at least as incompatible with a specified null hypothesis would be if that hypothesis and the model assumptions were true. The listed values are unadjusted. They do not account for the fact that multiple groups or endpoints may be examined. A p-value does not measure the probability that the null hypothesis is true, nor does it measure clinical importance. In this setting, the p-values concern baseline mean comparisons, not treatment-related change. The registry record does not report a multiplicity-adjusted analysis for these comparisons.

Why do randomization and baseline summaries matter?

Random allocation aims to make groups comparable in expectation, including on characteristics not used to assign treatment. It does not guarantee that every characteristic will have identical observed means in a finite trial. Baseline summaries help readers assess the observed starting values, but significance tests of baseline differences are generally not treatment-effect tests: assigned treatment has not yet had time to alter the baseline measurement. A numerical imbalance may be due to chance and does not by itself demonstrate a problem with randomization.

What can and cannot be inferred from the posted analysis?

The comparison method treats the outcome as a continuous measure and reports unadjusted mean differences with confidence intervals. The registry entries do not describe the original analysis model, any covariate adjustment, missing-data method, or distributional diagnostics. Those details are not reported in the registry record. In general, a mean comparison can be sensitive to skewness or unusual observations, and an analysis model may use assumptions about the outcome’s distribution and variance. These are general considerations, not claims about procedures used in this trial.

The distinction between an outcome’s measurement time and its name also matters. HbA1c is a clinically relevant measure of glycemic control, but the analyzed timeframe is baseline. The listed secondary outcomes identify follow-up HbA1c changes and body-weight changes, but numerical analyzed results for these outcomes are not included in the registry record. Without those results, no statistical method applied to baseline summaries can answer the central longitudinal efficacy question.

Overall, these methods describe group averages and uncertainty in baseline differences. Their proper role is to characterize the randomized groups at study entry, not to establish the effect of treatment. The reported analysis contains no sponsor-versus-recalculated discrepancy, so no precedence issue arises between the posted sponsor result and an independent recalculation.

11. Confidence Intervals and Precision

The confidence intervals for the five comparisons with placebo are: -0.502 to 0.362 for ertugliflozin 1 mg; -0.575 to 0.174 for ertugliflozin 5 mg; -0.382 to 0.482 for ertugliflozin 10 mg; -0.197 to 0.637 for ertugliflozin 25 mg; and -0.242 to 0.562 for sitagliptin 100 mg. All are reported for differences in baseline mean HbA1c.

Every interval spans zero and permits values on either side of zero. This means the direction of each group’s baseline difference from placebo is not determined precisely. The intervals are not evidence that the groups are exactly equal; they show that the observed data remain compatible with a range of possible differences, including no difference. Their width reflects the uncertainty of the estimates, and the number of participants in each comparison is between 54.0 and 55.0 per group.

Precision and relevance must be interpreted in relation to the endpoint. These intervals concern baseline HbA1c and cannot be interpreted as intervals for treatment-related change. Even if the intervals were narrow, they would only make the initial group comparison more precise. The registry record does not report confidence intervals for follow-up changes in HbA1c in the results. As a result, the available precision information does not quantify uncertainty about the treatment effects on glycemic control over the 12-week period.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size illustrations express the number of participants per arm for a two-group comparison. They are based on the observed mean difference and the pooled variability estimate for the particular comparison. For planning at 80% power, the stated number per arm is the approximate group size intended to give an 80% chance of detecting an effect of the specified size under the assumptions, if that effect and the model are correct. The 90% power column uses a larger target chance of detecting the same specified effect and therefore requires a different planned group size.

The 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 the stated fraction of the observed effect. Rows describing planning for 100%, 75%, or 50% of the observed effect are sensitivity illustrations: they show how the proposed group size changes when the target effect is smaller than, or equal to, the observed estimate. Smaller effects need more participants to distinguish them from random variation with the same power target.

These figures are planning illustrations calculated from the posted summaries, not the trial’s original sample-size justification. The original design assumptions are not reported in the registry record. These numbers are not observed power: they do not measure the probability that this completed trial detected an effect, and they do not establish whether an effect exists. For the continuous outcomes, the figures are participants per arm, not total events.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -0.070; pooled standard deviation σ = 1.144.
2. n = 2 × (1.96 + 0.842)² × 1.144² / -0.070² = 4,195.1, rounded up to 4,196 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -0.0700000000000003                      # observed difference in means
sigma <- 1.14433386736564                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(1059825)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 4,196 (80% power), 5,617 (90% power)
 75% of observed effect: n per arm = 7,459 (80% power), 9,985 (90% power)
 50% of observed effect: n per arm = 16,781 (80% power), 22,465 (90% power)
power.t.test: 4196.1 
Simulated power at n = 4,196 per arm: 0.800 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

The study record describes several treatment groups and lists multiple secondary outcomes, including repeated HbA1c and body-weight measurements over follow-up. Examining many comparisons increases the opportunity for chance findings. A prespecified hierarchy, a family-wise error procedure, or another multiplicity strategy may be used to address this issue, but the statistical plan and any adjustment are not reported in the registry record. The reported comparison p-values are unadjusted and should be read with that limitation in mind.

The record identifies the primary population as all randomized participants for baseline HbA1c. It does not report the analysis population used for follow-up outcomes, whether all randomized participants were included in each analysis, or how participants with missing measurements were handled. Details such as imputation, model-based use of incomplete observations, or a complete-case approach are not reported in the registry record. Missing-data assumptions can affect estimates, especially when participants with missing outcomes differ from those who remain observed.

Participant flow, withdrawal reasons, adherence, and the amount of missing follow-up data are not reported in the registry record. Nor is it reported whether the primary analysis followed an intention-to-treat principle or another defined population. These omissions limit assessment of how well any future-posted treatment estimate would represent the randomized groups. They do not alter the interpretation of the baseline summaries, but they prevent a full appraisal of longitudinal treatment comparisons.

The original sample-size justification, planned power target, analysis model, and any interim analyses are also not reported in the registry record. The separate planning illustrations are based on observed effects and assumptions stated for those illustrations; they should not be mistaken for the trial’s prespecified design plan.

15. 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 serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: acute myocardial infarction (1.8%), cellulitis (1.8%), syncope (1.8%), coronary artery stenosis (1.8%), food allergy (0.3%).

The registry reports serious adverse events among participants at risk in each treatment group. The counts are 0 of 54 for placebo, 0 of 54 for ertugliflozin 1 mg, 2 of 55 for ertugliflozin 5 mg, 0 of 55 for ertugliflozin 10 mg, 1 of 55 for ertugliflozin 25 mg, and 1 of 55 for sitagliptin 100 mg. The separate metformin run-in group reports 2 serious adverse events among 375 at risk. These are counts, not estimates of comparative risk adjusted for follow-up time or participant characteristics.

The record also lists other adverse events and selected serious-event terms. Those counts should not be combined with the serious adverse event counts: they describe a different category. Deaths are not reported in the registry record. With the group sizes and short 12-week study period, event counts describe what was recorded in this study but provide limited precision for comparing uncommon events. They do not by themselves establish whether a treatment caused an event or characterize safety beyond the recorded study period.

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

The results establish that baseline mean HbA1c was recorded for the randomized groups and that the posted group averages were between 7.88% and 8.30%. The reported comparisons quantify how those starting averages differed from placebo, with confidence intervals that all include zero. This is a description of the groups at entry to the treatment period.

They do not show whether any treatment lowered or raised HbA1c, whether the effect varied by dose, or whether ertugliflozin differed from sitagliptin in treatment response. They also do not establish an effect on body weight. Although the study description includes glycemic control and body weight, the results needed to make those follow-up comparisons are not reported in the registry record. A baseline measurement cannot substitute for a treatment-period endpoint.

The same restraint applies to safety. The serious adverse event counts report events recorded in each group. Small counts do not establish that events were caused by treatment, and zero recorded events in a group does not prove that an event cannot occur. The record does not report deaths. It also does not provide the details needed to assess missing follow-up or longer-term outcomes.

Statistical significance is not the same as clinical importance. The unadjusted p-values and intervals relate to baseline differences; they do not answer whether a clinically meaningful treatment effect occurred. Likewise, sample-size illustrations based on observed baseline differences are planning calculations, not evidence of efficacy or observed power.

The most defensible conclusion is narrow: the registry presents baseline HbA1c summaries and unadjusted comparisons across randomized groups, alongside selected safety counts. The treatment-effect and broader safety questions raised by the study description require results and analysis details that are not reported in the registry record.

17. Why This Trial Matters Statistically

This trial is statistically instructive because the name of an outcome does not determine what the result means; the measurement timeframe does. HbA1c is often used to evaluate glycemic control, but the posted primary measure is explicitly at baseline. Reading it as an efficacy result would confuse a starting characteristic with a response to treatment.

The study has a randomized, double-blind, parallel-group design and multiple dose groups, features intended to support treatment comparisons. Yet design characteristics cannot compensate for the absence of posted follow-up estimates in the results. A reader needs the analyzed endpoint, its timeframe, the estimated comparison, and its uncertainty to understand what a trial found. When only baseline summaries are available, the correct interpretation remains descriptive.

The record also illustrates why uncertainty intervals and p-values need context. The intervals describe uncertainty around baseline differences, while the unadjusted p-values do not account for the range of outcomes and comparisons listed. Neither provides a treatment-effect test in this analysis. Interpreting a numerical estimate without checking its population and timeframe risks answering a different question than the one readers care about.

Finally, the separate sample-size illustrations show how planning depends on a target effect and assumptions. They are not evidence about the trial’s original design or the probability that the completed study succeeded. Distinguishing planning quantities, baseline descriptions, outcome estimates, and safety counts is central to sound statistical reading of clinical trial records.

18. 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 efficacy is that the primary measure analyzed is baseline HbA1c, not a post-treatment measurement or change from baseline. The registry lists several follow-up HbA1c and body-weight outcomes, but their numerical results are not reported in the registry record in the registry record. Consequently, treatment effects on the stated efficacy interests cannot be evaluated from these results.

The comparisons are unadjusted and their confidence intervals include zero. The registry record does not report a multiplicity strategy, covariate-adjusted model, or detailed statistical analysis plan. Multiple treatment groups and outcomes make interpretation of unadjusted comparisons more cautious, while the missing plan prevents assessment of prespecification.

Information about participant flow, loss to follow-up, adherence, missing data, and analysis populations for follow-up measures is not reported in the registry record. The original sample-size assumptions and interim-analysis procedures are also not reported. The planning figures based on observed differences do not resolve these design-information gaps.

The safety summaries provide event counts in the groups but do not give enough information to determine causality or provide a comprehensive assessment of adverse-event patterns. Deaths are not reported in the registry record. The study’s stated duration is 12 weeks, so these reported counts concern the recorded study period and do not describe longer-term outcomes.

These limitations are specific to the information available in this record analysis. They do not establish that unreported analyses were not conducted; they mean that such details and results are not reported in the registry record.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Study Of Safety And Efficacy Of Ertugliflozin (PF-04971729, MK-8835) In Participants With Type 2 Diabetes (MK-8835-016) — NCT01059825.
• Registry record last updated 2018-09-13; status last verified 2018-08.
• Results first posted 2017-10-04.
• 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.

22. Record Summary

NCT01059825 is a completed phase 2, randomized, double-blind, parallel-group study of ertugliflozin and sitagliptin in adults with type 2 diabetes inadequately controlled on metformin. The registry reports enrollment of 375 and a 12-week study period.

The posted primary measure is baseline HbA1c. Group means range from 7.88% to 8.30%; all five reported treatment-versus-placebo confidence intervals include zero. These are baseline comparisons, not estimates of treatment-related change. The record lists follow-up HbA1c and body-weight outcomes, but their numerical results are not reported in the registry record in the registry record.

Serious adverse event counts are reported by group, while deaths are not reported in the registry record. The original sample-size justification, detailed statistical plan, multiplicity procedures, and missing-data methods are also not reported.