Study STF115288, a Clinical Confirmation Study of GI148512 in the Treatment of Acne Vulgaris in Japanese Subjects: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study STF115288, a Clinical Confirmation Study of GI148512 in the Treatment of Acne Vulgaris in Japanese Subjects (NCT01400932), a randomized phase 3 study. The primary outcome is Absolute Change in Total Lesion Counts From Baseline to Week 12.

2. Clinical Question

The trial also assessed safety and several secondary outcomes, including inflammatory and non-inflammatory lesion counts, investigator global assessment, skin irritation scores, and symptoms such as itching and burning or stinging. The registry record identifies these as additional outcomes, but numeric results for most are not reported in the registry record. The primary comparison is therefore the clearest basis for describing the posted efficacy findings.

3. Trial Design

This was a Phase 3, multicenter, randomized, double-blinded, vehicle-controlled, parallel-group study in Japanese subjects with acne vulgaris. The record lists an enrollment of 360. Participants were assigned to GI148512 or vehicle gel, with both products applied topically once daily for 12 weeks. The record does not describe the randomization sequence or how allocation was concealed; those details are not reported in the registry record.

The primary completion date was 2012-04, and the study status is completed. The study start is recorded as 2011-07. The arms were designed to differ in the active ingredient: GI148512 is identified as benzoyl peroxide 3% gel, while the comparator was vehicle gel. Both regimens specified application over the entire face in the evening or at bedtime.

The primary endpoint was absolute change in total lesion counts from baseline to Week 12. The registry describes counting inflammatory and non-inflammatory lesions on the face at study visits. Its primary analysis population was the Intent-to-Treat population, defined in the record as all randomized participants who received at least one application of investigational product. Only participants with data available at the specified time point were included in the analysis for that time point.

The record gives an ANCOVA method for the primary analysis, but its description of the model is truncated after referring to baseline. The complete covariate specification, missing-data procedures, and other analysis details are not reported in the registry record. The original design assumptions, including any trial-specific sample-size justification, 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.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intent-to-Treat (ITT) Population: all randomized participants who received at least one application of investigational product. Only those participants with data available at the specified time point were analyzed. Analysis was based on an analysis of covariance (ANCOVA) model with terms for Baseline value, treatment, and center.

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.

6. Primary Endpoint

The registry lists the primary outcome as Absolute Change in Total Lesion Counts From Baseline to Week 12, measured over Baseline and Week 12.

The primary endpoint was absolute change in total lesion counts from baseline to Week 12. Investigators or subinvestigators counted facial inflammatory lesions—papules, pustules, and nodular lesions—and non-inflammatory lesions, including open and closed comedones. The endpoint combines those lesion types into a count of total facial lesions at each assessment. The reported arm values are least-squares means, with standard errors as the measure of dispersion.

A change score expresses how the count at follow-up differs from the baseline count. Negative values therefore indicate a reduction in the count relative to baseline. The primary comparison asks whether the average change differed between the GI148512 and vehicle groups, rather than considering either arm's change in isolation. The registry reports the contrast as a net mean difference from an ANCOVA analysis.

General: a total lesion count is a continuous outcome that retains information about the size of change, rather than reducing change to a yes-or-no response. It is clinically interpretable as a count of lesions, although a group mean does not describe every participant's experience or the spread of individual responses. The endpoint was chosen to assess change in the visible facial signs specified by the study; the registry record does not explain the rationale for selecting it as primary.

7. Results Posted in the Registry

• GI148512: mean -42.90 versus -22.00 on control; difference -20.90 (95% CI -26.19 to -15.61), standardized effect d = -0.82; z-test p = <0.001.

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.

Number of Participants Who Had a Minimum 2-grade Improvement in the Investigator's Static Global Assessment (ISGA) Score From Baseline to Week 12

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • GI148512: 18.9% (31/164) versus 1.2% (2/166) on control; risk difference 17.7 percentage points (95% CI 11.5 to 23.9), risk ratio 15.69 (3.82–64.49); unadjusted two-proportion z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically higher for GI148512 than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The registry lists secondary outcomes that address several aspects of acne assessment: total, inflammatory, and non-inflammatory lesion counts at multiple visits; investigator global-assessment responses; lesion-reduction thresholds; and local skin signs and symptoms. In principle, these measures could show whether the primary finding is accompanied by changes in distinct lesion types, patient-relevant response categories, or tolerability assessments. However, numeric results for most secondary outcomes are not reported in the registry record, so an overall pattern across the full set cannot be established.

The one secondary result with detailed counts concerns participants with a minimum 2-grade improvement in the Investigator's Static Global Assessment from baseline to Week 12. The posted counts and reported p-value point in the same general direction as the primary comparison. This concordance is supportive context, but it does not replace the primary endpoint or establish consistency across all other secondary outcomes. Results for the other secondary measures are not reported in the registry record.

Secondary findings generally carry less weight than the primary result when many outcomes or assessment times are examined. General: testing multiple outcomes increases the chance that at least one result will appear statistically notable by chance if no adjustment or prespecified hierarchy is used. The record does not report whether multiplicity was controlled, whether the secondary outcomes were ordered in a testing hierarchy, or how missing results were handled. The secondary p-value should therefore be read as a reported result, not as proof that the full family of secondary findings has been confirmed.

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

• Absolute Change in Total Lesion Counts From Baseline to Weeks 1, 2, 4, and 8
• Absolute Change From Baseline in Inflammatory Lesion (IL) Count and Non-inflammatory Lesion (NIL) Count to Weeks 1, 2, 4, 8, and 12
• Percent Change From Baseline in Total, Inflammatory, and Non-inflammatory Lesion Counts to Weeks 1, 2, 4, 8, and 12
• Number of Participants Who Had a Minimum 2-grade Improvement in the Investigator's Static Global Assessment (ISGA) Score From Baseline to Week 12
• Number of Participants Who Had an ISGA Score of 0 or 1 at Weeks 1, 2, 4, 8, and 12
• Number of Participants Who Had a Reduction in Total Lesions of at Least 50% From Baseline to Weeks 1, 2, 4, 8, and 12
• Mean Change From Baseline in Erythema, Dryness, and Peeling Scores at Weeks 1, 2, 4, 8, 12/Withdrawal
• Mean Change From Baseline in Itching and Burning/Stinging Scores at Weeks 1, 2, 4, 8, 12/Withdrawal

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous: it is a change in a count, and the registry reports a least-squares mean for each arm. A least-squares mean is a model-based estimate of an arm's mean outcome. It can account for terms included in the model, unlike a simple arithmetic mean calculated only from the observed values. The record names ANCOVA, or analysis of covariance, as the primary method. ANCOVA compares outcomes between arms while accounting for specified covariates. The registry's description ends after mentioning baseline, so the full model terms and the exact role of baseline are not reported in the registry record.

The reported arm-level changes are -42.9 for GI148512 and -22.0 for vehicle gel. The sponsor's ANCOVA contrast is -21.0, with a 95% confidence interval from -26.2 to -15.8 and p < 0.001. The contrast is presented as a net mean difference. The negative sign indicates that the estimated change was more negative in the GI148512 arm. Since negative change represents a reduction from baseline, this is the direction of a larger average reduction in that arm.

The secondary simple re-calculation uses the posted arm summaries to estimate an unadjusted mean difference of -20.9, with a confidence interval from -26.19 to -15.61 and p < 0.001. General: an unadjusted comparison does not apply covariate adjustment from a fitted model. It is useful as a transparent check based on summary data, but it does not replace an analysis using participant-level observations and the prespecified model. The posted recalculation also relies on an approximate pooled standard deviation, inferred from the standard errors and group sizes. It should therefore be read as a summary-statistic illustration, not as an independent reconstruction of every part of the sponsor's analysis.

The standard errors reported for the arm means describe uncertainty in the estimated means, not the range of individual participant outcomes. General: standard errors tend to become smaller as estimates become more precise, while the standard deviation describes variation among observations. The registry does not provide the full distribution of individual changes. A reader therefore cannot determine from the means and standard errors alone whether changes were concentrated around the average or varied widely between participants.

The reported p-value is below 0.001. General: a p-value is calculated under a statistical model that assumes a null hypothesis, such as no difference between groups, and describes how unusual the observed data or more extreme data would be under that model. It does not give the probability that the null hypothesis is true, and it does not quantify the practical importance of the estimated difference. The estimated contrast and confidence interval provide information about magnitude and uncertainty that the p-value alone cannot convey.

Over-dispersion is a general concern when analyzing count outcomes if observed variability exceeds what a chosen model assumes. In that situation, standard errors can be understated and tests may appear more precise than warranted unless the model accommodates the extra variability. The registry record does not report enough detail about the ANCOVA residual distribution or diagnostic checks to assess this issue. This is a general consideration for count outcomes, not a finding that over-dispersion occurred in this trial.

For the primary outcome, the registry defines the analysis population as all randomized participants who received at least one application of investigational product, with only participants having data at the specified time point included. This definition is narrower than an analysis of every randomized participant regardless of treatment exposure or outcome availability. The record does not state how missing measurements were handled beyond excluding participants without data at that time point. Imputation methods, sensitivity analyses, and reasons for missing observations are not reported in the registry record.

The reported secondary binary outcome counts participants with a minimum 2-grade improvement in the Investigator's Static Global Assessment at Week 12. The registry lists 31 participants among 164 analyzed in the GI148512 arm and 2 among 166 in the vehicle arm. The reported comparison uses a risk difference, with p < 0.001. General: a risk difference expresses the difference between the proportions experiencing an outcome in the compared groups. The registry's result is a secondary finding and should be interpreted with attention to the number of outcomes assessed and the lack of reported multiplicity procedures.

The registry also lists changes in inflammatory, non-inflammatory, and total lesion counts at several visits; proportions meeting lesion-reduction or global-assessment criteria; and local skin and symptom scores. These outcomes could provide complementary perspectives, but numeric results for most are not reported in the registry record. Whether they were analyzed using models suited to their outcome types, and whether any adjustment was made for repeated assessments or multiple comparisons, is not reported in the registry record.

11. Confidence Intervals and Precision

The sponsor-reported primary contrast is -21.0 lesions, with a 95% confidence interval from -26.2 to -15.8. This interval describes a range of values compatible with the observed data and the assumptions of the fitted analysis. It lies entirely below zero, matching the reported p < 0.001 for the comparison. The interval gives more information about the estimated magnitude than the p-value alone, but it does not capture every source of uncertainty, including limitations from missing data or model specification.

The simple unadjusted re-calculation gives -20.9 lesions, with a confidence interval from -26.19 to -15.61. The recalculation is based on posted summary statistics and is not the sponsor's fitted ANCOVA result. The two estimates are close, but they should not be treated as interchangeable: their methods differ, and the registry does not provide the full ANCOVA specification needed for an independent reproduction.

General: a confidence interval is not a guarantee that the true effect lies within its endpoints. It reflects sampling uncertainty under the analysis assumptions and method. Nor does a confidence interval describe the range of changes experienced by individual participants. The standard errors for the arm means are 1.93 for GI148512 and 1.89 for vehicle gel; these quantify uncertainty in the estimated arm means, rather than individual-level variability.

The record does not report confidence intervals for the other secondary outcomes in the available results. Thus precision cannot be evaluated across the complete set of secondary measures from the registry record. The reported 95% interval for the primary contrast should be read alongside the analysis-population definition and the unreported details of missing-data handling and model specification.

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 planning figures are participants per arm, not total events. They are illustrations based on the observed effect, rather than the trial's original design justification. The listed assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, a normal approximation, and an effect to detect set to the stated fraction of the observed effect. The trial's own original sample-size assumptions are not reported in the registry record.

The 80% power column means the number of participants per arm estimated to give an 80% chance of detecting the assumed effect under those planning assumptions. The 90% power column describes the corresponding planning target for a 90% chance. These are prospective planning concepts: they describe how sample size is related to a hypothesized effect and statistical test, not the probability that the observed result is correct.

The illustrations include planning for 100%, 75%, and 50% of the observed effect. For the primary continuous outcome, planning for 100% of the observed effect gives 24 participants per arm for 80% power and 32 participants per arm for 90% power. Planning for 75% gives 42 participants per arm for 80% power and 56 participants per arm for 90% power. Planning for 50% gives 95 participants per arm for 80% power and 126 participants per arm for 90% power. Smaller assumed effects require more participants to detect them under the same assumptions.

These values are not observed power. They are planning illustrations recalculated from the observed effect and should not be taken as evidence that the original trial was designed using these assumptions or that the study had a particular probability of success after its results were observed.

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 = -20.900; pooled standard deviation σ = 25.586.
2. n = 2 × (1.96 + 0.842)² × 25.586² / -20.900² = 23.5, rounded up to 24 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 <- -20.9                      # observed difference in means
sigma <- 25.5861374296987                     # 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(1400932)
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 = 24 (80% power), 32 (90% power)
 75% of observed effect: n per arm = 42 (80% power), 56 (90% power)
 50% of observed effect: n per arm = 95 (80% power), 126 (90% power)
power.t.test: 24.5 
Simulated power at n = 24 per arm: 0.788 (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. Analyses Reported by the Sponsor

The sponsor's posted primary analysis is an ANCOVA comparison, reported as a net mean difference of -21.0 lesions, with a 95% confidence interval from -26.2 to -15.8 and p < 0.001. The simple unadjusted re-calculation from posted summaries is -20.9, with a confidence interval from -26.19 to -15.61 and p < 0.001. The recalculation uses arm-level summaries and an approximate pooled standard deviation; it is not a substitute for the sponsor's model-based analysis.

The registry marks no discrepancy between the posted result and the re-calculation. The estimates are close, but the sponsor's analysis remains the primary reported analysis because it is the analysis identified in the registry. The record does not provide enough detail to reconstruct all ANCOVA terms or independently verify the adjusted estimate from participant-level data. No claim about the exact reason for any difference in reported precision is warranted from the available information.

For the secondary global-assessment outcome, the sponsor reports p < 0.001, while a separate numerical effect estimate and confidence interval are not listed in the reported analysis. The registry therefore supports describing the reported significance result and the posted participant counts, but it does not supply a sponsor-reported adjusted effect estimate for that outcome.

15. Multiplicity, Missing Data and Analysis Populations

The registry identifies one primary endpoint and lists multiple secondary outcomes measured across several visits. The primary endpoint is total lesion-count change from baseline to Week 12. Secondary measures include other lesion-count definitions and time points, investigator global-assessment outcomes, lesion-reduction thresholds, and skin signs and symptoms. The breadth of outcomes creates a multiplicity question: repeated testing can increase the chance of observing a small p-value even when effects are absent. The record does not report a multiplicity adjustment, a hierarchy for testing outcomes, or whether the secondary analyses were intended to be confirmatory.

The primary population is described as randomized participants who received at least one application of investigational product. Only participants with data at the specified time point were analyzed. This time-point availability rule means the analyzed group can vary by outcome or visit. The record does not report how many participants lacked data for each assessment, why data were missing, or whether the reasons differed between arms.

Missing-data methods beyond analysis of available observations are not reported in the registry record. There is no reported imputation method, sensitivity analysis, or comparison of participants with and without endpoint data. Consequently, the effect of missing observations on the estimate cannot be assessed from the registry results alone. The record also does not specify whether any additional analysis populations were used, such as a per-protocol population.

The description of the primary ANCOVA model is truncated after referring to baseline. The complete covariates, assumptions, and model diagnostics are not reported in the registry record. The registry also does not report interim analyses, stopping rules, or the original sample-size justification. These omissions limit assessment of the analysis plan and the potential influence of decisions made during the study, without implying that any particular procedure was or was not used.

16. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent non-serious adverse event terms

The registry reports 0 serious adverse events among 178 participants at risk in the GI148512 group and 0 among 182 participants at risk in the vehicle group. These are event counts as recorded for the participants listed at risk. They do not show that no non-serious adverse events occurred. The record lists 78 participants with other adverse events in the GI148512 group and 61 in the vehicle group.

The reported serious-event counts are limited to the registry's recorded categories and denominators. The record does not provide serious adverse event terms, and deaths are not reported in the available result. The safety figures should not be interpreted as a complete account of tolerability: the registry also lists local skin signs and symptoms among the secondary outcomes, but their numeric results are not reported in the registry record.

General: a count of zero observed serious events does not establish that an event is impossible or that uncommon risks are absent. Safety interpretation depends on the size and follow-up of the analyzed population, the definitions used, and the completeness of event reporting. These figures describe what the registry reports, not a recommendation about treatment.

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

The primary registry result is an estimated greater reduction in total facial lesion counts from baseline to Week 12 in the GI148512 arm than in the vehicle arm. The sponsor's ANCOVA comparison is -21.0 lesions, with a 95% confidence interval from -26.2 to -15.8 and p < 0.001. The interval conveys uncertainty around the estimated group contrast under the analysis assumptions; it is not a prediction for any particular participant.

The result applies to the study population and conditions recorded: Japanese subjects with acne vulgaris in a randomized, double-blinded, vehicle-controlled, parallel-group study, using once-daily application for 12 weeks. It does not by itself establish that the same estimate would apply to other populations, treatment schedules, comparators, or follow-up periods. The registry record does not report numeric results for most secondary outcomes, so the primary count result cannot be used to infer results for every measure of acne severity or skin irritation.

A statistically small p-value is not the same as proof of clinical importance. The registry does not report a threshold for a clinically important difference in total lesion counts, and the group average does not show the range of individual responses. The finding also depends on the analysis population and available outcome data; reasons for missing data and methods beyond analyzing available cases are not reported in the registry record.

The serious adverse event counts are 0 in each arm among the participants listed at risk, while other adverse events were also recorded. These results do not establish an absence of risk, and the record does not provide a complete account of all safety outcomes in the available results. Overall, the record supports a precise description of the posted primary comparison, but it does not answer every question about clinical importance, individual outcomes, longer-term effects, or safety.

18. Why This Trial Matters Statistically

This trial illustrates the distinction between a within-arm change and a between-arm comparison. Both arms had negative mean changes, but the primary question is whether the estimated changes differed between GI148512 and vehicle gel. The sponsor's ANCOVA net mean difference directly addresses that contrast. Considering only the change in one arm could incorrectly attribute changes that also occurred in the comparator arm to the active treatment.

It also shows why an effect estimate, confidence interval, and p-value answer different questions. The estimated difference describes the direction and scale of the comparison; the confidence interval expresses its sampling uncertainty under the model; and the p-value summarizes compatibility with a null comparison under specified assumptions. None alone describes the entire clinical meaning of the result.

The posted summary-statistic recalculation is close to the sponsor's ANCOVA estimate, offering a useful numerical cross-check while retaining a clear distinction between unadjusted and model-based analyses. The incomplete model description, limited reporting of secondary outcomes, and lack of detail on missing-data and multiplicity procedures demonstrate how registry reporting affects statistical appraisal. These are limitations of what can be evaluated from the record, not evidence that a particular undisclosed method was inappropriate.

Finally, the planning illustrations show how assumed effect size shapes sample-size requirements. They are not the original design justification and do not describe observed power. Keeping that distinction clear helps prevent retrospective planning calculations from being mistaken for evidence about the trial's design or the certainty of its results.

19. 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 registry reports an enrollment of 360, but the primary analysis lists 177 participants for GI148512 and 182 for vehicle gel. The primary population required at least one application, and only participants with data at the specified time point were analyzed. The record does not explain the difference between enrollment and the analysis counts, give reasons for missing data, or describe additional missing-data analyses. This limits assessment of whether availability of outcomes could have influenced the comparison.

The primary ANCOVA description is incomplete, ending after reference to baseline. Its full model terms, diagnostic checks, and any other adjustments are not reported in the registry record. This prevents exact replication of the sponsor's analysis from the information recorded. The posted unadjusted recalculation is only a summary-statistic check and should not be mistaken for a full reanalysis.

Numeric results are available for the primary endpoint and one secondary global-assessment outcome, but results for most listed secondary outcomes are not reported in the registry record. This limits evaluation of consistency across lesion subtypes, assessment times, and local skin signs or symptoms. Multiplicity procedures are also not reported, so the confirmatory status of secondary findings cannot be assessed.

The record does not report the original sample-size justification, interim analyses, or trial-specific design assumptions. It also does not provide serious adverse event terms or a death count in the available results. Finally, the study description is specific to Japanese subjects with acne vulgaris and a 12-week once-daily regimen; the registry results alone do not establish how broadly the estimates generalize beyond those recorded conditions.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Study STF115288, a Clinical Confirmation Study of GI148512 in the Treatment of Acne Vulgaris in Japanese Subjects — NCT01400932.
• Registry record last updated 2014-08-05; status last verified 2012-05.
• Results first posted 2014-08-05.
• 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.

23. Record Summary

NCT01400932 is a completed Phase 3 randomized, double-blinded, vehicle-controlled, parallel-group study of GI148512 (benzoyl peroxide 3% gel) in Japanese subjects with acne vulgaris. The intervention and vehicle gel were applied once daily for 12 weeks. The record lists enrollment of 360 and a primary completion date of 2012-04.

The primary outcome was absolute change in total facial lesion counts from baseline to Week 12. The sponsor-reported ANCOVA net mean difference was -21.0 lesions, with a 95% confidence interval from -26.2 to -15.8 and p < 0.001. The registry also reports 0 serious adverse events in each arm among participants listed at risk. Details of the complete statistical model, missing-data handling, multiplicity procedures, and original sample-size justification are not reported in the registry record.