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Papulopustular Rosacea (PPR) Phase 3 Binary Endpoint NCT01493687

Phase 3 Papulopustular Rosacea Study: Complete Statistical Analysis

This analysis examines the randomized, vehicle-controlled phase of a study of CD5024 1% cream for papulopustular rosacea, focusing on the Week 12 Investigator Global Assessment success rate. It also considers the posted lesion-count outcome, planning illustrations, and adverse-event summaries.

Trial start: 2011-12  ·  Enrollment: 683  ·  Sponsor: Galderma R&D
Scope of this record

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 Phase 3 Papulopustular Rosacea Study (NCT01493687), a randomized phase 3 study. The primary outcome is Success Rate.

683
Enrollment
Phase 3
2
Arms
In the primary outcome
+26.7 pts
Risk difference
CD5024 1% Cream
20.6 to 32.8 pts
95% CI
Two-sided
FeatureRegistry value
ClinicalTrials.gov identifierNCT01493687
PhasePhase 3
ConditionPapulopustular Rosacea (PPR)
AllocationRandomized
Design modelParallel
MaskingTriple
Enrollment683
Arms in the primary outcome2
Lead sponsorGalderma R&D
Results postedYes

2. Clinical Question

Population

Participants with papulopustular rosacea (PPR) were enrolled. The registry record lists total enrollment of 683. The primary outcome uses the ITT-LOCF population, with 451 participants in the CD5024 1% Cream group and 232 in the CD5024 Vehicle Cream group.

Intervention

CD5024 1% cream was applied once daily at bedtime during the 12-week period described in the study summary. The primary comparison concerns this cream versus its vehicle.

Comparator

The comparator for the primary Week 12 question was CD5024 Vehicle Cream. The study also included a 40-week investigator-blinded extension comparing CD5024 1% cream with azelaic acid 15% gel for long-term safety.

Primary question

At Week 12, what percentage of participants achieved an Investigator Global Assessment score of Clear or Almost Clear, and how did that percentage compare between CD5024 1% cream and vehicle? The registry-defined success outcome uses ITT-LOCF.

3. Trial Design

The registry describes a randomized, parallel-group, triple-masked, phase 3 study. Its official title identifies a 12-week vehicle-controlled phase followed by a 40-week investigator-blinded extension. In the initial phase, the comparison was CD5024 1% cream versus CD5024 Vehicle Cream. The extension compared CD5024 1% cream with azelaic acid 15% gel for long-term safety. The registry record lists Galderma R&D as the sponsor and the study status as completed.

Total enrollment was 683. The primary Week 12 outcome is reported for an ITT-LOCF population, with 451 participants in the CD5024 1% Cream group and 232 in the vehicle group. The record’s study summary describes once-daily bedtime application during the 12-week period. It does not provide enough detail to explain how the stated triple masking was implemented or which individuals were masked in each phase.

The distinction between the initial efficacy comparison and the extension matters when interpreting results. The primary endpoint is a Week 12 response compared with vehicle; it is not a result from the full extension period. The extension is described as a long-term safety comparison involving azelaic acid, but the record does not give a primary endpoint or detailed analysis plan for that phase. Original sample-size assumptions, the rationale for the selected enrollment, and any interim-analysis plan 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.

Part A Vehicle Control (12 Weeks)

StageCD5024 1% CreamCD5024 Vehicle Cream/Azelaic Acid 15% Gel
STARTED451232
COMPLETED414210
NOT COMPLETED3722

Reasons for not completing this period:

ReasonCD5024 1% CreamCD5024 Vehicle Cream/Azelaic Acid 15% Gel
Pregnancy20
Lack of Efficacy01
Adverse Event74
Withdrawal by Subject187
Protocol Violation21
Lost to Follow-up78
Other (noted on CRF)11

Part B Long Term Active Control 40 Weeks

StageCD5024 1% CreamCD5024 Vehicle Cream/Azelaic Acid 15% Gel
STARTED412210
COMPLETED351175
NOT COMPLETED6135

Reasons for not completing this period:

ReasonCD5024 1% CreamCD5024 Vehicle Cream/Azelaic Acid 15% Gel
Pregnancy51
Lack of Efficacy23
Adverse Event54
Withdrawal by Subject2716
Protocol Violation10
Lost to Follow-up1610
Other (noted on eCRF)51

Part C Safety Follow up (4 Weeks)

StageCD5024 1% CreamCD5024 Vehicle Cream/Azelaic Acid 15% Gel
STARTED350175
COMPLETED350174
NOT COMPLETED01

Reasons for not completing this period:

ReasonCD5024 1% CreamCD5024 Vehicle Cream/Azelaic Acid 15% Gel
Adverse Event01

Analysis population for the primary outcome, as defined in the registry: LOCF, ITT

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: ITT population

CharacteristicUnitCD5024 1% CreamCD5024 Vehicle Cream/Azelaic Acid 15% GelTotal
Participants analysed451232683
Age, ContinuousYears49.9 (SD 12.15)51.6 (SD 11.92)50.4 (SD 12.09)
Sex: Female, Male: FemaleParticipants314152466
Sex: Female, Male: MaleParticipants13780217
Ethnicity (NIH/OMB): Hispanic or LatinoParticipants552378
Ethnicity (NIH/OMB): Not Hispanic or LatinoParticipants396209605
Ethnicity (NIH/OMB): Unknown or Not ReportedParticipants000
Race (NIH/OMB): American Indian or Alaska NativeParticipants000
Race (NIH/OMB): AsianParticipants336
Race (NIH/OMB): Native Hawaiian or Other Pacific IslanderParticipants000
Race (NIH/OMB): Black or African AmericanParticipants639
Race (NIH/OMB): WhiteParticipants437220657
Race (NIH/OMB): More than one raceParticipants000
Race (NIH/OMB): Unknown or Not ReportedParticipants5611
Skin Photo Type: IParticipants391655
Skin Photo Type: IIParticipants18590275
Skin Photo Type: IIIParticipants16786253
Skin Photo Type: IVParticipants512677
Skin Photo Type: VParticipants81119
Skin Photo Type: VIParticipants134

6. Primary Endpoint

The registry lists the primary outcome as Success Rate, measured over Week 12.

ElementRegistry entry
Result typeNumber
Measure of spreadnot applicable
UnitPercentage of participants
Endpoint classificationBinary Endpoint

The primary endpoint is the percentage of participants who achieved an Investigator Global Assessment (IGA) score of Clear or Almost Clear at Week 12. The IGA is a five-point scale: Clear is score 0, Almost Clear is score 1, Mild is score 2, Moderate is score 3, and Severe is score 4. The record describes the scale in terms of inflammatory lesions and erythema. For example, Clear corresponds to no inflammatory lesions and no erythema, while Almost Clear allows very few small papules or pustules and very mild erythema.

The endpoint turns this ordered clinical assessment into a binary success outcome: scores 0 or 1 count as success, while scores 2, 3, or 4 do not. A binary responder outcome is useful for communicating the proportion reaching a defined state, rather than only describing average change across all participants. It also makes the treatment groups’ success rates directly comparable. That simplification has a trade-off: it does not distinguish between the two success categories, nor does it show how participants who are not classified as successes are distributed across the remaining IGA scores.

The registry specifies Week 12 and an ITT-LOCF population for this endpoint. Further detail about missing observations and the handling of individual assessment records is not reported in the registry record.

7. Results Posted in the Registry

Risk difference: CD5024 1% Cream

+26.7

95% CI: 20.6 to 32.8 percentage points

Recalculated from the posted summary statistics

Primary outcome by arm, with 95% confidence intervals
Primary outcome by arm with 95% confidence intervals4.613.021.329.738.146.4CD5024 1% Cream (n=451)CD5024 Vehicle Cream (n=232)% of participants (95% CI)
Treatment effect versus the control arm
Forest plot of risk difference (percentage points) vs control (95% CI)CD5024 1% Cream-2.634.9913202835risk difference (percentage points) vs control (95% CI)

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.

Secondary outcomeTypeEffect measureEstimate (95% CI)Planning size, 80% power
Percent Change in Inflammatory Lesion Count From Baseline to Week 12 (ITT-LOCF)Continuous EndpointMean difference-23.30 (-29.51 to -17.09)46 per arm

Percent Change in Inflammatory Lesion Count From Baseline to Week 12 (ITT-LOCF)

Treatment effect versus the control arm
Forest plot of mean difference vs control (95% CI)CD5024 1% Cream-32-25-18-11-4.492.36mean difference vs control (95% CI)

The registry lists one secondary outcome: percentage change in inflammatory lesion count from baseline to Week 12. The posted group means indicate decreases in both groups, with a larger decrease in the CD5024 group. The recalculated comparison and sponsor-reported p-value are consistent with a difference between group summaries. This broadly aligns with the primary result, which compares the proportions reaching the defined IGA success threshold.

The outcomes are related but not redundant. The IGA endpoint classifies participants according to a prespecified category threshold, whereas the lesion-count endpoint summarizes change in counts as a group mean. A participant’s lesion-count change and IGA category need not correspond exactly, and the record does not report individual-level relationships between these outcomes. The secondary result therefore provides supporting context rather than a direct replication of the primary endpoint.

Secondary findings generally carry less confirmatory weight when a trial evaluates multiple outcomes, because repeated testing can increase the chance of at least one apparently strong result arising by chance. In general, statistical plans may control this through a prespecified testing hierarchy or multiplicity adjustment. Whether either approach was used is not reported in the registry record. The record also does not describe a confirmatory status for this secondary outcome, so its p-value should not be interpreted as though an adjustment were known to have been applied.

The registry indicates three outcome measures and three analyses overall, while only one secondary outcome is posted in the record. Additional outcome details and the relationship among all analyses are not reported in the registry record. The secondary evidence is thus best treated as a complementary description of the Week 12 findings, with less weight than a clearly prespecified, multiplicity-controlled confirmatory analysis.

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

9. Statistical Interpretation

Clinical Biostats interpretation

At Week 12, the posted success rate was 38.4% with CD5024 1% cream and 11.6% with vehicle. The unadjusted recalculation reports a risk difference of 0.267, with an interval from 0.206 to 0.328. In plain terms, the estimated difference in the proportions meeting the IGA success definition favors the CD5024 group in this trial. The interval expresses uncertainty around that unadjusted difference; it does not mean that every value in the interval is equally likely or that the result will necessarily recur in another study.

The posted counts underlying the primary rates are 173 successes among 451 participants for CD5024 1% cream and 27 among 232 for vehicle. The sponsor’s reported comparison gives p < 0.001 using a Cochran-Mantel-Haenszel method. The unadjusted recalculation also gives p < 0.001. These analyses address evidence against a no-difference comparison, but a p-value does not measure the size or clinical importance of the effect. The estimated rates and risk difference provide the more direct description of magnitude.

The secondary endpoint concerns percentage change in inflammatory lesion count from baseline to Week 12. The posted means are -64.9 for CD5024 1% cream and -41.6 for vehicle, with a recalculated mean difference of -23.3 and an interval from -29.51 to -17.09. The negative direction represents decreases in lesion counts, as specified by the endpoint’s percentage-change measure. These posted results point in the same broad direction as the primary comparison, but they describe a different outcome: change in lesion counts rather than the proportion reaching an IGA score of Clear or Almost Clear. The registry reports p < 0.001 for the sponsor analysis of this endpoint as well.

The two outcomes offer complementary descriptions, not interchangeable evidence. One reports whether participants crossed a specified IGA threshold; the other reports mean change in lesion count. Their agreement in direction can be informative, but the record does not establish that the analyses were adjusted for multiple testing or specify a hierarchy among secondary outcomes. The posted results therefore need to be read with the analysis details and reporting limitations in mind. The registry record does not report a detailed protocol statistical plan, missing-data diagnostics, or subgroup results. The result describes the trial’s reported endpoints and population; it does not establish how the comparison would perform in different populations or settings.

10. Statistical Methods Explained

The primary outcome is binary: each participant is classified as a Week 12 IGA success or not, using the record’s threshold of Clear or Almost Clear. For a binary outcome, the success rate is the proportion in a group who meet the definition. Comparing those proportions keeps the clinical definition visible and avoids treating the distance between the IGA categories as though it were necessarily equal. The endpoint does, however, compress a five-category assessment into two groups, so the success rates do not describe all shifts across the original scale.

How the risk difference reads

The unadjusted recalculation expresses the comparison as a risk difference. It subtracts the vehicle success proportion from the CD5024 success proportion, with a positive estimate indicating a higher observed success proportion in the CD5024 group. The reported estimate is 0.267, and its interval runs from 0.206 to 0.328. These are proportions on the risk-difference scale, not a ratio of probabilities. A difference is often straightforward to interpret because it describes the separation between group rates in the same units as the outcome.

Other relative measures can also describe binary outcomes, but they answer a different question. A risk ratio compares the group probabilities as a ratio, while an odds ratio compares odds. Relative measures may look more or less pronounced depending on the outcome frequency and scale. The primary interpretation gives priority to the posted group rates and the recalculated risk difference rather than substituting a relative measure for the observed percentages.

What a confidence interval communicates

A confidence interval gives a range of effect estimates compatible with the observed data under the method used and its assumptions. It helps readers assess precision: a narrower interval indicates less statistical uncertainty on that scale than a wider interval. It is not a range containing individual participant outcomes, and it is not a guarantee that a future trial’s estimate will fall within it. The interval also does not address biases or differences in study conduct that are not represented by the calculation.

The registry record lists a sponsor analysis using the Cochran-Mantel-Haenszel method and reports p < 0.001. In general, this method compares categorical outcomes across strata, combining information while accounting for stratification. The strata and implementation details for the sponsor’s analysis are not reported in the registry record. The unadjusted recalculation is a separate, simple comparison from posted summary statistics; it should not be mistaken for a reconstruction of the sponsor’s full analysis.

Interpreting the lesion-count outcome

The secondary outcome is continuous: it reports percentage change in inflammatory lesion count from baseline to Week 12, with a mean and standard deviation for each group. The recalculated mean difference is -23.3, with an interval from -29.51 to -17.09. A mean difference compares group averages. It does not imply that every participant experienced a change near the group mean, which is why the standard deviations are also relevant descriptions of variation among participants.

In general, standard deviation describes the spread of individual observations around a group mean. It is not the same as the standard error, which describes uncertainty in an estimated mean. A treatment-group average can be estimated more precisely when there is more information and less variability, but averages alone do not describe the full distribution of participant outcomes. The registry’s posted standard deviations are 39.91 for CD5024 and 38.83 for vehicle.

The registry also lists a Cochran-Mantel-Haenszel result for this secondary endpoint with p < 0.001, but no corresponding sponsor estimate or interval. Because the endpoint is continuous and the record does not explain how the reported method relates to its analysis, its exact implementation is not reported in the registry record. The recalculated continuous comparison is an unadjusted mean-difference analysis and should be understood separately.

Over-dispersion and model choice

In general, over-dispersion occurs when observed variation is greater than a statistical model expects. It can make standard errors too small and confidence intervals too narrow if the model does not account for the extra variation. This is a general issue in statistical modelling, not a finding established by the posted summaries. The registry record does not report a model-based assessment of over-dispersion for these outcomes.

Likewise, the posted summary statistics do not identify all assumptions behind the sponsor’s analysis, such as the handling of strata, covariates, or missing observations. The record states ITT-LOCF for the primary endpoint and the secondary lesion-count outcome, but detailed implementation and sensitivity analyses are not reported in the registry record. The recalculations are consequently best read as transparent, unadjusted summaries rather than as replacements for a fully specified trial analysis.

11. Confidence Intervals and Precision

For the primary binary outcome, the recalculated risk difference is 0.267, with an interval from 0.206 to 0.328. This interval describes uncertainty about the difference between the observed success proportions on the risk-difference scale. Its endpoints are both above zero, which is consistent with the direction of the reported group rates. The interval does not account for every possible source of uncertainty, including limitations in outcome measurement, missing-data handling, or generalizability.

The observed group proportions are 38.4% for CD5024 1% cream and 11.6% for vehicle. The confidence interval is for the difference, not an interval for either group’s rate. The interval’s width gives a sense of the statistical precision of the difference estimate, but precision should not be confused with clinical importance. Whether a particular difference is meaningful depends on context not established by the statistical interval alone.

For the secondary lesion-count outcome, the recalculated mean difference is -23.3, with an interval from -29.51 to -17.09. That interval describes uncertainty on the mean-change scale and is separate from the primary risk-difference interval. The secondary outcome’s standard deviations, 39.91 and 38.83, describe participant-level spread and should not be read as confidence limits for the group means.

The record does not state the confidence level for the recalculated intervals in the posted results. Neither interval resolves uncertainty about the study’s missing-data assumptions, analysis choices, or applicability beyond the trial population. The sponsor reports p < 0.001 for both comparisons, but p-values alone do not indicate precision or quantify the range of plausible effect sizes.

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.

Effect to detectParticipants per arm, 80% powerParticipants per arm, 90% power
100% of the observed effect4154
75% of the observed effect6687
50% of the observed effect131175
Sample size needed versus the size of the effect to detect
Sample size needed versus size of effect to detect5010020050040%60%80%100%80% power90% powersize of effect to detect, as % of the effect observed (log vertical scale: participants per arm)
Method and assumptions. Two-sided α = 0.05, 1:1 allocation, pooled-variance normal approximation for two proportions. Counts were reconstructed from the posted percentages and arm sizes, so small rounding differences are possible. Calculated for the comparison: CD5024 1% Cream.

The planning figures are participants per arm for the binary primary outcome and for the continuous lesion-count outcome; they are not total event counts. The stated planning assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The effect to detect is set as the stated fraction of the observed effect. The registry record does not report the assumptions used for the trial’s original design or its original sample-size justification.

The 80% power column gives the number of participants per arm in the planning illustration for a design with an 80% chance of detecting the specified effect under those assumptions, if that effect and assumptions were correct. The 90% power column gives the corresponding number for a 90% chance. These are planning calculations, not guarantees about a future study’s result. The values are derived from the observed effect in this trial, rather than from an independently established target effect.

Rows using a smaller fraction of the observed effect require more participants per arm than rows based on the full observed effect. That is a general feature of study planning: smaller differences are harder to distinguish from random variation when other assumptions stay fixed. The estimates are illustrations and should not be treated as the trial’s intended enrollment target or as proof that the study had a particular probability of success.

This is not observed power. Observed power is not a useful substitute for interpreting the effect estimate and its uncertainty after results are available. The planning figures answer a hypothetical design question under explicit assumptions; the trial’s actual results are described by the posted group outcomes, effect estimates, and intervals.

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 z1−α/2 = 1.960) and the desired power (z1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n = [ z1−α/2 √(2p̄(1−p̄)) + z1−β √(p0(1−p0) + p1(1−p1)) ]2 / (p1 − p0)2

n is the number of participants in each arm, p0 and p1 are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

  1. Control proportion p0 = 0.116; treatment proportion p1 = 0.384; average p̄ = 0.250.
  2. First term: z1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.6124 = 1.2002.
  3. Second term: z1−β × √[p0(1−p0) + p1(1−p1)] = 0.842 × 0.5825 = 0.4902.
  4. n = (1.2002 + 0.4902)2 / (0.2672)2 = 40.0, rounded up to 41 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
p0 <- 0.116379310344828                          # control proportion
p1 <- 0.383592017738359                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^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 (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(1493687)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 41 (80% power), 54 (90% power)
 75% of observed effect: n per arm = 66 (80% power), 87 (90% power)
 50% of observed effect: n per arm = 131 (80% power), 175 (90% power)
power.prop.test: 40 
Simulated power at n = 41 per arm: 0.830 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-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

MethodEstimate95% CIP-value
Cochran-Mantel-Haenszelnot reported< 0.001

For the primary outcome, the registry reports a sponsor analysis using the Cochran-Mantel-Haenszel method and gives p < 0.001. The unadjusted recalculation from the posted group counts also gives p < 0.001 and estimates a risk difference of 0.267, with an interval from 0.206 to 0.328. The sponsor’s analysis and the simple recalculation therefore agree in the reported direction and in the reported threshold for the p-value.

The methods are not identical descriptions of an analysis. Cochran-Mantel-Haenszel is the sponsor-reported method, while the recalculation is an unadjusted comparison from summary statistics. Details of the sponsor’s strata and other implementation choices are not reported in the registry record. The sponsor’s own analysis takes precedence as the trial’s reported analysis; the recalculation is supplementary and helps express the result in an interpretable effect scale.

For the secondary lesion-count endpoint, the registry also reports p < 0.001 from a Cochran-Mantel-Haenszel analysis, without posting a sponsor estimate or interval. The separate unadjusted recalculation reports a mean difference of -23.3, with an interval from -29.51 to -17.09. The registry record does not explain the relationship between the sponsor’s listed method and this continuous outcome, so the two analyses should not be conflated.

15. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when several hypotheses are tested in the same study. Even when each test uses a conventional significance threshold, repeated testing can increase the overall chance of a false-positive finding. Common approaches include adjusting thresholds, controlling an overall error rate, or specifying an ordered testing strategy. These are general statistical options; the registry record does not report whether multiplicity was addressed, which outcomes were included in any adjustment, or whether the primary and secondary outcomes followed a formal hierarchy.

The record identifies the primary endpoint and one posted secondary endpoint, but also reports three outcome measures and three analyses overall. The complete set of analyses and their prespecified status are not described in enough detail to establish how many hypotheses were tested or how the reported results should be ordered inferentially. The p-values should therefore be read as reported, without assuming a multiplicity adjustment.

The primary population is described as ITT-LOCF. In general, intention-to-treat analysis seeks to retain participants in their randomized groups, while last observation carried forward fills a missing endpoint using an earlier recorded observation. LOCF relies on assumptions about what would have happened after the last recorded assessment; those assumptions may not fit every participant’s course. The registry record does not state how many observations were missing, why they were missing, when the carried-forward values were taken, or whether other missing-data methods were used in sensitivity analyses.

Missing-data methods can affect both estimated group rates and their uncertainty. An analysis population label alone does not show whether missingness was balanced between groups or whether the results would be robust to alternative assumptions. The record’s use of ITT-LOCF is important context, but detailed participant flow, missingness patterns, sensitivity analyses, and the full statistical plan are not reported in the registry record. Interim analyses and stopping rules are also not reported in the registry record.

16. Safety Results

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

ArmParticipants with serious adverse eventsParticipants at riskPercentage
CD5024 1% Cream - Part A34520.7%
CD5024 Vehicle Cream - Part A12310.4%
CD5024 1% Cream - Part B74121.7%
Azelaic Acid 15% Gel - Part B82103.8%
CD5024 1% Cream - Part C03500.0%
CD5024 Vehicle Cream/Azelaic Acid 15% Gel - Part C11750.6%
CD5024 1% Cream - Overall104522.2%
CD5024 Vehicle Cream/Azelaic Acid 15% Gel - Overall92323.9%
Participants with at least one serious adverse event
Serious adverse events by armCD5024 1% Cream - Part A0.7%CD5024 Vehicle Cream - Part A0.4%CD5024 1% Cream - Part B1.7%Azelaic Acid 15% Gel - Part B3.8%CD5024 1% Cream - Part C0.0%CD5024 Vehicle Cream/Azelaic …0.6%CD5024 1% Cream - Overall2.2%CD5024 Vehicle Cream/Azelaic …3.9%% of participants with at least one serious adverse event

Other (non-serious) adverse events

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

ArmParticipants affected of at risk
CD5024 1% Cream - Part A30 of 452
CD5024 Vehicle Cream - Part A10 of 231
CD5024 1% Cream - Part B93 of 412
Azelaic Acid 15% Gel - Part B47 of 210
CD5024 1% Cream - Part C4 of 350
CD5024 Vehicle Cream/Azelaic Acid 15% Gel - Part C0 of 175

Most frequent serious adverse event terms

Event termOrgan systemCD5024 1% Cream - Part ACD5024 Vehicle Cream - Part ACD5024 1% Cream - Part BAzelaic Acid 15% Gel - Part BCD5024 1% Cream - Part CCD5024 Vehicle Cream/Azelaic Acid 15% Gel - Part C
Transient ischaemic attackNervous system disorders0 of 4520 of 2311 of 4122 of 2100 of 3500 of 175
Acute myocardial infarctionCardiac disorders0 of 4520 of 2311 of 4121 of 2100 of 3500 of 175
Atrial fibrillationCardiac disorders0 of 4520 of 2310 of 4122 of 2100 of 3500 of 175
Renal failure acuteRenal and urinary disorders0 of 4520 of 2310 of 4122 of 2100 of 3500 of 175
CholelithiasisHepatobiliary disorders0 of 4520 of 2311 of 4120 of 2100 of 3500 of 175
CholecystitisHepatobiliary disorders1 of 4520 of 2310 of 4120 of 2100 of 3500 of 175
Transitional cell carcinomaNeoplasms benign, malignant and unspecified (incl cysts and polyps)0 of 4520 of 2311 of 4120 of 2100 of 3500 of 175
Breast cancerNeoplasms benign, malignant and unspecified (incl cysts and polyps)0 of 4520 of 2311 of 4120 of 2100 of 3500 of 175
Squamous cell carcinoma of skinNeoplasms benign, malignant and unspecified (incl cysts and polyps)0 of 4520 of 2311 of 4120 of 2100 of 3500 of 175
Pancreatic carcinomaNeoplasms benign, malignant and unspecified (incl cysts and polyps)0 of 4520 of 2310 of 4120 of 2100 of 3501 of 175

Most frequent non-serious adverse event terms

Event termOrgan systemCD5024 1% Cream - Part ACD5024 Vehicle Cream - Part ACD5024 1% Cream - Part BAzelaic Acid 15% Gel - Part BCD5024 1% Cream - Part CCD5024 Vehicle Cream/Azelaic Acid 15% Gel - Part C
NasopharyngitisInfections and infestations12 of 4526 of 23154 of 41231 of 2101 of 3500 of 175
Upper respiratory tract infectionInfections and infestations6 of 4522 of 23131 of 41214 of 2102 of 3500 of 175
HeadacheNervous system disorders13 of 4524 of 23117 of 4128 of 2101 of 3500 of 175

Serious events with the highest arm-level rate: atrial fibrillation (1.0%), transient ischaemic attack (1.0%), renal failure acute (1.0%), pancreatic carcinoma (0.6%), ascites (0.6%).

Do not overextend the safety comparison. Serious-adverse-event counts are safety observations, not efficacy outcomes, and should not be combined with the primary result into a single benefit-risk number.

The registry separates adverse-event summaries into Part A, Part B, Part C, and overall groups. For the overall summaries, serious adverse events were reported for 10 of 452 participants in the CD5024 1% Cream group and 9 of 232 in the CD5024 Vehicle Cream/Azelaic Acid 15% Gel group. Other adverse events were reported for 110 of 452 and 52 of 232 participants, respectively. These are counts and group denominators as posted, not adjusted comparisons.

The combined vehicle/azelaic-acid label and the different part labels matter: the overall safety groups are not simply the same comparison as the randomized vehicle-controlled primary efficacy phase. The registry record does not provide enough detail in these summaries to align each participant’s exposure duration or treatment sequence. Event counts should not be summed across parts, since the record does not establish that the groups are independent or that the same participant could not contribute to more than one part.

Deaths are not reported in the registry record. Serious adverse-event counts summarize events meeting the registry’s serious-event category; they do not by themselves establish whether an event was caused by treatment. The listed serious-event terms are descriptive and do not establish causality.

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

The results describe a Week 12 comparison in a randomized, vehicle-controlled study of participants with papulopustular rosacea. The posted IGA success proportion was higher in the CD5024 1% Cream group than in the vehicle group, and the unadjusted risk-difference interval is consistent with a positive difference in this trial. The sponsor-reported primary analysis gives p < 0.001. The lesion-count outcome also shows a larger mean decrease in the CD5024 group, with a recalculated mean difference whose interval does not include zero.

These findings do not, by themselves, establish the size or importance of an effect in every patient or setting. The primary endpoint reduces the five-point IGA scale to a binary success classification, so it does not describe the full range of scores or the distribution of responses. The mean lesion-count result likewise does not show how much individual participants varied. Statistical evidence for a group difference is not the same as a judgment about clinical importance.

The registry record does not report the full statistical analysis plan, multiplicity procedures, detailed missing-data patterns, or sensitivity analyses. Those omissions limit assessment of how robust the reported results are to analysis choices. The trial’s extension is described as a long-term safety comparison with azelaic acid 15% gel, but the primary Week 12 efficacy result is not an extension-period efficacy comparison.

The adverse-event summaries are descriptive counts. They do not establish that a treatment caused or prevented an event, and differing treatment phases and group labels complicate direct comparisons. These statistics are not individualized predictions and do not replace a broader assessment of benefits and risks. They should be interpreted as the posted findings for the populations, outcomes, and timeframes recorded, with the reporting limitations kept in view.

18. Why This Trial Matters Statistically

This trial illustrates why statistical interpretation benefits from separating an endpoint’s clinical definition from the statistical scale used to compare groups. The primary endpoint is an IGA responder threshold, while the reported effect can be expressed as a risk difference. That difference directly describes how far apart the observed group success proportions are, and an interval adds information about uncertainty that a p-value alone cannot provide.

The record also shows how sponsor analyses and transparent recalculations can serve different purposes. The sponsor reports a Cochran-Mantel-Haenszel p-value, while an unadjusted calculation from posted counts provides an interpretable risk-difference estimate and interval. Agreement in the direction and reported p-value threshold is useful context, but it does not make the methods interchangeable. The sponsor analysis remains the trial’s reported analysis; the simple recalculation is a supplementary summary.

A further statistical lesson is that outcomes can be related without measuring the same thing. The IGA success rate and mean lesion-count change point in a similar broad direction, yet one captures a threshold-based classification and the other an average change. Their interpretation depends on their definitions, analysis populations, uncertainty, and place in the testing plan. The registry record does not report enough about multiplicity or missing-data sensitivity to treat every result as equally confirmatory.

Finally, planning illustrations based on an observed effect are not evidence of the study’s original design assumptions or its probability of success. Distinguishing hypothetical sample-size planning from observed results prevents a common interpretive error. Together, these considerations support a reading that attends to effect magnitude, precision, outcome definition, and reporting gaps rather than relying on statistical significance alone.

19. Limitations

Several limitations are specific to the available record. The primary endpoint is reported for an ITT-LOCF population, but the record does not give missing-observation counts, reasons for missingness, or sensitivity analyses using alternative assumptions. The impact of carrying forward earlier measurements therefore cannot be assessed from the posted summaries.

The registry identifies a sponsor-reported Cochran-Mantel-Haenszel analysis but does not describe its strata or implementation. For the secondary continuous outcome, it lists the same method without an associated sponsor estimate or interval, leaving the relationship between that analysis and the outcome’s scale unclear. The unadjusted recalculations do not resolve those reporting gaps.

The record does not report whether results were adjusted for multiplicity, the full prespecified outcome hierarchy, interim analyses, or original sample-size assumptions. These omissions limit assessment of confirmatory status and of whether the reported tests reflect the planned analysis. The trial’s enrollment and posted analysis denominators are known, but participant flow and reasons for any difference between them are not reported in the registry record.

The long-term extension is described as an investigator-blinded safety comparison with azelaic acid 15% gel, yet detailed exposure durations, treatment sequences, and extension analyses are not included in the posted summaries. Safety groups carry different part labels, including a combined vehicle/azelaic-acid group, which limits simple comparisons across phases. The record also does not report death counts. These constraints mean that the Week 12 efficacy statistics and the safety summaries should be interpreted as distinct, limited views of the study rather than a complete account of all trial analyses.

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23. Record Summary

The registry record describes a completed randomized, parallel-group, triple-masked phase 3 study in papulopustular rosacea, sponsored by Galderma R&D. It reports total enrollment of 683 and a 12-week comparison of CD5024 1% cream with CD5024 Vehicle Cream, followed by a 40-week investigator-blinded extension comparing CD5024 1% cream with azelaic acid 15% gel for long-term safety.

The primary Week 12 endpoint was the percentage achieving an IGA score of Clear or Almost Clear in the ITT-LOCF population. Posted rates were 38.4% and 11.6%, respectively; the unadjusted recalculation reports a risk difference of 0.267, with an interval from 0.206 to 0.328. The sponsor reports p < 0.001. One secondary outcome, percentage change in inflammatory lesion count, is also posted. Details of multiplicity, missing-data sensitivity analyses, and the full statistical plan are not reported in the registry record.

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