A Study of the Safety and Efficacy of DFD-03 for the Treatment of Acne Vulgaris: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of the Safety and Efficacy of DFD-03 for the Treatment of Acne Vulgaris (NCT03290027), a randomized phase 3 study. The primary outcome is Absolute Change in the Inflammatory Lesion Counts on the Face.

2. Clinical Question

The study was designed to compare the change in inflammatory lesion counts between the randomized groups. The registry also describes assessment of an Investigator’s Global Assessment scale and counts of inflammatory and non-inflammatory facial lesions at scheduled visits. The primary endpoint, however, is specifically the absolute change in inflammatory lesion counts from baseline to Week 12.

This framing is important: the endpoint is a change over time in a count, not simply the number of lesions at the final visit. The registry record identifies the population and intended comparison, but it does not report the group means, the estimated between-group contrast, a confidence interval, or a p-value for the primary endpoint. Therefore, the registry record establishes what the trial set out to assess, not the size or precision of the treatment-group difference.

3. Trial Design

This was a Phase 3, randomized, parallel-group, vehicle-controlled study of DFD-03 lotion for acne vulgaris. The registry describes quadruple masking. It lists 550 participants as the enrollment and identifies Dr. Reddy’s Laboratories Limited as the sponsor. The study is marked completed. Its recorded start date is 2017-07-31, and its primary completion date is 2018-04-19.

The active group received DFD-03, described as 0.1% tazarotene lotion. The comparator group received vehicle lotion, described as 0% tazarotene. A vehicle comparator allows the randomized groups to differ in the active ingredient while using a lotion comparator; the record does not give further details about how the lotions were made or administered. The schedule and duration are described as 12 weeks.

The brief summary describes enrollment of subjects with mild to moderate facial acne. Efficacy assessments included an Investigator’s Global Assessment scale and counts of inflammatory and non-inflammatory lesions on the face at baseline and Weeks 4, 8, and 12. Safety assessments included investigator ratings of local cutaneous tolerance, vital signs, and adverse events. The named local tolerance features were dryness, non-lesional erythema, peeling, stinging, burning, and itching.

The registry specifies an ITT population for the primary endpoint, defined as all subjects randomized and dispensed study medication. It does not report additional details about the randomization procedure, allocation concealment, masking roles, treatment adherence, or handling of participants who discontinued treatment. Those features 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.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Intent To Treat (ITT) Population - All subjects randomized and dispensed study medication.

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: Intent to Treat (ITT) - The ITT population was the primary efficacy analysis data set and consisted of all subjects who were randomized and dispensed study medication.

6. Primary Endpoint

The registry lists the primary outcome as Absolute Change in the Inflammatory Lesion Counts on the Face, measured over Baseline to Week 12.

The primary endpoint is the absolute change in inflammatory lesion counts on the face from baseline to Week 12. It is a continuous outcome summarized by a mean and standard deviation, even though each participant’s underlying lesion count is a whole-number count. The endpoint focuses on inflammatory lesions rather than combining inflammatory and non-inflammatory lesions.

A change endpoint describes how a measurement differs between baseline and a later assessment. This can make the treatment comparison more informative than comparing final values alone when participants begin with different baseline measurements. The analysis description specifies a two-way analysis of covariance (ANCOVA) model for the change from baseline. The record does not identify the model’s factors, covariates, or detailed coding.

Lesion counts provide a direct measure of one component of facial acne burden, while the Investigator’s Global Assessment gives a separate clinical rating. The two types of assessment capture different aspects of the condition and should not be treated as interchangeable. The registry lists the primary endpoint timeframe as baseline to Week 12, with other efficacy assessments scheduled at Weeks 4 and 8 as well as Week 12.

No primary endpoint group means, standard deviations, adjusted contrast, confidence interval, or p-value are reported in the registry record. The endpoint definition therefore clarifies what was intended to be measured, but it does not establish the observed direction, magnitude, or precision of a group difference.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the primary outcome measure?

The endpoint is absolute change in facial inflammatory lesion counts from baseline to Week 12. The record describes the outcome as a mean with standard deviation. A mean summarizes the group’s average change, while a standard deviation describes how variable individual changes are around that average. Neither summary is reported for the primary endpoint in the registry record, so the amount of change and its variation cannot be evaluated from this record.

Although lesion counts are counts at the participant level, the registry specifies a continuous-outcome summary and an ANCOVA model. A general reason to use a model-based comparison is to estimate the group contrast while accounting for selected features of the analysis. In this trial, the record says two-way ANCOVA was used for the change outcome, but does not identify the factors, covariates, or exact model specification. It would be inappropriate to assume which terms were included.

What does ANCOVA contribute?

In general, analysis of covariance compares outcomes across groups while incorporating one or more covariates. If baseline measurement is included, the model can account for baseline differences when estimating a treatment-group contrast. The record names ANCOVA but does not explicitly describe the covariate set or the reported estimate, so this general explanation should not be mistaken for a complete description of the trial’s fitted model.

A model’s estimate is not the same as a raw difference between two group summaries. An adjusted estimate depends on the model terms and analysis population. To interpret it, readers need the estimate itself and a measure of uncertainty, commonly a confidence interval, along with the stated analysis plan. Those primary efficacy results are not reported in the registry record.

Why do variability and distribution matter?

General statistical context is useful because a mean alone does not describe how participant-level results vary. The standard deviation is one summary of that variation, but it does not show the full shape of the outcome distribution. Count outcomes may be unevenly distributed, and a few high values can affect a mean. Whether those features were assessed or addressed in this trial is not reported in the registry record.

Over-dispersion is a general issue for count data: it occurs when variability is greater than a particular count model expects. When relevant, it can make standard errors from an overly restrictive model too small and confidence intervals too narrow. This is general statistical context, not a claim that over-dispersion occurred in this study. The registry describes a mean-based endpoint and ANCOVA; it does not report diagnostic checks or a separate count-regression analysis.

How should statistical significance be read?

In general, a p-value describes how unusual data at least as incompatible with a specified null hypothesis would be under the assumptions of a statistical test. It does not measure the size or clinical importance of an effect, and it does not give the probability that the null hypothesis is true. A confidence interval adds information about the range of estimates compatible with the data and method. Neither a p-value nor a confidence interval for the primary endpoint is reported in the registry record.

A statistically significant result, if reported, would not by itself establish that the difference is important to patients. Conversely, a result that did not meet a significance threshold would not establish equivalence. Such conclusions require the estimate, its uncertainty, and a suitable prespecified framework. The registry record does not report an equivalence or non-inferiority framework for this endpoint.

What can planning calculations tell readers?

General sample-size illustrations based on an observed effect are planning exercises. They ask how many participants per arm might be needed under stated assumptions to detect a chosen fraction of that effect at a specified power and significance level. They are not observed power, do not recover missing trial results, and do not describe the original study’s design rationale unless the record says they were used for that purpose. The registry record does not report a sample-size justification or the trial’s own planning assumptions. Any planning illustration should therefore be understood as separate from the trial’s observed outcome and not as evidence about the result.

The stated analysis description is brief. It does not report model diagnostics, standard-error methods, the exact treatment contrast, confidence-interval construction, or whether adjustments were made for multiple comparisons. These omissions limit replication and prevent a full assessment of the statistical analysis from the registry record alone.

10. Multiplicity, Missing Data and Analysis Populations

The registry describes several efficacy assessments: an Investigator’s Global Assessment scale and inflammatory and non-inflammatory facial lesion counts, measured at baseline and follow-up visits. The primary endpoint is specifically the change in inflammatory lesion counts from baseline to Week 12. With multiple outcomes or timepoints, general statistical practice distinguishes the primary comparison from additional comparisons because repeated testing can increase the chance of at least one false-positive finding. The record does not report a multiplicity adjustment, a testing hierarchy, or how secondary outcomes were handled. These details are not reported in the registry record.

The primary outcome description indicates that it has several categories or timepoints and is not reduced to a single comparison in the available analysis. No efficacy estimate is reported for the primary endpoint in the registry record. The record also does not describe whether there were interim analyses or whether any decisions were based on interim results.

The stated primary analysis population is the ITT Population, defined as all subjects randomized and dispensed study medication. The record does not explain how missing Week 12 measurements, treatment discontinuation, or other missing outcome data were handled. It does not report imputation methods, sensitivity analyses, or the number of participants contributing observed outcome data at each visit. These details are not reported in the registry record.

Missing-data methods matter because an analysis may depend on assumptions about why outcomes are unavailable and how unobserved values relate to observed information. Different reasonable assumptions can produce different estimates. Without a description of missingness and the analysis approach, the robustness of a primary endpoint result cannot be evaluated; in any case, the result itself is not reported in the registry record.

11. Safety Results

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

Deaths

Other (non-serious) adverse events

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

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: overian cyst ruptured (0.4%), anxiety (0.4%), polyps/epithelioid (0.4%).

The registry lists serious adverse events for the active and vehicle groups. In the active group, 2 of 277 participants at risk were reported as affected by a serious adverse event; in the vehicle group, 1 of 273 were reported as affected. The listed count of other adverse events was 0 in each group, and the listed death count was 0 in each group. These are reported counts, not estimates of comparative risk.

The registry also lists “Overian cyst ruptured,” “Anxiety,” and “Polyps/Epithelioid,” each with 0.4% beside the term. The record does not provide further context for these terms, including a full account of event timing, severity, attribution, or participant-level details. The spelling and labels are reproduced as recorded.

A serious adverse event is a safety category, not a conclusion that the study treatment caused the event. The counts alone do not establish causality or a reliable difference between groups. The record does not report a statistical comparison for serious adverse events. A zero in a listed category means no events were recorded for that category in the reported group data; it does not establish that an event could never occur. These figures should be read as the registry’s reported safety entries, not as a complete evaluation of safety.

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

The registry record is useful for identifying the study question and the outcome selected to address it. It describes a randomized, parallel-group comparison of DFD-03 lotion with vehicle lotion in subjects with mild to moderate facial acne. It specifies change in inflammatory facial lesion counts from baseline to Week 12 as the primary endpoint and names a two-way ANCOVA analysis.

Those design details do not establish what the trial found. The primary efficacy estimate, group summaries, confidence interval, and p-value are not reported in the registry record. As a result, the direction and size of the comparison and the uncertainty around it cannot be interpreted from this information. The absence of a reported estimate is not a finding of no difference, nor is it a finding of benefit.

The record’s scheduled assessments and safety entries likewise do not answer every question about efficacy or safety. The assessment schedule shows what was intended to be measured; it does not state the observed values. Serious adverse event counts describe recorded events, but without fuller clinical detail and an analysis they cannot establish treatment causation or a comparative safety conclusion.

In general, a clinical trial result is most informative when the estimate, its uncertainty, the analysis population, missing-data approach, and prespecified analysis plan can be considered together. The registry record gives some design and endpoint information, but it does not report several of these elements. Readers should therefore separate the existence of a trial and its planned measurement from evidence about the outcome. No medical conclusion about the effect of DFD-03 can be drawn from the unreported primary efficacy results.

13. Why This Trial Matters Statistically

This trial illustrates why registry design information and outcome reporting serve different purposes. Randomization, a vehicle comparator, parallel groups, and masking describe how the comparison was structured. The primary endpoint definition describes what outcome the trial intended to analyze. Neither design features nor a named statistical model supplies the missing estimate.

It also highlights the importance of distinguishing an endpoint from its analysis result. Facial inflammatory lesion count change is a particular outcome, measured over a specified interval. The record’s use of a mean and standard deviation and its description of ANCOVA signal the intended summary and modeling approach, but readers still need the estimated group contrast and uncertainty to assess what the data indicate.

Multiple assessments make clear reporting especially important. The record mentions a global assessment and more than one lesion-count category across visits, while identifying one primary endpoint timeframe. Clear reporting of which comparisons were primary, how other comparisons were handled, and how missing measurements were analyzed would help readers understand the evidential weight of each result. Those details are not reported in the registry record.

Finally, safety counts and efficacy outcomes answer different questions. Serious adverse event entries can describe events recorded during the trial, but they do not provide the missing efficacy estimate and cannot, on their own, establish causation. The record is therefore informative about the intended design and the limits of what can be concluded from the posted outcome information.

14. Limitations

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

The main limitation for interpreting efficacy is that the registry record does not report the primary endpoint result. It gives no group-level mean change, standard deviation, treatment contrast, confidence interval, or p-value. Consequently, neither the magnitude nor the precision of the primary comparison can be assessed.

The statistical description is limited to a two-way ANCOVA model for change from baseline. The record does not identify the factors or covariates in that model, the exact contrast, or diagnostic procedures. It also does not report how missing Week 12 outcomes or treatment discontinuations were handled, or whether sensitivity analyses were conducted. These details are not reported in the registry record.

The efficacy summary names an Investigator’s Global Assessment and counts of inflammatory and non-inflammatory lesions at scheduled visits, but does not give their results in the information available for this analysis. The record does not report a multiplicity strategy for the several assessments or timepoints. This limits interpretation of how any secondary findings would relate to the primary question.

The safety entries provide limited event counts and selected terms, without detailed context or a reported comparative analysis. They should not be treated as a comprehensive safety assessment. The record also does not report treatment adherence, the extent of outcome data at each visit, or detailed masking and randomization procedures. These limitations concern what can be assessed from the registry record; they do not establish that the trial did or did not collect further information.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Study of the Safety and Efficacy of DFD-03 for the Treatment of Acne Vulgaris — NCT03290027.
• Registry record last updated 2021-03-01; status last verified 2021-02.
• Results first posted 2020-05-26.
• 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.

18. Record Summary

NCT03290027 is a completed Phase 3 randomized, quadruple-masked, parallel-group, vehicle-controlled study of DFD-03 lotion for acne vulgaris. The registry lists Dr. Reddy’s Laboratories Limited as sponsor, enrollment of 550, a start date of 2017-07-31, and a primary completion date of 2018-04-19.

The study compared DFD-03 lotion, described as 0.1% tazarotene, with vehicle lotion, described as 0% tazarotene, over 12 weeks. The primary endpoint was absolute change in facial inflammatory lesion counts from baseline to Week 12, analyzed using a two-way ANCOVA model in the ITT population as defined in the record.

The registry describes additional efficacy assessments and safety monitoring, and lists serious adverse event counts for both groups. It does not report the primary efficacy estimate or its uncertainty, nor does it provide details of missing-data handling or multiplicity procedures.