A Study of A-101 Solution in Subjects With Common Warts.: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of A-101 Solution in Subjects With Common Warts. (NCT02669862), a randomized phase 2 study. The primary outcome is Efficacy Based on Mean Change in Physician Wart Assessment Over Time.

2. Clinical Question

The study also recorded PWA responder status at Day 57 and durability of response among participants clear at Visit 10. These outcomes provide related but distinct views of response: the primary endpoint uses a change in a scored measure, while responder status classifies participants according to a response criterion. The criterion for PWA responder is not described in the available registry record, so its precise operational definition is not reported in the registry record.

The clinical question is therefore comparative and specific to these two concentrations, this vehicle comparator, and the outcomes and follow-up recorded in the trial. The registry record identifies the study as Phase 2 and reports enrollment of 98. It does not, in the information available for this analysis, establish how the findings should be applied beyond the studied participants, treatment schedule, and assessment period.

3. Trial Design

This was a randomized, double-blind, vehicle-controlled, parallel-group study in participants with common warts. The record lists three groups: A-101 Solution 40, A-101 Solution 45, and Vehicle Solution. Each solution was administered once per week. Randomization and double masking can help reduce systematic differences in treatment assignment and assessment, although the registry information does not describe how the random sequence was generated, how allocation was concealed, or how masking was maintained.

The trial is listed as Phase 2, with enrollment of 98 and completed status. Its recorded start date is 2015-12-21 and its primary completion date is 2016-09-16. The primary outcome timeframe is 57 Days; the secondary PWA responder outcome is recorded at Day 57. The primary analysis compared mean change from Visit 2 to Visit 10 in Physician Wart Assessment. The registry description states that the intended primary analysis used analysis of covariance, with Visit 2 PWA as a covariate.

The primary outcome summaries list 32 participants in the A-101 Solution 40 group, 31 in the A-101 Solution 45 group, and 27 in the Vehicle Solution group. Those are the group counts for the posted primary outcome summaries, not a statement about the number enrolled or the safety analysis populations. The record defines the primary analysis population as participants completing the protocol through Visit 10. It does not give a full account of participant flow, reasons for non-completion, or how missing observations were handled.

The registry record does not report the original sample-size justification, the intended effect size, or the trial’s detailed statistical analysis plan. It also does not report whether interim analyses were planned or performed. Those omissions limit what can be concluded about the study’s original design assumptions and analysis procedures, even though the record names ANCOVA as the primary method.

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: Number of participants analyzed is the number of participants completing the protocol through visit 10.

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 Efficacy Based on Mean Change in Physician Wart Assessment Over Time, measured over 57 Days.

The primary endpoint is the mean change in Physician Wart Assessment from Visit 2 to Visit 10, assessed over 57 Days. The scale runs from 0, meaning clear, to 3, meaning a clinically diagnosable raised wart with an obviously rough surface. A change score captures how the recorded assessment moved over the treatment and observation period, rather than describing only the final visit. Because a lower PWA score is nearer to clear on the scale, a negative mean change represents movement toward a lower score in the group summary.

The registry record says the primary effectiveness analysis was to use ANCOVA, with Visit 2 PWA as a covariate. In general, adjusting for the starting assessment can account for baseline differences in the measured outcome and can improve the precision of a group comparison when the model is appropriate. The registry record does not provide the adjusted effect estimate or its confidence interval for the sponsor’s ANCOVA analyses; it reports p-values for those analyses.

A mean is useful when the research question concerns the average change in a continuous score across participants. It retains gradations in the PWA measure, unlike a responder outcome that sorts participants into categories. The posted summaries also give standard deviations, which describe variation in individual changes around each group mean. A group mean does not show how many participants became clear, how outcomes varied over time within individuals, or whether every participant changed in the same direction. The endpoint therefore supplies one defined measure of comparative change, not a complete account of the clinical course or individual outcomes.

7. Results Posted in the Registry

• A-101 Solution 40: mean -0.38 versus -0.44 on control; difference 0.06 (95% CI -0.35 to 0.47), standardized effect d = 0.08; z-test p = 0.776.
• A-101 Solution 45: mean -1.00 versus -0.44 on control; difference -0.56 (95% CI -1.03 to -0.09), standardized effect d = -0.61; z-test p = 0.019.

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.

PWA Responder

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • A-101 Solution 40: 3.1% (1/32) versus 3.7% (1/27) on control; risk difference -0.6 percentage points (95% CI -9.9 to 8.8), risk ratio 0.84 (0.06–12.86); unadjusted two-proportion z-test p = 0.903.
  • A-101 Solution 45: 25.8% (8/31) versus 3.7% (1/27) on control; risk difference 22.1 percentage points (95% CI 5.1 to 39.1), risk ratio 6.97 (0.93–52.20); unadjusted two-proportion z-test p = 0.020.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between A-101 Solution 40 and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically higher for A-101 Solution 45 than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The secondary endpoints add information from a different angle than the primary mean-change measure. PWA responder classifies participants rather than retaining the full continuous change score, and durability of response concerns whether participants clear at Visit 10 remain clear at Visit 13. The registry lists these two secondary outcomes, but the posted numerical details available for interpretation include PWA responder; numerical results for durability are not reported in the registry record.

Across the reported responder comparisons, the general pattern is that the A-101 Solution 40 result is close to the vehicle result, while the A-101 Solution 45 result is higher. This direction is consistent with the pattern of the primary group means, where the 45% group had a more negative mean change than vehicle and the 40% group was comparatively close to vehicle. Similar direction across different outcome forms can be informative, but it does not make the endpoints interchangeable or establish that they measure the same aspect of response.

The responder outcome is secondary, and its definition is not described in the registry record. The record does not report a multiplicity adjustment or a hierarchy governing interpretation of the secondary outcomes. When many outcomes or comparisons are examined, the chance of finding a nominally notable result by chance can increase. Unless the analysis plan establishes how those tests should be interpreted, unadjusted secondary p-values carry less weight than a prespecified primary analysis. They are best treated as supportive and exploratory rather than as independent confirmation.

The registry record reports sponsor chi-squared tests and also permits simple recalculated binary comparisons, but those methods do not exactly reproduce one another. The sponsor’s own results take precedence where the record flags a discrepancy. The secondary evidence should therefore be interpreted alongside the primary result, the analysis methods, and the limitations in reporting, rather than as a separate definitive conclusion.

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

• Durability of Response - Percentage of Participants That Were Clear at Visit 10 That Are Still Clear at Visit 13
• PWA Responder

9. Statistical Interpretation

10. Statistical Methods Explained

The primary analysis named in the registry record is analysis of covariance, or ANCOVA. It compares groups while including Visit 2 PWA as a covariate. In general, a covariate is a measured characteristic included in a statistical model to account for variation in the outcome. Here, Visit 2 PWA is the recorded starting assessment for the change from Visit 2 to Visit 10. ANCOVA can produce an adjusted group comparison that differs from a direct comparison of the group means, because the model uses the baseline measure as well as the outcome. The full model specification, assumptions checks, and adjusted effect estimates are not reported in the registry record.

What do the recalculated mean differences represent?

The recalculated comparisons use posted group summary statistics to form simple, unadjusted contrasts between each A-101 group and Vehicle Solution. For the continuous primary outcome, the estimate is a difference in means. Its sign indicates the direction of the contrast: a negative estimate means the A-101 group’s mean change is more negative than the vehicle group’s mean change, while a positive estimate means it is less negative. These contrasts do not adjust for Visit 2 PWA and should not be confused with the sponsor’s ANCOVA results.

The recalculated intervals describe a range of effect values compatible with the summary data under the assumptions of that calculation. Their width reflects uncertainty: broader intervals allow a wider range of possible differences, while narrower intervals are more precise. The interval’s confidence level is not specified in the recalculated comparison information, so it should not be assigned a particular level based on the registry material alone. The corresponding recalculated p-values are also unadjusted. They address the specific comparison under the calculation’s assumptions and do not incorporate adjustment for multiple outcomes or comparisons.

Why do the sponsor results and recalculations differ?

The sponsor reports ANCOVA analyses for the primary comparisons, with p-values of 0.555 for A-101 Solution 40 versus vehicle and 0.009 for A-101 Solution 45 versus vehicle. The recalculated unadjusted p-values are 0.776 and 0.019, respectively. These are not competing estimates from identical methods: the sponsor’s results are from the stated adjusted analysis, whereas the recalculations use summary statistics and do not include the baseline covariate. The record flags a discrepancy, so the sponsor’s own analysis takes precedence. The registry does not provide enough detail to reconstruct the ANCOVA or determine exactly which analysis choices account for the differences.

What does standard deviation add?

The primary group summaries report standard deviations of 0.75, 0.97, and 0.85 units for A-101 Solution 40, A-101 Solution 45, and vehicle, respectively. In general, a standard deviation describes the spread of participant-level values around a group mean. It is not the same as the standard error, which describes uncertainty in an estimated mean or contrast, and it is not a range containing every participant’s result. The standard deviations help show that individual changes varied within each group, but they do not reveal the shape of the distributions or the presence of outliers.

How should the responder analysis be understood?

PWA responder is a binary outcome, reported as a percentage of responders at Day 57. The record gives group percentages and reports chi-squared tests for comparisons with vehicle. In general, a chi-squared test evaluates whether categorical outcome proportions differ between groups under the test’s assumptions. The responder definition itself is not described in the available record, and the group counts behind the percentages are small. Thus, the secondary results should be interpreted as a separate, categorical analysis rather than as another expression of the continuous mean-change endpoint.

The recalculated binary comparisons use risk differences from posted counts and percentages. A risk difference expresses the difference between group response proportions; it is not a ratio. The recalculated p-values for these comparisons are unadjusted and need not match the sponsor’s chi-squared results. For the secondary comparisons, the sponsor reports chi-squared p-values of 0.931 and 0.024, while the recalculated values are 0.903 and 0.02. As with the primary outcome, the sponsor’s own reported analysis takes precedence where the record flags a discrepancy.

For every method, the registry’s reporting limits what can be checked independently. It does not provide the full statistical analysis plan, complete model output, all assumptions diagnostics, or a detailed account of how missing observations were treated. Statistical methods are useful only in relation to their assumptions and the analysis population; they do not remove uncertainty from limited sample sizes or incomplete reporting.

11. Confidence Intervals and Precision

Precision concerns how tightly an estimate is determined by the data. The recalculated mean difference for A-101 Solution 40 versus vehicle is 0.06 units, with an interval from -0.353 to 0.473. The interval covers both negative and positive differences, so the summary-based comparison is compatible with more than one direction of contrast. The estimate itself is close to zero, but its interval makes clear that the data do not pin down the difference closely.

For A-101 Solution 45 versus vehicle, the recalculated mean difference is -0.56 units, with an interval from -1.028 to -0.092. This interval is entirely negative, but it still spans a range of possible magnitudes. It is an unadjusted interval calculated from posted summaries; it is not the interval from the sponsor’s ANCOVA analysis. The registry record reports no interval for the sponsor’s ANCOVA estimates, so the precision of those adjusted effects cannot be assessed from the reported p-values alone.

In general, an interval is more informative than a point estimate alone because it communicates uncertainty about the magnitude and direction of an effect. Its interpretation depends on the method and assumptions used to construct it. The confidence level for the recalculated intervals is not stated in the registry record, and no confidence interval is reported for the sponsor’s analyses. These omissions limit direct interpretation of interval coverage and precision.

The group sizes for the primary summaries are 32, 31, and 27. The standard deviations indicate variability in participant changes, while the intervals reflect uncertainty in the recalculated group contrasts. Neither the p-value nor whether an interval crosses zero tells whether a difference is clinically important. The registry record does not state a threshold for a clinically meaningful PWA change. Consequently, statistical precision and clinical relevance cannot be equated using these results alone.

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 illustrations based on the observed effect, not a report of the trial’s original design calculation. For these continuous two-group comparisons, the displayed figures are participants per arm, not total participants or total events. The planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. Each scenario uses the stated fraction of the observed effect as the effect to detect. The original sample-size assumptions for this trial are not reported in the registry record.

The 80% power column gives the planned participants per arm under those assumptions for a design with an 80% chance of detecting the specified effect if that effect is real and the assumptions hold. The 90% power column uses a higher target chance of detection, which generally requires more participants. For example, using the full observed A-101 Solution 45 effect gives 43 participants per arm for 80% power and 57 for 90% power; planning for 75% of that observed effect gives 75 and 101, respectively. These are planning illustrations, not observed power.

Rows planning for a smaller fraction of the observed effect require more participants because smaller differences are harder to distinguish from random variation. The calculations use the observed effect as their starting point, and observed effects from small studies can be uncertain. They should therefore be read as conditional illustrations, not as evidence that the observed effect will recur or as a recommendation for a future study’s design.

The accompanying curve should be interpreted in the same planning context: it relates a chosen effect size to the required group size under the stated assumptions. It does not represent the actual enrollment or the trial’s achieved probability of success. The original design rationale and the trial’s own target power are not reported in the registry record.

13. How the Sample Size Is Derived

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

Formula

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

Worked calculation for this trial

1. Observed difference Δ = 0.060; pooled standard deviation σ = 0.797.
2. n = 2 × (1.96 + 0.842)² × 0.797² / 0.060² = 2,771.0, rounded up to 2,772 participants per arm for 80% power.

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

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- 0.06                      # observed difference in means
sigma <- 0.797171534953645                     # 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(2669862)
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 = 2,772 (80% power), 3,710 (90% power)
 75% of observed effect: n per arm = 4,927 (80% power), 6,595 (90% power)
 50% of observed effect: n per arm = 11,085 (80% power), 14,839 (90% power)
power.t.test: 2772 
Simulated power at n = 2,772 per arm: 0.795 (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 registry record reports the sponsor’s primary comparisons using ANCOVA, as specified in the primary endpoint description. The reported p-value is 0.555 for A-101 Solution 40 versus vehicle and 0.009 for A-101 Solution 45 versus vehicle. For PWA responder, the sponsor reports chi-squared p-values of 0.931 for A-101 Solution 40 versus vehicle and 0.024 for A-101 Solution 45 versus vehicle.

The recalculated comparisons are simple, unadjusted analyses of posted summary statistics. For the primary endpoint, their p-values are 0.776 and 0.019; for PWA responder, they are 0.903 and 0.02. Differences between those values and the sponsor’s results are expected to be possible because the methods and, potentially, analysis details differ. The recalculation does not reproduce the primary ANCOVA.

The record identifies a discrepancy. Under that circumstance, the sponsor’s own analysis takes precedence over the simple recalculation. This does not make every aspect of the sponsor analysis independently verifiable: the registry does not report the adjusted effect estimates, confidence intervals, or complete model details. The recalculated effect estimates and intervals remain useful as descriptive, unadjusted checks of the posted summaries, but they should not be presented as the trial’s primary adjusted results.

15. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when a study evaluates multiple outcomes, treatment comparisons, time points, or statistical tests. In general, conducting more tests can increase the chance that at least one result appears statistically notable by chance, even when no corresponding effect exists. Prespecifying a primary endpoint and an analysis hierarchy can help readers distinguish the main confirmatory question from secondary or exploratory questions. The registry record identifies a primary endpoint and lists secondary outcomes, but it does not report a multiplicity adjustment, testing hierarchy, or detailed plan for interpreting results across all outcomes and comparisons.

The record lists three outcome measures and four analyses. It identifies PWA responder and durability of response among the secondary outcomes. The available numerical results include the primary comparisons and PWA responder comparisons; numerical results for durability are not reported in the registry record. The record does not explain whether all planned outcomes were reported, how analyses were selected for posting, or whether any analyses were added after the study began. These details should not be inferred.

Missing-data methods are also important because the primary analysis population is described as participants completing the protocol through Visit 10. That definition indicates a completion-based analysis population, but the registry record does not report how many participants discontinued, why they discontinued, or how missing Visit 10 assessments were treated. It does not state whether an intention-to-treat analysis was performed or whether imputation or another missing-data method was used. Without those details, the potential influence of incomplete follow-up on the primary estimate cannot be assessed fully.

The primary outcome summaries and the safety summaries use different reported group counts. The record does not provide enough participant-flow detail to reconcile those analysis populations, so their counts should not be treated as interchangeable. More generally, the available record does not report a full protocol or statistical analysis plan, interim analysis details, or the original sample-size justification. These gaps constrain assessment of prespecification, analysis populations, and the scope of statistical claims.

16. 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 5% reporting threshold.

Most frequent non-serious adverse event terms

The safety record lists serious adverse events for each group, with zero serious events in the A-101 Solution 40 group, zero in the A-101 Solution 45 group, and zero in the Vehicle Solution group. It also reports zero deaths in each group. The corresponding serious-event risk sets are 33, 34, and 31. No serious adverse event terms are listed.

These figures describe what was recorded in the registry safety summaries; they do not establish that no safety concerns occurred. The record reports other adverse events affecting 8 participants in the A-101 Solution 40 group, 6 in the A-101 Solution 45 group, and 10 in the Vehicle Solution group, but those counts are not serious adverse event counts. The information does not give event types, severity, relatedness, or timing for those other events.

The safety groups’ risk sets differ from the primary outcome analysis counts. The registry record does not explain the difference or provide enough participant-flow detail to reconcile them. A lack of reported serious events in these groups should be interpreted within the recorded trial and its follow-up, not generalized beyond it. The safety figures alone do not characterize every possible risk or establish comparative safety.

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

The posted results describe group-level changes in a wart assessment score and the proportion classified as PWA responders at Day 57. In the primary summaries, the 45% group had a more negative mean change than vehicle, whereas the 40% group’s mean change was close to the vehicle mean. The recalculated unadjusted comparison for the 45% group has an interval below zero; the interval for the 40% group includes differences in both directions. The sponsor’s reported ANCOVA p-values are the primary adjusted results and take precedence over the recalculations because the record identifies a discrepancy.

These findings do not, by themselves, establish the size of a clinically important benefit. The registry record does not state a threshold for meaningful change on the PWA scale, and p-values do not measure clinical importance. The sponsor’s adjusted effect estimates and confidence intervals are not reported, which limits assessment of the magnitude and precision of the primary adjusted comparisons. The recalculated estimates are not substitutes for those missing adjusted quantities.

The results also do not establish outcomes beyond the trial’s reported measures and timeframe. PWA responder was assessed at Day 57, and durability was defined in relation to Visit 10 and Visit 13, but numerical durability results are not reported in the registry record. The posted summaries do not show every participant’s trajectory or provide a complete account of missing observations. They cannot answer questions about longer-term outcomes or other populations not represented by this study.

Randomization, masking, and a vehicle comparator are features that support a controlled comparison, but they do not resolve every uncertainty. The registry record does not include the complete protocol, detailed analysis plan, or full information about attrition, missing-data handling, and multiplicity. The result should therefore be read as evidence from this particular completed Phase 2 study, with the reported methods and limitations, rather than as a stand-alone conclusion about all settings or outcomes.

18. Why This Trial Matters Statistically

This trial is statistically useful as an example of why the analysis method matters. The registry describes ANCOVA with Visit 2 PWA as a covariate for the primary endpoint, while simple recalculations from posted summaries compare group means without that adjustment. The two approaches answer related but not identical statistical questions and produce different p-values. Readers should distinguish the sponsor’s adjusted analysis from an unadjusted check rather than treating every reported number as interchangeable.

The trial also illustrates why effect estimates and precision deserve attention alongside tests of statistical significance. A p-value does not show how large a difference is or how narrowly it has been estimated. The recalculated mean differences and intervals help describe the size and uncertainty of the unadjusted contrasts, while the absence of reported adjusted effect estimates and intervals limits evaluation of the primary ANCOVA results.

Another important issue is the relationship between a continuous endpoint and a responder endpoint. Mean change in PWA preserves variation in the score; responder status summarizes outcomes by category. Their patterns can be compared for context, but they are not interchangeable, and the registry does not report the responder definition. The secondary results also raise the general issue of multiplicity: without a reported adjustment or hierarchy, secondary p-values carry less confirmatory weight.

Finally, the record shows how reporting detail affects reproducibility. It identifies the broad design and primary method but does not provide the complete analysis plan, missing-data procedures, or original sample-size rationale. Those omissions do not erase the reported findings; they define how confidently readers can evaluate the analyses and their scope.

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 record leaves important details about the primary analysis unavailable. It names ANCOVA and the Visit 2 covariate but does not report the adjusted effect estimates, confidence intervals, full model specification, or diagnostics. Because the recalculated contrasts are unadjusted, they cannot fill those gaps. The record flags a discrepancy between recalculations and the sponsor’s analysis, making the sponsor results the appropriate primary reference while limiting independent verification.

The analysis population is described as participants who completed the protocol through Visit 10. Participant flow, reasons for non-completion, and handling of missing assessments are not reported in the registry record. The primary summaries also have group counts that differ from those in the safety summaries, and the record does not reconcile them. This makes it difficult to assess whether incomplete follow-up could affect the outcome summaries.

The registry does not report the original sample-size justification, the intended detectable effect, or the study’s planned power. Planning illustrations based on observed effects do not reveal the design assumptions used when the trial was initiated. The record also does not report whether interim analyses occurred or describe a detailed statistical analysis plan.

Several endpoint details are limited. The definition of PWA responder is not reported in the registry record, and numerical results for durability of response are not reported. The confidence level for recalculated intervals is not specified in the comparison information, and adjusted intervals for the sponsor analyses are absent. The registry does not state a clinically meaningful threshold for change in PWA or explain how multiple outcomes and comparisons were addressed.

Finally, the available safety summary gives event counts but not detailed event descriptions, severity, relatedness, or timing for other adverse events. These reporting limitations mean the results can describe the recorded comparisons, but cannot fully characterize all aspects of efficacy, safety, or bias in the trial.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: A Study of A-101 Solution in Subjects With Common Warts. — NCT02669862.
• Registry record last updated 2018-12-07; status last verified 2018-11.
• Results first posted 2018-12-07.
• 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

NCT02669862 is a completed Phase 2 randomized, double-blind, vehicle-controlled, parallel-group study of A-101 Solution 40, A-101 Solution 45, and Vehicle Solution in participants with common warts. Enrollment was 98. The recorded start date is 2015-12-21, and primary completion was 2016-09-16. Each solution was administered once per week.

The primary endpoint was mean change in Physician Wart Assessment from Visit 2 to Visit 10 over 57 Days, with ANCOVA using Visit 2 PWA as a covariate described as the intended primary analysis. The sponsor reported ANCOVA p-values for both comparisons with vehicle; simple recalculations from posted summaries differ, and the sponsor’s own analysis takes precedence. The secondary outcomes include PWA responder and durability of response, although numerical durability results are not reported in the registry record.

The record does not report the full analysis plan, original sample-size justification, multiplicity procedures, or missing-data handling. These limitations should accompany interpretation of the posted results.