Safety and Efficacy Study of Photodynamic Therapy With Levulan Kerastick + Blue Light for Actinic Keratoses on the Upper Extremities: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Safety and Efficacy Study of Photodynamic Therapy With Levulan Kerastick + Blue Light for Actinic Keratoses on the Upper Extremities (NCT02137785), a randomized phase 3 study. The primary outcome is Complete Clearance Rate.

2. Clinical Question

The clinical question is whether the observed complete-clearance outcome differed between the ALA-PDT and vehicle groups under the study conditions. It is a comparison of group results, not a measure of how much an individual participant’s lesion count changed. The outcome’s definition is specific: a participant counts as completely clear only when the treatment area has zero lesions at the stated assessment.

The registry records 269 participants and identifies the primary analysis population as ITT. It does not report further details about the population’s age, sex, disease severity, or prior treatments. The results therefore describe the trial groups as recorded, without establishing how closely those groups represent people outside the study.

3. Trial Design

This was a completed phase 3, randomized, double-masked, parallel-group study sponsored by DUSA Pharmaceuticals, Inc. The registry records a start in 2014-05 and primary completion in 2015-03. Enrollment was 269 participants. These design features describe how the trial was classified in the registry; further details about the randomization procedure, masking procedures, or allocation concealment are not reported in the registry record.

The study compared ALA-PDT with topical solution vehicle, with blue-light photodynamic therapy used in both groups as described by the official title. The intervention list names aminolevulinic acid, topical solution vehicle, and the BLU-U illuminator. The posted arm descriptions do not add details about how the treatments were administered. The registry’s stated purpose was to assess safety and efficacy for actinic keratoses on the upper arms and hands.

The primary endpoint was complete clearance at Week 12, defined as zero lesions in the treatment area. The primary result is reported for the ITT population. The posted results include counts for the two arms and a reported superiority analysis using the Cochran-Mantel-Haenszel method. The registry also reports a lesion-clearance outcome at Week 12 and a complete-clearance outcome at Week 8.

The original sample-size justification, the trial’s planned statistical analysis details, and any interim analyses are not reported in the registry record. The planning illustrations calculated from the observed results are separate from the original design rationale and should not be read as evidence about what assumptions guided enrollment.

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: 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

6. Primary Endpoint

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

Complete clearance at Week 12 is a binary participant-level endpoint: each participant either had zero lesions in the treatment area at that assessment or did not. The registry reports the number of participants meeting the definition in each group. In the ALA-PDT group, 42 of 135 participants met it; in the Vehicle group, 17 of 134 did. The corresponding posted proportions are 0.311 and 0.127.

This endpoint is used to express whether the treatment area was lesion-free at a specified follow-up, rather than to summarize partial reduction in lesion counts. That makes its interpretation direct, while also making it a demanding threshold: a participant with remaining lesions does not meet the complete-clearance definition, regardless of how many lesions may have cleared. The registry does not report a separate endpoint definition for the amount of change required to count as partial improvement.

The risk difference for ALA-PDT versus Vehicle is 0.184, with interval limits of 0.088 and 0.281. In plain terms, the estimate compares the observed proportions meeting the endpoint, and the interval communicates uncertainty around that contrast. The endpoint does not by itself describe durability beyond Week 12, changes in symptoms, or outcomes beyond the treatment area; those matters are not reported in the registry record.

7. Results Posted in the Registry

• ALA-PDT: 31.1% (42/135) versus 12.7% (17/134) on control; risk difference 18.4 percentage points (95% CI 8.8 to 28.1), risk ratio 2.45 (1.47–4.08); unadjusted two-proportion z-test p = <0.001.

8. Secondary Efficacy Endpoints

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

AK Clearance Rate

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • ALA-PDT: mean 69.10 versus 29.90 on control; difference 39.20 (95% CI 28.29 to 50.11), standardized effect d = 0.87; z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically higher for ALA-PDT than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Complete Clearance Rate

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • ALA-PDT: 25.9% (35/135) versus 9.0% (12/134) on control; risk difference 17.0 percentage points (95% CI 8.1 to 25.8), risk ratio 2.90 (1.57–5.33); unadjusted two-proportion z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically higher for ALA-PDT than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The secondary results broadly follow the direction of the primary result: the posted ALA-PDT group values are higher than the Vehicle values for the additional clearance outcomes. The Week 12 AK clearance rate is reported as a mean percentage of baseline lesions cleared, and the other detailed secondary result is complete clearance at Week 8. These outcomes are related to the primary endpoint because they also describe lesion clearance, but they measure different features or assess a different timepoint. They are not interchangeable replications of the Week 12 complete-clearance endpoint.

The registry lists AK Clearance Rate, Complete Clearance Rate, and Subject Satisfaction Score among secondary outcomes, with some outcome names repeated. It reports four secondary outcomes, while detailed numerical results are available for two of them in the record. A numerical result for subject satisfaction is not reported in the registry record. No additional interpretation of an unreported result is warranted.

The sponsor reports p < 0.001 for the Week 12 clearance-rate analysis using Mixed Models Analysis, and p< 0.001 for the Week 8 complete-clearance analysis using Cochran-Mantel-Haenszel. The unadjusted recalculations also report p-values below 0.001 for those comparisons. These results are supportive descriptions of the posted secondary outcomes, but they do not change which endpoint is primary.

Multiplicity matters because evaluating several outcomes creates more opportunities for a nominally small p-value to occur by chance. Whether and how the trial controlled that issue is not reported in the registry record. Accordingly, unadjusted secondary findings carry less confirmatory weight than the primary result and should be treated as additional evidence to interpret cautiously, rather than as independent proof of multiple distinct effects.

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

• AK Clearance Rate
• AK Clearance Rate
• Complete Clearance Rate
• Subject Satisfaction Score

9. Statistical Interpretation

10. Statistical Methods Explained

The main outcomes use different statistical scales. Complete clearance is binary because each participant either met the zero-lesion criterion or did not. The lesion-clearance outcome is continuous because it is reported as a percentage of baseline lesions cleared, summarized by a mean and standard deviation. The analysis method and interpretation should follow the type of outcome rather than treating all outcomes as interchangeable.

How should a risk difference be read?

For a binary outcome, a risk difference subtracts the proportion meeting the endpoint in one group from the proportion in the other. The posted primary comparison is expressed as ALA-PDT versus Vehicle. Its recalculated risk difference is 0.184. A positive value in this comparison means that the observed proportion meeting the endpoint was higher in the ALA-PDT group. The interval limits, 0.088 and 0.281, describe uncertainty around this estimated difference. General explanation: unlike a relative measure, a risk difference stays on the same absolute-proportion scale as the outcome itself.

What do the relative measures add?

The registry also posts a relative risk of 2.452, with interval limits of 1.472 and 4.085, and an odds ratio of 3.108, with interval limits of 1.662 and 5.811. These express the contrast on relative scales rather than as a difference between proportions. General explanation: a relative risk compares the probabilities of an event, while an odds ratio compares event odds. They answer related but distinct questions, and neither replaces the directly interpretable risk difference. The odds ratio can differ substantially in its numerical value from the relative risk when an outcome is not rare.

What does the sponsor’s method do?

The reported primary analysis is Cochran-Mantel-Haenszel. General explanation: this method can combine evidence from comparisons organized into strata. The registry does not report the strata, the variables used to define them, or the details of the sponsor’s calculation, so the exact role of any stratification cannot be described. The posted unadjusted recalculation instead compares the two groups using the summary counts. It is a straightforward calculation from the posted arm results, not a replacement for the sponsor’s own analysis.

How should the continuous outcome be read?

For the Week 12 AK clearance rate, the outcome is the percentage of baseline lesions cleared. The ALA-PDT mean is 69.1 with standard deviation 37.4 among 132 participants; the Vehicle mean is 29.9 with standard deviation 51.5 among 130 participants. The recalculated mean difference is 39.2, with interval limits of 28.29 and 50.11. General explanation: a mean difference expresses the contrast in the outcome’s original units, while the standard deviation describes variation among participant values within a group. A larger standard deviation indicates greater spread in those observed values, not greater uncertainty in the mean by itself.

The sponsor’s reported method for the Week 12 continuous outcome is Mixed Models Analysis, with p < 0.001. General explanation: mixed models can represent structured or correlated observations, depending on how a model is specified. The model structure, included terms, and handling of repeated observations are not reported in the registry record. The posted unadjusted mean-difference calculation uses group-level summary statistics and should be distinguished from that sponsor analysis.

What does a p-value say?

General explanation: a p-value measures how incompatible the observed data are with a specified null model, under the assumptions of the analysis. It is not the probability that the null hypothesis is true, nor a measure of the size or practical importance of an effect. The primary unadjusted recalculation reports p < 0.001; the sponsor reports p< 0.001. Both are evidence against a no-difference null under their respective analyses, but neither p-value describes the range of plausible effect sizes. The interval and the observed group results add information about magnitude and precision.

For Week 8 complete clearance, the posted counts are 35 of 135 for ALA-PDT and 12 of 134 for Vehicle. Its unadjusted risk difference is 0.170, with interval limits of 0.081 and 0.258, and the unadjusted p-value is <0.001. The sponsor’s reported method is again Cochran-Mantel-Haenszel, with p< 0.001. These are secondary results and should be interpreted with the multiplicity and reporting limitations described elsewhere in the registry record.

11. Confidence Intervals and Precision

The primary risk-difference estimate is 0.184, with interval limits of 0.088 and 0.281. The interval is a way to express how much uncertainty remains around an estimate based on a finite group of participants. General explanation: an interval procedure produces a range of values that would be compatible with the observed data under its statistical assumptions. A narrower interval generally indicates greater precision than a wider interval, but precision is not the same as freedom from bias or certainty about an individual outcome.

The registry does not report the confidence level for the recalculated intervals. The interval limits should therefore be read as the posted limits, without assigning them a confidence percentage that is not stated. The registry also does not report whether the sponsor’s reported analysis has an effect estimate or interval; only its method and p-value are posted for the primary comparison.

The Week 12 mean difference in percentage of baseline lesions cleared is 39.2, with interval limits of 28.29 and 50.11. The Week 8 risk-difference estimate is 0.170, with limits of 0.081 and 0.258. These intervals concern different endpoints and timepoints, so their widths should not be compared as if they measured uncertainty on the same scale. The binary outcomes are expressed as differences in proportions, while the continuous outcome is expressed in percentage points of baseline lesions cleared.

Interval estimates do not account automatically for every limitation. For example, they do not resolve uncertainty about missing-data handling, analysis choices, or the clinical meaning of the endpoint. Those details are not reported in the registry record. The observed counts and summary values remain important context for interpreting the estimates and their precision.

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 estimates are participants per arm, not total participants across the trial and not total events. The assumptions listed for these illustrations are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Each row considers detecting the stated fraction of the observed effect. The trial’s own original design assumptions and sample-size justification are not reported in the registry record.

For the primary complete-clearance comparison, planning for 100% of the observed effect gives 78 participants per arm for 80% power and 104 participants per arm for 90% power. Planning for 75% of the observed effect gives 129 participants per arm for 80% power and 172 participants per arm for 90% power. Planning for 50% of the observed effect gives 264 participants per arm for 80% power and 353 participants per arm for 90% power.

In general, power is the chance that a study will detect an effect of the specified size under the stated assumptions if that effect is present. The 80% power column and 90% power column therefore describe different target chances of detecting the chosen effect; the higher target generally requires more participants. The smaller-effect rows require more participants because a subtler difference is harder to distinguish from random variation. The curve expresses this same planning relationship across effect sizes, rather than reporting outcomes observed during the trial.

These figures are planning illustrations based on the observed effect and are not observed power. They do not establish the trial’s original rationale, and they should not be interpreted as a retrospective judgment about whether the trial was adequately designed. The displayed assumptions are specific to the illustration; the registry record does not report whether they match the original protocol.

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, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.127; treatment proportion p₁ = 0.311; average p̄ = 0.219.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.5849 = 1.1463.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.5702 = 0.4799.
4. n = (1.1463 + 0.4799)² / (0.1842)² = 77.9, rounded up to 78 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 <- 0.126865671641791                          # control proportion
p1 <- 0.311111111111111                          # 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(2137785)
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 = 78 (80% power), 104 (90% power)
 75% of observed effect: n per arm = 129 (80% power), 172 (90% power)
 50% of observed effect: n per arm = 264 (80% power), 353 (90% power)
power.prop.test: 77.9 
Simulated power at n = 78 per arm: 0.810 (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

For the primary comparison, the sponsor reports a Cochran-Mantel-Haenszel analysis with p< 0.001. For the unadjusted recalculation, the risk difference is 0.184, with interval limits of 0.088 and 0.281, and p < 0.001. The sponsor’s reported analysis and the recalculation point in the same direction: the observed complete-clearance proportion is higher in the ALA-PDT group.

The two p-values should not be treated as though they came from the same calculation. The sponsor’s method is named as Cochran-Mantel-Haenszel, while the recalculation is an unadjusted comparison from the posted summary counts. The registry does not report the detailed model specifications or other analysis details that would explain the numerical difference between the p-values. The registry does not flag a discrepancy. If a discrepancy were identified, the sponsor’s own analysis would take precedence over this simple unadjusted recalculation.

The registry reports no sponsor effect estimate or interval for the primary analysis; it gives the method and p-value. The recalculated risk difference and interval add an absolute-scale summary derived from the posted arm counts. They complement, rather than replace, the sponsor’s analysis. The sponsor’s secondary analyses are also reported by method and p-value, while the posted recalculations provide unadjusted contrasts based on summary statistics.

15. Multiplicity, Missing Data and Analysis Populations

The primary outcome is identified as complete clearance at Week 12, and its population is ITT. The registry also lists multiple secondary outcomes and reports several analyses. It does not report a multiplicity adjustment or a prespecified hierarchy for interpreting the secondary outcomes. Without those details, the degree to which testing across outcomes was accounted for cannot be determined from the registry record.

General explanation: when many outcomes or comparisons are examined, the chance of finding at least one apparently unusual result can increase. Adjustment procedures or a planned testing hierarchy can address that issue, but the registry does not state whether such procedures were used. The reported secondary p-values are therefore best read as unadjusted evidence unless the record documents otherwise; a multiplicity-adjusted interpretation is not reported.

The primary endpoint is marked ITT, but details about how the analysis population was defined and how participants with missing Week 12 measurements were handled are not reported in the registry record. The amount and pattern of missing outcome data, any imputation method, and any sensitivity analyses are also not reported. These omissions limit assessment of whether missing observations could affect the estimates.

Randomization and double masking are recorded, but further details of their implementation are not reported. The registry names the sponsor’s methods and p-values but does not provide a complete statistical analysis plan, including model specifications or the exact handling of analysis strata. Interim analyses and stopping rules are not reported in the registry record. These are limits on what can be concluded about the analysis process, not evidence that a particular procedure was or was not used.

The registry does not report the original sample-size calculation or its assumptions. The separate planning illustrations are derived from observed results and cannot fill that gap. Taken together, the missing analysis details mean that the posted results can be described and compared, but some aspects of their prespecification, robustness, and handling of incomplete data cannot be evaluated from the record.

16. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 3% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: dyspnoea (1.5%), iron deficiency anaemia (0.7%), pancreatitis (0.7%), angina unstable (0.7%), atrial fibrillation (0.7%).

The registry reports serious adverse events affecting 5 of 135 participants in the ALA-PDT group and 2 of 134 in the Vehicle group. Other adverse events affected 6 participants in each group, with 135 at risk in ALA-PDT and 134 at risk in Vehicle. These are participant counts in the posted safety results; they do not describe event duration, severity beyond the serious classification, or whether an event was considered related to treatment.

The listed serious adverse-event terms include Dyspnoea at 1.5%, and Iron Deficiency Anaemia, Pancreatitis, Angina Unstable, Atrial Fibrillation, and Chest Pressure at 0.7% each. The registry does not provide an arm-specific breakdown for those terms in the information. The death fields have no reported values, so deaths are not reported in the registry record; that should not be read as a reported count of zero.

These figures describe the safety events recorded during the study, but the registry does not report further detail about event collection, follow-up duration, attribution, or comparative statistical testing. Counts alone do not establish whether an observed difference is meaningful or caused by an intervention. They should be read as descriptive safety information alongside the limits of the posted record.

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

The results show a higher observed proportion of participants with zero lesions in the treatment area at Week 12 in the ALA-PDT group than in the Vehicle group. The primary unadjusted risk-difference estimate is 0.184, with interval limits of 0.088 and 0.281. This is evidence about the specified endpoint in these randomized groups, under the analyses described in the registry.

The result does not establish that every participant in the ALA-PDT group achieved complete clearance, or that any individual participant would have a particular outcome. It also does not establish how long clearance might last, whether lesions later recur, or what happens beyond the treatment area. Those outcomes are not reported in the registry record. The secondary clearance measures add information about other aspects of lesion clearance but do not answer those unreported questions.

The p-values indicate statistical evidence against a no-difference null under the respective analyses; they do not measure the importance of the observed contrast or the probability that a treatment is beneficial. The registry does not report a threshold for a clinically important difference. The interval quantifies uncertainty in the estimated contrast under its calculation, but does not account for all possible limitations in trial conduct or reporting.

The study concerns actinic keratoses on the upper extremities and compares ALA-PDT with vehicle under the recorded study conditions. The results do not by themselves establish whether the findings apply to other populations, settings, treatment schedules, or outcomes. Additional population and protocol details are not reported in the registry record.

These distinctions keep the conclusion tied to what was measured: a group-level difference in Week 12 complete clearance, with supporting posted clearance outcomes and limited posted safety information. The data do not support a guarantee of response, a statement about longer-term outcomes, or individualized medical guidance.

18. Why This Trial Matters Statistically

This trial illustrates why an endpoint’s definition matters. Complete clearance is not a general measure of improvement: it requires zero lesions in the treatment area at the specified assessment. The participant counts and proportions therefore answer a precise question, while the separate mean clearance outcome answers a broader question about the percentage of baseline lesions cleared.

It also demonstrates the value of stating an absolute contrast alongside p-values. The risk difference of 0.184 expresses the observed primary contrast on the scale of the outcome, and its interval limits show uncertainty around that estimate. A small p-value alone would not communicate the size or precision of the difference. Conversely, an estimate should not be treated as certain simply because its p-value is small.

The sponsor’s named analysis and the unadjusted recalculation illustrate how analysis methods can yield different numerical summaries while indicating the same direction in the posted results. Clear reporting of the sponsor’s effect estimate, interval, model details, missing-data handling, and multiplicity approach would make the analysis easier to assess. Those details are not reported in the registry record.

Finally, planning illustrations based on an observed effect are distinct from an original design justification. Their assumptions and per-arm interpretation can help readers understand how sample-size needs vary with target effect size and power, but they do not reconstruct the trial’s original planning. Keeping design assumptions, observed results, and recalculated planning scenarios separate is essential to sound statistical interpretation.

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.

Several trial-specific details needed for a fuller assessment are not reported in the registry record. These include participant characteristics and further eligibility criteria, the randomization and masking procedures, the full treatment administration details, and the original sample-size justification. The registry identifies the study as randomized and double-masked, but those labels alone do not describe how those procedures were implemented.

The primary endpoint is reported for the ITT population, but the definition of that population and the handling of missing Week 12 measurements are not reported. Missing-data counts, methods for incomplete outcomes, and sensitivity analyses are also not reported. The registry does not provide enough information to assess how these issues could affect the estimates.

For the sponsor’s primary analysis, the method and p-value are reported, but an effect estimate and interval are not. The details of the Cochran-Mantel-Haenszel analysis, including any strata, are not reported. The continuous secondary analysis is named Mixed Models Analysis, but its specification is not reported. Multiplicity procedures and the analysis hierarchy are not reported either, which limits the confirmatory interpretation of secondary findings.

The record lists subject satisfaction among the secondary outcomes, but a numerical result for it is not reported in the registry record. The safety information includes serious and other adverse-event counts and selected serious-event terms, but details about attribution, follow-up, and arm-specific term counts are not reported. Death values are not reported. These limitations constrain what can be inferred from the posted efficacy and safety results, without implying that unreported procedures were not performed.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Safety and Efficacy Study of Photodynamic Therapy With Levulan Kerastick + Blue Light for Actinic Keratoses on the Upper Extremities — NCT02137785.
• Registry record last updated 2015-09-16; status last verified 2015-08.
• Results first posted 2015-09-16.
• 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

The registry record describes a completed phase 3, randomized, double-masked, parallel-group study of ALA-PDT versus topical solution vehicle with blue-light photodynamic therapy for actinic keratoses on the upper extremities. It records 269 participants, a study start in 2014-05, and primary completion in 2015-03. The primary outcome was complete clearance at Week 12, defined as zero lesions in the treatment area, in the ITT population.

At Week 12, 42 of 135 participants in ALA-PDT and 17 of 134 in Vehicle met the complete-clearance definition. The unadjusted risk difference is 0.184, with interval limits of 0.088 and 0.281; the sponsor reports a Cochran-Mantel-Haenszel p-value of < 0.001. Secondary results describe lesion clearance at Week 12 and complete clearance at Week 8. The record also contains limited adverse-event counts. Several details about analysis planning, missing data, multiplicity, and safety follow-up are not reported in the registry record.