Study to Evaluate the Safety, Tolerability and Efficacy of BF-200 ALA (Ameluz®) in the Field-directed Treatment of Actinic Keratosis (AK) on the Extremities and Neck/Trunk With Photodynamic Therapy (PDT) Using a RhodoLED Lamp: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study to Evaluate the Safety, Tolerability and Efficacy of BF-200 ALA (Ameluz®) in the Field-directed Treatment of Actinic Keratosis (AK) on the Extremities and Neck/Trunk With Photodynamic Therapy (PDT) Using a RhodoLED Lamp (NCT05662202), a randomized phase 3 study. The primary outcome is Overall Subject Complete Response Rate.

2. Clinical Question

This is a comparison of treatment strategies, not a comparison of BF-200 ALA alone against no treatment: both groups received photodynamic therapy. The registry describes a randomized, vehicle-controlled study, so the intended contrast is the addition of active topical treatment within the same general light-treatment approach. The primary outcome is participant-based: a participant counted as a complete response only if all target lesions were clinically clear at the specified assessment. This differs from a lesion-level outcome, which counts individual lesions, and from a measure of partial improvement.

The trial enrolled 172 participants. The registry lists actinic keratoses as the condition and describes treatment of lesions on the extremities and neck/trunk. A separate secondary outcome concerns participants with lesions treated on the extremities. The registry record does not report a corresponding numerical result for every outcome named in its record, so the main numerical comparison is the overall participant-level endpoint.

3. Trial Design

The registry classifies the study as phase III, randomized, parallel-group, and quadruple-masked. Its official title describes it as double-blind. Both groups received topical treatment followed by red-light photodynamic therapy: one group received BF-200 ALA and the other vehicle. The planned comparison therefore concerns the treatment packages as assigned, with vehicle plus the same general photodynamic approach serving as the control.

Enrollment was 172. The registry reports 136 participants in the BF-200 ALA group and 36 in the vehicle group for the primary outcome. The study is listed as completed. Its start date is 2022-12-12, and its primary completion date is 2025-09-03. The title identifies a multicenter study and specifies use of the BF-RhodoLED XL or BF-RhodoLED lamp. Details such as the number of centers and how participants were allocated among them are not reported in the registry record.

The primary endpoint was assessed 12 weeks after the last photodynamic treatment, at Visit 4 or Visit 6. The registry describes secondary outcomes including responses for lesions treated on the extremities and neck/trunk, lesion-level response, severe-lesion response, response after the first photodynamic treatment, and investigator-assessed esthetic appearance. It lists 26 outcome measures and 17 posted secondary outcomes. The registry record does not report the full protocol, the original statistical analysis plan, the allocation ratio as a design specification, or details of how masking was maintained. The title and masking classification use different descriptions; the record does not explain that difference.

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:

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: Participants were randomized to the treatment arms in 4:1 ratio.

6. Primary Endpoint

The registry lists the primary outcome as Overall Subject Complete Response Rate, measured over 12 weeks after the last PDT (Visit 4 or Visit 6).

The primary endpoint is the overall subject complete response rate, measured 12 weeks after the last photodynamic treatment. A participant is counted as a complete response when all actinic keratosis target lesions are clinically clear. The endpoint is therefore a binary participant-level outcome: each participant is classified as having achieved complete response or not. It does not count how many individual lesions cleared, and it does not distinguish partial clearance from no clearance.

A participant-level measure can answer whether the treatment course was followed by complete clearance across that participant’s target lesions. This is distinct from a lesion-level response rate, where each lesion contributes separately; the registry lists lesion-level response as a secondary outcome. The chosen assessment is tied to a defined point after the final photodynamic treatment, at Visit 4 or Visit 6, rather than to a continuous measure over time. The registry record does not report further operational detail about clinical assessment, assessor procedures, or rules for handling participants whose status could not be determined.

In the posted primary results, 62 of 136 participants in the BF-200 ALA group and 6 of 36 in the vehicle group were recorded as complete responses. These are descriptive counts at the specified follow-up. The comparison should be read alongside its confidence interval and the limitations of the registry’s reported analysis details.

7. Results Posted in the Registry

• BF-200 ALA: 45.6% (62/136) versus 16.7% (6/36) on control; risk difference 28.9 percentage points (95% CI 14.1 to 43.7), risk ratio 2.74 (1.29–5.81); unadjusted two-proportion z-test p = 0.002.

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.

Overall Subject Complete Response Rate for Subjects With Lesions Treated on Extremities

• 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:
  • BF-200 ALA: 38.5% (42/109) versus 11.1% (3/27) on control; risk difference 27.4 percentage points (95% CI 12.5 to 42.4), risk ratio 3.47 (1.16–10.34); unadjusted two-proportion z-test p = 0.007.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically higher for BF-200 ALA than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

New Lesions Inside the Treatment Field During Treatment Phase

• 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:
  • BF-200 ALA: 17.6% (24/136) versus 16.7% (6/36) on control; risk difference 1.0 percentage points (95% CI -12.8 to 14.7), risk ratio 1.06 (0.47–2.39); unadjusted two-proportion z-test p = 0.890.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between BF-200 ALA and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes address several related but distinct questions: response by anatomical site, response at the lesion level, response among severe lesions, response after the first photodynamic treatment, esthetic appearance, and new lesions within the treatment field. These measures add context to the primary participant-level endpoint, but they do not all measure the same aspect of treatment. A participant-level complete response requires all target lesions to be clear, whereas lesion-level measures count lesions, and new-lesion outcomes address a different event.

The available numerical secondary comparisons do not form a single uniform pattern. The extremity-specific complete response comparison is directionally consistent with the primary result. The comparison for new lesions inside the treatment field has an interval that includes zero and does not establish a clear direction. These results should be interpreted according to their own definitions and follow-up periods rather than combined into a general claim about every secondary outcome.

The registry lists 26 outcome measures and 17 posted secondary outcomes, but detailed numerical analyses are not reported in the registry record for all named outcomes. It is therefore not possible to assess the full secondary-outcome pattern from the posted numerical comparisons alone. In particular, the registry record does not provide numerical results for every listed outcome, including the neck/trunk response outcome and the esthetic appearance assessment.

Unadjusted secondary p-values carry less weight when many outcomes are considered because repeated testing can increase the chance of apparently notable findings. The registry record does not report a multiplicity correction, a hierarchy of outcomes, or a prespecified distinction between confirmatory and exploratory analyses. Secondary results can help describe where the primary pattern may or may not be reflected, but they should not be treated as independent proof or as a replacement for the primary endpoint.

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

• Overall Subject Complete Response Rate for Subjects With Lesions Treated on Extremities
• Overall Subject Complete Response Rate for Subjects With Lesions Treated on Neck/Trunk
• Lesion Complete Response Rate
• Complete Response Rate for Severe Lesions
• Subject Complete Response Rate After PDT-1
• Lesion Complete Response Rate After PDT-1
• Complete Response Rate for Severe Lesions After PDT-1
• Esthetic Appearance at the End of Treatment Phase Assessed by the Investigator

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is binary: each participant either met the definition of complete response or did not. For a binary outcome, the observed count and the number assessed in each group describe the frequency of the event. The posted counts are 62 of 136 participants in the BF-200 ALA group and 6 of 36 in the vehicle group. The comparison is reported as a risk difference, which expresses the difference between the groups’ event proportions on an absolute scale. The registry gives the estimate as 0.289.

A risk difference is often useful because it keeps the comparison on the same scale as the outcome proportion. A positive estimate in this comparison means the complete response proportion was higher in the BF-200 ALA group in the posted data. The estimate is not an adjusted effect: the posted recalculation is a simple, unadjusted comparison derived from the arm summaries. The registry’s sponsor analysis is not reported in enough detail to describe its model or adjustment approach. The record reports no discrepancy between the posted arm counts and comparison, so the recalculated unadjusted result can be described as a summary-statistic comparison, not as a substitute for an undisclosed full analysis.

A confidence interval gives a range of values that are compatible with the data under the method used to calculate it. For the primary risk difference, the interval runs from 0.141 to 0.437. It conveys uncertainty about the effect estimate; it is not a range containing a fixed proportion of individual participant outcomes. The interval’s interpretation depends on the calculation and its assumptions. General statistical practice treats an interval as more informative than a point estimate alone because it displays both direction and precision.

The p-value for the primary comparison is 0.002 and is unadjusted. In general, a p-value assesses how compatible the observed data are with a specified null hypothesis under the assumptions of the test. It does not give the probability that the treatment has no effect, and it does not measure the size or importance of an effect. A small p-value does not remove uncertainty about the estimate or address bias from missing data, outcome assessment, or analysis choices.

Relative measures are also reported for the primary comparison: the risk ratio is 2.735, with limits 1.288 and 5.809; the odds ratio is 4.189, with limits 1.638 and 10.72. A risk ratio compares event proportions as a ratio, while an odds ratio compares event odds. These measures use different scales from the absolute risk difference and can be less intuitive when the outcome is not rare. They should be interpreted as distinct summaries of the same group comparison, not as separate findings. The registry record does not specify a preferred effect measure beyond the endpoint and comparison information posted.

Randomization is intended to support a fair comparison by assigning participants to study groups through a chance-based process. In general, random assignment can reduce systematic differences between groups at baseline, but it does not guarantee that every potential source of bias is absent. The registry identifies the trial as randomized and parallel-group. It does not report the sequence-generation method, allocation concealment procedures, baseline characteristics, or the details of the randomization schedule. The unequal numbers reported in the two primary outcome groups should therefore be read as the observed group sizes, not as a reason to infer the planned allocation method.

Masking can reduce the chance that knowledge of assigned treatment influences participants, clinicians, or outcome assessment. The registry classification is quadruple masking, while the official title calls the study double-blind. Those descriptions are recorded, but the record does not explain who was masked or how masking was maintained. The outcome includes clinical assessment, so information about assessor masking and assessment procedures would help readers evaluate the potential for measurement bias; those details are not reported in the registry record.

The trial compares topical active treatment plus red-light photodynamic therapy with vehicle plus red-light photodynamic therapy. This structure helps isolate the contrast between active gel and vehicle within the study’s photodynamic treatment approach. It does not estimate the effect of photodynamic therapy versus no photodynamic therapy, because the control group also received photodynamic therapy. Nor does the primary endpoint separately identify the contribution of the topical agent, the lamp, or their interaction.

General statistical caution applies when a study has multiple outcomes. Testing or interpreting many outcomes can increase the chance that at least one result appears noteworthy by chance, particularly when no adjustment or prespecified hierarchy is described. The record lists 26 outcome measures and 17 posted secondary outcomes, but a multiplicity strategy is not reported in the registry record. The secondary p-values are therefore best treated as exploratory unless a fuller analysis plan establishes otherwise.

The registry record does not report how missing outcome data were handled, which analysis population was used for the primary endpoint, whether outcomes were analyzed according to randomized assignment, or whether an adjusted model was prespecified. These details matter because exclusions or missing assessments can affect group comparisons. General explanation cannot resolve those uncertainties: the available arm counts and unadjusted comparisons describe the posted results, while the unreported analytic plan and participant flow limit assessment of robustness.

11. Confidence Intervals and Precision

The primary risk difference is 0.289, with a 95% confidence interval from 0.141 to 0.437. The interval is wholly above zero, so it is compatible with a positive absolute difference in complete response proportions for BF-200 ALA plus photodynamic therapy compared with vehicle plus photodynamic therapy. It also shows that the effect is not pinned down to the single point estimate: a range of values remains compatible with the data under the interval method.

Precision depends in part on the amount of information in the comparison. The primary outcome includes 136 participants in the BF-200 ALA group and 36 in the vehicle group. The confidence interval reflects uncertainty in the group contrast; it should be considered together with these group sizes and the event counts, not read as a guarantee about future results. The registry record does not report the confidence-interval method or an adjusted interval from the sponsor’s analysis.

The extremity-specific secondary risk difference is 0.274, with a 95% confidence interval from 0.124 to 0.424. For new lesions inside the treatment field, the estimate is 0.010 and the 95% confidence interval runs from -0.128 to 0.147. The latter interval includes zero and spans negative and positive values, indicating substantial uncertainty about the direction and size of that comparison. The endpoints have different definitions and assessment windows, so their intervals should not be treated as direct substitutes for the primary interval.

In general, a confidence interval describes uncertainty in an estimated effect under a statistical method and its assumptions; it does not establish that every value in the interval is equally likely, nor does it capture all sources of bias. The interval alone does not address unreported missing-data handling, analysis-population choices, or multiplicity. The posted precision is therefore informative about sampling uncertainty in the reported comparisons, but it is not a complete measure of all uncertainty surrounding the trial.

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 expressed as participants per arm, not as total events. They use the observed effect as a reference and show scenarios for detecting 100%, 75%, or 50% of that observed effect. For each scenario, the figures give the participants per arm associated with 80% power and with 90% power. In plain terms, power is the chance that a planned study would identify a difference under the assumed effect and statistical conditions if that effect were the true one.

The stated planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is the stated fraction of the observed effect. Under these assumptions, planning for 100% of the observed effect gives 40 participants per arm for 80% power and 52 participants per arm for 90% power. Planning for 75% gives 66 participants per arm for 80% power and 87 participants per arm for 90% power. Planning for 50% gives 136 participants per arm for 80% power and 181 participants per arm for 90% power.

Smaller effects are harder to distinguish from random variation, so planning for a smaller effect requires more participants. These figures are illustrations derived from the observed comparison, not the trial’s original design calculation. The registry record does not report the trial’s original sample-size assumptions or justification. They are not observed power.

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 = 0.167; treatment proportion p₁ = 0.456; average p̄ = 0.311.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.6548 = 1.2834.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.6220 = 0.5235.
4. n = (1.2834 + 0.5235)² / (0.2892)² = 39.0, rounded up to 40 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 <- 0.166666666666667                          # control proportion
p1 <- 0.455882352941176                          # 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(5662202)
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 = 40 (80% power), 52 (90% power)
 75% of observed effect: n per arm = 66 (80% power), 87 (90% power)
 50% of observed effect: n per arm = 136 (80% power), 181 (90% power)
power.prop.test: 39 
Simulated power at n = 40 per arm: 0.813 (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. Multiplicity, Missing Data and Analysis Populations

The registry lists 26 outcome measures and 17 posted secondary outcomes. Considering multiple outcomes creates a statistical interpretation issue: when many comparisons are examined, some may appear noteworthy by chance even if there is no underlying difference for those outcomes. In general, a trial can address this through prespecified outcome hierarchies or multiplicity-adjusted procedures. The registry record does not report whether either approach was planned or used, and the posted secondary p-values are unadjusted.

The primary outcome is identified, but the registry record does not report a complete statistical analysis plan describing how the primary and secondary outcomes were prioritized, which comparisons were confirmatory, or whether subgroup analyses were prespecified. It also does not report whether interim analyses took place. Those details should not be inferred from the phase, masking classification, or the existence of a primary endpoint.

Missing-data methods and analysis populations are also not reported in the registry record. The record does not specify how participants with missing assessments were handled, whether any participants were excluded from the endpoint analysis, how protocol deviations were treated, or whether the primary comparison followed randomized assignment. These choices can affect a binary outcome because the classification of participants without an observed assessment may change the analysis denominator or require an imputation rule.

The posted results give group sizes and counts for the primary endpoint, but those numbers alone do not show participant flow or explain whether every randomized participant was assessed. Nor do they establish whether the reported comparison was the sponsor’s prespecified primary analysis. The registry record does not report baseline-adjusted results or other model-based analyses. Without those details, the unadjusted comparison can be read as a transparent summary of the posted counts, while its status relative to the full planned analysis remains unclear.

These reporting gaps do not negate the numerical findings, but they limit evaluation of how robustly the analysis addressed multiple outcomes, missing assessments, and departures from the planned treatment course. A fuller protocol and statistical analysis report would be needed to resolve those questions.

15. 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 serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: gastrooesophageal reflux disease (2.8%), hiatus hernia (2.8%), pelvic fracture (2.8%), keratoacanthoma (2.8%), squamous cell carcinoma of skin (2.8%).

The registry reports 12 participants with serious adverse events among 136 in the BF-200 ALA group and 4 among 36 in the vehicle group. It reports other adverse events for 132 participants in the BF-200 ALA group and 24 in the vehicle group. No deaths are listed in either group. These are group counts; they should be interpreted alongside the group sizes and not as a complete account of event severity, duration, or relatedness.

The registry lists serious adverse event terms with percentages, including gastrooesophageal reflux disease, hiatus hernia, pelvic fracture, keratoacanthoma, squamous cell carcinoma of skin, and basal cell carcinoma of skin. The record does not provide the event-level context needed to infer causality from these terms. In particular, the listed percentages do not by themselves establish that an event was caused by study treatment.

The safety figures describe events recorded in the trial. The registry record does not report a detailed assessment of treatment relatedness, exposure-adjusted analyses, or further safety follow-up. The counts should therefore be read as descriptive safety information, not as a standalone comparison of risk beyond the trial’s reported observation.

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

The primary comparison describes more complete responses in the BF-200 ALA group than in the vehicle group at the specified assessment 12 weeks after the last photodynamic treatment. The posted risk difference is 0.289, with a 95% confidence interval from 0.141 to 0.437, and the unadjusted p-value is 0.002. These results quantify the observed difference and its sampling uncertainty under the reported comparison.

The result does not show that every participant will respond, or that every lesion will clear. Complete response is a participant-level classification requiring all target lesions to be clinically clear; it is not the same as partial improvement or lesion-level response. The endpoint is assessed at a defined time after the final treatment, so it does not establish durability beyond that follow-up or describe longer-term recurrence.

The study compares BF-200 ALA plus photodynamic therapy with vehicle plus photodynamic therapy. It does not compare photodynamic therapy with no treatment, and it does not separate the effect of the topical gel from every other part of the treatment context. The result also does not by itself establish how the comparison would generalize to people, settings, or treatment conditions not represented in the trial.

Statistical significance is not the same as clinical importance. The p-value does not measure the magnitude of benefit, the probability that a hypothesis is true, or the balance of benefits and harms. The confidence interval adds information about the range of effect sizes compatible with the data, but does not account for every possible source of bias or uncertainty.

The registry record does not report the full analysis plan, missing-data procedures, or multiplicity strategy. This limits assessment of whether the posted estimates reflect all prespecified analyses and how sensitive they are to analytic choices. Secondary results offer additional, distinct outcome information, but unadjusted results across multiple outcomes should be interpreted cautiously. The trial’s posted statistics are evidence about the recorded comparison in this study, not a universal guarantee of an individual outcome.

17. Why This Trial Matters Statistically

This trial illustrates why endpoint definition matters in clinical research. A complete response measured at the participant level answers whether all target lesions were clear for each participant, while a lesion-level response answers a different question. The distinction affects both what the result means and how it should be communicated: counts of responding participants cannot be substituted for counts of responding lesions.

It also illustrates the value of reporting an absolute contrast with an interval. The primary risk difference of 0.289 is paired with a 95% confidence interval from 0.141 to 0.437. The interval conveys uncertainty that a point estimate alone would conceal. The unadjusted p-value adds a test-based summary, but it does not replace interpretation of the effect size, interval, endpoint, or study context.

The vehicle group received photodynamic therapy, which defines the treatment contrast. The primary result is about active topical BF-200 ALA versus vehicle in combination with photodynamic therapy, not about photodynamic therapy versus no photodynamic therapy. Making the comparator explicit prevents a broader causal claim than the trial design addresses.

The registry also provides an example of why secondary outcomes and multiplicity need context. Several outcomes are named, but the record does not report a multiplicity strategy or full numerical results for every listed outcome. Unadjusted secondary comparisons can be useful descriptively, but their evidential role depends on prespecification and the total set of analyses. Finally, clear reporting of analysis populations and missing-data handling would help readers assess how the reported group counts connect to the randomized trial. Those details are not reported in the registry record.

18. 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 primary endpoint is a clinical complete-response classification assessed 12 weeks after the last photodynamic treatment. The registry record does not report longer-term follow-up for this endpoint, so these results do not describe persistence of response or later recurrence. The endpoint also requires clearance of all target lesions for a participant; it does not provide a complete account of partial responses or lesion-by-lesion changes.

The comparison is specific to active topical BF-200 ALA with red-light photodynamic therapy versus vehicle with red-light photodynamic therapy. It does not estimate the effect of photodynamic therapy without topical treatment. The study title names the BF-RhodoLED XL or BF-RhodoLED lamp, but the registry record does not report enough detail to assess outcomes by lamp, anatomical site beyond the posted secondary result, or other treatment subgroups.

The group sizes reported for the primary endpoint are 136 and 36. The registry record does not explain the allocation schedule or provide participant-flow details that would clarify the difference in observed group sizes. It also does not report baseline characteristics, the primary analysis population, missing-data procedures, or whether any adjustments were used in the sponsor’s analysis. Those omissions limit assessment of comparability and analytic robustness.

Although multiple secondary outcomes are listed, a multiplicity plan is not reported, and numerical analyses are not available for every named outcome. The registry record does not give detailed outcome-assessment procedures or explain the difference between its quadruple-masking classification and the double-blind wording in the official title. These reporting limitations warrant caution when extending the primary comparison to other outcomes or settings.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Study to Evaluate the Safety, Tolerability and Efficacy of BF-200 ALA (Ameluz®) in the Field-directed Treatment of Actinic Keratosis (AK) on the Extremities and Neck/Trunk With Photodynamic Therapy (PDT) Using a RhodoLED Lamp — NCT05662202.
• Registry record last updated 2026-08-21; status last verified 2026-07.
• Results first posted 2026-08-21.
• 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.

22. Record Summary

This completed phase III randomized, parallel-group study enrolled 172 participants with actinic keratosis on the extremities and neck/trunk. It compared topical BF-200 ALA containing 10% 5-ALA HCl plus red-light photodynamic therapy with vehicle plus red-light photodynamic therapy. The registry classifies masking as quadruple; the official title describes the study as double-blind.

The primary outcome was participant-level complete response 12 weeks after the last photodynamic treatment. The posted counts were 62 of 136 participants with BF-200 ALA and 6 of 36 with vehicle. The unadjusted risk difference was 0.289, with a 95% confidence interval from 0.141 to 0.437 and an unadjusted p-value of 0.002. The record lists multiple secondary outcomes, but does not report a multiplicity strategy, missing-data methods, or a full analysis plan.