Topical Dermaprazole for Radiation Dermatitis in Breast Cancer Patients (TOPAZ): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Topical Dermaprazole for Radiation Dermatitis in Breast Cancer Patients (TOPAZ) (NCT05269160), a non-randomized phase 1, phase 2 study. The primary outcome is Number of Participants With Dose-Limiting Toxicity(DLT) in Phase I.

2. Clinical Question

3. Trial Design

TOPAZ was registered as a Phase I/II study of topical Dermaprazole for radiation dermatitis in breast cancer patients. The registry describes a non-randomized, unmasked, sequential design. Its official title identifies post-mastectomy breast cancer patients, and its brief summary frames the purpose as assessing safety and tolerability in Phase I and preliminary efficacy in Phase II.

The intervention descriptions specify Dermaprazole cream at concentrations of 1% and 2%. For each concentration, the intended application was twice daily, beginning at CT simulation and continuing through radiation treatment. These descriptions do not establish that participants received both concentrations. The population information reports that three patients completed treatment with Dermaprazole 1%, with no dose-limiting toxicity observed, and that no more patients were enrolled. Results for participants treated with the 2% concentration are not reported in the registry record.

Enrollment was 3. The study started on 2023-04-24, had a primary completion date of 2023-06-26, and is listed as terminated. The reason for termination is not reported in the registry record. Nor is the planned allocation sequence, the rationale for stopping, or whether the Phase II portion began. The designation “sequential” is reported, but further operational detail about how participants were assigned to concentrations is not reported.

Because allocation was non-randomized and masking was absent, this record does not support interpreting the concentrations as balanced comparison groups. In addition, the registry does not describe a separate untreated or standard-care control group. Any comparison between concentrations would require results and design details that are not reported in the registry record. The small number of reported completers and early termination also mean that the record offers limited information about outcomes beyond the observed experience of those three patients.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Three patients completed the treatment with dermaprazole 1% and no DLT was observed. No more patients were enrolled. The study was terminated before identifing DLT.

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 Number of Participants With Dose-Limiting Toxicity(DLT) in Phase I, measured over from the first day applying the Dermaprazole cream until 1 month after the subject has completed their last radiation treatment, up to 13 weeks.

The Phase I primary endpoint counts participants with dose-limiting toxicity, or DLT. It is a safety and tolerability endpoint: rather than measuring an average change, it records whether a participant experienced an event meeting the protocol’s stated DLT definition during the specified observation period. The registry defines that period as starting on the first day of cream application and ending 1 month after the last radiation treatment, up to 13 weeks.

The definition includes skin toxicity outside the radiation field and radiation dermatitis within the treatment field, with the latter required to be probably or definitely related to Dermaprazole. The listed grading criteria refer to CTCAE V5.0, with a radiation oncologist evaluating dermatitis weekly. Patient-reported quality of life was to be assessed using SkinDex16, but it is not the primary endpoint.

In general, a DLT endpoint can make early-phase safety monitoring more operational by specifying which toxicities count and when they are assessed. The registry reports that three patients completed Dermaprazole 1% treatment and that no DLT was observed. It also says the study was terminated before identifying a DLT. This result describes the recorded observations; it does not establish that DLT cannot occur or provide a precise estimate of its frequency.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is a count of participants with an event: specifically, participants meeting the registry’s definition of DLT during the stated observation period. In general, binary outcomes classify each participant according to whether an event occurred. Counts retain the observed number of events, while interpretation also depends on how many participants were assessed. Here, the registry reports three patients completing Dermaprazole 1% treatment and no observed DLT. It does not report a confidence interval or a model-based estimate for this endpoint.

What does a DLT count capture?

The DLT definition combines event type, severity, location, and attribution. It includes skin toxicity outside the radiation field above Grade 2, and radiation dermatitis above Grade 2 within the treatment field when considered probably or definitely related to Dermaprazole. The registry describes the relevant dermatitis using CTCAE V5.0 criteria and says a radiation oncologist would evaluate patients weekly. This definition determines which observations count toward the endpoint; it is not simply a count of all skin symptoms or all adverse events.

In general, explicit endpoint criteria help make outcome classification more consistent, particularly when clinical judgment is involved. They do not by themselves guarantee that evaluators were blinded or that assessments were complete. The study is listed as having no masking, and the record does not report additional procedures for independent review or disagreement resolution. Patient-reported quality of life was to be evaluated with SkinDex16, but no SkinDex16 result is reported.

What does the design allow analysts to compare?

The registry labels the design non-randomized, unmasked, and sequential. In general, random allocation can help balance measured and unmeasured participant characteristics between groups, while masking can reduce some risks of bias in assessment or behavior. Neither feature is present in the registry description. That does not prove that a particular bias occurred, but it limits how strongly differences between groups could be interpreted if such results were available.

The record describes 1% and 2% Dermaprazole arms, but its participant summary reports three completers at 1% and no more enrollment. Results for the 2% arm are not reported in the registry record. There is no reported control group for a like-for-like comparison. Accordingly, there is no basis in the posted information for estimating a comparative effect between concentrations or against another treatment.

What statistical analysis is reported?

The registry reports no analyses. It does not report a statistical model, hypothesis test, confidence interval, covariate adjustment, or method for handling repeated assessments. In general, a confidence interval expresses the precision of an estimate under its statistical assumptions; it is not a guarantee that the true value lies within its bounds. No interval is available for this result, so its precision cannot be judged from an interval estimate.

For outcomes observed over time, such as time to occurrence or healing, general statistical approaches can account for the timing of events and for participants whose event time is not observed. The registry lists median time-to-event outcomes but does not report their results, censoring information, or an analysis method. No time-to-event estimate should therefore be inferred from the endpoint descriptions alone.

How should planning illustrations be understood?

The planning assumptions described for the sample-size illustrations use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a stated fraction of the observed effect. For time-to-event outcomes, those illustrations refer to total events using the Schoenfeld approach; other outcomes are expressed as participants per arm. These are planning illustrations, not evidence of the study’s own design or observed power. The trial’s sample-size justification and intended statistical power are not reported in the registry record.

In general, a planning calculation describes what might be needed under its stated assumptions; it does not show that a study actually enrolled enough participants or that a result is precise. It should not be read as an analysis of the three reported completers. The registry’s actual enrollment was 3, and the study was terminated. Without a reported analysis plan or adequate outcome data, the illustrations cannot fill the gaps in the trial record.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Dermaprazole 1% (Breast)")
n      <- c(3)
events <- c(0)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Dermaprazole 1% (Breast)  3  0  0.0  0.0  70.8  0.0  56.1  0.6  60.2

11. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary endpoint and multiple secondary outcomes, including the number of participants with Grade 2 or higher acute radiation dermatitis, time to occurrence and healing, peak total quality-of-life score, and missed radiation treatments due to skin toxicity. The record counts seven outcome measures, but results for the listed secondary outcomes are not reported in the registry record.

In general, testing or interpreting many outcomes can increase the chance of finding an apparently notable result by chance. Statistical plans may address this through a prespecified hierarchy, adjustment, or other approach. The registry does not report a multiplicity strategy, and it reports no statistical analyses. Therefore, there are no reported p-values or adjusted inferences whose multiplicity treatment can be assessed.

Missing-data methods and completeness of outcome follow-up are also not reported in the registry record. The record states that three patients completed treatment with Dermaprazole 1% and no DLT was observed, but it does not describe a broader analysis population, exclusions, withdrawals, or the completeness of assessments for every endpoint. The sample enrolled should not automatically be treated as the analysis denominator for every secondary outcome.

In general, missing observations can affect interpretation when the likelihood of missingness is related to participant characteristics or outcomes. Methods such as imputation or sensitivity analyses can be used in some settings, but no such method is reported. The reason for termination, the handling of any incomplete observations, and the populations included in analyses are not reported in the registry record. These omissions prevent assessment of whether missing data or multiple outcomes influenced the reported findings.

12. Safety Results

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

Deaths

Other (non-serious) adverse events

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

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: pregnancy, puerperium and perinatal conditions - other, specify (33.3%).

The registry reports three participants at risk for serious adverse events and one participant with a serious adverse event. It reports three participants at risk for other adverse events and three participants with other adverse events. The record also reports 0 deaths. These figures describe participant counts, not the total number of individual events, and the two adverse-event groupings should be kept distinct.

The listed leading serious adverse-event category is “Pregnancy, puerperium and perinatal conditions - Other, specify,” reported as 33.3%. This is a registry category label and does not, by itself, explain the event’s clinical details or relationship to treatment. The registry information does not establish whether an adverse event was caused by Dermaprazole or radiation. Attribution and further event-level context are not reported in the registry record.

In general, serious adverse-event summaries describe events meeting seriousness criteria, while “other” adverse events are reported separately according to the registry’s classification. Participant counts alone do not convey duration, severity details, recurrence, or timing. They also do not establish comparative risk, particularly in a non-randomized study without a reported control group. The small number of reported participants makes these figures descriptive rather than a precise characterization of safety.

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

The result supports a narrow statement: among the three patients reported to have completed Dermaprazole 1% treatment, no DLT was observed. The registry says the study was terminated before identifying DLT. This is a description of the recorded experience, not proof that DLT cannot occur or an estimate precise enough to characterize risk in a broader population.

The result does not establish safety for the 2% concentration, because outcomes for that concentration are not reported in the registry record. It does not compare Dermaprazole with no cream, usual care, or another intervention. The non-randomized, unmasked design and absence of a reported control group mean the record cannot provide a randomized comparative estimate.

The study’s stated aims included preliminary efficacy, but the registry does not report results for the listed dermatitis, healing-time, quality-of-life, or missed-treatment outcomes. Consequently, the DLT result does not show whether dermatitis incidence or severity differed, whether healing time changed, or whether radiation treatments were missed less often. No treatment benefit or lack of benefit can be concluded from the reported primary endpoint alone.

More generally, early-phase safety observations can help describe what was recorded during a limited period of treatment and follow-up. Their interpretation depends on the number of participants, the completeness and duration of observation, how events are defined, and whether there is a suitable comparison. Here, the endpoint definition and observation period are stated, but the sample is small, the study ended early, and further analysis details are absent.

The appropriate statistical conclusion is therefore restrained. The record documents no observed DLT among three Dermaprazole 1% completers, alongside termination before a DLT was identified. It leaves substantial uncertainty about the frequency of DLT, outcomes at the other concentration, and efficacy-related outcomes. The reason for termination and the study’s analysis populations are not reported in the registry record.

14. Why This Trial Matters Statistically

This trial illustrates why a numerical result needs its design and denominator alongside it. A count of no observed DLT is informative about the experience of the participants recorded, but the small enrollment means the finding cannot precisely describe the range of possible safety outcomes. Statistical interpretation must distinguish the observed count from the underlying event frequency, which remains uncertain.

The study also highlights the difference between a safety endpoint and an efficacy outcome. The primary endpoint counted participants with DLT, while the registry separately listed outcomes related to dermatitis, healing, quality of life, and missed radiation treatments. Because the latter results are not reported, the safety observation cannot answer the broader efficacy questions stated for the study.

Design features shape what comparisons are possible. Non-randomized allocation, no masking, and the absence of a reported control group limit causal interpretation. The sequential label and two concentration descriptions do not make the concentration arms equivalent comparison groups. The record’s statement that three patients completed 1% treatment, with no more participants enrolled, underscores how study status and enrollment affect the scope of the evidence.

Finally, early termination and absent analysis details are not minor reporting details. They leave unanswered why enrollment stopped, whether planned Phase II work occurred, how incomplete observations were handled, and what statistical approach was intended. These gaps demonstrate that statistical interpretation depends not only on the observed endpoint count but also on the study conduct and reporting needed to assess precision, bias, and generalizability.

15. 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 most direct limitation is the small number of reported completers: three patients received Dermaprazole 1%, with no DLT observed. This count cannot characterize uncommon events or provide a precise estimate of DLT frequency. Results for the 2% concentration are not reported in the registry record, so neither its safety experience nor a concentration comparison can be assessed.

The study is listed as non-randomized and unmasked, and a control group is not described. These features limit comparative interpretation and leave potential for differences in participant characteristics or outcome assessment to influence any between-group comparisons. The registry does not report enough detail about allocation to determine how the sequential design operated in practice.

The study is listed as terminated, and the registry says it ended before identifying DLT. The reason for termination and whether the Phase II portion proceeded are not reported. The primary completion date and enrollment are recorded, but the record does not provide further detail about follow-up completion or the completeness of assessments for each outcome.

Although several secondary outcomes are listed, their results are not reported in the registry record. The registry also reports no statistical analyses, and does not describe confidence intervals, missing-data handling, analysis populations, or a multiplicity approach. The sample-size justification and detailed statistical plan are not reported. These limits make it impossible to evaluate the precision of estimates, the handling of incomplete data, or the statistical interpretation of secondary outcomes.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Topical Dermaprazole for Radiation Dermatitis in Breast Cancer Patients (TOPAZ) — NCT05269160.
• Registry record last updated 2026-02-17; status last verified 2025-07.
• Results first posted 2026-02-17.
• 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.

19. Record Summary

TOPAZ, NCT05269160, is registered as a Phase I/II study of topical Dermaprazole for radiation dermatitis in breast cancer patients. The design is listed as non-randomized, unmasked, and sequential. The registry describes 1% and 2% cream concentrations, each applied twice daily from CT simulation through radiation treatment.

The Phase I primary endpoint was the number of participants with DLT during the specified treatment and follow-up period. The record reports that three patients completed Dermaprazole 1% treatment and no DLT was observed; no more patients were enrolled, and the study was terminated before a DLT was identified. The reason for termination is not reported.

Results for secondary outcomes and the 2% concentration are not reported in the registry record. No statistical analyses are reported. The available result is a limited descriptive safety observation, not a comparative estimate or an efficacy finding.