This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for A Study of Patidegib Topical Gel, 2%, for the Reduction of Disease Burden of Persistently Developing Basal Cell Carcinomas in Patients With Non-Gorlin High Frequency BCC (NCT04155190), a randomized phase 2 study. The primary outcome is Number of Participants With New Surgically Eligible Basal Cell Carcinomas (nSEBs).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04155190 |
| Phase | Phase 2 |
| Condition | Recurrent Basal Cell Carcinoma |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 50 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Sol-Gel Technologies, Ltd. |
| Results posted | Yes |
2. Clinical Question
Population
The study focused on adults with non-Gorlin high-frequency basal cell carcinoma, described in the record as non-Gorlin HF-BCC. The planned treatment was applied to the face, and the primary outcome concerned new surgically eligible basal cell carcinomas developing on the face. The registry lists recurrent basal cell carcinoma as the condition. It does not report further eligibility details or characterize the enrolled participants beyond the study description.
Intervention
The intervention was Patidegib Topical Gel, 2%, applied topically to the face twice daily for 9 months, according to the brief summary. The study description says participants were assigned to the treatment or vehicle group. The record does not give arm-specific enrollment or establish how many participants received each intervention.
Comparator
The comparator was Patidegib Topical Gel, Vehicle, also planned for 9 months. The study was described as vehicle-controlled, with 1:1 randomization and stratification by gender. A vehicle comparator helps distinguish the treatment formulation from its delivery vehicle in the planned comparison; the registry does not report results that would quantify any difference between the groups.
Primary question
The primary question was whether the groups differed in new surgically eligible basal cell carcinomas over up to 9 months. The primary outcome is titled as the number of participants with new surgically eligible basal cell carcinomas, while the brief summary describes the number of nSEBs that develop on the face. These descriptions identify the intended clinical outcome, but no numerical efficacy result or statistical comparison is reported in the registry record. The record also notes that data were unavailable to the sponsor on whether any basal cell carcinoma events met the protocol-specific criteria to count as nSEBs, making the endpoint's classification particularly important to interpretation.
3. Trial Design
This was a Phase 2, multicenter, randomized, parallel-group study with a vehicle control. The registry lists the allocation as randomized and the model as parallel. The planned allocation was 1:1 between Patidegib Topical Gel, 2%, and Patidegib Topical Gel, Vehicle. The brief summary says randomization was stratified by gender. The registry lists masking as triple, whereas the brief summary describes the study as double-blind; the record does not explain this difference.
The treatment period was planned to last 9 months, with topical application to the face twice daily. The primary endpoint timeframe is listed as up to 9 months. Enrollment is listed as 50. This is the registry's enrollment figure; the record does not report arm-specific numbers or how many participants completed treatment or follow-up.
The study started on 2019-12-20, and primary completion is listed as 2021-04-23. Its status is terminated. The reason for termination is not reported in the registry record, so the status alone does not establish why the study stopped or what follow-up was completed.
The primary outcome concerned new surgically eligible basal cell carcinomas. A secondary outcome listed in the record was the number of participants with treatment-emergent adverse events. Although the record lists two outcome measures, it contains no posted statistical analyses. The design describes the intended comparison, not evidence that the planned assessment was completed or that a treatment effect was established.
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.
Before assignment: The study was originally planned as a 2-arm study. However, participant-level data were collected and reported only in aggregate for the overall study, rather than by treatment arm for participant flow, study outcome measures, all-cause mortality, and adverse event data. The current Sponsor (Sol-Gel) prepared a Note to File for the Statistical Analysis Plan (SAP) to document how the data were collected.
Overall Study
| Stage | Overall Study |
|---|---|
| STARTED | 50 |
| Intent to Treat Set | 47 |
| Received at Least 1 Dose of Patidegib or Vehicle | 47 |
| COMPLETED | 20 |
| NOT COMPLETED | 30 |
Reasons for not completing this period:
| Reason | Overall Study |
|---|---|
| Sponsor decision | 24 |
| Other than specified | 1 |
| Withdrawal by Subject | 2 |
| Randomized, not treated | 3 |
Analysis population for the primary outcome, as defined in the registry: As detailed in the current Sponsor's Note to File for the Statistical Analysis Plan, Sol-Gel was not provided data to indicate if any of the basal cell carcinomas (BCC) events met the protocol-specified criteria to determine the event as a nSEB.
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
Population: Intent to treat set included all participants who received at least 1 dose of study drug.
| Characteristic | Unit | Patidegib Topical Gel, 2% | Vehicle | Total |
|---|---|---|---|---|
| Participants analysed | 23 | 24 | 47 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 7 | 4 | 11 |
| Age, Categorical: >=65 years | Participants | 16 | 20 | 36 |
| Sex: Female, Male: Female | Participants | 7 | 8 | 15 |
| Sex: Female, Male: Male | Participants | 16 | 16 | 32 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 23 | 24 | 47 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): White | Participants | 23 | 24 | 47 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With New Surgically Eligible Basal Cell Carcinomas (nSEBs), measured over Up to 9 months.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is titled as the number of participants with new surgically eligible basal cell carcinomas (nSEBs). The brief summary describes the primary endpoint as the number of nSEBs that develop on the face during the 9-month treatment period. It says lesions were to be assessed by imaging and tracked consistently during the study to identify nSEBs. These descriptions indicate that the outcome was intended to capture new lesions meeting a surgical-eligibility definition, rather than every basal cell carcinoma event without qualification.
Such an endpoint can represent disease burden through new lesions that meet a clinically consequential classification. For interpretation, however, the classification rule must be applied consistently: whether an observed lesion qualifies as an nSEB affects what is counted. The registry's primary-outcome population note states that, according to the sponsor's note to file for the statistical analysis plan, data were unavailable to the sponsor to indicate whether any basal cell carcinoma events met the protocol-specified criteria for nSEB status.
The record reports no endpoint count, group-specific estimate, uncertainty interval, or statistical comparison. It therefore does not establish the observed burden in either group or the size and precision of any between-group difference. The protocol-specific criteria and details of their application are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry describes a randomized comparison of Patidegib Topical Gel, 2%, with vehicle in adults with non-Gorlin high-frequency basal cell carcinoma. Its primary question concerned new surgically eligible basal cell carcinomas on the face over up to 9 months. Those design details describe what the study set out to assess; they are not evidence of the direction or magnitude of an efficacy result.
No numerical result for the primary endpoint is reported in the registry record. There is no posted estimate for either group, no between-group effect estimate, and no confidence interval or p-value for the primary comparison. The record lists zero statistical analyses. Without an endpoint result, the treatment groups cannot be compared using the posted efficacy data, and neither the size nor the precision of a possible difference can be evaluated.
Endpoint classification is a particular interpretive concern. The primary outcome concerns nSEBs, but the registry's population note reports that the sponsor did not have data indicating whether any basal cell carcinoma events met the protocol-specified nSEB criteria. A count of recorded basal cell carcinoma events would not necessarily resolve the primary question unless the criteria for classifying nSEBs were applied and documented. The registry does not report how this issue affected the endpoint assessment.
The study status is terminated, but a reason for termination is not reported in the registry record. The record also does not establish whether planned enrollment, treatment, imaging, or follow-up was completed. Enrollment is listed as 50, but this does not show how many participants contributed evaluable primary-outcome data. No arm-specific enrollment, completion, or analysis-population counts are reported.
The serious adverse event information is descriptive and is not broken down by treatment group. It cannot be used to compare serious-event risk between patidegib and vehicle. The record lists two participants affected by serious adverse events among 47 at risk, no participants affected by other adverse events among 47 at risk, and no deaths. These overall figures do not answer the primary efficacy question, and the absence of a reported group comparison should not be mistaken for evidence of equivalence or absence of an effect.
Overall, the posted record supports a description of the study's intended design and a limited reading of its overall safety counts. It does not support a quantitative conclusion about the primary efficacy endpoint. No sponsor analysis is available in the registry record to interpret alongside an independently recalculated result.
9. Statistical Methods Explained
The registry identifies the study as randomized, parallel-group, and vehicle-controlled. Randomization is a design method intended to make treatment groups comparable on average with respect to measured and unmeasured baseline characteristics. Stratification by gender, as described in the brief summary, means assignment was planned to account for gender when forming treatment groups. These design features can strengthen a comparison, but they do not by themselves show whether the groups were comparable in the enrolled sample or whether the endpoint was measured as planned.
What would an effect estimate tell the reader?
A between-group effect estimate would summarize the observed difference in the primary outcome under the study's analysis method. Its interpretation depends on the outcome definition, the population included, and how incomplete observations were handled. For this trial, the intended outcome concerns new surgically eligible basal cell carcinomas, and the registry gives no numerical group estimates or comparison. The treatment effect and its direction therefore cannot be assessed from the posted efficacy information.
How should uncertainty be read?
A confidence interval is a statistical range that expresses uncertainty around an estimate under the assumptions of the analysis. A narrow interval generally indicates greater precision than a wide interval, while the interval's position relative to values representing no difference can help readers assess compatibility with those values. No confidence interval is reported for the primary endpoint in this registry record. Consequently, there is no posted interval from which to judge the precision of an efficacy estimate.
A p-value, when reported, describes how compatible the data are with a specified null model under the analysis assumptions. It does not measure the size or clinical importance of an effect. No primary-endpoint p-value is reported. A missing p-value is not evidence that a comparison was non-significant, and the absence of an analysis is not evidence that the groups had identical outcomes.
What does the endpoint classification imply?
The primary endpoint depends on deciding whether a basal cell carcinoma event meets the protocol-specific criteria for an nSEB. Classification rules are part of measurement: if events cannot be assigned to the endpoint category consistently, the resulting count may not represent the intended outcome in a reliable way. The registry's note says data were unavailable to the sponsor about whether any events met those criteria. The record does not report the criteria themselves, the number of events reviewed, or how classification uncertainty was addressed.
What are planning calculations?
Sample-size calculations are planning illustrations about the number of participants that might be needed under stated assumptions to detect a specified effect with a chosen probability. They are not observed power, and they do not establish what the trial found. The registry's planning assumptions describe a two-sided significance level of 0.05, equal allocation, and a normal approximation; the effect to detect is framed as a stated fraction of the observed effect. Such illustrations depend on having a usable observed effect and on assumptions about the analysis. No numerical efficacy estimate is reported, so no observed effect or precision can be interpreted from the registry's primary outcome record. The planning assumptions should not be mistaken for the trial's own documented design rationale.
General statistical practice also requires attention to the distribution of count outcomes. Counts may vary more than a simple model assumes, a condition often called over-dispersion. If present, over-dispersion can make standard errors too small under an unsuitable model and can make uncertainty appear lower than it is. The registry record does not report the model used for the primary outcome, whether over-dispersion was assessed, or any fitted estimates. This is a general consideration, not a claim that over-dispersion occurred in this study.
Likewise, an analysis should specify which participants and observations were included and how missing measurements were treated. Those choices affect the estimate and its uncertainty, particularly if missingness differs across groups or relates to outcome status. The registry record does not report an analysis population, missing-data method, or statistical model for the primary endpoint. With no posted analysis, readers cannot determine whether these methods were used or evaluate their suitability.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists the primary outcome as the number of participants with new surgically eligible basal cell carcinomas and identifies treatment-emergent adverse events as a secondary outcome. It does not report a statistical analysis plan detailing how multiple outcomes, timepoints, or comparisons were handled. A multiplicity procedure, when relevant, can limit the chance of misleading findings from examining several hypotheses; no such procedure is reported in the registry record. The record also does not report interim analyses or other planned efficacy looks.
No primary-endpoint analysis is posted, and the record lists zero statistical analyses. It does not report the analysis population, whether all randomized participants were intended for a particular analysis set, or how participants who did not complete follow-up were treated. Missing-data assumptions and methods are not reported in the registry record. These omissions prevent assessment of whether incomplete observations could have affected the estimated treatment comparison.
Endpoint ascertainment adds a specific concern: the sponsor's note states that data were unavailable to indicate whether basal cell carcinoma events met the protocol-specific criteria for nSEB status. The record does not describe how unclassifiable events, if any, were handled. Without that information and a posted analysis, the reader cannot assess the completeness or consistency of the primary endpoint.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Overall Study | 2 | 47 | 4.3% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Overall Study | 0 of 47 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Overall Study | 0 of 47 |
Most frequent serious adverse event terms
| Event term | Organ system | Overall Study |
|---|---|---|
| Respiratory syncytial virus infection | Infections and infestations | 1 of 47 |
| Myocardial Infarction | Cardiac disorders | 1 of 47 |
Serious events with the highest arm-level rate: respiratory syncytial virus infection (2.1%), myocardial infarction (2.1%).
The registry reports adverse-event figures for the Overall Study, not separate results for the patidegib and vehicle groups. It lists 47 participants at risk for serious adverse events, with 2 affected. For other adverse events, it lists 47 at risk and 0 affected. The death count is 0. The record also lists Respiratory syncytial virus infection and Myocardial Infarction among the top serious terms, each at 2.1%.
These are descriptive registry figures. Because arm-specific event counts and denominators are not reported, they do not support a comparison of serious adverse events between treatments. The listed terms and percentages should not be treated as evidence that an event was caused by a study treatment. The registry does not provide further detail in these figures about timing, severity beyond the serious classification, or clinical course.
The overall safety counts also do not resolve the efficacy question. They should be read alongside the terminated status and the absence of posted statistical analyses, not as a substitute for an arm-level safety analysis.
12. What the Result Does, and Does Not, Mean
The record describes the question this randomized study was designed to address: whether topical Patidegib Gel, 2%, differed from vehicle in new surgically eligible basal cell carcinomas over up to 9 months in adults with non-Gorlin high-frequency basal cell carcinoma. It also reports that enrollment was listed as 50 and that the study status is terminated. These details provide context for the intended comparison but do not reveal its efficacy result.
The posted record does not report the primary endpoint counts, a group comparison, an effect estimate, or its uncertainty. It therefore does not show whether the observed endpoint favored either group, how large any difference might have been, or how precisely it was estimated. No conclusion about the presence or absence of an efficacy effect can be drawn from the missing results. A lack of posted statistical analysis is not the same as a finding of no difference.
The endpoint note further limits interpretation: the sponsor did not have data indicating whether basal cell carcinoma events met the protocol's nSEB criteria. Without documented endpoint classification and results, the intended measure of new surgically eligible lesions cannot be evaluated from the record.
The overall serious adverse event figures offer limited descriptive safety information, but they are not separated by treatment arm and do not establish comparative safety. The reason for termination, completed follow-up, analysis population, and methods for missing data are not reported in the registry record. These gaps mean that the posted information cannot establish the completeness of the intended assessment or explain the study's termination.
13. Why This Trial Matters Statistically
This trial illustrates why a randomized design and an interpretable result are separate parts of evidence. Randomization, a vehicle comparator, and planned gender stratification describe methods intended to support a fair treatment comparison. Yet readers still need the endpoint data, an analysis method, and an estimate with uncertainty to judge what the comparison showed. The registry record does not include those efficacy results.
It also highlights the importance of operational endpoint definitions. The primary outcome is not simply any basal cell carcinoma event; it concerns events meeting protocol-specific criteria for a new surgically eligible basal cell carcinoma. The registry notes that data were unavailable to the sponsor about whether events met those criteria. This makes transparent classification and complete reporting central to interpreting the intended disease-burden measure.
Finally, the terminated status and overall safety counts show the limits of relying on study descriptors alone. Status does not explain why the study stopped, and pooled adverse-event counts do not permit an arm-level safety comparison. The record is therefore useful for identifying the planned design and gaps in the posted evidence, while not supporting a numerical assessment of the primary treatment comparison.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The most consequential limitation is the absence of a numerical primary-endpoint result and any posted statistical analysis. The record does not report group-specific counts, an effect estimate, an uncertainty interval, or a primary comparison. It also notes that data were unavailable to the sponsor about whether basal cell carcinoma events met the protocol-specific criteria for nSEB classification. This leaves both the endpoint data and their classification unresolved in the posted record.
The status is terminated, but the reason for termination is not reported in the registry record. Enrollment is listed as 50, but the record does not give arm-specific enrollment, treatment completion, follow-up completion, or the number contributing to endpoint assessment. The record does not report the analysis population, handling of missing observations, or the statistical model used.
Safety information is reported only for the Overall Study, without treatment-arm breakdowns. The registry also has a masking discrepancy: the masking field says triple, while the brief summary says double-blind; no explanation is reported. These limitations prevent assessment of efficacy, comparative safety, and the completeness of the planned analysis from registry information alone.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Study of Patidegib Topical Gel, 2%, for the Reduction of Disease Burden of Persistently Developing Basal Cell Carcinomas in Patients With Non-Gorlin High Frequency BCC — NCT04155190.
- Registry record last updated 2026-07-21; status last verified 2026-06.
- Results first posted 2026-07-21.
- 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.
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18. Record Summary
The registry describes a multicenter, randomized, parallel, vehicle-controlled Phase 2 study of Patidegib Topical Gel, 2%, in adults with non-Gorlin high-frequency basal cell carcinoma. The planned comparison was with vehicle over 9 months, with topical application twice daily to the face and randomization stratified by gender. Enrollment is listed as 50; the study status is terminated.
The primary outcome concerned new surgically eligible basal cell carcinomas. No numerical efficacy result or statistical analysis is reported in the registry record. The record notes that data were unavailable to the sponsor on whether basal cell carcinoma events met the protocol-specific criteria for nSEB status. Overall safety figures list 2 participants affected by serious adverse events among 47 at risk, 0 affected by other adverse events among 47 at risk, and 0 deaths. The reason for termination and further details of the efficacy analysis are not reported.