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 Safety and Efficacy Study of Bimatoprost in the Treatment of Women With Female Pattern Hair Loss (NCT01325350), a randomized phase 2 study. The primary outcome is Change From Baseline in Target Area Hair Count (TAHC).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01325350 |
| Phase | Phase 2 |
| Condition | Alopecia, Baldness |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 306 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Allergan |
| Results posted | Yes |
2. Clinical Question
Population
Women with female pattern hair loss were the intended population. The registry lists alopecia and baldness as conditions. The primary outcome population was defined as participants in the Modified Intent-to-Treat Population who received treatment and had both baseline and post-baseline measurements, with data available for that outcome.
Intervention
The study evaluated three bimatoprost formulations. Each was described as approximately one mL applied evenly to a prespecified scalp area once daily for 6 months.
Comparator
The comparison treatments were bimatoprost vehicle solution and minoxidil 2% solution. Vehicle was applied once daily for 6 months; minoxidil was applied twice daily for 6 months. The registry describes minoxidil as open-label, while the other treatments were provided in a double-blinded fashion.
Primary question
The primary outcome was change from baseline to Month 6 in target area hair count, measured in terminal hairs/cm^2. A positive change was defined as an increase in terminal hair count, and a negative change as a decrease. The registry record does not report the results needed to determine the observed changes or compare treatments statistically.
3. Trial Design
This was a Phase 2, randomized, parallel-group study. The registry lists enrollment as 306 and status as completed. The recorded study start is 2011-06, and primary completion is 2012-07. Allergan is listed as the sponsor.
Five treatment arms are described: bimatoprost Formulations A, B, and C; bimatoprost vehicle solution; and minoxidil 2% solution. The bimatoprost formulations and vehicle were described as approximately one mL applied to a prespecified scalp area once daily for 6 months. Minoxidil 2% solution was described as approximately one mL applied to the area twice daily for 6 months.
The registry lists triple masking, while the study summary clarifies that minoxidil was open-label and the other treatments were provided in a double-blinded fashion. These descriptions indicate that masking was not identical across all treatment groups. The registry record does not specify the roles included in its triple-masking label or give further details of masking procedures.
The primary endpoint was change from baseline in target area hair count at Month 6. The primary analysis population was a Modified Intent-to-Treat Population, defined for this outcome as randomized participants who received treatment and had baseline and post-baseline measurements, with outcome data available. Allocation details beyond the randomized parallel design, including the method used to generate or conceal the allocation sequence, are not reported in the registry record.
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
| Stage | Bimatoprost Formulation A | Bimatoprost Formulation B | Bimatoprost Formulation C | Vehicle to Bimatoprost | Minoxidil 2% Solution |
|---|---|---|---|---|---|
| STARTED | 61 | 61 | 61 | 61 | 62 |
| COMPLETED | 55 | 56 | 44 | 52 | 50 |
| NOT COMPLETED | 6 | 5 | 17 | 9 | 12 |
Reasons for not completing this period:
| Reason | Bimatoprost Formulation A | Bimatoprost Formulation B | Bimatoprost Formulation C | Vehicle to Bimatoprost | Minoxidil 2% Solution |
|---|---|---|---|---|---|
| Adverse Event | 3 | 3 | 3 | 1 | 2 |
| Pregnancy | 0 | 0 | 1 | 0 | 1 |
| Lost to Follow-up | 1 | 0 | 5 | 1 | 5 |
| Personal Reasons | 2 | 1 | 6 | 5 | 3 |
| Protocol Violation | 0 | 0 | 0 | 1 | 0 |
| Withdrawal by Subject | 0 | 0 | 1 | 1 | 0 |
| Did Not Receive Treatment | 0 | 1 | 1 | 0 | 1 |
Analysis population for the primary outcome, as defined in the registry: Participants from the Modified Intent-to-Treat Population (all randomized participants who received treatment and had both Baseline and post-Baseline measurements) who had data available for this outcome measure.
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.
| Characteristic | Unit | Bimatoprost Formulation A | Bimatoprost Formulation B | Bimatoprost Formulation C | Vehicle to Bimatoprost | Minoxidil 2% Solution | Total |
|---|---|---|---|---|---|---|---|
| Participants analysed | 61 | 61 | 61 | 61 | 62 | 306 | |
| Age, Customized: 18 to 34 years | Participants | 12 | 13 | 12 | 13 | 12 | 62 |
| Age, Customized: 35 to 59 years | Participants | 49 | 48 | 49 | 48 | 50 | 244 |
| Sex: Female, Male: Female | Participants | 61 | 61 | 61 | 61 | 62 | 306 |
| Sex: Female, Male: Male | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Change From Baseline in Target Area Hair Count (TAHC), measured over Baseline, Month 6.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | terminal hairs/cm^2 |
| Endpoint classification | Continuous Endpoint |
The primary endpoint was change from baseline in target area hair count, abbreviated in the registry description as TAHC. It was measured at baseline and Month 6 using digital imaging analysis and reported in terminal hairs/cm^2. The registry defines a positive change as an increase in terminal hair count and a negative change as a decrease.
Hair count is a continuous measure: it can represent the size and direction of change rather than assigning each participant to a simple response category. The registry specifies that the summary parameter was the mean and that dispersion was described using the standard deviation. The mean gives the average change among participants included in the outcome population; the standard deviation describes the spread of individual measurements around that average. Neither statistic alone describes the uncertainty in a treatment comparison.
A measured scalp area and a defined follow-up time allow change to be assessed consistently within the study. Digital imaging analysis is the stated measurement approach, but the image-reading procedures, measurement reliability, and rules for handling unusable images are not reported in the registry record. The primary endpoint results, including group means, standard deviations, treatment contrasts, and confidence intervals, are also not reported in the registry record. Consequently, the direction, magnitude, and precision of the observed primary outcome cannot be described from the record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies the primary outcome and its intended measurement but does not report numerical results for it. There are no posted group-level changes in target area hair count, standard deviations, treatment comparisons, confidence intervals, or p-values in the record described. It is therefore not possible to state which group had a larger mean change, how large any difference was, or how precisely an effect was estimated.
The primary endpoint was evaluated from baseline to Month 6. Its sign has a specified interpretation: a positive change represents an increase in terminal hairs, while a negative change represents a decrease. That definition explains how a reported value would be read, but it does not establish that any treatment produced a particular change. Without the outcome values, a statistical or clinical comparison among the bimatoprost formulations, vehicle, and minoxidil cannot be made.
The registry says the primary outcome population included randomized participants who received treatment and had both baseline and post-baseline measurements, with data available for the outcome. This is narrower than an analysis of every randomized participant. The number excluded from the outcome analysis, reasons for unavailable measurements, and any consequences for the comparison are not reported in the registry record.
The record does include selected adverse-event figures by treatment group. These describe counts of participants affected among those at risk for serious and other adverse events. They are safety summaries, not efficacy comparisons. They do not replace the missing primary endpoint results, and the counts alone do not establish whether differences between groups are due to treatment, chance, or other factors. No statistical tests or adjusted safety comparisons are reported in the registry record.
Because no primary outcome estimates or inferential analyses are posted, the central result of the trial cannot be characterized as statistically significant or not statistically significant. A missing p-value is not evidence of no effect, and a missing estimate cannot be treated as a zero effect. The registry record supports describing the design, endpoint definition, analysis population, and listed safety counts; it does not support a conclusion about the comparative hair-count outcomes.
9. Statistical Methods Explained
The primary measure is continuous, and the registry specifies that it was summarized using a mean and standard deviation. In general, a mean represents the average observed value in a group. A standard deviation describes how dispersed the individual observations are around that mean. These statistics answer different questions: the mean describes the group average, while the standard deviation describes participant-level variability. A standard deviation is not a confidence interval and does not, by itself, show how precisely the group mean or a between-group difference has been estimated.
A treatment comparison for a continuous endpoint would generally focus on an estimated difference between groups, with a confidence interval describing the range of effect sizes compatible with the data and analysis assumptions. In general, a confidence interval conveys uncertainty around an estimate; it does not guarantee that the true effect lies within the interval. A p-value, when reported, addresses compatibility of the data with a specified null model and is not a measure of effect size or clinical importance. The registry record does not report a primary treatment contrast, confidence interval, or p-value, so none of these quantities can be interpreted for this trial.
What does change from baseline represent?
Change from baseline compares a participant’s follow-up measurement with that participant’s baseline measurement. For this endpoint, the registry identifies baseline and Month 6 as the measurement times and defines the direction of change. An analysis of change can account for the starting measurement in its outcome definition, but the registry record does not describe the statistical model, any baseline adjustment, or the exact method used to compare groups. It would be inappropriate to assume a particular model from the fact that change from baseline was reported as the endpoint.
What is the role of the analysis population?
The Modified Intent-to-Treat Population for the primary outcome included randomized participants who received treatment and had both baseline and post-baseline measurements, with data available for the outcome. This definition identifies who could contribute to the reported endpoint. It does not tell how many randomized participants lacked measurements, why measurements were missing, or whether participants with missing outcomes differed from those analyzed. The registry record does not report those details or the method, if any, used to account for missing values.
Why do the masking details matter?
The record labels the trial triple-masked but also states that minoxidil 2% solution was open-label, while the other treatments were double-blinded. In general, masking can reduce the influence of treatment expectations on behavior, assessments, and reporting. An open-label comparison can leave participants and relevant study personnel aware of the assigned treatment. The extent to which that could affect an outcome depends on the procedures and measurement process; those details are not reported in the registry record. The primary measure used digital imaging analysis, but the record does not explain whether image assessors were masked to treatment assignment.
How should planning calculations be understood?
In general, a sample-size planning calculation asks how many participants per arm would be needed under specified assumptions to detect an effect at a chosen significance level and power. The assumptions described for the planning illustration use a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. These are planning assumptions, not evidence that the trial was designed using that approach. The trial’s own sample-size rationale is not reported in the registry record. The numerical outputs of the planning illustration are not included in the record described, and such planning estimates should not be interpreted as observed power.
More generally, a planning calculation depends on the chosen effect size, variability, allocation, and analysis method. If the assumed effect differs from the effect that is clinically meaningful or from the effect ultimately observed, the resulting participant requirement may not answer the intended research question. Calculations based on an observed effect are retrospective illustrations; they do not establish the probability that a completed study detected a real effect. No outcome estimate is available in the registry record to assess the assumptions against this trial’s observed primary results.
What can the safety counts establish?
Safety summaries count participants with events within each group. In general, a count is descriptive; it does not indicate whether an event was caused by treatment. Comparisons also need to account for the group sizes and follow-up, and formal inference requires an analysis plan and appropriate estimates of uncertainty. The registry reports counts at risk and affected for serious and other adverse events but does not report comparative statistical analyses. Event categories can also include more than one type of event, so a list of event terms should not be assumed to represent a complete account of individual participants’ experience.
10. Multiplicity, Missing Data and Analysis Populations
The trial lists a primary outcome of change from baseline in target area hair count and secondary outcomes covering Investigator Global Assessment response categories, Global Panel Review response categories, target area hair width, and target area hair darkness. Testing several outcomes, treatment groups, time points, or response categories can increase the chance of at least one apparently notable result when many statistical tests are conducted. In general, a prespecified multiplicity strategy may control that risk, for example by defining a testing hierarchy or adjusting inference across comparisons. The registry record does not report whether multiplicity was addressed, which comparisons were considered primary, or how any adjustment was performed.
The record identifies a Modified Intent-to-Treat Population for the primary outcome: randomized participants who received treatment and had baseline and post-baseline measurements, with data available for that endpoint. The number of participants with missing outcome data, reasons for missingness, and handling of those data are not reported in the registry record. The record also does not describe imputation, sensitivity analyses, or methods for participants who discontinued treatment or missed a scheduled assessment.
Although enrollment is listed as 306, the registry record does not provide the outcome analysis counts by group in the information described. The trial’s own sample-size rationale, power target, and any interim analyses are not reported in the registry record. No statistical analysis plan or model specification is reported. These omissions limit assessment of whether the analyses followed prespecified procedures, how missingness might affect estimates, and how to interpret results across multiple outcomes. They do not establish that a particular method was or was not used; they mean that the details are not reported in the registry record.
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 |
|---|---|---|---|
| Bimatoprost Formulation A | 4 | 61 | 6.6% |
| Bimatoprost Formulation B | 4 | 60 | 6.7% |
| Bimatoprost Formulation C | 3 | 60 | 5.0% |
| Vehicle to Bimatoprost | 1 | 61 | 1.6% |
| Minoxidil 2% Solution | 1 | 61 | 1.6% |
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 |
|---|---|
| Bimatoprost Formulation A | 17 of 61 |
| Bimatoprost Formulation B | 17 of 60 |
| Bimatoprost Formulation C | 15 of 60 |
| Vehicle to Bimatoprost | 20 of 61 |
| Minoxidil 2% Solution | 24 of 61 |
Most frequent serious adverse event terms
| Event term | Organ system | Bimatoprost Formulation A | Bimatoprost Formulation B | Bimatoprost Formulation C | Vehicle to Bimatoprost | Minoxidil 2% Solution |
|---|---|---|---|---|---|---|
| Osteoarthritis | Musculoskeletal and connective tissue disorders | 2 of 61 | 0 of 60 | 0 of 60 | 0 of 61 | 0 of 61 |
| Intervertebral disc protrusion | Musculoskeletal and connective tissue disorders | 0 of 61 | 0 of 60 | 1 of 60 | 1 of 61 | 0 of 61 |
| Death | General disorders | 0 of 61 | 0 of 60 | 1 of 60 | 0 of 61 | 0 of 61 |
| Cholecystitis | Hepatobiliary disorders | 0 of 61 | 1 of 60 | 0 of 60 | 0 of 61 | 0 of 61 |
| Appendicitis | Infections and infestations | 0 of 61 | 1 of 60 | 0 of 60 | 0 of 61 | 0 of 61 |
| Gastroenteritis | Infections and infestations | 0 of 61 | 0 of 60 | 1 of 60 | 0 of 61 | 0 of 61 |
| Arthralgia | Musculoskeletal and connective tissue disorders | 0 of 61 | 1 of 60 | 0 of 60 | 0 of 61 | 0 of 61 |
| Rotator cuff syndrome | Musculoskeletal and connective tissue disorders | 0 of 61 | 1 of 60 | 0 of 60 | 0 of 61 | 0 of 61 |
| Chondropathy | Musculoskeletal and connective tissue disorders | 0 of 61 | 0 of 60 | 0 of 60 | 0 of 61 | 1 of 61 |
| Benign ovarian tumour | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 0 of 61 | 1 of 60 | 0 of 60 | 0 of 61 | 0 of 61 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Bimatoprost Formulation A | Bimatoprost Formulation B | Bimatoprost Formulation C | Vehicle to Bimatoprost | Minoxidil 2% Solution |
|---|---|---|---|---|---|---|
| Nasopharyngitis | Infections and infestations | 1 of 61 | 2 of 60 | 2 of 60 | 6 of 61 | 7 of 61 |
| Upper respiratory tract infection | Infections and infestations | 6 of 61 | 5 of 60 | 0 of 60 | 1 of 61 | 2 of 61 |
| Headache | Nervous system disorders | 1 of 61 | 1 of 60 | 4 of 60 | 5 of 61 | 1 of 61 |
| Application site pruritis | General disorders | 0 of 61 | 3 of 60 | 2 of 60 | 0 of 61 | 5 of 61 |
| Hypertrichosis | Skin and subcutaneous tissue disorders | 5 of 61 | 1 of 60 | 0 of 60 | 1 of 61 | 3 of 61 |
| Procedural pain | Injury, poisoning and procedural complications | 2 of 61 | 1 of 60 | 3 of 60 | 2 of 61 | 1 of 61 |
| Application site dryness | General disorders | 1 of 61 | 1 of 60 | 0 of 60 | 2 of 61 | 4 of 61 |
| Sinusitis | Infections and infestations | 1 of 61 | 3 of 60 | 1 of 60 | 2 of 61 | 1 of 61 |
| Hypertension | Vascular disorders | 0 of 61 | 0 of 60 | 3 of 60 | 1 of 61 | 0 of 61 |
Serious events with the highest arm-level rate: osteoarthritis (3.3%), death (1.7%), cholecystitis (1.7%), appendicitis (1.7%), gastroenteritis (1.7%).
The registry reports serious adverse-event counts and other adverse-event counts separately for each treatment group. For serious adverse events, the record lists 4 affected among 61 at risk in Formulation A, 4 among 60 in Formulation B, 3 among 60 in Formulation C, 1 among 61 in vehicle, and 1 among 61 in minoxidil 2% solution. For other adverse events, it lists 17 among 61, 17 among 60, 15 among 60, 20 among 61, and 24 among 61, respectively.
These are descriptive participant counts. They should be read within the corresponding group rather than as direct evidence that one treatment caused more or fewer events. The record does not provide comparative tests, uncertainty intervals, event timing, or a causal assessment for these counts. It lists serious adverse-event terms including osteoarthritis at 3.3%, and death, cholecystitis, appendicitis, gastroenteritis, and arthralgia at 1.7% each. The term Death in that list is not a substitute for a reported group-specific death count; deaths are not reported in the registry record. The listed terms and percentages do not establish whether events were treatment-related.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a randomized Phase 2 study evaluated three bimatoprost formulations alongside vehicle and minoxidil 2% solution in women with female pattern hair loss. It defines the primary outcome as change from baseline to Month 6 in target area hair count, measured by digital imaging analysis and expressed in terminal hairs/cm^2. It also defines the direction of improvement and reports selected safety counts.
Those details describe what the study was designed to measure and some of the safety information entered in the record. They do not reveal the primary outcome values. Without group-level changes and uncertainty estimates, the magnitude and precision of any difference in hair count cannot be assessed. The registry record also does not report inferential analyses, so it cannot support a statement about statistical significance. A lack of posted results is not evidence that treatments had identical outcomes or that a treatment had no effect.
The safety counts likewise do not establish causation or comparative risk. The registry does not provide the event-level details or adjusted analyses needed to interpret the counts as treatment effects. The reported term Death should be understood as an entry in the serious adverse-event term list; a group-specific death count is not reported in the registry record.
More broadly, the record does not report the statistical analysis plan, how missing outcome data were handled, or whether multiplicity was addressed. Those details matter when interpreting several treatment groups and outcome measures. Accordingly, conclusions should remain limited to the design, endpoint definitions, stated analysis population, and descriptive safety figures. The registry information does not establish the clinical importance or comparative effectiveness of any study treatment.
13. Why This Trial Matters Statistically
This trial is statistically notable as a multi-arm randomized study with three bimatoprost formulations and two comparator treatments. That structure creates several possible comparisons, while the record also lists multiple secondary outcomes. In general, multiple comparisons raise questions about which contrasts were prespecified and how the possibility of chance findings across analyses was handled. The registry record does not report a multiplicity strategy or a detailed analysis plan.
The primary endpoint is a continuous imaging-based measure, reported as mean change with standard deviation. That format can communicate both average change and variability, but interpreting a treatment contrast also requires its uncertainty and a clear account of the analysis. The primary results and inferential statistics are not reported in the registry record, preventing assessment of the estimated effect or its precision.
The outcome population is defined using receipt of treatment and availability of baseline and post-baseline measurements. This makes the handling of missing measurements particularly relevant to interpretation. The number and reasons for missing measurements and any sensitivity analyses are not reported in the registry record. The stated masking arrangements also merit attention: minoxidil was open-label, while the other treatments were described as double-blinded, despite the registry’s overall triple-masking label. The image-assessment masking procedures are not reported.
Finally, the posted safety information is descriptive rather than a comparative statistical analysis. The study’s design and the endpoint definitions are useful for understanding what was evaluated, but the absence of outcome estimates and analysis details limits what can be concluded about comparative results. This makes the distinction between a study’s intended question and the results available in the registry especially important.
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 registry record does not report the primary endpoint results, including mean changes, standard deviations, between-group estimates, confidence intervals, or p-values. As a result, the primary comparative question cannot be answered from the record. Secondary outcome results are also not presented in the information described, despite the listed outcome categories.
Details needed to assess the analysis are limited. The statistical model, baseline adjustment, exact comparison structure, multiplicity handling, missing-data methods, and any sensitivity analyses are not reported in the registry record. The outcome population requires baseline and post-baseline measurements and available outcome data, but the number and reasons for unavailable measurements are not reported. The trial’s own sample-size rationale and interim analyses are not reported either.
The masking information is not fully elaborated. The registry identifies triple masking, while the summary says minoxidil was open-label and the remaining treatments were double-blinded. The record does not specify which personnel were masked for each arm or whether those who assessed the digital images remained unaware of treatment assignment.
The safety information is limited to group-level counts and a short list of serious adverse-event terms with percentages. The registry does not report event timing, duration, severity beyond the serious-event classification, relationship assessments, or comparative safety analyses in the information described. Death counts are not reported in the registry record. These limitations restrict interpretation of both efficacy and safety, and they should not be replaced with assumptions about unreported procedures or results.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety and Efficacy Study of Bimatoprost in the Treatment of Women With Female Pattern Hair Loss — NCT01325350.
- Registry record last updated 2014-04-09; status last verified 2014-03.
- Results first posted 2014-04-09.
- 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 completed Phase 2 randomized parallel-group study sponsored by Allergan, with enrollment listed as 306. It evaluated three bimatoprost formulations, vehicle, and minoxidil 2% solution in women with female pattern hair loss. Bimatoprost and vehicle were described as once-daily treatments for 6 months; minoxidil was described as twice daily for 6 months and open-label.
The primary outcome was change from baseline to Month 6 in target area hair count, measured by digital imaging analysis. The Modified Intent-to-Treat outcome population required treatment, baseline and post-baseline measurements, and available data. The registry reports selected serious and other adverse-event counts by treatment group but does not report primary outcome results or statistical comparisons. The analysis plan, missing-data methods, and multiplicity procedures are not reported in the registry record.