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 Pilot Trial Using BR55 Ultrasound Contrast Agent in the Assessment of Prostate Cancer (NCT02142608), a na phase 1, phase 2 study. The primary outcome is Number of Lesions With Gleason Score ≥ 7 Identified by Ultrasound Molecular Imaging.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02142608 |
| Phase | Phase 1, Phase 2 |
| Condition | Prostate Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 19 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Bracco Diagnostics, Inc |
| Results posted | Yes |
2. Clinical Question
Population
The study enrolled participants with prostate cancer. The registry record lists an enrollment of 19. It does not report further eligibility details or describe the characteristics of the participants or the lesions assessed.
Intervention
All participants received BR55 as a single intravenous injection at a dose of 0.03 mL/kg. The study evaluated ultrasound molecular imaging after administration of the contrast agent.
Comparator
This was a single-group study, not a comparison of BR55 with a control treatment. Histopathology served as the reference for assessing whether lesions had Gleason Score ≥7.
Primary question
The primary question was whether BR55 ultrasound molecular imaging could identify prostate cancer lesions with Gleason Score ≥7, using histopathology as the truth standard. The registry record does not report the number of qualifying lesions identified.
The question is about identifying lesions, rather than comparing participant outcomes between treatment groups. The registry describes the primary measure as the number of lesions with Gleason Score ≥7 identified by ultrasound molecular imaging, within 30 minutes after BR55 administration. It also describes an assessment of BR55 binding level in relation to Gleason score in malignant lesions assessed by off-site histopathology.
That setup makes the pathology assessment central to interpreting the imaging question: it is the stated reference against which the imaging result was to be considered. It does not, by itself, establish how accurately the imaging identified lesions. Measures such as the number of lesions assessed, the number correctly identified, or diagnostic accuracy estimates are not reported in the registry record.
3. Trial Design
This completed pilot trial is listed as Phase 1 and Phase 2. It enrolled 19 participants and used a single-group design. The registry lists allocation as not applicable and masking as none. All participants received BR55; there was no randomized control arm or like-for-like treatment comparison.
The intervention is described as a single intravenous injection of BR55 at 0.03 mL/kg. The primary outcome timeframe was within 30 minutes after administration. Histopathology was the stated reference for determining whether lesions had Gleason Score ≥7. The record describes this as an assessment of BR55 binding level in relation to Gleason score in malignant lesions from off-site histopathology.
The registry lists the study start as 2014-08 and primary completion as 2015-07, with status recorded as completed. Bracco Diagnostics, Inc is listed as the sponsor. These record entries describe the study’s administrative and structural features; they do not establish what analyses were performed or what the primary assessment found.
A single-group design can describe observations after an intervention, but it does not create a randomized treatment contrast. In this trial, the role of histopathology is a reference standard for lesion assessment, not a separate intervention arm. The registry record does not report details such as the number of lesions evaluated, how imaging assessments were scored, who performed or interpreted them, or how disagreements between imaging and pathology were handled.
The record does not report a statistical analysis plan, a sample-size justification, or details of interim analyses. The sample-size planning illustrations associated with the posted results are not the trial’s own design justification, and no observed-effect estimate is reported in the registry record for interpreting such illustrations.
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: One participant was not dosed with BR55. Patient signed informed consent but did not receive investigational product. During pre-dose safety evaluations, it was discovered that patient may have potentially clinical significant abnormal ECGs (atrial fibrillation).
Overall Study
| Stage | BR55 |
|---|---|
| STARTED | 18 |
| COMPLETED | 18 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: BR55 binding level versus Gleason score in malignant lesions from off-site histopathology
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 | BR55 |
|---|---|---|
| Participants analysed | 18 | |
| Age, Continuous | years | 62.6 (SD 4.68) |
| Age, Customized: 18-64 years | Participants | 12 |
| Age, Customized: >= 65 years | Participants | 6 |
| Sex: Female, Male: Female | Participants | 0 |
| Sex: Female, Male: Male | Participants | 18 |
| Race/Ethnicity, Customized: American Indian or Alaska Native | Participants | 0 |
| Race/Ethnicity, Customized: Asian | Participants | 1 |
| Race/Ethnicity, Customized: Black | Participants | 1 |
| Race/Ethnicity, Customized: Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race/Ethnicity, Customized: White | Participants | 16 |
| Race/Ethnicity, Customized: Other | Participants | 0 |
| Weight | kg | 83.62 (SD 15.573) |
| Height | cm | 172.6 (SD 8.71) |
6. Primary Endpoint
The registry lists the primary outcome as Number of Lesions With Gleason Score ≥ 7 Identified by Ultrasound Molecular Imaging, measured over Within 30 minutes after administration of BR55.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | number of lesions |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the number of lesions with Gleason Score ≥7 identified by ultrasound molecular imaging after BR55 administration. Its stated timeframe is within 30 minutes. The endpoint targets lesions rather than participants, and the reference for the Gleason score is histopathology.
In general, an endpoint is a defined measurement used to address a study question. Here, a count of identified lesions is intended to describe the imaging findings for the category of lesions specified by the registry. It is important to distinguish that count from a diagnostic accuracy measure. A count alone does not show what proportion of all qualifying lesions was identified, nor does it describe how often imaging indicated a qualifying lesion when histopathology did not.
To interpret such a count fully, readers would need the result and relevant denominators, including how many lesions were assessed and how many met the pathology criterion. Those details, along with the primary endpoint result, are not reported in the registry record. The record therefore defines the intended measurement but does not provide enough information to quantify the imaging performance or its precision.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a specific primary question: whether BR55 ultrasound molecular imaging identified prostate cancer lesions with Gleason Score ≥7, with histopathology as the reference. It describes the measurement and its timeframe, but it does not report a numerical primary outcome result. It also lists zero analyses. Consequently, the record does not support a statistical estimate of how many qualifying lesions were identified, how variable that result was, or how closely imaging findings corresponded with pathology.
This absence matters because the endpoint is a lesion count, not a direct participant-level comparison. Without the number of lesions assessed and the number meeting the pathology criterion, a count of identified lesions cannot be interpreted as a proportion or as a measure of diagnostic accuracy. Sensitivity, specificity, predictive values, and confidence intervals for those quantities are not reported in the registry record. No such values can be inferred from the design description alone.
The study enrolled 19 participants, but enrollment does not reveal how many lesions were assessed. The registry record does not describe whether all enrolled participants contributed evaluable imaging or pathology data, nor does it identify an analysis population for the primary outcome. It therefore does not establish the extent to which the enrolled group and the population contributing to the primary endpoint were the same.
The safety entries report zero serious adverse events among 18 participants at risk and one other adverse event among 18 participants at risk. Deaths are recorded as zero. These are registry counts with an at-risk denominator of 18; the record does not explain the difference between that denominator and the enrollment of 19. They should be read as the posted safety counts, not as a complete characterization of all possible harms or as evidence about the primary imaging question.
There was no randomized comparator and masking is listed as none. Thus the study design does not provide a randomized comparison of BR55 with another intervention, and the record does not report whether imaging readers were blinded to pathology or other information. The intended comparison with histopathology is a diagnostic reference comparison, distinct from a controlled treatment comparison.
Overall, the record gives useful information about the pilot study’s structure and intended endpoint, but it does not post the primary result or analysis needed to quantify that endpoint. The evidence available in the registry record is therefore descriptive of the planned assessment and limited safety counts, rather than a reported estimate of lesion identification performance.
9. Statistical Methods Explained
General: A study design determines what comparisons the data can support. A single-group study observes participants who receive the same intervention. It can describe outcomes in that group, but it does not by itself provide a randomized contrast against a control group. In this trial, the registry lists a single-group model, no applicable allocation, and no masking. The design therefore differs from a randomized controlled comparison.
General: A diagnostic reference standard is used to classify the condition or feature that an assessment is intended to detect. The registry identifies histopathology as the truth standard for classifying lesions by Gleason score. That reference has a different role from a control arm: it is used to evaluate correspondence between imaging and pathology, rather than to compare two assigned treatments.
For the primary endpoint, the intended observation is a count of lesions with Gleason Score ≥7 identified by ultrasound molecular imaging. The registry specifies a timeframe within 30 minutes after BR55 administration. It does not report the observed count, the total number of lesions examined, or the number of lesions classified as Gleason Score ≥7 by histopathology. Without those figures, it is not possible to derive a proportion identified or a diagnostic accuracy estimate from the registry record.
General: A confidence interval describes a range of values compatible with an estimate under the assumptions of a statistical method. Its width reflects the precision of that estimate, among other factors. No confidence interval for the primary endpoint is reported in the registry record. Because there is no posted primary estimate, the precision of the primary result cannot be assessed from this record.
General: The unit of analysis should match the question and the structure of the data. A participant-level analysis and a lesion-level analysis answer different questions. This endpoint is defined in terms of lesions, while enrollment is reported in participants. The number of lesions per participant, the approach to handling more than one lesion from a participant, and any method accounting for such data structure are not reported in the registry record. These details would be relevant to understanding how uncertainty was estimated if a lesion-level analysis were presented.
General: If observations are more variable than a simple model assumes, a model that accounts for over-dispersion may be needed to avoid understating uncertainty. Whether over-dispersion is relevant depends on the outcome and the data structure. The registry record does not report a statistical model, a dispersion estimate, or an assessment of model fit, so there is no basis for describing how this issue was handled in the trial.
General: A sample-size calculation is a planning tool based on assumptions about the effect to be detected, variability, significance level, and design. It is not an observed result and does not show that a study had a particular probability of detecting an effect after the data have been collected. The planning illustrations associated with the posted results 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 fraction of an observed effect. Those are illustration assumptions, not a reported design rationale for this single-group trial. The registry record does not report a sample-size justification or an observed effect estimate on which to ground the illustrations.
General: A recalculation from posted summary statistics can differ from a sponsor’s analysis if the methods, adjustment, or underlying data differ. No recalculated primary analysis or sponsor analysis is reported in the registry record. There is therefore no basis to compare a recalculation with a sponsor result or to select between competing estimates.
The registry lists two outcome measures and identifies the number of participants with adverse events as a secondary outcome. It lists zero analyses. The specific analysis methods for the primary endpoint and safety outcome, including any adjustment or approach to uncertainty, are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
Multiplicity concerns arise when a study evaluates multiple outcomes, comparisons, or statistical tests. In general, testing many hypotheses can increase the chance of finding an apparently notable result by chance unless the analysis plan accounts for that testing structure. The registry lists two outcome measures, including the primary lesion-identification measure and a secondary measure concerning participants with adverse events. It does not report a multiplicity strategy or a set of analyses; the analysis count is zero.
The registry record does not describe how missing observations were handled. It does not report the number of participants with missing imaging or pathology assessments, whether any lesions were unevaluable, or whether incomplete observations were excluded or otherwise addressed. The impact of missing data on the endpoint therefore cannot be assessed.
Analysis populations are also not described. The record reports enrollment of 19 participants and an at-risk count of 18 for the safety figures, but it does not explain the relationship between those counts. It does not identify a population used for the primary endpoint, state whether all enrolled participants were included, or report the number contributing evaluable endpoint data.
These omissions limit interpretation of both the primary endpoint and the safety counts. In general, transparent reporting of the analysis population, missing-data handling, and multiplicity approach helps readers understand which observations contributed to each result and how uncertainty should be interpreted. Those methods 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 |
|---|---|---|---|
| BR55 | 0 | 18 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| BR55 | 0 of 18 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| BR55 | 1 of 18 |
Most frequent non-serious adverse event terms
| Event term | Organ system | BR55 |
|---|---|---|
| Diarrhea | Gastrointestinal disorders | 1 of 18 |
| Headache | Nervous system disorders | 1 of 18 |
The registry records zero serious adverse events among 18 participants at risk, one other adverse event among 18 participants at risk, and zero deaths. No serious adverse event terms are listed. The entries distinguish serious events from other adverse events; they should not be collapsed into a single category or treated as a full account of every safety detail.
General: “Serious” is a classification of an adverse event based on regulatory criteria; it is not simply a description of how intense a symptom felt. The registry’s serious-event count should therefore be read as the count recorded in that category, not as a measure of all event severity.
The safety denominator is 18, whereas total enrollment is 19. The registry record does not explain why the at-risk count differs from enrollment, identify the safety follow-up period, or provide further detail about the other adverse event. These counts are descriptive registry entries and do not establish that no other events occurred beyond those recorded in the posted results. They also do not answer the primary question about lesion identification.
12. What the Result Does, and Does Not, Mean
The record establishes that a pilot study was designed to examine BR55 ultrasound molecular imaging of prostate cancer lesions, with histopathology as the reference for Gleason Score ≥7. It documents a single-group study in which participants received BR55, and it defines a lesion-count endpoint within 30 minutes after administration. It also reports limited safety counts.
However, the registry does not report the primary endpoint result or an analysis. As a result, readers cannot use this record to quantify the number of qualifying lesions identified, determine the proportion of qualifying lesions detected, assess agreement with pathology, or judge the precision of an estimate. Diagnostic accuracy measures and confidence intervals are not reported in the registry record.
The design also does not support a randomized comparison between BR55 and a control intervention: there was one study group, and allocation was not applicable. Histopathology is the stated reference for evaluating lesions, not an alternative treatment group. The record does not report whether imaging interpretation was masked to pathology.
The safety counts describe what was entered for the participants at risk, but they do not provide a complete account of event timing, severity beyond the serious/non-serious classification, or the reason the safety denominator is 18 rather than the enrollment of 19. The absence of a listed serious event is not a substitute for the unreported primary endpoint result.
General: A study’s results are interpreted in light of its question, design, analysis, and precision. In this case, the registry information is enough to understand the intended assessment and several design features, but not enough to determine how the imaging performed. No conclusion about treatment benefit or lack of benefit follows from the missing primary outcome result.
13. Why This Trial Matters Statistically
This trial illustrates why the outcome’s unit matters. Enrollment is reported in participants, while the primary endpoint counts lesions. Those are distinct units, and the registry record does not report how many lesions were assessed or how lesion-level observations were analyzed. A participant count alone cannot describe the amount of information available for a lesion-count endpoint.
It also illustrates the difference between a diagnostic reference and a randomized comparator. Histopathology was designated as the reference for judging lesion Gleason score. That can support an imaging-versus-pathology question when results are reported, but it does not create a controlled comparison of BR55 with another intervention.
For statistical interpretation, a defined endpoint is only one part of the evidence. Readers also need the observed result, the analysis population, relevant denominators, and a measure of uncertainty. The registry record specifies the primary measurement and timeframe but reports no analysis. It therefore presents the question more clearly than it presents evidence that answers it.
The safety record similarly shows the importance of distinguishing counts from context. It lists the number of events and participants at risk, but does not explain the difference between the at-risk count and enrollment or provide fuller event details. These limitations do not negate the value of a clearly defined pilot question; they identify what remains necessary for statistical interpretation.
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 primary limitation for interpreting the trial is that the registry record does not report the primary outcome result, despite defining the endpoint. It also lists zero analyses. As a result, the central imaging question cannot be quantified from the posted registry information.
The study enrolled 19 participants, but the record does not report the number of lesions evaluated or the number meeting the histopathology criterion. Because the endpoint is expressed as a lesion count, the participant enrollment alone does not provide its denominator. The record also does not describe the analysis population, missing imaging or pathology observations, or any approach to uncertainty at the lesion level.
The single-group design, absence of masking, and lack of a randomized comparator limit the types of comparisons available. Histopathology is described as the reference standard, but the registry does not report details of image interpretation, whether readers knew pathology findings, or how discordant assessments were resolved.
The safety entries use an at-risk denominator of 18, while enrollment is 19. The registry does not explain this difference or state the safety follow-up period. It reports one other adverse event, zero serious adverse events, and zero deaths, but provides no serious event terms and no further description of the other event.
Finally, a sample-size justification, statistical analysis plan, multiplicity strategy, and missing-data methods are not reported in the registry record. These are specific gaps in the posted information; they should not be filled by assumptions about how the study may have been planned or analyzed.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Pilot Trial Using BR55 Ultrasound Contrast Agent in the Assessment of Prostate Cancer — NCT02142608.
- Registry record last updated 2021-03-29; status last verified 2021-03.
- Results first posted 2020-08-27.
- 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 record describes a completed Phase 1 and Phase 2 pilot trial of BR55 ultrasound molecular imaging in prostate cancer. The study enrolled 19 participants in a single-group design, with no masking and no applicable allocation. All participants received a single intravenous BR55 injection at 0.03 mL/kg.
The primary endpoint was the number of lesions with Gleason Score ≥7 identified by ultrasound molecular imaging within 30 minutes after administration, using histopathology as the reference. The primary result and analysis are not reported in the registry record.
Safety entries list zero serious adverse events among 18 participants at risk, one other adverse event among 18 participants at risk, and zero deaths. The reason the at-risk count differs from enrollment is not reported in the registry record.