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 Pivotal Study of the NanoKnife System for the Ablation of Prostate Tissue (NCT04972097), a na na study. The primary outcome is Number of Participants With a Negative In-field Biopsy at 12 Months.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04972097 |
| Phase | NA |
| Condition | Prostate Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 121 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Angiodynamics, Inc. |
| Results posted | Yes |
2. Clinical Question
The study evaluates irreversible electroporation (IRE) using the NanoKnife System as a focal treatment for prostate tissue in an intermediate-risk prostate cancer population. Its primary question concerns the biopsy result in the treated region of the prostate at 12 months. The registry record identifies the endpoint but does not report the number of participants with a negative in-field biopsy.
Population
Participants with intermediate-risk prostate cancer enrolled in the study. The registry lists an enrollment of 121.
Intervention
IRE treatment with the NanoKnife System. The arm description states that all enrolled participants receive this treatment.
Comparator
There is no separate control group in the registry record. It describes a single-group study, not a randomized comparison.
Primary question
How many participants have a negative biopsy in the prostate region treated with the study device at 12 months?
The endpoint addresses a local tissue finding in the treated area; it is not, by itself, a comparison of IRE with another treatment. The registry also lists secondary assessments concerning urinary and erectile function, prostate-specific antigen (PSA) kinetics, prostate volume, prostate tissue evaluated by mpMRI, and the need for secondary or adjuvant treatment. Their presence indicates a broader assessment program, but the primary question remains the in-field biopsy result at the specified follow-up time.
3. Trial Design
This is a completed, single-group device study of IRE treatment with the NanoKnife System. The registry lists 121 participants as enrolled and identifies prostate cancer as the condition. The study title and description specify an intermediate-risk patient population and describe the device as a focal therapy option. The arm description says that all enrolled participants receive IRE treatment.
The registry lists allocation as NA and masking as NONE. A single-group design does not include a concurrent control arm for a like-for-like comparison. As a result, the study record does not establish a randomized contrast between IRE and another treatment or control condition. The phase is listed as NA. The sponsor is Angiodynamics, Inc.
The recorded study start date is 2022-03-29, the primary completion date is 2024-08-14, and the status is COMPLETED. These dates describe the registry record's study timeline; they do not supply the results of the primary endpoint. Although the primary endpoint is defined as the number of participants with a negative in-field biopsy at 12 months, its result is not reported in the registry record.
Eleven outcome measures are listed, including the primary biopsy endpoint and secondary assessments of function, PSA, prostate volume, imaging, and further treatment. The registry record lists zero analyses. It does not report a detailed statistical analysis plan, a sample-size justification for the trial's own design, or information about interim analyses. Those details should not be inferred from the study's completed status or its outcome descriptions.
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 | NanoKnife System |
|---|---|
| STARTED | 121 |
| COMPLETED | 110 |
| NOT COMPLETED | 11 |
Reasons for not completing this period:
| Reason | NanoKnife System |
|---|---|
| Death | 1 |
| Lost to Follow-up | 2 |
| Withdrawal by Subject | 3 |
| Lack of Efficacy | 2 |
| Physician Decision | 1 |
| Adverse Event | 2 |
Analysis population for the primary outcome, as defined in the registry: ITT Population, n=14 subjects with missing biopsy information at 12 months were imputed as positive.
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: ITT Population
| Characteristic | Unit | IRE Treatment Arm |
|---|---|---|
| Participants analysed | 121 | |
| Age, Continuous | Years | 66.6 (SD 7.16) |
| Sex: Female, Male: Female | Participants | 0 |
| Sex: Female, Male: Male | Participants | 121 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 4 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 110 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 7 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 7 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 10 |
| Race (NIH/OMB): White | Participants | 100 |
| Race (NIH/OMB): More than one race | Participants | 1 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 3 |
| Region of Enrollment: United States | participants | 121 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With a Negative In-field Biopsy at 12 Months, measured over 12 months.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with a negative biopsy in the prostate region treated with the study device at 12 months. It is a count of participants, and the registry describes the target population for the endpoint as the ITT Population. The record states that 14 subjects with missing biopsy information at 12 months were imputed as positive.
A biopsy from the treated region provides a tissue-based assessment of that region at the specified follow-up. In general, a local endpoint is useful for describing findings in the area directly addressed by a focal intervention; it does not automatically describe outcomes across the whole prostate or establish a comparison with another treatment. The endpoint is therefore specific to the treated region and to biopsy status at 12 months.
The endpoint's meaning depends on both the biopsy assessment and the handling of missing biopsy information. Assigning missing results as positive means those participants are not counted as having a negative result under this definition. The registry record does not report the resulting number of participants with a negative in-field biopsy, so the endpoint's observed value cannot be described from the record. Nor does the endpoint alone provide a complete account of urinary function, erectile function, PSA measures, imaging findings, or subsequent treatment; those are separately listed outcome areas.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record specifies a clinically interpretable primary outcome: the number of participants whose biopsy is negative in the treated prostate region at 12 months. It also identifies an ITT population and states how missing biopsy information was handled. However, it does not report the observed primary endpoint count. Without that result, the endpoint cannot be quantified, and no conclusion about the frequency of negative in-field biopsies can be drawn from the registry record.
The record lists an enrollment of 121 and says that 14 subjects with missing biopsy information at 12 months were imputed as positive. Those details describe the study population and an analysis rule; they do not reveal the number of positive or negative biopsies among participants with available information. No denominator for an observed negative-biopsy proportion, and no estimate of that proportion, is reported in the registry record. No confidence interval or p-value for the primary endpoint is reported there either.
In general, a confidence interval communicates the precision of an estimate by indicating a range of values compatible with the data and the method used. Its width and interpretation depend on the estimate, sample information, and analysis approach. Because the registry record does not report the primary endpoint estimate or interval, its precision cannot be assessed from this record.
The single-group design is important for interpretation. The study describes participants who received IRE; it does not include a separate control arm for a like-for-like comparison. An outcome observed in one group can describe that group's experience, but by itself it cannot distinguish the effect of treatment from other explanations for the observed outcome. The record's allocation entry is NA, and the study model is SINGLE GROUP.
The registry lists secondary outcome areas involving urinary and erectile function, PSA kinetics, prostate volume, mpMRI evaluation, and need for secondary or adjuvant treatment. Listing these outcomes does not establish their results. Their results, along with the primary biopsy count, are not reported in the registry record. The adverse-event entries provide separate descriptive safety information, but they do not supply the missing primary endpoint result or a control-group comparison.
Overall, the record supports a description of the study question, design, endpoint definition, missing-data rule, and selected safety counts. It does not support a numerical assessment of the primary endpoint's observed value, its uncertainty, or a comparative treatment effect.
9. Statistical Methods Explained
The registry describes a single-group study in which all enrolled participants receive IRE treatment with the NanoKnife System. The primary endpoint is a count: the number of participants with a negative biopsy in the treated region at 12 months. The record specifies the ITT Population and states that 14 subjects with missing biopsy information at that time were imputed as positive. It lists zero analyses, so detailed inferential methods for the primary outcome are not reported in the registry record.
What does a count endpoint describe?
As a general statistical point, a count endpoint records how many participants meet a defined outcome, rather than measuring the size of a continuous change such as a score or a laboratory value. For this study, the event of interest is having a negative in-field biopsy at 12 months. A count can be read as a direct tally, but interpretation also depends on the population included and the rules used for missing observations. The registry record gives the endpoint definition and missing-data rule, but not the observed count.
What does the ITT designation mean?
In general, an intention-to-treat population is intended to retain participants according to their study assignment or inclusion in the study, rather than limiting analysis only to those with complete follow-up or treatment adherence. In a single-group study, the term still identifies the analysis population specified by the record; it does not create a randomized comparison. Here, the registry identifies the ITT Population and describes how missing biopsy information is classified. Additional details about the operational definition of that population are not reported in the registry record.
How does the missing-data rule affect interpretation?
The registry states that 14 subjects with missing biopsy information at 12 months were imputed as positive. For an endpoint counting negative biopsies, this rule does not count those missing observations as negative results. In general, an imputation rule makes an explicit analytic choice about values that were not observed; it is not the same as learning the participants' actual biopsy findings. The record does not report why biopsy information was missing or provide a separate analysis using a different assumption. Those aspects of the missing-data process are therefore not reported in the registry record.
What can be inferred from the design?
In general, a single-group study can describe outcomes observed in the treated group, but it lacks a concurrent control group for estimating a between-group contrast. The registry lists allocation as NA and masking as NONE, and describes all enrolled participants as receiving IRE. This means the record does not support a randomized comparison with another intervention. It also does not report an adjusted comparative analysis. The absence of a reported comparator should not be filled in by treating the sample-size illustration as though it described the actual trial arms.
How should the planning illustration be read?
The registry's sample-size assumptions describe a planning illustration computed from an observed effect, not the trial's own design. The stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect to detect set as a stated fraction of the observed effect. For time-to-event tables, the stated output is the total number of events using the Schoenfeld method; for other outcomes, it is participants per arm. These assumptions describe a hypothetical planning exercise, not the single-group allocation used in this study.
As a general statistical point, power calculations ask what sample size would be needed under specified assumptions about an effect, variability, significance level, and design. A planning illustration is conditional on those assumptions and is not evidence that a trial had a particular probability of detecting an effect after completion. Such sample sizes are not observed power. The specific sample-size outputs and the trial's own sample-size justification are not reported in the registry record.
What about multiplicity and uncertainty?
The registry lists eleven outcome measures, including several secondary areas, but lists zero analyses. It does not describe how multiple outcomes were handled, whether any multiplicity adjustment was planned, or which estimates and uncertainty measures were used. In general, testing or estimating many outcomes can raise questions about how chance findings and uncertainty should be interpreted. The appropriate approach depends on the prespecified analysis plan and the role of each outcome. Without that plan or analysis details in the registry record, no particular method should be assumed.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists eleven outcome measures, including the primary in-field biopsy endpoint and secondary measures concerning urinary function, erectile function, PSA kinetics, prostate volume, mpMRI assessment, and need for secondary or adjuvant treatment. It lists zero analyses. The registry record does not report a statistical plan describing which outcomes were designated for formal testing, how multiple outcomes were handled, or whether an adjustment for multiplicity was planned.
In general, when several outcomes are assessed, the interpretation of estimates and tests depends partly on whether they were prespecified as primary, secondary, or exploratory and on the approach to multiplicity. A correction or other strategy should not be presumed without a reported plan. The list of outcomes alone does not establish that all were tested or that any particular error-rate procedure was used.
For the primary endpoint, the registry identifies the ITT Population and specifies that 14 subjects with missing biopsy information at 12 months were imputed as positive. This is an explicit missing-data rule: those missing results are assigned to the positive category for the endpoint. The registry record does not report why the biopsy information was missing, whether other missing-data approaches were examined, or whether sensitivity analyses were conducted.
In general, an analysis population defines which participants contribute to an estimate, while a missing-data assumption determines how unavailable measurements are treated. Both can affect interpretation. Here, the ITT designation and positive imputation rule are reported, but the primary endpoint result and further analytic details are not reported in the registry record. Consequently, the effect of alternative assumptions and the robustness of any endpoint estimate cannot be assessed from the 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 |
|---|---|---|---|
| IRE Treatment Arm | 11 | 121 | 9.1% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| IRE Treatment Arm | 1 of 121 |
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 |
|---|---|
| IRE Treatment Arm | 100 of 121 |
Most frequent serious adverse event terms
| Event term | Organ system | IRE Treatment Arm |
|---|---|---|
| Haematuria | Renal and urinary disorders | 2 of 121 |
| Pneumonia | Infections and infestations | 2 of 121 |
| Disease progression | General disorders | 2 of 121 |
| Bladder spasm | Renal and urinary disorders | 1 of 121 |
| Urinary retention | Renal and urinary disorders | 1 of 121 |
| Urinary tract obstruction | Renal and urinary disorders | 1 of 121 |
| Diverticulitis | Infections and infestations | 1 of 121 |
| Urinary tract infection | Infections and infestations | 1 of 121 |
| Pyrexia | General disorders | 1 of 121 |
| Chills | General disorders | 1 of 121 |
Most frequent non-serious adverse event terms
| Event term | Organ system | IRE Treatment Arm |
|---|---|---|
| Haematuria | Renal and urinary disorders | 51 of 121 |
| Erectile dysfunction | Reproductive system and breast disorders | 22 of 121 |
| Dysuria | Renal and urinary disorders | 19 of 121 |
| Urinary retention | Renal and urinary disorders | 18 of 121 |
| Micturition urgency | Renal and urinary disorders | 17 of 121 |
| Pollakiuria | Renal and urinary disorders | 15 of 121 |
| Haematospermia | Reproductive system and breast disorders | 15 of 121 |
| Bladder spasm | Renal and urinary disorders | 10 of 121 |
| Urinary incontinence | Renal and urinary disorders | 7 of 121 |
| Urinary tract infection | Infections and infestations | 7 of 121 |
Serious events with the highest arm-level rate: haematuria (1.7%), pneumonia (1.7%), disease progression (1.7%), bladder spasm (0.8%), urinary retention (0.8%).
The registry reports safety counts for the IRE Treatment Arm, with 121 participants at risk in the serious and other adverse-event categories. It lists 11 participants affected by serious adverse events and 100 affected by other adverse events. The record also lists 1 death. These are descriptive figures for the treated group; there is no separate control group in this study record for comparison.
The registry lists the following serious adverse-event terms and percentages: Haematuria, 1.7%; Pneumonia, 1.7%; Disease progression, 1.7%; Bladder spasm, 0.8%; Urinary retention, 0.8%; and Urinary tract obstruction, 0.8%. These entries describe the terms and percentages recorded for the serious-event list. They do not establish that an event was caused by the device or procedure. The registry record does not report further details about the death or its relationship to treatment.
In general, adverse-event counts describe events or participants meeting the record's reporting definitions; they are not, without more information, a measure of comparative risk. The listed serious and other adverse-event counts should be read separately from the primary biopsy endpoint, and neither category supplies a control-group rate. The record does not provide enough information to make a causal comparison or to interpret these counts as treatment effects.
12. What the Result Does, and Does Not, Mean
The record establishes that a completed, single-group study evaluated NanoKnife IRE in an intermediate-risk prostate cancer population. Its primary endpoint is clearly defined as the number of participants with a negative biopsy in the treated prostate region at 12 months. The registry also reports an ITT population and an explicit rule for missing biopsy information: 14 subjects with missing information were imputed as positive.
What the record does not establish is the observed primary endpoint result. The number of participants with negative in-field biopsies is not reported in the registry record. It therefore cannot show, from the information recorded, how often the endpoint occurred or how precisely an estimate was measured. Secondary outcome results are also not reported in the registry record, despite the listed assessments of urinary and erectile function, PSA, prostate volume, imaging, and subsequent treatment.
The design also limits the kind of conclusion that can be drawn. All enrolled participants receive IRE, and the study is described as single-group, with allocation listed as NA. In general, outcomes observed in a single treated group do not provide a randomized comparison with another treatment or control. The registry record therefore does not establish a comparative treatment effect.
The safety entries document serious and other adverse-event counts, selected serious-event terms, and a death. They are useful as descriptive information about the study group, but do not by themselves establish causation or comparative safety. Overall, the record describes the study's purpose, design, endpoint definition, missing-data handling, and selected safety information. It does not report the result needed to quantify the primary endpoint or the analyses needed to assess its uncertainty.
13. Why This Trial Matters Statistically
This study is statistically notable for the distinction between a well-defined endpoint and an unreported endpoint result. The primary question is specific: the count of participants with a negative biopsy in the treated prostate region at 12 months. The registry also makes an important analysis choice visible by stating that 14 subjects with missing biopsy information were imputed as positive. These details help readers understand what the primary measure is intended to represent and how missing observations were classified.
The single-group design is equally important. All enrolled participants receive IRE with the NanoKnife System, and the registry identifies no like-for-like control arm. In general, descriptive outcomes from one group answer a different statistical question from a randomized comparison. The former describes what was observed in the group; the latter can estimate a contrast between assigned strategies under the study's design and assumptions. This registry record supports the former design description, not a randomized comparative conclusion.
The record also lists multiple outcome areas, from biopsy findings to function, PSA, imaging, and further treatment. In general, a collection of outcomes requires clarity about the role of each outcome and how analyses account for multiple assessments. The registry lists eleven outcome measures but zero analyses, and does not report a detailed plan for multiplicity or uncertainty. That gap matters because outcome definitions alone do not reveal which estimates were calculated or how they should be interpreted.
Finally, the sample-size assumptions are explicitly framed as a planning illustration rather than the trial's own design. Their hypothetical two-arm assumptions should not be confused with the single-group study structure. Together, these points make the registry useful for understanding the question and design while leaving the primary numerical result and its inferential interpretation unreported.
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 efficacy is that the registry record does not report the primary endpoint result. Although it defines the outcome and states the missing-biopsy rule, it does not give the number of participants with a negative in-field biopsy at 12 months or an estimate of uncertainty. The listed secondary outcome areas likewise do not include reported results in the record.
The study is single-group, and the registry lists no like-for-like control comparison. Therefore, the record cannot establish a randomized contrast between IRE and another intervention. The allocation entry is NA, and masking is listed as NONE. The registry record does not report a detailed statistical analysis plan, adjustment methods, interim analyses, or the trial's sample-size justification.
Missing biopsy information is handled by imputing 14 subjects as positive, but the reason for missingness and the results of any sensitivity analyses are not reported in the registry record. The reader therefore cannot assess how the primary endpoint might change under alternative assumptions about missing information.
For safety, the record lists participant counts, selected serious adverse-event terms and percentages, and a death, but does not provide a control group for comparison. Further details about the death and its relationship to treatment are not reported in the registry record. These limitations constrain causal and comparative interpretations; they do not alter the descriptive details that the registry does report.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Pivotal Study of the NanoKnife System for the Ablation of Prostate Tissue — NCT04972097.
- Registry record last updated 2026-06-02; status last verified 2026-05.
- Results first posted 2026-06-02.
- 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.
Continue through the Clinical Biostats statistical pathway
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18. Record Summary
The registry record describes a completed, single-group study of IRE with the NanoKnife System in an intermediate-risk prostate cancer population. It lists 121 enrolled participants, allocation as NA, and masking as NONE. The recorded study start date is 2022-03-29, and the primary completion date is 2024-08-14.
The primary endpoint is the number of participants with a negative biopsy in the treated prostate region at 12 months. The record identifies the ITT Population and says 14 subjects with missing biopsy information were imputed as positive, but does not report the primary endpoint result. Eleven outcome measures are listed, while the registry lists zero analyses.
Safety entries include 11 participants affected by serious adverse events, 100 affected by other adverse events, and 1 death. The record does not provide a randomized comparator. Its design, endpoint definition, missing-data rule, and selected safety counts are reported; the primary endpoint result and detailed statistical analysis are not reported in the registry record.