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 Assessment of Safety, Tolerability, Radiation Dosimetry, Imaging Properties of 89Zr-girentuximab in Patients With NMIBC (NCT04897763), a na early/phase 1 study. The primary outcome is Number of Participants With Uptake Spot in 89Zr-girentuximab PET/CT Images.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04897763 |
| Phase | EARLY/Phase 1 |
| Condition | Bladder Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 6 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Institut Cancerologie de l'Ouest |
| Results posted | Yes |
2. Clinical Question
Population
Patients with non-muscle-invasive bladder cancer (NMIBC). The registry record lists an enrollment of 6 participants.
Intervention
89Zr-TLX250, also called 89Zr-girentuximab, with PET/CT imaging. The study description identifies the agent as a carbonic anhydrase IX (CAIX)-targeted radiopharmaceutical.
Comparator
There is no comparison group in this single-group study. The allocation field is listed as not applicable, and the record does not describe a control arm.
Primary question
Did bladder and whole-body PET/CT images show an uptake spot in the bladder wall after 89Zr-girentuximab? The primary outcome is the number of participants with an uptake spot within the stated 3 days timeframe.
The study focuses on whether uptake can be observed on imaging, rather than on a comparison of treatment outcomes. Its stated purpose is to evaluate the safety, tolerability, radiation dosimetry, and imaging properties of 89Zr-labeled girentuximab in patients with NMIBC. The registry also lists outcomes concerning CAIX expression in tumor cells, adverse events, serious adverse events, and radiation protection management.
As a general statistical distinction, a count of participants with an imaging finding can describe whether the finding was observed in the enrolled group. Without a comparator, that count cannot estimate how the imaging finding differs from a separate group or establish a causal effect. The record does not report how many participants had an uptake spot, so the primary question cannot be answered from its posted outcome information.
3. Trial Design
The registry describes a pilot, open-label, feasibility study in early phase 1. It is a single-group study with an enrollment of 6 participants. The listed intervention is 89Zr-TLX250, which the record also calls 89Zr-girentuximab. The arm description says PET/CT was performed for all participants in the group.
There is no randomized allocation or masking: allocation is listed as not applicable, and masking is listed as none. Because there is no separate control arm, outcomes from this study are descriptive of the enrolled participants and cannot be read as a head-to-head comparison. The registry explicitly flags that the arms are not a like-for-like control comparison.
The recorded study start date is 2021-12-15, and the primary completion date is 2022-08-24. Its status is completed. The official title describes assessment of safety, tolerability, radiation dosimetry, and imaging properties. The brief summary describes the aim as evaluating a CAIX-targeted PET/CT radiopharmaceutical for imaging NMIBC.
The primary outcome is the number of participants with an uptake spot in 89Zr-girentuximab PET/CT images, with a stated timeframe of 3 days. The registry lists 7 outcome measures overall. It does not report participant-level primary outcome results or an analysis of them. A protocol-level rationale for the enrollment target, including a sample-size justification, is not reported in the registry record.
The registry record supports describing this as a small, open-label feasibility investigation. It does not give enough information to characterize additional operational features, such as the detailed imaging schedule or the procedures used to assess images; those details 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.
Before assignment: All screened patients have been enrolled
Overall Study
| Stage | 89Zr-TLX250 PET/CT |
|---|---|
| STARTED | 6 |
| COMPLETED | 6 |
| NOT COMPLETED | 0 |
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 | 89Zr-TLX250 |
|---|---|---|
| Participants analysed | 6 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 |
| Age, Categorical: >=65 years | Participants | 6 |
| Sex: Female, Male: Female | Participants | 2 |
| Sex: Female, Male: Male | Participants | 4 |
| Race and Ethnicity Not Collected | Participants | — |
| Region of Enrollment: France | Participants | 6 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Uptake Spot in 89Zr-girentuximab PET/CT Images, measured over 3 days.
| 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 an uptake spot in the bladder wall on 89Zr-girentuximab bladder and whole-body PET/CT images. The registry specifies a timeframe of 3 days. In statistical terms, this is a participant count for a binary finding: each participant is classified according to whether an uptake spot is present or absent.
As a general explanation, a binary imaging endpoint can be useful in a feasibility study because it records whether a prespecified type of imaging finding was observed. The count may help describe the imaging signal within the studied group, while the underlying image interpretation and any criteria for deciding what qualifies as an uptake spot are important to understanding how consistently the finding was assessed.
The registry description identifies the presence or absence of an uptake spot, but it does not report detailed image-reading criteria, reader blinding, or procedures for resolving disagreement. Those methods are not reported in the registry record. Nor does the record report the number of participants with or without an uptake spot. Without that result, the endpoint's observed frequency and its precision cannot be described.
This endpoint is an imaging measure, not a direct comparison of clinical outcomes. It can characterize an observation in this group, but by itself it cannot establish diagnostic accuracy, predict an individual patient's outcome, or show a difference from an alternative imaging approach. Such conclusions would require information and comparisons not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a clearly defined primary imaging outcome: the number of participants with an uptake spot in the bladder wall on 89Zr-girentuximab PET/CT images within the stated 3 days timeframe. However, it does not report the observed count, the number without an uptake spot, or a statistical analysis of that endpoint. Consequently, the primary imaging result cannot be interpreted from the registry record, and no estimate of its precision is available there.
The safety information is more concrete but remains limited. For the 89Zr-TLX250 group, the registry lists 6 participants at risk of serious adverse events and 2 affected. It lists 6 participants at risk of other adverse events and 1 affected, with 0 deaths. Urinary retention and bladder bleeding are each listed among the top serious adverse event terms at 16.7%. The record does not clarify whether those terms occurred in the same participants or give fuller event-level details.
These safety counts describe what the registry reports for this small enrolled group; they should not be treated as a comparative estimate. No untreated or alternative-imaging group is listed, and the study is open-label. The counts therefore do not establish whether an event rate differs from another setting or whether an event was caused by the imaging agent. The registry lists outcomes related to adverse events, but does not provide a detailed account of assessment procedures or exposure time for each event.
As a general statistical principle, a count from a small cohort is subject to substantial uncertainty about the frequency that might be seen in a broader population. A confidence interval would convey some of that uncertainty, but no interval for the primary endpoint or safety outcomes is reported in the registry record. A point count alone should not be mistaken for a highly precise estimate.
The record lists 7 outcome measures and no analyses. It does not report a statistical analysis plan, adjusted estimates, p-values, or methods for handling missing outcome information. The posted the registry entries therefore support a description of the study design and the stated safety counts, but not an inferential conclusion about the primary imaging outcome. The absence of a reported primary result is not evidence that uptake was absent; it means the registry record does not state the result.
9. Statistical Methods Explained
What does the primary count represent?
The primary outcome is a count of participants classified by whether an uptake spot was present in the bladder wall on the specified PET/CT images. This is a binary outcome recorded at the participant level, rather than a continuous measurement such as a numerical imaging value. The registry describes the presence or absence of the finding and gives a timeframe of 3 days.
As a general explanation, a count is easiest to interpret when its denominator, outcome definition, and assessment process are clear. The group size is listed as 6, but the registry does not report the primary outcome count, image-reading rules, or whether any images were unavailable or unevaluable. The count and its denominator therefore cannot be fully interpreted from the outcome reporting.
Why is a single-group design important?
The study is listed as single-group, with no masking and allocation marked not applicable. A descriptive count can show what was recorded among the enrolled participants, if that result is reported. It cannot, on its own, estimate a difference between imaging approaches or separate the effect of the intervention from other explanations. A comparison requires a relevant comparator and a design that supports interpreting the groups fairly; neither is described.
As a general concept, randomization can help make treatment groups comparable on average, and masking can reduce some forms of assessment or expectation bias. Those design features are not present in this record. This does not invalidate the study's feasibility purpose, but it limits the kinds of comparative inferences its results could support.
How should uncertainty be understood?
Any estimate based on a small group is uncertain. A confidence interval is a range calculated from data under a statistical model that communicates the uncertainty around an estimate. It is not a guarantee that the true value lies in the interval, and its width depends on the data and method. No confidence interval for the primary imaging endpoint is reported in the registry record, and the endpoint count itself is also not reported.
For participant counts, the number of people with an event and the number observed are both important. A percentage may make a count easier to compare descriptively, but with a small denominator a small change in the number of participants can substantially change the percentage. No percentage for the primary endpoint can be described because its result is absent from the registry record. The serious adverse event figures should likewise be read as counts in this enrolled group, not as precise estimates for a wider population.
What does over-dispersion mean in general?
Over-dispersion is a general issue for count data when observed variability is greater than a model assumes. If a statistical model assumes observations vary less than they actually do, standard errors can be too small and intervals or tests can appear more certain than warranted. This concept is not a reported feature or analysis of this study: the registry does not provide a count model, dispersion estimate, or inferential analysis for the primary endpoint.
What do the planning assumptions mean?
The record's sample-size assumptions describe planning illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The stated effect to detect is a fraction of the observed effect. These are planning assumptions, not a description of the actual single-group study, which has no like-for-like control arm. The registry record does not provide a protocol sample-size justification, and the planning assumptions should not be interpreted as observed power. A planning illustration estimates what a hypothetical design might require under its assumptions; it does not establish the probability that the completed study detected an effect.
As a general explanation, power is a design property calculated under specified assumptions about an effect, variability, significance threshold, and analysis. It is not a measure of how convincing a completed study's result is. Because the registry does not report the primary outcome result or a study-specific analysis, no conclusion about observed power or statistical evidence for the imaging endpoint follows from this record.
What analyses are reported?
The registry lists 7 outcome measures and no analyses. It does not report a statistical analysis plan, model, hypothesis test, adjusted estimate, or sensitivity analysis for the primary endpoint. The absence of a posted analysis does not show that no analysis was conducted outside the registry; it means those details are not reported in the registry record. Any interpretation should therefore stay close to the design and descriptive details that are recorded.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 7 outcome measures, including the primary imaging outcome and secondary outcomes concerning serious adverse events, CAIX expression in tumor cells, adverse events related to 89Zr-girentuximab, and radiation protection management. Radiation Protection Management appears twice in the listed secondary outcomes. The record does not explain whether these entries represent distinct measures or a duplicated listing.
As a general statistical concept, multiplicity arises when several outcomes or hypotheses are examined. The more tests conducted, the greater the chance that some may appear notable by chance if no adjustment or other plan is used. The registry record does not report how multiplicity was handled, whether formal hypothesis tests were planned, or whether any outcome was designated for confirmatory inference beyond the stated primary endpoint.
The primary outcome result and analysis are not reported, and the record lists no analyses. It also does not report the number of participants with missing or unevaluable primary images, missing-data rules, imputation methods, or sensitivity analyses. The analysis population is not described beyond the enrolled group and the intervention-arm safety denominators. These details are not reported in the registry record, so the effect of missing information on the outcome cannot be assessed.
These omissions matter for interpretation, but they do not establish that missing data or multiplicity problems occurred. They indicate that the registry does not provide enough detail to determine how those issues were addressed. The available information supports describing the planned outcomes and the reported safety counts, not reconstructing an unreported analysis.
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 |
|---|---|---|---|
| 89Zr-TLX250 | 2 | 6 | 33.3% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| 89Zr-TLX250 | 0 of 6 |
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 |
|---|---|
| 89Zr-TLX250 | 1 of 6 |
Most frequent serious adverse event terms
| Event term | Organ system | 89Zr-TLX250 |
|---|---|---|
| Urinary retention | Renal and urinary disorders | 1 of 6 |
| Bladder bleeding | Renal and urinary disorders | 1 of 6 |
Most frequent non-serious adverse event terms
| Event term | Organ system | 89Zr-TLX250 |
|---|---|---|
| Urethral bleeding | Renal and urinary disorders | 1 of 6 |
Serious events with the highest arm-level rate: urinary retention (16.7%), bladder bleeding (16.7%).
For the 89Zr-TLX250 group, the registry lists 6 participants at risk of serious adverse events, with 2 affected. It lists 6 participants at risk of other adverse events, with 1 affected, and records 0 deaths. The top serious adverse event terms are urinary retention and bladder bleeding, each listed at 16.7%.
These figures are descriptive registry counts. The record does not provide a detailed event-level account, clarify whether the two serious adverse event terms occurred in the same participant, or report the timing and duration of follow-up for each event. The listed percentages should therefore be read as the registry's reported term-level figures, not as a complete description of every participant's safety experience.
As a general statistical point, safety counts in a small group provide limited precision. They do not establish how often events would occur in a broader population, and the absence of a comparison group prevents a direct comparison with another intervention or setting. The counts alone also do not establish causality. Although the registry lists an outcome concerning adverse events related to 89Zr-girentuximab, it does not report further results or adjudication details for that outcome.
12. What the Result Does, and Does Not, Mean
The record identifies a feasibility study of 89Zr-girentuximab PET/CT in patients with NMIBC and defines its primary imaging question as whether an uptake spot was present in the bladder wall. It also reports limited safety counts for the enrolled group. Those details describe the study's focus and some posted safety information, but they do not supply the primary imaging result.
Accordingly, the registry record cannot establish how many participants had an uptake spot, how often the finding occurred, or how precisely its frequency was estimated. The absence of a reported result should not be interpreted as a zero count or as evidence that the imaging agent did not produce an observable finding. The result is simply not reported in the registry record.
The study's single-group, open-label design is consistent with an exploratory feasibility assessment, but it does not support a like-for-like comparison with another imaging approach. A count in the enrolled group would describe that group; without a comparator and additional supporting methods, it would not establish diagnostic performance or a causal effect. The record also does not report the analysis details needed to assess the endpoint beyond its stated definition.
As a general statistical distinction, feasibility and imaging signal questions are not the same as demonstrating clinical benefit. An observed image finding, if reported, would not by itself establish how useful it is for diagnosis or how it relates to patient outcomes. The registry record does not report such a clinical comparison or outcome.
The posted safety counts are also limited in scope. They show 2 participants with serious adverse events among 6 at risk, 1 with other adverse events among 6 at risk, and 0 deaths. The record does not provide enough event-level detail or a comparator to attribute events to the intervention or to estimate comparative safety. These findings should be read as observations from the enrolled group, not as definitive evidence for a wider population.
13. Why This Trial Matters Statistically
This study is statistically relevant because it illustrates the distinction between a feasibility question and a comparative efficacy question. Its stated focus is whether a CAIX-targeted radiopharmaceutical can be assessed through PET/CT imaging in patients with NMIBC, alongside safety, tolerability, radiation dosimetry, and imaging properties. The single-group format can support descriptive learning about the enrolled participants, but it does not create a direct comparison with another approach.
The endpoint is a participant count based on the presence or absence of an imaging finding. That is a straightforward outcome type, but interpretation still depends on transparent image assessment rules, a reported result, and an account of missing or unevaluable images. The registry gives the endpoint description and timeframe but does not report its result or those assessment details. This makes clear how endpoint specification and outcome reporting are distinct parts of statistical interpretation.
The limited cohort also underscores the role of precision. As a general statistical principle, small samples tend to leave substantial uncertainty around event frequencies. Reporting a count alone does not remove that uncertainty, and a study with a feasibility aim should not be judged as if it were a definitive comparative trial. Here, the primary outcome count is not available in the registry record, so even a descriptive estimate cannot be assessed.
Finally, the registry's safety counts can be stated without overstating what they show. They describe events among participants in the intervention group, while the absence of a comparator limits causal and comparative interpretation. This is a useful example of why design, outcome reporting, and uncertainty need to be considered together rather than treating a count as a conclusion by itself.
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 enrolled group is small, with 6 participants, and the study has a single-group, open-label design. There is no randomized comparator or masking. These features limit the ability to distinguish an intervention-related finding from other explanations or to compare outcomes with another imaging approach. They are particularly important when interpreting safety counts or any imaging observation.
The most consequential reporting limitation is that the registry does not report the primary endpoint result. The number of participants with an uptake spot and the number without one are not stated. No estimate of precision, such as a confidence interval, is reported for that endpoint. As a result, the central imaging question cannot be answered from the registry record.
Details about image-reading criteria, reader procedures, missing or unevaluable images, and the analysis population are not reported in the registry record. The record also does not report a statistical analysis plan or how multiplicity and missing data were handled. These gaps prevent a fuller assessment of how the primary outcome was measured and analyzed.
The registry lists 7 outcome measures and no analyses. Some secondary outcomes are named, but results for those outcomes are not provided in the registry record recorded. Radiation Protection Management appears twice in the secondary-outcome list, without an explanation of whether the entries are distinct. The safety information includes counts and two top serious adverse event terms, but not detailed event-level descriptions or enough information to interpret timing and overlap.
These limitations concern what can be concluded from the registry record. They do not establish that particular procedures were absent or that unreported analyses were never performed; those details are not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Assessment of Safety, Tolerability, Radiation Dosimetry, Imaging Properties of 89Zr-girentuximab in Patients With NMIBC — NCT04897763.
- Registry record last updated 2026-01-07; status last verified 2025-09.
- Results first posted 2026-01-07.
- 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
NCT04897763 is a completed early phase 1, pilot, open-label, single-group study sponsored by Institut Cancerologie de l'Ouest. It enrolled 6 patients with bladder cancer, with the study description focused on non-muscle-invasive bladder cancer. The recorded start date is 2021-12-15, and the primary completion date is 2022-08-24.
The intervention is 89Zr-TLX250, also identified as 89Zr-girentuximab, with PET/CT imaging. The primary outcome is the number of participants with an uptake spot in the bladder wall on bladder and whole-body images within a timeframe of 3 days. The registry record does not report the primary outcome result or an analysis of it.
For safety, the record lists 2 participants with serious adverse events among 6 at risk, 1 participant with other adverse events among 6 at risk, and 0 deaths. Urinary retention and bladder bleeding are each listed at 16.7% among the top serious adverse event terms. No comparison group is described.