A Phase 3 Single-Arm Study of UGN-102 for Treatment of Low-Grade Intermediate-Risk Non-Muscle Invasive Bladder Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Phase 3 Single-Arm Study of UGN-102 for Treatment of Low-Grade Intermediate-Risk Non-Muscle Invasive Bladder Cancer (NCT05243550), a na phase 3 study. The primary outcome is Complete Response Rate (CRR).

2. Clinical Question

3. Trial Design

This is a Phase 3, multinational, single-arm study sponsored by UroGen Pharma Ltd. Its stated purpose was to evaluate the efficacy and safety of UGN-102 as primary chemoablative therapy in patients with recurrent low-grade intermediate-risk non-muscle invasive bladder cancer. The study is identified as NCT05243550. The registry lists an enrollment of 240, a start date of 2022-03-01, and a primary completion date of 2023-04-26. Its current status is active, not recruiting.

All participants in the treatment group were assigned to receive UGN-102. The regimen is described as 6 once-weekly intravesical instillations of UGN-102 (75 mg mitomycin). There was no randomized allocation, no masking, and no like-for-like control arm. A single-arm study can describe outcomes among treated participants, but its design cannot isolate a treatment effect by comparing outcomes against a concurrent group receiving another treatment or control.

The primary outcome was complete response rate at 3 months, measured as a percentage of participants. The defined primary analysis population includes all patients who received any dose of UGN-102. Secondary outcomes include duration of response, durable complete response rate, and disease-free survival among participants who achieved complete response at the 3-month visit. Safety outcomes include treatment-emergent adverse events, serious treatment-emergent adverse events, events of special interest, and post-baseline potentially clinically significant hematology and chemistry values.

The registry record does not report the protocol’s sample-size justification, the planned statistical analysis details beyond the endpoint’s confidence interval, or whether interim analyses were planned. The planning illustration described with the posted material uses a two-arm framework and is not the design of this single-arm study.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All patients who received any dose of UGN-102.

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: All patients who received any dose of UGN-102.

6. Primary Endpoint

The registry lists the primary outcome as Complete Response Rate (CRR), measured over 3 months.

The primary endpoint is the complete response rate at 3 months. It is defined as the percentage of participants who achieved a complete response at the 3-month visit. A participant counted as having a complete response only when no detectable disease was found in the bladder based on white light cystoscopy, biopsy of remaining lesions if applicable, and voiding urine cytology. The stated population is all patients who received any dose of UGN-102.

This endpoint brings together visual examination, tissue assessment when lesions remain, and urine cytology. In general, combining assessment methods can make a response definition more comprehensive than relying on a single observation. The endpoint is a binary outcome at a specified visit: each participant is classified as having achieved complete response or not, and the response rate expresses the proportion classified as responders.

The registry specifies a 95% confidence interval for the response rate. In general, a confidence interval communicates the statistical uncertainty around an estimated percentage; its width depends on the amount of information and the observed data. The registry record does not report the observed percentage, the interval limits, or the method used to calculate the interval. Without those results, the endpoint definition can be described, but the observed response and its precision cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is a percentage: participants are classified according to whether they achieved complete response at the 3-month visit, and the response rate describes the share classified as responders. This kind of endpoint is often called binary because each participant’s endpoint status falls into one of two categories. The registry defines the assessment criteria and specifies that the response rate is reported with a 95% confidence interval. It does not report the calculation method or the actual estimate and interval.

What does a confidence interval communicate?

In general, a confidence interval gives a range of values compatible with the data under the statistical method used. It is a measure of uncertainty around an estimate, not a guarantee that the true value lies within the particular interval. A narrower interval indicates greater precision under the method’s assumptions; a wider interval indicates less precision. The width depends on factors such as the amount of information and the observed response pattern. Since the interval limits are not reported in the registry record, its precision cannot be evaluated for this endpoint.

What can a single-arm estimate establish?

A single-arm design estimates outcomes among participants receiving the study intervention. It can describe the response rate observed in the treated group, using the chosen endpoint definition and analysis population. It does not provide a concurrent control-group estimate. Without a randomized comparison, differences between treated participants and an external benchmark could reflect differences in participant characteristics, assessment practices, follow-up, or other factors, as well as any treatment effect. This is why a single-group response percentage should not be read as a direct estimate of the effect relative to another intervention.

The registry classifies allocation as not applicable, masking as none, and the model as single group. These design features are consistent with the absence of a randomized or masked comparison. The record does not report a planned model for adjustment, an external comparator, or a statistical hypothesis test for the primary endpoint. It is not possible to infer such plans from the study phase or endpoint type.

How should the planning illustration be understood?

The planning assumptions associated with the posted material describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. They define the effect to detect as a stated fraction of the observed effect. The assumptions also distinguish between participants per arm for outcomes other than time-to-event outcomes and total events for time-to-event outcomes. These are planning assumptions for an illustration based on an observed effect, not a description of the single-arm trial’s actual design or its original sample-size justification.

A planning illustration answers a hypothetical question about the sample size or event total under specified assumptions. It does not show how many participants were observed to respond, and it is not observed power. The registry record does not report the trial’s own sample-size justification or the assumptions used to set its enrollment. The posted material does not include the values needed to interpret a particular planning estimate in the registry record for this analysis.

What is not available about the statistical analysis?

The registry record lists no posted analyses. It does not specify the method used to calculate the primary confidence interval, how missing endpoint assessments were treated, or whether the primary analysis was adjusted for any covariates. It also does not report an interim analysis plan or a strategy for controlling multiplicity across endpoints. These omissions prevent a detailed reconstruction of the statistical analysis plan.

In general, over-dispersion is a concern when observed variability is greater than a statistical model expects. It can make standard errors and confidence intervals too small if the model does not account for the extra variability. Whether this issue is relevant depends on the endpoint and analysis method. The registry record does not identify a model for the primary binary endpoint, so no claim can be made about whether over-dispersion was assessed or how it was handled.

For the secondary time-to-event outcomes, interpretation generally depends on follow-up time, event definitions, censoring rules, and the analysis population. Duration of response and disease-free survival are described for participants who achieved complete response at the 3-month visit. The record does not report their event counts, time-to-event estimates, censoring details, or analysis methods. The existence of a named outcome is not evidence that an analysis result has been posted.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("UGN-102")
n      <- c(240)
events <- c(184)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  UGN-102  240  184  76.7  70.8  81.9  70.9  81.6  70.9  81.6

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists one primary endpoint, complete response rate at the 3-month visit, and several secondary outcome measures. The secondary outcomes include duration of response, durable complete response rate, and disease-free survival among participants who achieved complete response at the 3-month visit, as well as adverse-event and laboratory safety measures. The record does not report a statistical strategy for handling multiple endpoints or comparisons. In general, testing or interpreting multiple outcomes can increase the chance of finding an apparently notable result by chance; a prespecified multiplicity strategy can help address that concern. No such strategy is reported.

The registry specifies the primary endpoint population as all patients who received any dose of UGN-102. It does not report the number of participants included in the primary endpoint analysis, the number with missing or unevaluable response assessments, or the method used to handle missing data. Missing-data methods can affect an estimated response rate, especially when the outcome status of participants without an assessment is unknown. The record does not say whether such participants were excluded, treated as nonresponders, or handled by another approach, so none of these approaches should be assumed.

The secondary response-duration and survival outcomes are restricted to participants who achieved complete response at the 3-month visit. The record does not report how participants entered those analyses, how incomplete follow-up was addressed, or how censoring was defined. Those details matter because time-to-event analyses rely on knowing when events occur and how participants without an observed event contribute follow-up information.

The registry lists no posted analyses. It also does not report interim analyses or stopping rules. These omissions mean the available record supports an account of the planned endpoints and their stated populations, but not a full assessment of missing-data handling, multiplicity, or analysis-set implementation.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 3% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: atrial fibrillation (0.8%), covid-19 (0.8%), urinary retention (0.8%), angina pectoris (0.4%), atrioventricular block second degree (0.4%).

The registry lists 240 participants at risk for the UGN-102 group. It reports 29 participants with serious adverse events and 129 with other adverse events; it also reports 3 deaths. These are descriptive counts, not comparative estimates. The record does not provide the information needed to determine from these counts alone whether events were related to treatment, when they occurred, or how long participants were followed.

The listed serious adverse event terms include atrial fibrillation, COVID-19, and urinary retention, each reported as 0.8%. Angina pectoris, atrioventricular block second degree, and cardiac failure are each reported as 0.4%. These are the selected terms listed in the registry record; the percentages should be read as reported, not recalculated. They do not describe the full range of events or establish causation.

In general, a count of participants with an event differs from an event rate that accounts for time at risk, and a serious-event count is not the same as a severity grading or treatment-attribution assessment. The registry information cited does not report exposure-adjusted rates, event timing, relatedness, or a control-group comparison. The deaths are listed as a count without cause or attribution in this record.

13. What the Result Does, and Does Not, Mean

The study was designed to evaluate UGN-102 as primary chemoablative therapy in patients with recurrent low-grade intermediate-risk non-muscle invasive bladder cancer. Its primary endpoint is clearly defined: the percentage of participants achieving complete response at the 3-month visit, based on cystoscopy, biopsy of remaining lesions when applicable, and voiding urine cytology. The registry also identifies the primary analysis population and selected safety outcomes.

However, the registry record does not report the observed complete response rate or its 95% confidence interval. It therefore does not allow readers to assess the size or precision of the primary endpoint result. It also does not report results for the listed secondary efficacy outcomes. A study’s stated endpoint and design describe what it intended to evaluate; they are not substitutes for the observed results.

The single-arm design can describe outcomes among participants who received UGN-102, but it cannot directly show how those outcomes compare with another treatment or a control group. Without a concurrent comparator, the registry record does not establish the difference in outcome attributable to treatment. The safety counts similarly describe events in the study group, but do not establish causation or comparative risk.

The reported information is useful for understanding the study’s population, intervention schedule, response definition, and selected adverse-event counts. It is not enough to judge a treatment effect, assess the precision of the primary estimate, or make a comparative safety assessment. Those questions would require outcome and analysis details that are not reported in the registry record.

14. Why This Trial Matters Statistically

This study raises a useful statistical distinction between defining an outcome and reporting its result. The registry specifies a clinically structured complete-response definition and a follow-up time, and it identifies the population used for the primary endpoint. Those details are essential for interpreting a response estimate. But without the percentage and confidence interval, the endpoint description cannot tell readers what response was observed or how precise the estimate was.

The single-arm design is also important to statistical interpretation. A response rate from one treated group is a descriptive estimate for that group under the study’s conditions. A randomized comparator can support a direct estimate of a between-group difference; this registry record does not describe such a comparison. This distinction prevents a response percentage, if reported elsewhere, from being mistaken for a randomized treatment effect.

The endpoint’s assessment criteria bring together visual examination, biopsy when applicable, and urine cytology. In general, the operational details of an endpoint shape what is counted as a response and how consistently it can be assessed. The registry’s definition makes the intended classification rule explicit, while the absence of reported analysis details leaves questions about missing assessments and implementation unanswered.

Finally, the record illustrates why safety counts require context. Counts of serious and other adverse events, selected event terms, and deaths are informative descriptions, but they are not causal or comparative conclusions. Timing, follow-up, event attribution, and a comparator can all influence how safety findings are interpreted. The available record identifies some of these outcomes without supplying enough detail for a broader comparative assessment.

15. 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 main limitation for statistical interpretation is that the registry record does not report the primary complete response rate or its confidence interval. No posted analyses are listed, so the observed primary result and its precision cannot be evaluated from this record. The listed endpoints and definitions should not be mistaken for completed outcome findings.

The study has a single-group design with no randomized comparison. Any response or safety estimate from the treated group would be descriptive and would not provide a direct contrast with another treatment or control. This design limitation is especially relevant when interpreting outcomes as treatment effects or comparing them with results from other settings.

The record identifies the primary population as all patients who received any dose, but does not report the number with an evaluable 3-month assessment or how missing assessments were handled. It also does not report whether the endpoint analysis followed any other population definition. This leaves uncertainty about the completeness and implementation of the primary analysis.

For secondary outcomes, the registry record does not report outcome estimates, follow-up details, event counts, or analysis methods. The response-duration and survival outcomes apply to participants who achieved complete response at the 3-month visit, but the record does not describe censoring or the handling of incomplete follow-up. A multiplicity strategy is not reported, nor are interim analyses or stopping rules.

The safety information is limited to selected counts and serious-event terms. The record does not report event timing, attribution, exposure-adjusted rates, or a comparison group. It also does not give a cause or attribution for the 3 deaths. The protocol’s sample-size justification and detailed statistical analysis plan are not reported in the registry record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Phase 3 Single-Arm Study of UGN-102 for Treatment of Low-Grade Intermediate-Risk Non-Muscle Invasive Bladder Cancer — NCT05243550.
• Registry record last updated 2026-05-11; status last verified 2026-04.
• Results first posted 2024-11-04.
• 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.

19. Record Summary

NCT05243550 is a Phase 3, multinational, single-arm study sponsored by UroGen Pharma Ltd. It evaluated UGN-102 as primary chemoablative therapy for recurrent low-grade intermediate-risk non-muscle invasive bladder cancer. The regimen is described as 6 once-weekly intravesical instillations of UGN-102 (75 mg mitomycin); the registry lists enrollment of 240 and status active, not recruiting.

The primary endpoint is complete response rate at 3 months among patients who received any dose. The response definition uses white light cystoscopy, biopsy of remaining lesions when applicable, and voiding urine cytology. The registry record does not report the primary response result or confidence interval, and lists no posted analyses. It reports 29 participants with serious adverse events, 129 with other adverse events, and 3 deaths. The study has no concurrent comparator, and the registry does not report the detailed analysis, missing-data, or multiplicity plans.