Study of BN83495 in Post-menopausal Women With Endometrial Cancer Post-chemotherapy: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study of BN83495 in Post-menopausal Women With Endometrial Cancer Post-chemotherapy (NCT01251354), a na phase 2 study. The primary outcome is Determination of Clinical Benefit (CB), Defined as Sum of Patients Who Present Complete Response (CR), Partial Response (PR) or Stable Disease (SD) ≥12 Weeks (CB=CR+PR+SD≥12 Weeks) Using Response Evaluation Criteria in Solid Tumors (RECIST Version1.1).

2. Clinical Question

In practical terms, the study was intended to describe tumor response or disease stability after BN83495 in a specific post-chemotherapy population. The record also lists secondary outcomes concerning adverse events, time to progression, progression-free survival, overall response rate, duration of response and overall survival. Those outcomes describe different aspects of safety and disease course; they are not interchangeable with the primary clinical-benefit measure. The registry does not report analysed efficacy results for these outcomes.

3. Trial Design

This was a Phase II, international, multicenter, open-label, proof-of-concept study of BN83495. The registry classifies it as a single-group study with no masking and no applicable allocation. The title and official title describe postmenopausal women with advanced, metastatic or recurrent ER-positive endometrial carcinoma who had received one line of chemotherapy in the adjuvant or metastatic setting. Enrollment was 6.

A single-group design can describe what happened among participants receiving the study intervention, but it does not directly estimate how outcomes would have differed under a separate control treatment. Without a randomized comparator, differences attributable to the intervention cannot be separated from other explanations using this trial alone. The open-label designation means masking was not used; the registry lists masking as none. Details about outcome-assessment procedures beyond the stated RECIST criteria are not reported in the registry record.

The study status is terminated, and the registry records early termination. The primary endpoint description states that data were not collected or analysed for that endpoint because of the low number enrolled. The record does not report why the study was terminated, the intended enrollment target, or whether recruitment stopped for a particular operational or scientific reason.

The intervention list contains BN83495 as a drug, but the treatment dose and schedule are not reported in the registry record. The listed timeframe for the primary endpoint is 12 weeks. The registry also names several secondary outcomes, but it reports no analyses. Consequently, the design establishes what investigators intended to study, while the record does not establish an efficacy result for the planned primary question.

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: Six patients from five centres were screened for inclusion. All six patients were enrolled and treated

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The study was terminated early and due to the low number of patients enrolled, data was not collected/analysed for this endpoint

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.

6. Primary Endpoint

The registry lists the primary outcome as Determination of Clinical Benefit (CB), Defined as Sum of Patients Who Present Complete Response (CR), Partial Response (PR) or Stable Disease (SD) ≥12 Weeks (CB=CR+PR+SD≥12 Weeks) Using Response Evaluation Criteria in Solid Tumors (RECIST Version1.1), measured over 12 weeks.

The primary endpoint was clinical benefit, defined as the sum of participants with complete response, partial response or stable disease lasting at least 12 weeks. The criteria were based on RECIST version 1.1, which uses changes in measured target lesions and the appearance of new lesions to classify disease response or progression.

Under the registry definitions, complete response requires disappearance of all target lesions, with pathological lymph nodes reduced to less than 10 mm in short axis. Partial response requires at least a 30% decrease in the sum of target-lesion diameters from baseline. Stable disease means neither enough shrinkage for partial response nor enough increase for progressive disease, using the smallest sum measured while on study as the reference. Progressive disease includes at least a 20% increase from the smallest on-study sum and an absolute increase of at least 5 mm; a new lesion also counts as progression.

Combining response and sustained stable disease into a clinical-benefit endpoint can describe disease control over a specified period, rather than counting only tumor shrinkage. The duration condition matters because a response or stable measurement is only counted when it meets the stated time criterion. Here, however, the registry says the endpoint data were not collected or analysed after early termination and low enrollment. The endpoint definition is therefore available, but an observed clinical-benefit result is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies a planned clinical-benefit endpoint based on RECIST version 1.1, but reports no analyses for the study. The distinctions below explain the statistical concepts relevant to reading the design and the posted information; they do not imply that a particular analysis was carried out.

What does a single-group design estimate?

In a single-group study, outcomes can be described among participants who receive the intervention. Without a concurrent comparator, the study does not directly estimate a treatment contrast. A change in tumor measurements or a clinical event during follow-up cannot, on its own, establish what would have happened to the same participants under another treatment. Randomized comparison is useful because it aims to create groups that are comparable, on average, with respect to both measured and unmeasured factors. This study is explicitly not a randomized comparison; the registry lists one group, no masking and allocation as not applicable.

Consequently, an outcome proportion in a single-group study would be descriptive. It would characterize the enrolled participants under the study conditions, not prove a causal effect. This limitation is separate from the fact that the primary endpoint was not analysed: even a reported single-group result would need interpretation as non-comparative evidence.

What does the clinical-benefit endpoint combine?

The endpoint combines complete response, partial response and stable disease lasting at least 12 weeks. These categories summarize different patterns of tumor measurement. Complete response describes disappearance of target lesions under the stated criteria. Partial response describes a sufficient decrease in the sum of target-lesion diameters. Stable disease falls between the response and progression criteria. The duration condition makes the endpoint a measure of sustained response or stability rather than a classification at an unspecified moment.

Composite endpoints can provide a single summary across clinically distinct outcomes, but their meaning depends on the components and rules. A participant counted through stable disease did not necessarily have tumor shrinkage; the definition also counts qualifying stability. The registry defines the components but says the endpoint data were not collected or analysed. Thus, a composite result cannot be reconstructed from the endpoint definition alone.

Why do precision and confidence intervals matter?

A point estimate, when available, is a summary of the observed data. A confidence interval describes the uncertainty around an estimate under the assumptions of the statistical method. With a small enrolled group, estimates can be imprecise: the data may be compatible with a broad range of underlying values. A confidence interval does not repair the lack of a comparator, and it cannot be calculated or interpreted as a trial result when the endpoint was not analysed. The registry does not report a primary endpoint estimate or its confidence interval.

The absence of an efficacy analysis should not be represented by a zero estimate. Zero would be a numerical outcome; no analysed result is a different state of information. The record states that low enrollment led to no data collection or analysis for the primary endpoint. That statement limits what can be inferred, rather than indicating that all enrolled participants failed to meet the definition.

How should sample-size planning be distinguished from observed evidence?

Sample-size calculations are planning tools. They describe how many participants might be needed under chosen assumptions to target a specified ability to detect an effect. Such calculations depend on assumptions about the effect, variability or event rate, significance level, allocation and analysis method. They do not reveal what the study observed, and they are not a substitute for an outcome analysis.

The planning illustration associated with the statistical material is described as using a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect set as a stated fraction of the observed effect. For time-to-event planning, the described quantity is a total number of events; other planning quantities are participants per arm. These are hypothetical planning conventions, not the design or observed results of this single-group trial. In particular, the trial did not have two randomized arms. The registry record does not report a sample-size justification for the actual study, and the small enrollment should not be recast as an observed-power result.

What is over-dispersion, in general?

Over-dispersion is a general statistical issue that arises when observed variation is greater than a model assumes. If a model underestimates variability, standard errors may be too small and confidence intervals too narrow. Methods that allow for extra variation can improve uncertainty estimates when the relevant data and model support them. The registry record does not report a model for count outcomes or an over-dispersion assessment, and no such analysis can be attributed to this study.

What can be concluded from the posted analyses?

The registry lists no analyses. That means there is no reported inferential result for the primary endpoint in the record, and the named secondary outcomes cannot be treated as analysed results. General methods can clarify the meaning of a planned endpoint or a design, but they cannot supply missing observations, estimates or uncertainty measures. The appropriate reading is therefore limited to the recorded design, endpoint definition, termination statement and posted safety counts.

10. Multiplicity, Missing Data and Analysis Populations

The registry names several secondary outcomes in addition to the primary clinical-benefit endpoint. These include adverse events, time to progression, progression-free survival, overall response rate, duration of response and overall survival. Multiple outcomes raise a general multiplicity issue: when many hypotheses are tested, the chance of at least one apparently unusual result can increase unless the analysis plan addresses that issue. The registry record does not report a multiplicity strategy, a hierarchy among outcomes, or an adjustment method. Because no analyses are listed, it is not possible to assess how multiplicity was handled in practice.

The record states that data for the primary endpoint were not collected or analysed because of early termination and low enrollment. It does not describe missing-data procedures, rules for censoring, the analysis population for each endpoint, or how participants with incomplete follow-up would have been handled. These details are important in clinical research because different definitions of who is included and how incomplete observations are treated can affect an estimate. Their absence from the registry record prevents assessment of those choices; it does not establish that any particular procedure was or was not used outside the record.

The registry’s enrollment count is 6, but it does not report the number of participants contributing data to each secondary outcome or define an intention-to-treat, per-protocol or safety population. The posted adverse-event group reports 6 at risk for serious and other adverse events. That does not provide an analysis population definition for efficacy endpoints. As a result, the record supports a limited description of the safety counts, but not a reconstruction of endpoint-specific denominators, missingness or analysis decisions.

For these reasons, the absent efficacy result should not be interpreted as a null finding. It is not an estimate with missing precision; the registry says the primary endpoint was not analysed. Any conclusions about multiplicity adjustment, missing-data bias or analysis-population selection would go beyond what is reported in the registry record.

11. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: subdural hematoma (16.7%), colonic obstruction (16.7%).

The registry lists one BN83495 group, with 6 participants at risk for serious adverse events and 2 participants affected. For other adverse events, it lists 6 at risk and 6 affected. These are descriptive counts from the posted safety record. They do not provide a comparison against another group, because the study had no comparator.

The serious adverse-event terms listed among the top terms are subdural hematoma and colonic obstruction, each reported as 16.7%. These term-level percentages should be read as the registry presents them; they do not establish a causal relationship to BN83495. The record does not report further detail about timing, severity grading, relatedness, recurrence or participant-level overlap among terms, so those features cannot be inferred from the summary.

The death count is not reported in the registry record. A missing value should not be interpreted as zero deaths. The safety counts also come from a group of 6, so they are descriptive of this small enrolled group and do not precisely characterize rates in a wider population. They should not be turned into a comparative risk estimate or a treatment conclusion.

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

The registry record documents a Phase II, open-label, single-group study of BN83495 in postmenopausal women with advanced, metastatic or recurrent ER-positive endometrial cancer after one line of chemotherapy in the adjuvant or metastatic setting. It records enrollment of 6 and an intended primary endpoint based on clinical benefit under RECIST version 1.1. These registry entries describe the study’s scope and its planned question.

The record does not report an analysed result for the primary endpoint. It explicitly says the study terminated early and that data were not collected or analysed for clinical benefit because of low enrollment. Therefore, the record cannot tell readers how many participants had complete response, partial response or stable disease lasting at least 12 weeks. It also cannot support a conclusion that the intervention did or did not produce clinical benefit. An unanalysed endpoint is not a negative endpoint result.

There is also no control group. Even if a single-group efficacy estimate were available, it would describe outcomes among enrolled participants and would not establish how those outcomes compared with another treatment. The open-label design and absence of masking are relevant features to keep in mind, but the registry does not report enough detail to assess all potential sources of bias.

The safety record includes descriptive adverse-event counts for the BN83495 group and two serious adverse-event terms with reported percentages. These figures are not a controlled comparison, and the record does not provide all clinical details needed to characterize timing or attribution. The death count is not reported in the registry record.

Thus, what this record contributes is information about design, intended outcomes, enrollment, early termination and selected safety summaries. It does not provide the efficacy analysis needed to answer the primary clinical question. The distinction between an intended endpoint and a reported result is central to interpreting this study accurately.

13. Why This Trial Matters Statistically

This trial illustrates why a registry record should be read as both a description of intent and a source of results, without treating the two as equivalent. The clinical-benefit endpoint is clearly defined, including response categories, lesion-measurement rules and a 12-week duration criterion. Yet the record states that the endpoint was not collected or analysed after early termination and low enrollment. A detailed definition cannot substitute for observed endpoint data.

The study also highlights the limits of small, non-comparative evidence. Enrollment was 6, and there was no control group. A single-group study can document outcomes among participants, but it cannot directly distinguish intervention effects from other explanations. Small groups also leave little basis for precise estimates, even when outcomes are available. In this record, there is no primary efficacy estimate at all, so the issue is not merely wide uncertainty around a result.

Its safety entries show a further interpretive distinction: event counts and term-level percentages are descriptive summaries, not proof of causation or comparative risk. The posted record lists 2 participants with serious adverse events and 6 with other adverse events among 6 at risk in each category. That information can be described, while recognizing the limited size and absence of a comparator.

Finally, this case demonstrates the importance of reporting analysis methods and populations. The registry does not report an analysis plan, multiplicity handling, missing-data procedures, or efficacy analyses. Without those details and results, readers should separate known design details from unanswered statistical questions. That careful separation prevents a planned question, a missing result and a negative finding from being mistaken for one another.

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.

Several trial-specific limitations constrain interpretation. The study enrolled 6 participants and was terminated early. The registry attributes the absence of primary endpoint data to low enrollment and states that the endpoint was not collected or analysed. As a result, no clinical-benefit estimate is reported, and the primary question cannot be answered from the record.

The single-group design has no randomized comparator, and the study was open-label with no masking. Outcomes in the BN83495 group therefore cannot be contrasted with outcomes under a control treatment within this study. The registry record also does not report enough detail to assess how open-label status may have affected outcome assessment or other study procedures.

The record does not report the reason for early termination, the target enrollment, a sample-size justification for the actual study, or a statistical analysis plan. It does not provide efficacy analyses, endpoint-specific analysis populations, missing-data procedures or a multiplicity strategy. Treatment dose and schedule are also not reported in the registry record. These omissions limit the ability to evaluate design choices and reproduce or independently assess intended analyses.

Safety information is limited to summary counts and selected serious adverse-event terms. The record does not report deaths, timing, severity grading or relatedness details in the posted summary. The small enrolled group and lack of comparator make those counts descriptive rather than comparative. These limitations do not establish that unreported outcomes were absent; they identify information that is not reported in the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Study of BN83495 in Post-menopausal Women With Endometrial Cancer Post-chemotherapy — NCT01251354.
• Registry record last updated 2019-01-14; status last verified 2019-01.
• Results first posted 2015-09-02.
• 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.

18. Record Summary

NCT01251354 is a Phase II, international, multicenter, open-label, single-group study of BN83495 in postmenopausal women with advanced, metastatic or recurrent ER-positive endometrial carcinoma after one line of chemotherapy in the adjuvant or metastatic setting. The registry records enrollment of 6 and a terminated status.

The primary endpoint was clinical benefit, defined as complete response, partial response or stable disease lasting at least 12 weeks under RECIST version 1.1. The registry states that early termination and low enrollment meant primary endpoint data were not collected or analysed. No analyses are listed. The posted safety summary records 2 participants with serious adverse events and 6 with other adverse events among 6 at risk; the death count is not reported in the registry record.