A Study of BBI503 in Asymptomatic Recurrent Ovarian Cancer Patients With CA-125 Elevation: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of BBI503 in Asymptomatic Recurrent Ovarian Cancer Patients With CA-125 Elevation (NCT02432690), a na phase 2 study. The primary outcome is Disease Control Rate (DCR).

2. Clinical Question

The clinical question was whether disease control could be assessed among asymptomatic patients with recurrent ovarian cancer and elevated CA-125 who received BBI503. The endpoint description defines disease control by combining complete response, partial response, and stable disease, with assessment based on CA-125 and, where applicable, measurable disease criteria. This makes the endpoint broader than tumor shrinkage alone: stable disease is included alongside response categories.

The registry does not report an analyzed DCR result, so the central question has no reported answer in the posted results. The study also listed progression-free survival, progression-free survival at 6 months, objective response rate, overall survival at 6 months, and adverse events as secondary outcomes. Their inclusion in the record does not establish that results were collected or analyzed for each outcome.

3. Trial Design

This was an open-label, single-group Phase II clinical study of BBI503 in adults with asymptomatic recurrent ovarian cancer and elevated CA-125. The registry identifies Sumitomo Pharma America, Inc. as the sponsor. It records enrollment of 13 and lists the trial status as terminated. The study began in 2015-06, and the primary completion date is 2017-01-02.

Because the study had a single group and no randomized allocation, it was not designed as a randomized comparison between BBI503 and a control treatment. Open-label means the study was not masked. These design features matter when interpreting outcomes: observations within a single group do not, by themselves, establish how outcomes would have differed under another treatment or under no study treatment.

The primary endpoint was DCR. The registry describes assessment from the date of first treatment, every 8 weeks, until the first documented objective disease progression, up to 24 weeks. The stated assessment approach used Gynecologic Cancer Intergroup guidelines, incorporating CA-125 response and RECIST 1.1 for patients with measurable disease. However, the registry explicitly says that DCR analysis was not performed because data were not collected.

The record lists six outcome measures and zero analyses. It names progression-free survival, progression-free survival at 6 months, objective response rate, overall survival at 6 months, and adverse events among the secondary outcomes. It does not report analysis results for these outcomes in the registry record for this account. A detailed protocol, analysis plan, eligibility criteria beyond the brief description, treatment dosing details, and reasons for termination beyond the sponsor’s stated development decision are not reported in the registry record.

The sponsor’s stated reason for discontinuing the amcasertib development was a lack of efficacy in solid tumor indications evaluated in early-stage trials. The record does not present this as a result from the ovarian cancer study itself. The trial-specific primary endpoint analysis was not conducted because its data were not collected.

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: Participants who died, withdrew consent to survival follow up or were lost to follow up were considered to have completed the study.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Due to a lack of efficacy in the solid tumor indications that were evaluated in early-stage trials of this compound, the entirety of the amcasertib development was discontinued by the sponsor. Analysis of the DCR was not performed since data were not collected.

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 Disease Control Rate (DCR), measured over From the date of first treatment, every 8 weeks, until the date of first documented objective disease progression, up to 24 weeks.

Disease control rate is defined in the registry as the proportion of patients whose overall response was complete response, partial response, or stable disease. It combines outcomes in which disease is recorded as having completely or partly responded with an outcome in which it is recorded as stable. The endpoint description says assessment followed Gynecologic Cancer Intergroup guidelines incorporating CA-125 response and RECIST 1.1; RECIST 1.1 applies to patients with measurable disease.

In general, a proportion-based endpoint expresses how many participants in a defined analysis group meet the endpoint definition. Its interpretation depends on the response criteria, the assessment schedule, the analysis population, and whether outcome information is available for participants. The registry specifies assessments every 8 weeks, from first treatment until documented objective progression, up to 24 weeks. It does not provide a DCR estimate or explain how participants with missing assessments would have been handled.

DCR can be used to describe disease status across response and stability categories over a specified assessment period. It is not interchangeable with objective response rate, which is separately listed as a secondary outcome. The registry does not report the planned statistical method for either endpoint.

Most importantly, the primary endpoint result is unavailable: the registry says that DCR analysis was not performed because data were not collected. No proportion, uncertainty interval, or conclusion about the endpoint can be drawn from the posted record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a single-group design estimate?

In general, a single-group study describes outcomes among participants who received the study intervention. Without a concurrent comparison group, it does not directly estimate the difference between outcomes under the intervention and outcomes under an alternative. Changes or events observed in a single group can have multiple explanations, and the design alone cannot separate those explanations.

This study is identified as single-group and open-label, with no randomized allocation. The registry does not report a control arm. Accordingly, there is no between-arm treatment comparison to interpret. This design point is separate from the question of whether a within-group endpoint could be calculated: the registry says the primary DCR analysis was not performed because data were not collected.

What does DCR measure?

The primary endpoint combines complete response, partial response, and stable disease into a proportion. The registry says assessment followed Gynecologic Cancer Intergroup guidelines, which incorporate CA-125 response and RECIST 1.1 for participants with measurable disease. In general, defining an endpoint in advance makes clear which observed states count as meeting it. Interpretation still depends on applying the stated criteria consistently and having the necessary assessment data.

The assessment period is described as beginning at first treatment, with assessments every 8 weeks until first documented objective progression, up to 24 weeks. In general, endpoint timing matters because participants must be evaluated at relevant time points for their status to be classified. The record does not report how incomplete follow-up or missed assessments would have been handled. More fundamentally, it says the data needed for the DCR analysis were not collected.

Why would precision usually be reported?

In general, an estimate such as a proportion is more informative when accompanied by a confidence interval. A confidence interval communicates the statistical uncertainty around an estimate under the assumptions of the method used. It does not resolve design limitations, missing outcome information, or uncertainty about whether the analysis population represents a wider patient group. No DCR estimate or confidence interval is reported in this registry record, so its precision cannot be assessed.

Hypothesis tests and p-values answer questions about compatibility between observed data and a specified statistical model or null hypothesis. They do not measure the probability that a treatment works, and they do not substitute for an effect estimate with a measure of precision. The record reports zero analyses and does not provide a test statistic or p-value for the primary endpoint. No inferential conclusion about DCR can therefore be reconstructed from the posted information.

What do the listed secondary outcomes add?

Progression-free survival and overall survival are time-to-event outcomes in general: their analysis concerns the time until a defined event, while accounting for participants whose event has not been observed by the end of follow-up. The registry lists progression-free survival and overall survival at 6 months, but the registry entries do not give definitions of the events, follow-up details, censoring rules, estimates, or analyses. The label alone is not enough to recover those statistical details.

Objective response rate is listed separately from DCR. In general, response-rate endpoints count participants meeting a specified response definition, whereas DCR includes stable disease as well as response categories. The registry does not provide a numerical objective response rate or its analysis method. The listed outcomes should therefore be treated as outcome names, not evidence that results were analyzed.

How should planning illustrations be interpreted?

In general, sample-size planning calculations describe the number of participants or events that a proposed design would need under specified assumptions. They are not observed outcomes and are not a retrospective measure of whether a study succeeded. Any planning illustration based on an observed effect is conditional on that effect and on the assumptions used; it is not observed power. The assumptions stated for the illustration associated with this record include a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. Time-to-event illustrations refer to total events, while other illustrations refer to participants per arm.

Those assumptions describe a hypothetical two-arm planning framework; they do not change the actual study design, which is single-group. The registry record does not report the trial’s own sample-size justification, and no observed primary DCR effect is available because the DCR analysis was not performed. Consequently, such planning concepts cannot be used to claim that this study had a particular probability of detecting a trial-specific effect.

What can be inferred from the safety summaries?

In general, safety summaries may report participants affected, event counts, event terms, or some combination. These are not interchangeable: one participant can experience more than one event, and a category count may not indicate how many distinct people experienced each event unless the record says so. Here, the registry reports the number at risk and affected for serious and other adverse events, deaths, and three serious-event terms with percentages. It does not provide the additional detail needed to reconstruct timing, overlap, duration, severity grading, or attribution.

Statistical methods can describe the data available, but they cannot replace uncollected outcome data. For the primary endpoint, the critical limitation is not a choice among statistical tests; it is the registry’s statement that the analysis was not performed because data were not collected. The analysis method, handling of missing data, and analysis population are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The record lists six outcome measures, including DCR as the primary outcome and several secondary outcomes. When a study evaluates multiple outcomes, multiplicity can matter because repeated statistical testing can increase the chance of finding an apparently notable result by chance. In general, a statistical plan may specify which outcomes are primary, how comparisons are prioritized, and whether adjustment or another strategy is used. The registry record does not report a multiplicity strategy or a detailed statistical analysis plan.

The primary DCR analysis was not performed because data were not collected. The record lists zero analyses, and the registry entries do not provide numerical analyses for the secondary outcomes. As a result, there are no reported outcome tests in this account for which a multiplicity adjustment can be evaluated. The number of listed outcomes should not be mistaken for the number of analyses completed.

Missing-data handling is also not reported in the registry record. The endpoint description provides an assessment schedule, but not rules for participants who missed assessments, withdrew, or had an outcome that could not be classified. The primary analysis absence is described as a consequence of data not being collected; the record does not specify the extent or pattern of unavailable data or explain whether other outcome data were collected.

The analysis population is not reported in the registry record. In general, an analysis population defines which enrolled participants contribute to a particular result, and its definition can affect interpretation. No such population can be inferred from enrollment alone. The record also does not report interim analyses, stopping rules, or the trial’s own sample-size justification. These omissions limit assessment of the analysis process, but they do not change the explicit statement that the primary endpoint was not analyzed.

11. 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 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: blood creatinine increased (7.7%), acute kidney injury (7.7%), urinary tract obstruction (7.7%).

The registry reports safety information for Arm A, with 13 participants at risk. It records 1 participant affected by a serious adverse event, 9 affected by other adverse events, and 3 deaths. These are descriptive counts in the single study group, not comparisons with a control group. The record does not state whether the deaths were related to treatment or provide their causes.

The leading serious adverse event terms listed are Blood creatinine increased, Acute kidney injury, and Urinary tract obstruction, each reported as 7.7%. The registry entry does not provide event-level narratives or explain whether the terms occurred in distinct participants, at what time they occurred, or whether the events were judged related to BBI503. The percentages should be read as reported, without treating them as evidence of causation.

In general, serious adverse events are a seriousness category and are not synonymous with all adverse events. The registry separately presents serious and other adverse-event counts. It does not report enough detail to determine overlap between those categories or between the event terms and affected-participant counts. These data describe what the record lists; they do not establish comparative safety or a treatment effect.

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

The registry record establishes that an open-label, single-group Phase II study of BBI503 enrolled 13 adults with asymptomatic recurrent ovarian cancer and elevated CA-125. It defines DCR as the proportion with complete response, partial response, or stable disease, assessed using GCIG guidelines incorporating CA-125 response and RECIST 1.1 for participants with measurable disease. It also states that DCR analysis was not performed because data were not collected.

That missing primary result is not equivalent to a finding of no disease control. No DCR proportion or measure of uncertainty is reported, so the primary endpoint cannot be quantified from this record. Nor can a treatment comparison be made: the study had no listed comparator and no randomized allocation. The design and missing endpoint data limit what can be concluded, independent of the sponsor’s broader development decision.

The sponsor’s statement that amcasertib development was discontinued because of a lack of efficacy in solid tumor indications evaluated in early-stage trials should not be conflated with an analyzed ovarian cancer DCR result. The registry specifically says the DCR analysis for this study was not performed. The record does not provide a trial-specific efficacy estimate that would support a claim about the primary outcome.

The posted safety information gives counts for serious adverse events, other adverse events, and deaths, along with three serious-event terms and their reported percentages. These are observations within the study group. Without a comparator, detailed event descriptions, or attribution information, they do not establish that BBI503 caused or prevented any particular event.

The study record is therefore informative about the intended clinical question, design, endpoint definition, termination status, and selected safety entries. It is not an efficacy result for DCR, and the listed secondary outcomes cannot be interpreted as analyzed results from the information.

13. Why This Trial Matters Statistically

This trial illustrates why endpoint definitions and endpoint results must be kept distinct. The registry describes a specific primary outcome, including the response categories, assessment framework, and time window. Yet it also states that the analysis was not performed because data were not collected. A clear endpoint definition does not itself produce an estimate: the necessary participant-level outcome information must be available and analyzed.

The design also matters. A single-group, open-label study can describe outcomes observed among participants, but it does not supply a randomized control comparison. The registry lists no comparator, so readers should not interpret the study as a direct test of BBI503 against another treatment. The absence of a reported primary result makes that distinction especially important: there is no trial-specific DCR estimate to place in context.

The record also demonstrates the difference between an outcome being listed and an outcome being reported. Several secondary outcomes appear in the registry, but the registry entries do not contain numerical analyses for them. Outcome names alone cannot establish that data were collected, that analyses were completed, or what the results were.

Finally, the sponsor’s stated reason for discontinuing the development program is relevant context, but it is not a substitute for the missing analysis of this study’s primary endpoint. Keeping program-level context separate from trial-specific results is essential for precise statistical interpretation. The record supports a careful account of what was planned and what is reported, while leaving the primary efficacy question unanswered in the posted results.

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 was open-label and single-group, with no randomized allocation or comparator listed. Any observed outcomes would therefore lack a concurrent control comparison. In this record, the primary limitation is more direct: the DCR analysis was not performed because data were not collected.

The registry does not report a DCR estimate, confidence interval, hypothesis test, or analysis population. It does not describe how missing assessments would have been handled, and it does not report the extent or pattern of unavailable outcome data. Although the endpoint description specifies assessments every 8 weeks through up to 24 weeks, schedule information alone does not establish that assessments were completed.

The available record lists secondary outcomes but does not provide their numerical results or analysis methods. It does not report the detailed statistical analysis plan, multiplicity approach, interim analyses, sample-size justification, or stopping rules. These methods are not reported in the registry record, so they cannot be evaluated or inferred.

The safety entries are also limited in detail. They provide counts and selected serious-event terms, but not event timing, clinical narratives, attribution, or the relationship between events and deaths. The single-group design does not permit comparative safety estimates.

Finally, the sponsor’s explanation for discontinuing amcasertib development refers to lack of efficacy in solid tumor indications evaluated in early-stage trials. The record does not establish that this conclusion came from the ovarian cancer study’s DCR analysis, which it says was not performed. That context should not be treated as a substitute for trial-specific results.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Study of BBI503 in Asymptomatic Recurrent Ovarian Cancer Patients With CA-125 Elevation — NCT02432690.
• Registry record last updated 2023-11-15; status last verified 2023-11.
• Results first posted 2022-08-29.
• 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

The registry describes a terminated, open-label, single-group Phase II study of BBI503 (amcasertib) in adults with asymptomatic recurrent ovarian cancer and elevated CA-125. Enrollment was 13. The primary endpoint was disease control rate, defined as complete response, partial response, or stable disease, assessed using GCIG guidelines and RECIST 1.1 for participants with measurable disease.

The registry states that the DCR analysis was not performed because data were not collected. It lists six outcome measures and zero analyses. Secondary outcomes include progression-free survival, progression-free survival at 6 months, objective response rate, overall survival at 6 months, and adverse events.

For Arm A, the record reports 1 of 13 participants affected by a serious adverse event, 9 of 13 affected by other adverse events, and 3 deaths. Three serious adverse event terms are listed, each at 7.7%. The sponsor states that amcasertib development was discontinued because of a lack of efficacy in solid tumor indications evaluated in early-stage trials; the record does not report a trial-specific DCR result.