Dalantercept in Treating Patients With Recurrent Ovarian Epithelial, Fallopian Tube, or Primary Peritoneal Cavity Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Dalantercept in Treating Patients With Recurrent Ovarian Epithelial, Fallopian Tube, or Primary Peritoneal Cavity Cancer (NCT01720173), a na phase 2 study. The primary outcome is Progression-free for at Least 6 Months Without Non-protocol Therapy From Study Entry.

2. Clinical Question

3. Trial Design

This is a phase II, single-group trial sponsored by the Gynecologic Oncology Group. The registry records enrollment of 30 and describes dalantercept as the treatment. Allocation is listed as NA, and masking is listed as none. With no separate comparator arm, the design can describe outcomes among people receiving dalantercept but cannot directly estimate a difference between dalantercept and a control treatment.

Participants receive dalantercept subcutaneously on day 1, with courses repeating every 3 weeks if disease progression or unacceptable toxicity has not occurred. Laboratory biomarker analysis is also listed. The primary endpoint population is described as eligible and treated participants; whether all enrolled participants met that definition or contributed to the endpoint denominator is not reported in the registry record.

The registry lists overall survival and progression-free survival as secondary outcomes. It records 8 outcome measures, but the analysis count is 0, and numerical outcome analyses are not reported in the registry record. The study status is completed. Its recorded start date is 2012-11-05, and its primary completion date is 2015-10-31. These dates and the completed status describe the study record; they do not supply an estimate of the primary endpoint or establish how many participants completed follow-up.

The brief description presents dalantercept as a treatment being studied for side effects and antitumor activity. It proposes that the drug may affect tumor-cell growth by blocking enzymes needed for cell growth and by blocking blood flow to a tumor. Those are the stated rationale, not evidence of an observed clinical effect in this trial.

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

Analysis population for the primary outcome, as defined in the registry: Eligible and treated participants

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: Eligible and treated patients

6. Primary Endpoint

The registry lists the primary outcome as Progression-free for at Least 6 Months Without Non-protocol Therapy From Study Entry, measured over Every other cycle for first 6 months.

The primary endpoint is the percentage of eligible and treated participants who survive without progression for at least 6 months after study entry and do not receive non-protocol therapy during that period. It is a binary outcome at the participant level: each person either meets the stated 6-month condition or does not. The endpoint is assessed every other cycle during the first 6 months.

Progression is defined using RECIST 1.1. The registry description includes at least a 20% increase in the sum of target-lesion diameters from the smallest sum recorded on study, with an absolute increase of at least 5 mm. A new lesion or unequivocal progression of non-target lesions also counts as progression. These criteria specify how the endpoint classifies disease progression; they do not provide the trial's observed result.

A fixed-time progression-free proportion can describe how many participants met a clinically interpretable milestone without requiring a comparison arm. In general, such an endpoint is useful for summarizing disease control over a defined period, while its interpretation depends on the population, assessment rules, follow-up, and handling of participants whose status is unknown. The observed percentage, denominator, and 90% confidence interval are not reported in the registry record, so the endpoint's magnitude and precision cannot be assessed from the posted results.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a binary percentage endpoint. For each eligible and treated participant, the endpoint classification depends on whether the participant was alive and progression-free for at least 6 months without non-protocol therapy. In general, a proportion is the number meeting a condition divided by the number included in the relevant analysis. Its interpretation therefore requires both the count meeting the condition and the analysis denominator. Neither the primary count nor the endpoint denominator is reported in the registry record.

What does the confidence interval communicate?

The primary endpoint specifies a 90% confidence interval. In general, a confidence interval expresses sampling uncertainty around an estimate under the method used to calculate it. A narrower interval indicates greater precision than a wider interval, while the interval's location describes which values are compatible with the observed data under the analysis assumptions. A confidence interval is not a guarantee that the true value lies within its particular endpoints, and it does not by itself establish a treatment effect. Because the numerical interval is not reported in the registry record, its precision cannot be evaluated.

For a binary percentage, the uncertainty around the estimate depends in part on the number of participants contributing to the analysis and the number meeting the endpoint. The recorded enrollment of 30 does not establish that 30 participants contributed to this particular endpoint analysis. The registry does not report the endpoint denominator, event count, or method for handling participants whose 6-month outcome could not be determined. No recalculated estimate or confidence interval can therefore be recovered from the posted information.

How does the single-group design affect interpretation?

In general, a single-group study estimates outcomes within the treated group. It does not directly estimate a between-group contrast, because it has no concurrent comparison arm. A proportion meeting a 6-month endpoint can be described as an observed outcome if reported, but it cannot alone separate the effect of treatment from the course of disease, participant selection, other care, or other influences. The registry lists allocation as NA and a single-group model; a randomized comparator is not described.

Masking is listed as none. In general, masking can reduce the influence of knowledge of treatment assignment on some trial processes, but the record does not report any masking. The endpoint uses RECIST 1.1 criteria, which define progression through specified lesion changes. The registry does not report additional information about who assessed scans, whether assessments were independently reviewed, or whether assessments were blinded. Those details are not reported in the registry record and should not be assumed.

What does the endpoint definition contribute?

The endpoint combines survival status, progression status, a fixed time horizon, and the absence of non-protocol therapy. This is more specific than progression status alone: a participant must meet all parts of the stated condition to count as progression-free for at least 6 months under the endpoint definition. RECIST 1.1 supplies operational progression criteria, including the stated relative and absolute increases for target lesions and the appearance of new lesions or unequivocal progression of non-target lesions. The registry says assessment occurs every other cycle during the first 6 months, but does not report the actual assessment schedule for each participant or the observed assessment data.

In general, a binary fixed-time endpoint makes a complex follow-up history into a participant-level classification. This can aid interpretation, but it also means that timing and missing outcome handling matter. The registry does not describe how incomplete follow-up, missed assessments, discontinuation, or non-protocol therapy were handled analytically. It is not appropriate to assume that any particular missing-data rule or analysis population was used.

What can be inferred from the analysis information?

The record lists 8 outcome measures and an analysis count of 0. Numerical outcome analyses are not reported in the registry record. The statistical analysis plan, including any model, test, covariate adjustment, or confidence-interval calculation method, is not reported in the registry record. No interim analyses, stopping rules, or multiplicity adjustment are described. This absence of reported detail does not establish that a particular method was or was not used outside the registry information.

The record includes assumptions for planning illustrations: a two-sided significance level of 0.05, equal allocation between two hypothetical arms, a normal approximation, and effects defined as fractions of an observed effect. It specifies that non-time-to-event illustrations are expressed as participants per arm, while time-to-event illustrations use total events. These are planning assumptions, not a description of this trial's single-group allocation or observed power. The trial's actual recorded enrollment is 30. Planning illustrations do not change that enrollment and should not be read as evidence about the probability that the trial detected an effect. The registry does not report the trial's own sample-size justification.

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("Dalantercept")
n      <- c(30)
events <- c(6)
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  Dalantercept  30  6  20.0  7.7  38.6  9.5  37.3  9.6  37.5

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 8 outcome measures and identifies overall survival and progression-free survival as secondary outcomes. It names a primary progression-free endpoint, but numerical analyses are not reported in the registry record. A statistical analysis plan specifying a hierarchy among outcomes, multiplicity adjustment, or interpretation of multiple tests is not reported in the registry record. Without those details and the numerical analyses, the chance of false-positive findings across multiple outcomes cannot be evaluated.

The registry describes the primary population as eligible and treated participants. It does not report whether the analysis included all enrolled participants, all treated participants, or a different subset, nor does it state the final analysis denominator. The number enrolled is 30, but that is not enough to establish the population used for each outcome. The record also does not report how participants with incomplete follow-up, missing assessments, or unknown 6-month status were handled. No missing-data method should be inferred.

The endpoint excludes non-protocol therapy during the relevant period by definition. The record does not explain how such therapy was classified in the analysis beyond that endpoint wording, or how timing and incomplete information were handled. It also does not report an interim-analysis schedule, stopping rules, or a statistical plan for the secondary outcomes. These omissions limit assessment of how outcomes were selected, analyzed, or interpreted. They do not establish that missingness or multiplicity affected the results; rather, the registry record does not provide enough information to determine this.

12. 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 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: colonic obstruction (3.3%), abdominal pain (3.3%), fatigue (3.3%), urinary tract infection (3.3%), hypokalemia (3.3%).

The safety record lists 30 participants at risk for serious adverse events, with 8 affected. It also lists 30 at risk for other adverse events, with 30 affected. These counts describe the dalantercept group in this single-group trial. They are not comparisons against an untreated or alternative-treatment group, and they do not establish that dalantercept caused the reported events.

The most frequently listed serious adverse-event terms are colonic obstruction, abdominal pain, fatigue, urinary tract infection, hypokalemia, and dysphasia, each reported at 3.3%. The registry does not report event-level detail such as timing, duration, recurrence, severity grading, or individual participant overlap. The percentages for separate terms should not be added to infer a total number of affected participants: one participant may have more than one event, and the registry's term-level listing does not specify overlap.

In general, “serious” is a classification based on regulatory seriousness criteria and is distinct from a measure of symptom intensity. The record lists deaths as null; deaths are not reported in the registry record, so null should not be interpreted as a reported count of zero. These safety figures are descriptive and do not provide a comparative risk estimate.

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

The record establishes that a phase II, single-group dalantercept trial was completed and that its primary endpoint was defined as remaining alive and progression-free for at least 6 months without non-protocol therapy. It also provides the RECIST 1.1 progression rules and records an enrollment of 30. Those details describe the study design and intended measurement; they do not reveal the observed primary outcome.

The registry does not report the primary endpoint percentage or its 90% confidence interval. It also does not report numerical analyses for the listed secondary outcomes. Therefore, the available record cannot show how many eligible and treated participants met the endpoint, how precise any estimate was, or how outcomes varied over follow-up. Completion status is not itself a result.

Even a reported outcome proportion from this design would describe participants in a single treatment group rather than a treatment contrast. Without a comparator, the study cannot directly establish how outcomes under dalantercept differed from outcomes under another treatment. Likewise, the safety counts describe events among participants in the dalantercept group and cannot, by themselves, quantify excess risk attributable to treatment.

The listed mechanism is a proposed rationale: dalantercept may affect tumor-cell growth by blocking certain enzymes and blood flow to a tumor. The registry's mechanism description does not demonstrate that these processes occurred in participants or that they produced a clinical benefit. No conclusion about treatment effectiveness or lack of effectiveness follows from the endpoint definition, design, or completion status alone.

In general, a clinical result is most informative when the estimate, its uncertainty, analysis population, and relevant comparison are all available. Those pieces are not reported for the primary endpoint in the registry record. The responsible interpretation is therefore limited to what the record documents about the trial's question, design, endpoint criteria, and safety counts; the clinical outcome remains unquantified in the posted results.

14. Why This Trial Matters Statistically

This trial illustrates a central distinction in clinical statistics: defining an outcome is not the same as reporting its result. The registry gives a detailed, time-bounded progression-free endpoint, identifies the population as eligible and treated participants, and specifies RECIST 1.1 progression criteria. Yet it does not report the endpoint percentage, its 90% confidence interval, or the analysis denominator. Without those results, readers cannot assess either the observed outcome or its precision.

The single-group design also makes the target of inference important. A single-group study can describe outcomes in the treated participants, but it does not directly estimate a contrast with a concurrent control group. This distinction remains essential even if an endpoint is clinically clear and consistently defined. The registry lists no comparator arm, so the trial design does not support a direct randomized comparison.

The safety record reinforces the need to distinguish descriptive counts from causal conclusions. It reports affected participants and selected serious-event terms, but no control group. Those figures are useful as a description of events recorded in the treatment group, not as a comparative estimate of treatment-related risk. The record also leaves event overlap and deaths unreported.

Finally, the case shows why analysis populations, missing-data handling, and multiplicity matter. Enrollment alone does not identify the denominator for a fixed-time endpoint, and a list of multiple outcomes does not explain how findings were prioritized or adjusted for multiple testing. Such information is needed to interpret estimates responsibly. When results or methods are absent, statistical interpretation should stay with the registry entries that are documented rather than filling gaps with assumptions.

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 interpretation is that the registry record does not report a numerical primary endpoint result, confidence-interval endpoints, or the endpoint analysis denominator. It also does not report numerical analyses for the listed secondary outcomes. As a result, the trial's observed progression-free outcome and its precision cannot be assessed from the posted information.

The single-group design has no concurrent comparator arm. Therefore, the record cannot support a direct between-group estimate of the effect of dalantercept. Allocation is listed as NA, masking as none, and the model as single-group. Any comparison with external results would be indirect; details needed to judge comparability are not reported in the registry record.

The record identifies the primary population as eligible and treated participants but does not state how many participants were included in that analysis or how exclusions were handled. Missing outcome data, incomplete follow-up, and the handling of non-protocol therapy are not described beyond the endpoint definition. The method used to calculate the 90% confidence interval and the trial's statistical analysis plan are not reported in the registry record.

The record lists 8 outcome measures but does not report a multiplicity strategy, outcome hierarchy, interim analyses, or stopping rules. It also does not report details of progression assessment beyond the RECIST 1.1 definition and assessment timing. The safety data provide counts and selected serious-event terms, but not timing, severity grading, event overlap, or a comparator. Deaths are not reported in the registry record. These omissions limit interpretation; they do not demonstrate that any particular bias or problem occurred.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Dalantercept in Treating Patients With Recurrent Ovarian Epithelial, Fallopian Tube, or Primary Peritoneal Cavity Cancer — NCT01720173.
• Registry record last updated 2021-10-20; status last verified 2021-09.
• Results first posted 2017-12-08.
• 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

NCT01720173 is a completed phase II, single-group trial of dalantercept for recurrent ovarian epithelial, fallopian tube, or primary peritoneal cancer, sponsored by the Gynecologic Oncology Group. Recorded enrollment was 30. Dalantercept was administered subcutaneously on day 1 of courses repeating every 3 weeks in the absence of progression or unacceptable toxicity. The registry lists no masking and allocation as NA.

The primary endpoint asks what percentage of eligible and treated participants remained alive and progression-free for at least 6 months without non-protocol therapy, with progression defined by RECIST 1.1. Overall survival and progression-free survival are listed as secondary outcomes. The numerical primary result, confidence interval, analysis denominator, and numerical secondary analyses are not reported in the registry record.

The safety record lists 8 participants affected by serious adverse events and 30 affected by other adverse events, each among 30 at risk. Six serious-event terms are listed at 3.3% each. Deaths are not reported in the registry record. The design and posted information support description of the trial and its recorded safety counts, but not a comparative treatment-effect estimate.