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 A Trial of Intravenous Denileukin Diftitox in Stage III or IV Ovarian Cancer (NCT00880360), a na phase 2 study. The primary outcome is Number of Participants Demonstrating Clinical Response.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00880360 |
| Phase | Phase 2 |
| Condition | Epithelial Ovarian Cancer, Extraovarian Peritoneal Cancer, Fallopian Tube Carcinoma |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 19 |
| Arms in the primary outcome | n/a |
| Lead sponsor | The University of Texas Health Science Center at San Antonio |
| Results posted | Yes |
2. Clinical Question
Population
The trial concerned people with epithelial ovarian cancer, extraovarian peritoneal cancer, or fallopian tube carcinoma at advanced stages or in a setting where first-line therapy had failed or was unsuitable. The official title specifies FIGO Stage III or Stage IV for the ovarian cancer population. The registry describes the intended population but does not report detailed participant characteristics or how many enrolled participants had each diagnosis.
Intervention
Participants received Ontak, also identified as denileukin diftitox, by intravenous administration. The stated aim was to assess whether treatment could deplete regulatory T cells, boost tumor-specific immunity, and treat epithelial ovarian cancer. The record does not report dose, schedule, duration of administration, or treatment exposure.
Comparator
There was no listed comparison group. The registry classifies the trial as single-group and its allocation as not applicable; masking was none. Consequently, the record does not provide a concurrent control group for comparing outcomes or adverse events.
Primary question
The primary outcome was the number of participants demonstrating clinical response, assessed using RECIST criteria over 2 years. The description also refers to disease-free progression and overall survival. However, the registry record does not report response counts, response percentages, progression results, survival results, or analyses for these outcomes. It therefore identifies the question the study was intended to examine, but does not provide a result that answers it.
3. Trial Design
This was a Phase II, single-group trial of intravenous Ontak in people with selected advanced epithelial ovarian, extraovarian peritoneal, or fallopian tube cancers. The registry lists The University of Texas Health Science Center at San Antonio as sponsor. The study started in 2007-02, reached primary completion in 2010-04, and is recorded as completed. Enrollment was 19.
The design has no listed comparator or random allocation: allocation is recorded as not applicable, the model is single-group, and masking is none. Participants' outcomes therefore appear in the context of treatment with Ontak alone in the registry record. Without a concurrent control group, the record cannot directly compare outcomes under Ontak with outcomes under another treatment or no treatment. This is a design limitation, not evidence about the direction or size of a treatment effect.
The primary outcome is titled Number of Participants Demonstrating Clinical Response, with a timeframe of 2 years. Its description says efficacy was assessed through clinical response rate, disease-free progression, and overall survival. Response was to be measured by RECIST criteria and reported as a percent. The description states that 56 subjects needed to be recruited to determine efficacy, while the recorded enrollment is 19. These are distinct pieces of information: the former is the stated recruitment need, and the latter is enrollment recorded for the trial.
Toxicity is listed as a secondary outcome. The registry record does not report details of the treatment schedule, eligibility criteria beyond the broad disease description, follow-up procedures, or the operational definition of toxicity. It also does not report a statistical analysis plan or analysis results. The record states that analysis was on an intent-to-treat basis, but does not explain how that population was defined in practice.
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
| Stage | Ontak |
|---|---|
| STARTED | 19 |
| COMPLETED | 19 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: Measurements performed by RECIST criteria and response reported as a percent. 56 subjects needed to be recruited to the study to determine efficacy. Analysis was on an intent to treat basis.
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 | Ontak |
|---|---|---|
| Participants analysed | 19 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 11 |
| Age, Categorical: >=65 years | Participants | 8 |
| Age, Continuous | years | 63 (SD 1) |
| Sex: Female, Male: Female | Participants | 19 |
| Sex: Female, Male: Male | Participants | 0 |
| Region of Enrollment: United States | participants | 19 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants Demonstrating Clinical Response, measured over 2 years.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary outcome is the number of participants demonstrating clinical response. Its timeframe is 2 years, and the outcome description says measurements were made using RECIST criteria, with response reported as a percent. In general, standardized response criteria are used to classify changes in measurable disease consistently. A count of participants meeting a response definition can then be related to the group assessed, giving a response rate when the relevant denominator is known.
The registry's outcome description also mentions disease-free progression and overall survival as measures of efficacy. It does not clarify whether these were separate outcomes, components of a broader assessment, or additional summaries associated with the response endpoint. No operational definitions, assessment schedule, or analysis method for progression or survival are reported in the registry record.
Response is useful as an outcome because it describes whether participants met a prespecified clinical response criterion during the stated assessment period. It is not interchangeable with disease-free progression or overall survival: these outcomes describe different aspects of the disease course. In general, response counts alone do not establish how long a response lasts or what happens to survival.
The endpoint title identifies a participant count, and the outcome description says response would be reported as a percent. Yet the registry record does not provide the number of participants who responded, the denominator used for a response percentage, or an uncertainty estimate. Thus the outcome's intended meaning is described, but its observed result cannot be evaluated from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes that 19 participants were enrolled in a completed Phase II, single-group trial of intravenous Ontak. It also identifies the primary outcome as the number of participants demonstrating clinical response over 2 years. It does not report the clinical response count or percentage, results for disease-free progression or overall survival, or statistical analyses. No effect estimate, confidence interval, or p-value is reported in the registry record. Accordingly, the posted results do not quantify the clinical outcome or its precision.
The outcome description states that 56 subjects needed to be recruited to determine efficacy. The recorded enrollment is 19. This difference matters when judging how much information the registry contains, but it does not permit a conclusion about why enrollment was lower, whether recruitment ended early, or how the trial's conduct compared with its original protocol. Those explanations are not reported in the registry record. Nor does the enrollment figure by itself indicate whether any observed response would be large, small, or statistically persuasive.
The absence of a comparator is important for interpretation. A single-group record can describe what happened among participants who received Ontak, if outcome results are reported. It cannot, on its own, separate changes associated with treatment from changes that could arise from the disease course, participant selection, other care, or measurement. This general limitation does not imply that any particular alternative explanation occurred in this trial; the registry record does not report such information.
The safety record lists 19 participants at risk for serious adverse events and 0 affected. It also lists 19 at risk for other adverse events and 0 affected. The deaths field has no reported value. These registry counts describe what is entered in the safety record, not a comprehensive account of all possible harms. The record does not specify event definitions, collection procedures, exposure duration, or whether all events were captured in the same way.
The primary outcome description refers to response measured with RECIST and reported as a percent, but no response result appears. The stated intent-to-treat basis indicates an intended analysis population, but does not supply participant-level disposition or missing-outcome handling. With neither outcome counts nor analysis results, there is no basis in this record to judge the magnitude or precision of response, progression, or survival findings. The appropriate statistical reading is therefore descriptive: the design, intended outcome, enrollment, and recorded safety counts are available, while the primary efficacy result and its uncertainty are not reported in the registry record.
9. Statistical Methods Explained
The registry identifies a single-group design, no masking, and allocation recorded as not applicable. These features describe how the trial was structured in the record. In general, a single-group study observes outcomes in a group receiving the intervention rather than comparing separate treatment groups. That can describe the experience of enrolled participants, but it provides no concurrent randomized contrast. With no masking, the record does not indicate that participants or study personnel were blinded to treatment assignment. The record does not report whether outcome assessors were masked separately.
What does a response count describe?
The primary outcome is a count of participants demonstrating clinical response. The outcome description says RECIST criteria were used and that response was reported as a percent. In general, response criteria create a consistent rule for classifying disease measurements. A response count is a direct tally of participants who meet the defined rule; a percentage expresses that count relative to an identified denominator. The registry record does not report either the count or the denominator for the response result, and it does not provide the percentage. It also does not describe the specific RECIST version or additional details of assessment.
The outcome description includes disease-free progression and overall survival alongside clinical response rate. These are not statistically identical measures. In general, a response outcome records whether a defined state was reached, while progression and survival outcomes concern events occurring over time. Time-to-event analyses may account for differing follow-up and censoring, but the registry record does not report whether such analyses were used, how follow-up was handled, or any results for these outcomes.
How should uncertainty be read?
In general, a confidence interval expresses the range of values reasonably compatible with the data under a specified statistical model and procedure. A narrower interval indicates greater precision under those assumptions; a wider interval indicates more uncertainty. For a response proportion, uncertainty depends on the observed count and denominator, among other considerations. No confidence interval or other uncertainty estimate for clinical response is reported in the registry record. Therefore, the precision of any efficacy estimate cannot be assessed from this record.
A p-value, in general, measures how incompatible the observed data are with a specified null model, conditional on the model and assumptions. It does not by itself measure clinical importance, establish causality, or quantify the probability that a treatment effect is true. No p-value or inferential test result is reported. Because this is a single-group trial, a p-value would also require a clearly specified comparison or reference value; the registry record does not describe one.
What do the planning assumptions mean?
The sample-size assumptions describe an illustrative calculation based on an observed effect, not the trial's own design. The stated calculation assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. In general, a planning calculation asks what sample size could be needed under assumptions about the target effect and statistical procedure. It is not a count of participants actually studied, and it is not a statement of observed power. The record does not report that the trial used these assumptions to plan enrollment. The primary outcome description separately states that 56 subjects needed to be recruited.
The assumptions specify equal allocation between two arms, whereas the clinical trial is recorded as single-group. That makes the illustrative calculation distinct from the trial's design. In general, a planning illustration should be interpreted only in the context of its stated assumptions; it should not be treated as a reconstruction of the trial protocol. The registry record does not report a sample-size justification, the effect-size target used for the trial's original planning, or whether any planning calculation was revised.
Over-dispersion is a general concern for count outcomes when variability exceeds what a simple model assumes. Accounting for it can affect estimated uncertainty and conclusions from count-based analyses. The primary outcome is described as a participant count, but the registry record provides no analysis model, dispersion estimate, or inferential results. It would therefore be inappropriate to claim that over-dispersion was assessed or that a particular model was used.
What can the safety counts establish?
The safety record gives the number at risk and the number affected for serious and other adverse events. In general, a count of affected participants is descriptive and is not a rate per unit of treatment exposure unless the relevant exposure time and calculation are reported. The registry does not provide exposure duration or event-level detail. Nor does it describe how adverse events were defined or collected. The reported counts should therefore be read as entries in the registry record, not as a complete statistical comparison or a measure of risk over a specified exposure period.
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.
| Arm | Participants | Events | Observed % | Clopper-Pearson 95% CI | Wilson 95% CI | Bayesian 95% credible interval |
|---|---|---|---|---|---|---|
| Ontak | 19 | 19 | 100.0% | 82.4% to 100.0% | 83.2% to 100.0% | 83.2% to 99.9% |
R code and output
arm <- c("Ontak")
n <- c(19)
events <- c(19)
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 Ontak 19 19 100.0 82.4 100.0 83.2 100.0 83.2 99.911. Multiplicity, Missing Data and Analysis Populations
The registry names a primary response outcome and lists toxicity as a secondary outcome. The primary outcome description also refers to disease-free progression and overall survival. The record does not clarify whether these were separate endpoints, how many formal hypotheses were tested, or whether a multiplicity procedure was planned. In general, when multiple outcomes or repeated tests are considered, the chance of at least one apparently notable result can change; statistical plans may address this by defining priorities or adjusting inference. No such plan is reported in the registry record, and no outcome analysis results are listed.
The primary outcome description says analysis was on an intent-to-treat basis. In general, an intent-to-treat approach analyzes participants according to their assigned or enrolled group, preserving the benefits of the original assignment process in comparative trials. Since this trial is single-group, the record's statement identifies the intended analysis basis but does not explain its operational definition. It does not report whether every enrolled participant was included in each outcome analysis or how treatment discontinuation was handled.
Missing-data methods are not reported in the registry record. There is no description of how missing response assessments, incomplete follow-up, or unavailable outcome information were handled. No analysis population counts or participant disposition are provided beyond enrollment. Consequently, the extent and possible impact of missing outcome data cannot be evaluated from this record. The registry also does not report interim analyses or stopping rules; no conclusions about whether they occurred can be drawn from that absence.
12. 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 |
|---|---|---|---|
| Ontak | 0 | 19 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Ontak | 0 of 19 |
For the Ontak group, the registry lists 19 participants at risk for serious adverse events and 0 affected. It also lists 19 participants at risk for other adverse events and 0 affected. The deaths entry has no value reported. These are the figures recorded for the safety outcomes; the unreported deaths value should not be read as a zero.
In general, a count of participants affected is different from a count of event episodes: one participant may experience more than one event, while a participant-level count records whether the participant was affected. The registry record does not explain the unit or event-coding details beyond the counts, so the figures should be read as registry summaries rather than a detailed event listing. It also does not report the criteria used to classify an event as serious or other.
The counts do not establish that no adverse events occurred beyond those captured in these entries, and they do not compare safety with another group. The record does not provide treatment exposure duration, follow-up completeness, or detailed event information. In general, safety counts are interpreted in light of how events were defined, collected, and followed; those details are not reported in the registry record. The figures should therefore be described narrowly as the serious and other adverse-event counts recorded for this group.
13. What the Result Does, and Does Not, Mean
The registry record documents a completed Phase II trial in which 19 participants were enrolled in a single group receiving intravenous Ontak. It identifies clinical response over 2 years as the primary outcome, describes RECIST measurement, and states that an intent-to-treat analysis was planned. It also records safety counts for serious and other adverse events. These details describe the design and the information entered into the record.
They do not provide a clinical response result. No number of participants demonstrating response, response percentage, progression result, survival result, confidence interval, or p-value is reported in the registry record. Therefore, readers cannot determine from this record how many participants met the response criterion, how precise any response estimate would be, or whether any observed outcome differed from a specified reference. The stated recruitment need of 56 and enrollment of 19 do not fill that gap and do not, by themselves, indicate the direction or magnitude of an outcome.
The single-group design also limits what could be concluded even if outcome counts were available. In general, outcomes observed in one treated group do not provide a randomized comparison against an alternative. A description of outcomes can be informative about that group, but it does not by itself establish that the intervention caused those outcomes. This is a general point about the design, not a claim about what happened to these participants.
The adverse-event record lists 0 affected among 19 at risk for serious events and 0 affected among 19 at risk for other events; deaths are not reported. These entries should not be generalized beyond what the registry records, particularly because event definitions, duration of exposure, and follow-up completeness are not described.
Overall, the registry provides a trial framework, enrollment, intended outcome definitions, and limited safety counts, but not the efficacy results needed to estimate response or its uncertainty. The record therefore supports a description of what the trial set out to assess and what safety counts it lists; it does not support a conclusion about clinical benefit, lack of benefit, or comparative effectiveness.
14. Why This Trial Matters Statistically
This trial illustrates why a registry record needs to be read in two layers: the design and the results. The design information identifies a Phase II, single-group study of intravenous Ontak, a primary clinical response outcome, and a 2 years timeframe. The results information is much more limited: the registry record does not report the response count or percentage, progression or survival findings, or statistical analyses. A clearly stated endpoint is not itself an endpoint result.
The enrollment information also highlights the distinction between a planned recruitment target and the number recorded as enrolled. The outcome description states that 56 subjects needed to be recruited, while enrollment is 19. The record does not explain this difference. It is statistically important not to turn it into a claim about recruitment decisions, trial conduct, or the amount of information in an unreported outcome analysis. Those matters require information not reported in the registry record.
The study also shows how design governs interpretation. A single-group trial can describe outcomes among participants receiving the intervention, but has no concurrent control group for a direct randomized comparison. In general, this affects the kinds of causal questions that can be addressed, regardless of whether a numerical response result is available.
Finally, the safety entries illustrate the limits of sparse summaries. Counts of participants affected can be reported, but without event definitions, exposure, or detailed follow-up information, the scope of the safety summary is uncertain. Statistical interpretation depends not only on numerical estimates, but also on knowing what was measured, in whom, and how missing information was handled. This record makes some of those design intentions visible while leaving the primary efficacy findings and several analysis details unreported.
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 most consequential limitation for interpreting efficacy is that the registry record does not report results for the primary clinical response outcome. It also does not report disease-free progression or overall survival results, although these are mentioned in the outcome description. Without counts, percentages, time-to-event estimates, or uncertainty measures, efficacy cannot be quantified from this record.
The single-group design has no concurrent comparator. Even if outcome results were available, this design would not provide a randomized estimate of how outcomes compare with another treatment or control condition. The registry records no masking. It does not state whether outcome assessors were masked, so that aspect cannot be assessed.
The recorded enrollment is 19, while the primary outcome description says 56 subjects needed to be recruited. The registry does not explain this difference or report a sample-size justification. It also does not report participant characteristics, the number assessed for each outcome, treatment dose or schedule, duration of exposure, or participant disposition. These omissions prevent assessment of how closely the analyzed group, if any, corresponded to the intended population.
Missing-data handling, analysis details, multiplicity procedures, interim analyses, and stopping rules are not reported in the registry record. The record states an intent-to-treat basis but does not define the analysis population in practice. Safety reporting is limited to participant counts, without event definitions, event-level detail, or a reported deaths value. These limitations are specific to what is recorded and should not be mistaken for evidence that a procedure or event did or did not occur.
16. Related Tutorials
17. Related Statistical Calculators
18. Sources
- ClinicalTrials.gov: A Trial of Intravenous Denileukin Diftitox in Stage III or IV Ovarian Cancer — NCT00880360.
- Registry record last updated 2018-03-27; status last verified 2013-01.
- Results first posted 2012-10-19.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
19. Record Summary
NCT00880360 is recorded as a completed Phase II, single-group trial sponsored by The University of Texas Health Science Center at San Antonio. The study evaluated intravenous Ontak, also called denileukin diftitox, in selected advanced ovarian, extraovarian peritoneal, or fallopian tube cancers. Enrollment was 19; the primary outcome description states that 56 subjects needed to be recruited.
The primary outcome was the number of participants demonstrating clinical response over 2 years, assessed by RECIST and intended to be reported as a percent. The description also refers to disease-free progression and overall survival. The registry record does not report efficacy results or statistical analyses. It states that analysis was on an intent-to-treat basis.
For safety, the registry lists 0 affected among 19 at risk for serious adverse events and 0 affected among 19 at risk for other adverse events. The deaths value is not reported in the registry record. The trial has no listed comparator, and masking is recorded as none.