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 OPT-821 With or Without Vaccine Therapy in Treating Patients With Ovarian Epithelial Cancer, Fallopian Tube Cancer, or Peritoneal Cancer in Second or Third Complete Remission (NCT00857545), a randomized phase 2 study. The primary outcome is Progression-free Survival (PFS).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00857545 |
| Phase | Phase 2 |
| Condition | Stage IA Fallopian Tube Cancer, Stage IA Ovarian Cancer, Stage IB Fallopian Tube Cancer |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 171 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Gynecologic Oncology Group |
| Results posted | Yes |
2. Clinical Question
Population
The registry describes participants with epithelial ovarian, fallopian tube, or peritoneal cancer in a second or third complete remission. The listed conditions include stages IA through IV across these cancer types. The primary-outcome population is described as enrolled and randomized participants. Further eligibility details are not reported in the registry record.
Intervention
One randomized group received a polyvalent antigen-KLH conjugate vaccine together with the immunological adjuvant OPT-821. Both were administered subcutaneously. The registry lists treatment in weeks 1, 2, 3, 7, 11, 23, 35, 47, 59, 71, and 83, provided there was no disease progression or unacceptable toxicity.
Comparator
The comparison group received OPT-821 alone, administered subcutaneously according to the same schedule as the combination group. The registry describes the study as randomized, double-blind, and parallel-group. Details about who was blinded and how allocation was implemented are not reported in the registry record.
Primary question
The primary question was how progression-free survival, measured in months, compared between the two groups. The registry reports a median and a 95% confidence interval for each group. A direct between-group estimate or test is not reported in the registry record, so the posted medians alone do not establish the size or statistical certainty of a treatment contrast.
3. Trial Design
This was a phase II, randomized, double-blind, parallel-group trial sponsored by the Gynecologic Oncology Group. The registry lists 171 participants as enrolled. The primary outcome population is described as enrolled and randomized participants. The reported group sizes for that outcome are 86 for the vaccine-plus-OPT-821 group and 85 for the OPT-821-alone group.
The trial compared a polyvalent antigen-KLH conjugate vaccine plus OPT-821 with OPT-821 alone. Both interventions were administered subcutaneously. In the vaccine group, treatment was scheduled for weeks 1, 2, 3, 7, 11, 23, 35, 47, 59, 71, and 83, in the absence of disease progression or unacceptable toxicity. The OPT-821-alone group followed the same schedule. The registry lists laboratory biomarker analysis as an intervention, but details of those analyses are not reported in the registry record.
The start is listed as 2010-07, primary completion as 2015-09, and status as completed. The primary outcome was progression-free survival. Secondary outcomes listed are the incidence of adverse effects of Grade 3 or higher during the treatment period and overall survival. Numerical results for overall survival are not reported in the registry record. The registry does not report details of the randomization sequence, allocation concealment, the parties included in masking, protocol deviations, or the statistical plan. The phase label and design describe the trial structure; by themselves, they do not establish the precision intended for the primary comparison or how its results should be interpreted.
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 | Polyvalent Antigen-KLH+OPT-821 Vaccine | Non-specific Immunity With OPT-821 |
|---|---|---|
| STARTED | 86 | 85 |
| COMPLETED | 86 | 85 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: Enrolled and randomized participants. 95% two-sided confidence interval
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: Enrolled and randomized Participants
| Characteristic | Unit | Polyvalent Antigen-KLH+OPT-821 Vaccine | Non-specific Immunity With OPT-821 | Total |
|---|---|---|---|---|
| Participants analysed | 86 | 85 | 171 | |
| Age, Continuous | years | 61.3 (SD 8.6) | 59.1 (SD 9.1) | 60.2 (SD 8.9) |
| Age, Customized: 40-49 | Participants | 8 | 14 | 22 |
| Age, Customized: 50-59 | Participants | 29 | 31 | 60 |
| Age, Customized: 60-69 | Participants | 37 | 26 | 63 |
| Age, Customized: 70-79 | Participants | 10 | 14 | 24 |
| Age, Customized: 80-89 | Participants | 2 | 0 | 2 |
| Sex: Female, Male: Female | Participants | 86 | 85 | 171 |
| Sex: Female, Male: Male | Participants | 0 | 0 | 0 |
| Recurring and/or Persistent Disease | Participants | 86 | 85 | 171 |
| Cell Type: Adenocarcinoma with Squam. Diff ' n | Participants | 0 | 1 | 1 |
| Cell Type: Adenocarcinoma, Unsp. | Participants | 3 | 1 | 4 |
| Cell Type: Adenosquamous | Participants | 2 | 0 | 2 |
| Cell Type: Clear Cell Carcinoma | Participants | 1 | 1 | 2 |
| Cell Type: Endometrioid Adenocarcinoma | Participants | 6 | 1 | 7 |
| Cell Type: Mixed Epithelial Carcinoma | Participants | 2 | 2 | 4 |
| Cell Type: Other Carcinoma | Participants | 2 | 0 | 2 |
| Cell Type: Serous Adenocarcinoma | Participants | 69 | 76 | 145 |
6. Primary Endpoint
The registry lists the primary outcome as Progression-free Survival (PFS), measured over Every 3 month until 2 years from start of treatment, then every 6 months for 3 years; then annually if patient remains in remission..
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | 95% Confidence Interval |
| Unit | Months |
| Endpoint classification | Time-to-Event Analysis |
Progression-free survival is the time from randomization to the first clinical, biochemical, or radiological evidence of progression, death from any cause, or last contact, whichever occurs first, according to the registry’s description. Progression is described as increasing clinical, radiological, or histological evidence of disease. For progression identified clinically or histologically, the registry says an abdominal and pelvic CT scan must also be performed.
The reported summary is the median time in months, with a 95% confidence interval for each group. The median describes the time by which half of the observed participants have had the endpoint or reached the relevant censoring point, subject to the time-to-event analysis. General: time-to-event outcomes can accommodate different follow-up durations and participants whose endpoint has not been observed by their last recorded contact. Their contribution depends on appropriate censoring and follow-up procedures; those analysis details are not reported in the registry record.
Progression-free survival is used to summarize the time until disease progression or death, rather than only whether either event occurred. The registry specifies assessments every 3 month until 2 years from the start of treatment, then every 6 months for 3 years, and annually thereafter if the participant remains in remission. The posted median and intervals describe each group separately. A direct between-group estimate is not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry reports a median progression-free survival of 5.9 months for the polyvalent antigen-KLH plus OPT-821 group, with a 95% confidence interval from 5.4 to 7.7 months. For the OPT-821-alone group, the median is 6.5 months, with a 95% confidence interval from 5.1 to 7.9 months. These are group-specific summaries, not a direct estimate of the difference between groups.
The confidence intervals overlap. General: a confidence interval expresses uncertainty around an estimate under the analysis used to construct it. The intervals around two separate group medians are not a confidence interval for the between-group contrast, and their overlap or non-overlap is not, by itself, a formal test of that contrast. The registry record does not report a hazard ratio, a confidence interval for a between-group effect, or a p-value for progression-free survival. A formal comparison cannot be reconstructed from the posted medians and intervals alone.
The group sizes for the primary outcome are 86 and 85. Those counts describe the reported outcome populations; they do not reveal how many progression events occurred, how much follow-up each participant contributed, or how many observations were censored. The registry does not report those details. They matter because time-to-event estimates depend on event timing and follow-up, not just on the number of participants.
The posted results therefore support a descriptive reading of the two median estimates and their uncertainty. They do not establish the direction, magnitude, or statistical certainty of a treatment effect. The registry record also does not report a sponsor hazard ratio or a sponsor’s direct statistical comparison for this outcome. A comparison value is not estimable from the posted result as presented. The absence of a reported comparison should not be interpreted as evidence that the groups are equivalent.
Several distinct questions remain unanswered by the medians alone. The registry does not report whether the primary analysis followed an intention-to-treat principle, how censoring was handled, whether proportional hazards assumptions were assessed, or whether any adjusted analysis was used. These are not details that can be inferred from a median and its confidence interval. The reported numbers should therefore be read as descriptive time-to-event summaries, with the inferential limits noted above.
9. Statistical Methods Explained
Progression-free survival is a time-to-event endpoint: participants can experience the event at different times, and some may not have an event recorded before their last contact. The registry defines the outcome from randomization to the first evidence of progression, death from any cause, or last contact, whichever occurs first. It describes clinical, biochemical, and radiological evidence as possible ways of identifying progression, and gives an additional imaging requirement for progression established on a clinical or histological basis.
What does a median time-to-event estimate describe?
The median is a measure of the center of the event-time distribution. In general, it marks the time at which the estimated proportion remaining free of the event reaches one half. It is not the average follow-up time and does not describe the experience of every participant. A median can be estimated even when not all participants have experienced the event, provided the time-to-event methods and follow-up information support estimation. The registry reports medians of 5.9 months and 6.5 months for the two groups.
The median also does not convey the whole shape of the event-time pattern. Two groups could have the same median and different patterns before or after that point, or different medians while having similar patterns over part of follow-up. General: survival curves and event-time distributions can provide information about timing across the follow-up period, but the registry record does not report a sponsor hazard ratio or a direct two-group analysis for this outcome. The posted group medians cannot substitute for those results.
What does a 95% confidence interval add?
The registry reports a 95% confidence interval for each group’s median: 5.4 to 7.7 months for the vaccine-plus-OPT-821 group and 5.1 to 7.9 months for the OPT-821-alone group. General: a confidence interval describes the uncertainty associated with an estimate under the statistical method used. It does not mean that a fixed percentage of individual participants will have event times within the interval. It also does not directly give the uncertainty around a comparison between the two groups.
Because the intervals are attached to separate medians, they should not be read as a formal test of whether the treatments differ. A direct contrast would require an appropriate between-group estimate and its uncertainty, or a reported test. Neither is reported in the registry record. The record indicates that a two-arm comparison value was missing or not estimable for this median time endpoint.
Why do event timing and censoring matter?
General: time-to-event analyses use the time each participant is observed and whether the event occurred during that observation. A participant whose event has not been observed by last contact is commonly treated as censored at that contact, rather than as having experienced the event then. This approach can use partial follow-up, but it relies on appropriate assumptions and accurate follow-up information. The registry identifies last contact in its endpoint definition but does not report the number of censored participants, the censoring method, or the analysis procedures used to account for censoring.
The specified assessment schedule gives context for how outcomes were to be monitored: every 3 month until 2 years from treatment start, then every 6 months for 3 years, and annually if a participant remained in remission. The registry does not report the actual completeness of these assessments or the amount of follow-up in each group. Without such information, the medians and intervals cannot answer questions about differential follow-up or missing outcome assessments.
Why are separate medians not enough for a treatment comparison?
The primary endpoint is time-to-event, and the registry’s stated meaning for this endpoint says only sponsor-reported hazard ratios are used for a two-arm comparison. No sponsor hazard ratio is reported in the registry record. A hazard ratio, when reported, compares event rates over follow-up under a particular model; it is not the same quantity as a difference between medians. General: a hazard ratio also has assumptions and may not adequately describe the contrast if relative event rates change over time. The registry does not report whether those assumptions were evaluated.
The posted figures therefore permit description of each arm’s median and interval, but not a complete inferential comparison. No p-value, confidence interval for a comparative effect, or adjustment for prognostic factors is reported. The group sizes do not supply the missing event-time information needed to recreate such analyses.
How should planning illustrations be distinguished from trial results?
The registry record does not report the trial’s sample-size justification. Any planning illustration based on an observed effect is a hypothetical design calculation, not a result of the randomized comparison and not observed power. The stated assumptions for such illustrations are a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the effect to detect set as a stated fraction of the observed effect. Those assumptions describe the calculation, not necessarily the trial’s original design. No planning output should be treated as a measured treatment effect or as evidence about the probability that the trial detected an effect.
General: over-dispersion occurs when outcome variability is greater than a model assumes. It can make standard errors too small if it is ignored, reducing the reliability of confidence intervals and tests. That concept is not a reported feature of this time-to-event endpoint, and the registry does not describe an over-dispersion assessment. More broadly, the statistical methods used for the sponsor’s primary comparison, if any, are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists progression-free survival as the primary outcome and lists two secondary outcomes: incidence of adverse effects of Grade 3 or higher during the treatment period and overall survival. Numerical overall-survival results are not reported in the registry record. The record does not describe a multiplicity procedure, such as adjustment of significance thresholds across outcomes, or state how the primary and secondary outcomes were prioritized in a statistical testing plan. Without that information, the results cannot be interpreted as a family of confirmatory tests with a known error-control approach.
The primary-outcome population is described as enrolled and randomized participants. Whether the analysis used an intention-to-treat, per-protocol, or another population is not reported in the registry record. Details about exclusions, treatment discontinuation, protocol deviations, or participants omitted from particular analyses are also not reported.
For progression-free survival, the endpoint definition includes last contact, but the record does not describe the censoring rules, missing assessment procedures, or any sensitivity analyses. The number and timing of events and the amount of follow-up by group are not reported. It is therefore not possible to assess from the registry summary how missing observations or loss to follow-up may have affected the estimates.
Missing-data methods for the secondary outcomes are not reported in the registry record. The record also does not report interim analyses or stopping rules. These omissions do not establish that such procedures were absent; they mean that the record does not describe them. Accordingly, the posted outcome summaries should be interpreted without assuming a particular multiplicity adjustment, missing-data strategy, or analysis population beyond the primary population description.
11. 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 |
|---|---|---|---|
| Polyvalent Antigen-KLH+OPT-821 Vaccine | 5 | 86 | 5.8% |
| Non-specific Immunity With OPT-821 | 14 | 84 | 16.7% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Polyvalent Antigen-KLH+OPT-821 Vaccine | 84 of 86 |
| Non-specific Immunity With OPT-821 | 82 of 84 |
Most frequent serious adverse event terms
| Event term | Organ system | Polyvalent Antigen-KLH+OPT-821 Vaccine | Non-specific Immunity With OPT-821 |
|---|---|---|---|
| Small Intestinal Obstruction | Gastrointestinal disorders | 0 of 86 | 5 of 84 |
| Abdominal Pain | Gastrointestinal disorders | 2 of 86 | 2 of 84 |
| Urinary Tract Infection | Infections and infestations | 1 of 86 | 1 of 84 |
| Neoplasms Benign, Malignant And Unspecified (Incl cysts and polyps) | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 1 of 86 | 1 of 84 |
| Colonic Obstruction | Gastrointestinal disorders | 0 of 86 | 1 of 84 |
| Bloating | Gastrointestinal disorders | 0 of 86 | 1 of 84 |
| Ileal Obstruction | Gastrointestinal disorders | 0 of 86 | 1 of 84 |
| Fever | General disorders | 0 of 86 | 1 of 84 |
| Autoimmune Disorder | Immune system disorders | 0 of 86 | 1 of 84 |
| Skin Infection | Infections and infestations | 0 of 86 | 1 of 84 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Polyvalent Antigen-KLH+OPT-821 Vaccine | Non-specific Immunity With OPT-821 |
|---|---|---|---|
| Injection Site Reaction | General disorders | 72 of 86 | 68 of 84 |
| Fatigue | General disorders | 42 of 86 | 35 of 84 |
| Anemia | Blood and lymphatic system disorders | 31 of 86 | 33 of 84 |
| White Blood Cell Decreased | Investigations | 18 of 86 | 21 of 84 |
| Abdominal Pain | Gastrointestinal disorders | 17 of 86 | 19 of 84 |
| Neutrophil Count Decreased | Investigations | 16 of 86 | 17 of 84 |
| Peripheral Sensory Neuropathy | Nervous system disorders | 14 of 86 | 19 of 84 |
| Constipation | Gastrointestinal disorders | 15 of 86 | 16 of 84 |
| Platelet Count Decreased | Investigations | 13 of 86 | 17 of 84 |
| Nausea | Gastrointestinal disorders | 13 of 86 | 16 of 84 |
Serious events with the highest arm-level rate: small intestinal obstruction (6.0%), abdominal pain (2.4%), colonic obstruction (1.2%), bloating (1.2%), ileal obstruction (1.2%).
The registry’s serious adverse-effect summary reports 5 affected participants among 86 at risk in the polyvalent antigen-KLH plus OPT-821 group, and 14 among 84 at risk in the OPT-821-alone group. These are counts with the recorded at-risk denominators. The denominators differ from one another and from the primary-outcome group sizes, so the serious-event summary should be read using its own reported group counts rather than assuming identical analysis populations.
The most frequently listed serious-event terms include small intestinal obstruction at 6.0%, abdominal pain at 2.4%, and colonic obstruction, bloating, ileal obstruction, and fever at 1.2% each. These are registry-listed terms and percentages; the record does not provide a comparative statistical analysis for them. Death counts are not reported in the registry record.
Serious adverse effects are not interchangeable with the listed secondary outcome of adverse effects of Grade 3 or higher. Seriousness and severity are different classifications, and the registry summary does not establish that these categories contain the same events. The figures are descriptive. They do not by themselves establish whether an event was caused by treatment or whether the groups differ statistically in safety.
12. What the Result Does, and Does Not, Mean
The posted primary-outcome results describe median progression-free survival of 5.9 months in the vaccine-plus-OPT-821 group and 6.5 months in the OPT-821-alone group, each with its own 95% confidence interval. These estimates describe the randomized groups separately. They do not provide a direct estimate of how much one group’s outcome differed from the other’s, nor do they establish the statistical certainty of such a contrast.
The registry record does not report a sponsor hazard ratio, comparative confidence interval, or p-value for progression-free survival. It also does not report a numerical overall-survival result. Consequently, the available information does not establish whether the treatments differed on progression-free survival or overall survival, and it does not establish that the treatments were equivalent. A missing comparative result should not be treated as a finding of no difference.
The serious adverse-effect counts and listed event terms provide a descriptive safety account, but not a causal or statistically adjusted comparison. They do not show whether an individual event was attributable to treatment. The registry also lists a secondary outcome for Grade 3 or higher adverse effects, but the serious-event summary should not be assumed to represent that severity-based outcome.
General: a randomized comparison can support causal interpretation when the analysis follows the design and relevant assumptions, but interpretation also depends on complete outcome reporting, appropriate handling of follow-up and missing data, and a clearly reported comparison. The registry record does not include enough detail to evaluate those features fully. The results should therefore be understood as the reported group summaries and safety counts, with the unanswered comparative and methodological questions kept explicit.
13. Why This Trial Matters Statistically
This trial illustrates why a randomized design and a reported outcome summary are not the same as a fully reported treatment comparison. Randomization creates the framework for comparing assigned groups, while the reported progression-free survival results give a median and confidence interval for each group. Those summaries are informative about each group’s observed time-to-event distribution, but they do not replace a direct estimate of the contrast.
The distinction is especially important for time-to-event outcomes. Participants can have different follow-up durations, and some may have no recorded event before last contact. The timing of events and the way censoring is handled contribute to the estimate. Group sizes alone do not show how many events occurred or how much follow-up was available. Since those details and the direct comparative analysis are not reported, the medians cannot be used to reconstruct a reliable treatment-effect estimate.
The registry also demonstrates the importance of distinguishing safety classifications. A serious adverse effect is not automatically the same as an adverse effect of Grade 3 or higher. Reading the reported safety counts with their own denominators, and avoiding an unsupported causal or statistical conclusion, keeps the descriptive evidence separate from a comparative claim.
Finally, planning calculations are not trial findings. A hypothetical sample-size illustration based on an observed effect does not reveal the original design justification and is not observed power. Keeping design assumptions, outcome summaries, and inferential comparisons separate is essential when drawing conclusions from a registry record.
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.
The registry provides group-specific medians and confidence intervals for progression-free survival, but not a direct comparison between groups. A sponsor hazard ratio, comparative confidence interval, p-value, event count, and censoring details are not reported in the registry record. These omissions limit assessment of the magnitude and precision of the treatment contrast.
The primary population is described as enrolled and randomized participants, but the analysis population label and handling of protocol deviations are not specified. The record does not describe missing outcome data, follow-up completeness, or sensitivity analyses. It is therefore not possible to assess how missing assessments or censoring may have influenced the time-to-event summaries.
The registry lists overall survival and Grade 3 or higher adverse effects as secondary outcomes, but numerical results for overall survival are not reported. The serious-event counts and terms do not necessarily correspond to the Grade 3 or higher outcome. The record does not report a multiplicity strategy, interim analyses, stopping rules, or the sample-size justification.
Additional details about eligibility, allocation concealment, who was blinded, and the statistical methods are not reported in the registry record. These limits concern the information available in the record; they do not establish that the procedures were absent. They do mean that the displayed summaries should not be extended to conclusions that require those details.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: OPT-821 With or Without Vaccine Therapy in Treating Patients With Ovarian Epithelial Cancer, Fallopian Tube Cancer, or Peritoneal Cancer in Second or Third Complete Remission — NCT00857545.
- Registry record last updated 2017-09-13; status last verified 2016-12.
- Results first posted 2017-09-06.
- 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.
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18. Record Summary
NCT00857545 is a completed phase II, randomized, double-blind, parallel-group trial sponsored by the Gynecologic Oncology Group. The record lists 171 participants enrolled and compares a polyvalent antigen-KLH conjugate vaccine plus OPT-821 with OPT-821 alone in participants in a second or third complete remission from epithelial ovarian, fallopian tube, or peritoneal cancer.
Progression-free survival was the primary outcome. The registry reports group medians of 5.9 months and 6.5 months, with separate 95% confidence intervals, but does not report a direct between-group estimate or test. Secondary outcomes listed are Grade 3 or higher adverse effects and overall survival; numerical overall-survival results are not reported. The serious-event summary gives counts and selected terms, but does not establish a comparative safety effect. Important statistical-plan, missing-data, and follow-up details are not reported in the registry record.