Study of Ramucirumab in Ovarian Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study of Ramucirumab in Ovarian Cancer (NCT00721162), a na phase 2 study. The primary outcome is Percentage of Participants With Progression-Free Survival at 6 Months (PFS-6).

2. Clinical Question

This clinical question is descriptive of outcomes among participants treated in the study. Without a randomized comparator, it cannot isolate the effect of ramucirumab from other influences on observed outcomes. The record lists progression-free survival, overall survival, overall survival at 1 year, and treatment-emergent adverse events among the secondary outcomes. It does not provide their numerical results in the available results information. As a result, the clinical question can be described from the registered endpoint definition, but the size and precision of the primary outcome cannot be evaluated from this record.

3. Trial Design

The study, titled “Study of Ramucirumab in Ovarian Cancer,” is registered as NCT00721162. Its official title describes a Phase 2, non-randomized, open-label, multicenter study of IMC-1121B in persistent or recurrent epithelial ovarian, fallopian tube, or primary peritoneal carcinoma. The registered intervention is ramucirumab, administered as monotherapy. The study is marked completed, with enrollment of 60 participants. The registry record lists a start date of 2008-08 and a primary completion date of 2012-05.

The single-group design means that participants received the study intervention without a concurrent randomized control arm. Non-randomization and open-label conduct are important context when interpreting any outcome: the registry record does not provide a like-for-like control group, and the treatment assignment was not masked. These design features do not establish that a reported outcome was caused by the intervention. The record does not describe additional measures used to address possible bias.

The primary endpoint is the percentage of participants with progression-free survival at 6 months, defined as being without progressive disease or death from any cause at 6 months after the first dose. The endpoint population is all participants who received any amount of study drug. The record lists a 95% confidence interval as the measure of dispersion, but does not provide the estimate or confidence interval limits.

Secondary outcomes include progression-free survival, overall survival at 1 year, overall survival, and a summary listing of participants reporting drug-related treatment-emergent adverse events. The record lists 6 outcome measures and 0 analyses. It does not report a detailed statistical analysis plan, the handling of missing outcomes, or a sample-size justification. The enrollment figure describes the study as registered; it should not be assumed that all enrolled participants were included in the primary endpoint population.

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: 73 participants signed informed consent.

Overall Study

Analysis population for the primary outcome, as defined in the registry: All participants who received any amount of study drug.

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: All participants who received any amount of study drug.

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants With Progression-Free Survival at 6 Months (PFS-6), measured over First Dose to 6 Months.

The primary endpoint is the percentage of participants with progression-free survival at 6 months after the first dose. In this study, a participant meets the endpoint definition by having no progressive disease and no death from any cause by that time. The registry record specifies that the endpoint population includes all participants who received any amount of study drug.

Progressive disease was determined using Response Evaluation Criteria in Solid Tumors, or RECIST, version 1.0. Under the recorded definition, progression includes an increase of at least 20% in the sum of the longest diameters of target lesions, unequivocal progression of a non-target lesion, or a new lesion. These criteria make the progression component depend on documented tumor assessments; death from any cause is also included in the endpoint definition.

As a general statistical concept, a fixed-time progression-free survival percentage gives a snapshot of the proportion meeting the defined status at a specified time. It is used to describe disease control and survival together at that landmark, rather than reporting either component alone. The confidence interval communicates uncertainty around the estimated percentage: a narrower interval generally indicates greater precision, while a wider interval indicates less precision. The registry record states that a 95% confidence interval was used, but its limits and the endpoint estimate are not reported in the registry record. Therefore, neither the observed percentage nor its precision can be interpreted from the available registry results.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registered primary outcome is a binary status assessed at a fixed time: whether each participant was alive and without progressive disease at 6 months after the first dose. The study summarizes that status as a percentage of participants. For this endpoint, the favorable status is absence of both progression and death by the specified time. The registry record defines the population as participants who received any amount of study drug. It does not report how many participants met that population definition or how many had an observed endpoint assessment.

What does a confidence interval describe?

As a general statistical concept, a confidence interval expresses uncertainty in an estimate based on the observed data and the method used to calculate the interval. The point estimate alone gives a single summary of the observed percentage; the interval indicates the range of values compatible with the data under the method’s assumptions. A confidence interval is not a guarantee that the underlying value lies within its limits, and it does not by itself establish whether an outcome is clinically important. For this endpoint, the registry record specifies a 95% confidence interval but does not report the point estimate or interval limits. Precision therefore cannot be assessed from the record.

How should the fixed-time endpoint be understood?

The six-month endpoint is a landmark summary. It classifies participants by whether they meet the endpoint definition at that time. This differs from reporting the entire timing of progression or death for each participant. The listed secondary outcomes include progression-free survival and overall survival, but the record does not provide their numerical results or describe the analyses used for them. In general, time-to-event methods can use information about when events occur and account for participants whose follow-up ends before an event is observed. The registry record does not specify how such details were handled in this study.

What does RECIST contribute?

RECIST version 1.0 supplies criteria for classifying tumor response and progression. The registry definition includes an increase of at least 20% in the sum of the longest diameters of target lesions, unequivocal progression of a non-target lesion, or a new lesion. This makes the endpoint depend in part on tumor assessments and their classification. The record does not report assessment schedules, independent review procedures, or how disagreements in assessment were handled; those details are not reported in the registry record.

What can the design estimate?

A single-group study can describe outcomes among its treated participants. It cannot, by itself, estimate a randomized contrast against a control group. In general, random allocation helps make comparison groups similar on average at the start of a study, while a concurrent control supplies a reference for changes that might occur without the intervention. Neither feature is present as a comparison in this registered design: allocation is listed as not applicable and the model is single group. Accordingly, a percentage among participants in this study would remain a descriptive outcome rather than a randomized treatment-effect estimate.

The open-label designation means masking was absent. As a general matter, awareness of treatment assignment can influence assessment or reporting, although the extent depends on the outcome and study procedures. The registry record does not describe safeguards or assessment masking. It also does not report a detailed statistical analysis plan, including the specific estimator for the primary percentage, the interval method, or the handling of missing assessments. Those methods should not be inferred from the endpoint label alone.

How should planning calculations be distinguished from observed results?

General sample-size calculations ask how many participants might be needed to detect a specified effect under chosen assumptions. They are planning illustrations, not observed outcomes, and they do not show that a study had a particular probability of finding an effect. The record does not report the study’s own sample-size justification, target effect, or design assumptions. Any planning illustration should therefore be kept separate from the observed clinical results, and cannot fill the gap left by an unreported primary endpoint estimate.

Finally, the listed 6 outcome measures and 0 analyses describe the registry record’s outcome and analysis listings; they do not establish what analyses may have been conducted or reported elsewhere. No inferential statistic, adjusted estimate, or multiplicity procedure is reported in the registry record. Interpretation should be limited to the registered design and definitions, and to the safety figures that are actually recorded.

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("Ramucirumab")
n      <- c(60)
events <- c(15)
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  Ramucirumab  60  15  25.0  14.7  37.9  15.8  37.2  15.8  37.3

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists multiple outcomes: the primary six-month progression-free survival percentage and secondary outcomes involving progression-free survival, overall survival at 1 year, overall survival, and drug-related treatment-emergent adverse events. It lists 6 outcome measures and 0 analyses. It does not report a statistical analysis plan describing which outcomes were tested, which were considered primary for inference, or whether any adjustment for multiple comparisons was planned or used. As a general statistical matter, evaluating several outcomes can increase the chance of at least one apparently notable result if each is interpreted without accounting for multiplicity. The record does not allow an assessment of how that issue was handled.

Missing outcome information is also not described. The primary population is all participants who received any amount of study drug, but the record does not report the number treated, the number assessed at 6 months, or the number with missing endpoint status. It does not state whether missing assessments were excluded, treated as progression, or handled using another method. Those choices can affect a fixed-time percentage and its interpretation. No assumptions about missing data should be inferred.

The record also does not report a detailed analysis population for the secondary outcomes, reasons for missing follow-up, or sensitivity analyses. The enrollment figure of 60 does not establish that 60 participants contributed to each outcome. Without these details and the numerical endpoint results, the extent of missingness, its possible influence, and the impact of multiple-outcome testing are not reported in the registry record.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: neoplasm progression (6.7%), small intestinal obstruction (5.0%), expired drug administered (5.0%), intestinal perforation (3.3%), alanine aminotransferase increased (3.3%).

The registry record lists 60 participants at risk for serious adverse events and 60 at risk for other adverse events in the ramucirumab group. It records 22 participants affected by serious adverse events and 58 affected by other adverse events. These counts describe the recorded safety groups; they do not establish that every participant had the same observation time or exposure. The record does not report exposure duration or provide further context for interpreting event rates over time.

Selected serious adverse-event terms are listed with percentages: neoplasm progression, 6.7%; small intestinal obstruction, 5.0%; expired drug administered, 5.0%; intestinal perforation, 3.3%; alanine aminotransferase increased, 3.3%; and thrombocytopenia, 1.7%. These are reported term-specific percentages, not estimates of treatment effect. The record does not provide a comparator group for assessing whether these events were more or less frequent under another treatment.

As a general statistical distinction, the number of participants with at least one event is not interchangeable with the total number of event episodes; a participant can experience more than one event. The registry record does not explain event recurrence or the detailed coding and attribution procedures. Deaths are not reported in the registry record. Safety figures should therefore be read as descriptive registry summaries, not as causal comparisons or as a complete account of risk.

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

The study provides a registered framework for describing ramucirumab monotherapy in persistent or recurrent epithelial ovarian, fallopian tube, or primary peritoneal carcinoma. Its primary endpoint is clearly defined as the percentage of participants alive without progressive disease at 6 months after the first dose, using RECIST version 1.0 for progression. The record also specifies that the endpoint population consists of participants who received any amount of study drug.

What the registry entry does not provide is the numerical primary endpoint result or its confidence interval limits. Without those values, readers cannot determine the observed percentage or how precisely it was estimated. The enrollment count does not substitute for an outcome estimate, and safety counts do not answer the primary efficacy question.

The single-group, non-randomized design also limits interpretation. Even if a numerical outcome were available, the study would describe outcomes in its participants rather than establish how those outcomes compare with a concurrent control. In general, observed outcomes can reflect factors beyond treatment, and the record does not report a method for separating those influences. The absence of masking is also relevant context, but the registry record does not describe its effect on assessments.

The registry lists secondary survival and safety outcomes, but numerical results for those outcomes are not reported in the registry record. Serious and other adverse-event counts and selected serious-event percentages are available as descriptive information; they do not demonstrate a causal relationship or comparative risk. Overall, this record supports explanation of the study question, design, and recorded safety summaries, but not a conclusion about the primary endpoint result or a comparative treatment effect.

14. Why This Trial Matters Statistically

This trial is statistically informative as an example of the distinction between a well-defined endpoint and an interpretable numerical result. The primary endpoint specifies the clinical status of interest, the assessment time, the population definition, and the progression criteria. Those details clarify what the study intended to measure. Yet the registry record does not report the endpoint percentage or its confidence interval, so the central estimate and its precision cannot be evaluated.

The single-group design also illustrates the difference between describing an outcome and estimating a comparative effect. A proportion observed among participants can summarize what happened in that study population, but without a concurrent randomized comparator it cannot show how outcomes would differ under another treatment. This distinction is essential when interpreting a Phase 2, non-randomized study and prevents descriptive outcomes from being presented as causal evidence.

The record also raises practical questions about analysis transparency. It lists several outcome measures but 0 analyses, and does not report the analysis plan, missing-data approach, multiplicity handling, or sample-size justification. These omissions make it difficult to assess the strength and scope of any intended inference. They also show why endpoint definitions alone are not enough: interpretation depends on the observed results and on the methods used to estimate them.

Finally, the safety summaries show why counts, percentages, attribution, and comparison must be distinguished. The reported serious-event terms provide descriptive context, but do not establish comparative risk. Taken together, the record is useful for understanding the design and registered questions while underscoring the limits of inference when outcome estimates and analysis details are unavailable.

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 primary limitation for interpreting efficacy is that the registry record does not report the six-month progression-free survival percentage or its confidence interval limits. The record therefore does not permit assessment of the magnitude or precision of the primary endpoint. The endpoint population is defined, but the number of participants who received study drug and the number with an observed six-month status are not reported in the registry record.

The single-group, non-randomized, open-label design has no concurrent control comparison. It cannot support a direct estimate of relative outcomes against another treatment. The record does not describe procedures to reduce potential assessment bias, and does not give details of tumor assessment frequency, independent review, or missing assessments. These details are not reported in the registry record.

Although secondary outcomes are named, numerical results and analysis methods for them are not reported in the registry record. The record lists 6 outcome measures and 0 analyses, and does not describe multiplicity adjustment or a prespecified analysis hierarchy. It also does not report the study’s sample-size justification, interim analyses, or a detailed statistical analysis plan; none should be inferred.

Safety information is limited to the recorded affected counts and selected serious adverse-event terms. The record does not provide a concurrent comparator, detailed exposure time, event recurrence information, or a reported deaths figure. These limitations restrict safety interpretation to descriptive reporting and prevent comparative conclusions. The study status is completed, but completion alone does not supply the missing endpoint estimates or methodological details.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Study of Ramucirumab in Ovarian Cancer — NCT00721162.
• Registry record last updated 2019-09-26; status last verified 2019-09.
• Results first posted 2014-06-18.
• 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

NCT00721162 is a completed Phase 2, non-randomized, open-label, single-group study of ramucirumab monotherapy in persistent or recurrent epithelial ovarian, fallopian tube, or primary peritoneal carcinoma. Enrollment was 60. The registry record lists a start date of 2008-08 and a primary completion date of 2012-05.

The primary outcome is the percentage of participants alive without progressive disease at 6 months after the first dose, with progression assessed using RECIST version 1.0. The endpoint population is participants who received any amount of study drug, and a 95% confidence interval is specified. The endpoint estimate and confidence interval limits are not reported in the registry record.

Secondary outcomes include progression-free survival, overall survival at 1 year, overall survival, and drug-related treatment-emergent adverse events. The record lists 6 outcome measures and 0 analyses. It includes descriptive adverse-event counts and selected serious-event percentages, but no randomized comparison. The record does not report a detailed statistical plan, missing-data methods, or sample-size justification.