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Ovarian Cancer Phase 2 Binary Endpoint NCT00428610

A Study of Chemotherapy Treatment for Patients With Ovarian Cancer: Complete Statistical Analysis

This phase 2, single-group study examined LY573636-sodium in patients with platinum-resistant ovarian cancer. The registry record defines objective response as the primary endpoint but does not report its numerical result.

Trial start: 2007-02  ·  Enrollment: 103  ·  Sponsor: Eli Lilly and Company
Scope of this record

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 Study of Chemotherapy Treatment for Patients With Ovarian Cancer (NCT00428610), a na phase 2 study. The primary outcome is Percentage of Participants With Complete Response and Partial Response (Objective Response Rate).

103
Enrollment
Phase 2
n/a
Arms
In the primary outcome
n/a
Effect
No re-analysis shown
n/a
95% CI
See limitations
FeatureRegistry value
ClinicalTrials.gov identifierNCT00428610
PhasePhase 2
ConditionOvarian Cancer, Fallopian Tube Cancer, Primary Peritoneal Cancer
AllocationNot applicable (single group)
Design modelSingle Group
MaskingNone (open label)
Enrollment103
Arms in the primary outcomen/a
Lead sponsorEli Lilly and Company
Results postedYes

2. Clinical Question

Population

Patients with platinum-resistant ovarian cancer who received at least one dose of study drug were the primary endpoint population. The record also lists fallopian tube cancer and primary peritoneal cancer among the conditions associated with the study. It does not give a separate primary-endpoint result for each condition.

Intervention

Participants received intravenous LY573636-sodium, also called LY573636 in the study description. The stated regimen was an infusion once every 28 days, continuing until disease progression or other criteria for discontinuation were met.

Comparator

The study used a single-group model. The registry record does not describe a control group or a randomized comparison, so the primary question is not a between-treatment comparison.

Primary question

The primary objective was to assess whether LY573636 was effective in treating platinum-resistant ovarian cancer. The primary endpoint was the percentage of treated participants classified as having a complete or partial response under RECIST. The registry record defines this measure but does not report the observed response percentage or its confidence interval.

3. Trial Design

This was a phase 2, single-group study of LY573636-sodium for patients with platinum-resistant ovarian cancer. The listed enrollment was 103. The record gives a study start of 2007-02 and a primary completion of 2011-02, and lists the study status as completed. These record details describe the study registration; they do not establish how many participants contributed data to every outcome.

The treatment was an intravenous infusion once every 28 days. Participants were to continue until disease progression or another criterion for discontinuation was met. The summary describes computed tomography scans and CA-125 tests before the first dose and after every other treatment. The registry record does not provide further detail about how these assessments were scheduled for each participant or handled if an assessment was missed.

The primary endpoint population was all participants who received at least one dose. This is a treated population definition, not an intention-to-treat definition. The record does not state how many participants received a dose or how many had an evaluable response assessment.

The study did not use a randomized allocation or masking, and its model is listed as single group. The record also identifies target Cmax 420 µg/mL, target Cmax 360 μg/mL, and an albumin-tailored dose in the safety information. These group labels do not make the study a randomized, like-for-like comparison. The registry record does not describe a control arm or a method for comparing these dose groups as if they were assigned comparably.

Secondary outcomes listed include progression-free survival, overall survival, duration of response, duration of stable disease, clinical benefit rate, pharmacokinetics, and adverse events. Numerical results for these outcomes are not reported in the registry record.

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: The reasons for discontinuation listed in the participant flow are the reasons the participant discontinued treatment and a participant was considered to have "completed" the trial if they experienced progressive disease or an adverse event.

Overall Study

StageTarget Cmax 420 µg/mLTarget Cmax 360 μg/mLAlbumin-Tailored Dose
STARTED531832
Received at Least One Dose of Study Drug531832
COMPLETED000
NOT COMPLETED531832

Reasons for not completing this period:

ReasonTarget Cmax 420 µg/mLTarget Cmax 360 μg/mLAlbumin-Tailored Dose
Death Due to Adverse Event305
Death Due to Progressive Disease002
Adverse Event232
Investigator Decision211
Progressive Disease421422
Withdrawal by Subject400

Analysis population for the primary outcome, as defined in the registry: All participants who received at least one dose of the 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 enrolled participants who had at least one dose of study drug.

CharacteristicUnitTarget Cmax 420 µg/mLTarget Cmax 360 μg/mLAlbumin-Tailored DoseTotal
Participants analysed531832103
Age, Continuousyears56.88 (SD 11.12)59.88 (SD 8.98)56.83 (SD 10.37)57.39 (SD 10.51)
Sex: Female, Male: FemaleParticipants531832103
Sex: Female, Male: MaleParticipants0000
Race/Ethnicity, Customized: African Decent (black)Participants1012
Race/Ethnicity, Customized: CaucasianParticipants50183199
Race/Ethnicity, Customized: East AsianParticipants1001
Race/Ethnicity, Customized: HispanicParticipants1001
Region of Enrollment: United StatesParticipants32102163
Region of Enrollment: RussiaParticipants120012
Region of Enrollment: ItalyParticipants981128

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants With Complete Response and Partial Response (Objective Response Rate), measured over Baseline to measured progressive disease up to 12.68 months.

ElementRegistry entry
Result typeNumber
Measure of spread90% Confidence Interval
Unitpercentage of participants
Endpoint classificationBinary Endpoint

The primary endpoint is the percentage of participants with an objective response, defined as a complete response or partial response. Investigators classified response according to RECIST. A complete response means disappearance of all target and non-target lesions. A partial response means at least 30% decrease in the sum of the longest diameters of target lesions. The response percentage is defined as the number of participants with either response divided by the total number treated, multiplied by 100.

Objective response is used to describe tumor change under specified assessment criteria. Combining complete and partial responses gives a measure of participants whose observed disease findings meet either response category; it does not include stable disease in the primary endpoint. The study separately lists a clinical benefit rate that includes stable disease, but that is a secondary outcome.

The endpoint timeframe is baseline to measured progressive disease, up to 12.68 months. The registry record describes the endpoint and its intended population, but does not report the number of complete or partial responses, the observed response percentage, or the stated 90% confidence interval. Without those results, the magnitude and precision of the primary endpoint cannot be assessed from the record.

7. Why No Re-analysis Is Shown

Reported as posted, not recalculated. Not a randomized comparison (allocation: NA); arms are not a like-for-like control comparison. A result is recalculated only when the posted data support a clean two-arm comparison, so no result is shown beyond what the sponsor posted.

8. Statistical Interpretation

Clinical Biostats interpretation

The central statistical result needed to interpret this study would be the observed objective response percentage together with its 90% confidence interval. The registry record defines those quantities but does not report their values. Therefore, it is not possible to describe the response frequency, its precision, or whether the observed percentage is compatible with a range of underlying response rates. No response count or denominator for the endpoint is reported in the registry record.

The listed enrollment of 103 is not necessarily the number included in the primary endpoint calculation. The primary population is defined as participants who received at least one dose, and the endpoint denominator is described as the total number treated. The record does not report the treated count or explain whether every treated participant had an evaluable response assessment. Enrollment, treatment exposure, and endpoint evaluability are distinct quantities and should not be treated as interchangeable.

This was a single-group study, not a randomized comparison. Any response observed during treatment would describe outcomes in this study population; by itself, it would not estimate a treatment contrast against a concurrent control. Differences from results in other populations or studies could reflect differences in participants, assessment, follow-up, or other factors. The registry record does not provide a controlled comparison that could resolve those possibilities.

The endpoint uses investigator-assessed RECIST categories, with CT scans and CA-125 tests mentioned in the study summary. The stated response definition is based on lesion measurements. The registry record does not describe independent review, adjudication, or the handling of discordant assessments, so those procedures cannot be assumed.

The safety information lists serious adverse-event terms and group-level counts, but it does not provide the primary endpoint result or a statistical comparison of safety between groups. The dose-group labels are descriptive in this single-group context. They should not be interpreted as randomized treatment contrasts.

In general, a confidence interval conveys uncertainty around an estimate; a wider interval indicates less precision than a narrower one. Here, the 90% confidence interval is named in the endpoint definition, but its numerical bounds are not reported in the registry record. No p-value or formal inferential result for the primary endpoint is reported. The statistical interpretation is consequently limited to the design and endpoint definition, rather than an assessment of the observed treatment outcome.

9. Statistical Methods Explained

What does the primary endpoint quantify?

The endpoint is a proportion expressed as a percentage: participants with a complete or partial response divided by the treated population, then multiplied by 100. The response categories are investigator classified under RECIST. Complete response requires disappearance of all target and non-target lesions. Partial response requires at least 30% decrease in the sum of the longest diameters of target lesions. These are endpoint rules, not results. The registry record does not report how many participants met either category.

What does the confidence interval convey?

The endpoint specifies a 90% confidence interval. In general, a confidence interval presents a range of values compatible with the observed estimate under the statistical procedure used. It helps readers judge precision: an estimate with a relatively broad interval is less precise than one with a narrower interval. The interval does not guarantee that the true value lies within its bounds, and it does not by itself establish clinical importance. The numerical interval and the method used to construct it are not reported in the registry record, so its precision cannot be evaluated.

Why does the single-group design matter?

With a single group, the primary endpoint describes the observed response proportion among treated participants. A randomized control group would support a direct comparison under the conditions of the trial; this record does not describe one. General statistical interpretation therefore distinguishes an observed outcome rate from a causal treatment effect. A response rate in one group cannot, on its own, show what would have happened to the same participants under another treatment or without the study treatment. The registry record does not report a comparator-based estimate.

The safety information identifies target Cmax 420 µg/mL, target Cmax 360 μg/mL, and an albumin-tailored dose. Because the record does not describe random assignment between these groups, their event counts should be read descriptively rather than as a controlled dose comparison. Differences between groups could reflect how participants entered or were managed in those groups, but the registry record does not describe those processes. No adjustment method or comparative statistical model is reported.

What is the role of the assessment schedule?

The study summary describes CT scans and CA-125 testing before the first dose and after every other treatment. The primary outcome timeframe runs from baseline to measured progressive disease, up to 12.68 months. In general, response assessment depends on when and how measurements are made, because tumor status may change between assessments. The record does not give a detailed assessment schedule, independent review process, or rules for resolving missing or uncertain measurements. Those details should not be inferred from the general schedule description.

What can the planning illustrations say?

Planning illustrations use the observed effect as an assumed target and explore how a future study might be sized under stated assumptions. They are not observed power, and they do not change the result of this completed study. The stated illustration 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. The record also notes that time-to-event illustrations use a total event count, whereas other illustrations use participants per arm. The observed primary endpoint effect is not reported in the registry record, so the result itself cannot be assessed from these assumptions.

In general, sample-size planning depends on the assumed effect, variability or event rate, error rate, allocation, and analysis method. Changing an assumption can change the planned sample size. A planning calculation is not evidence that a study had a particular probability of detecting an effect after it was completed. No trial-specific sample-size justification or design rationale is reported in the registry record.

What inferential details are absent?

The registry record does not report a primary endpoint estimate, confidence interval bounds, p-value, or analysis method beyond the stated endpoint definition and 90% confidence interval. It does not describe covariate adjustment, interim analyses, a multiplicity procedure, or a statistical analysis plan. These omissions prevent a fuller assessment of the inferential framework and of how the posted outcome would have been analyzed. They do not justify assuming that a particular method was or was not used outside the information 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.

ArmParticipantsEventsObserved %Clopper-Pearson 95% CIWilson 95% CIBayesian 95% credible interval
Target Cmax 420 µg/mL5347.5%2.1% to 18.2%3.0% to 17.9%3.1% to 17.9%
Target Cmax 360 μg/mL1800.0%0.0% to 18.5%-0.0% to 17.6%0.1% to 17.6%
Albumin-Tailored Dose3213.1%0.1% to 16.2%0.6% to 15.7%0.7% to 15.8%

R code and output

arm    <- c("Target Cmax 420 µg/mL", "Target Cmax 360 μg/mL", "Albumin-Tailored Dose")
n      <- c(53, 18, 32)
events <- c(4, 0, 1)
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  Target Cmax 420 µg/mL  53  4  7.5  2.1  18.2  3.0  17.9  3.1  17.9
ARM  Target Cmax 360 μg/mL  18  0  0.0  0.0  18.5  -0.0  17.6  0.1  17.6
ARM  Albumin-Tailored Dose  32  1  3.1  0.1  16.2  0.6  15.7  0.7  15.8

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists a primary endpoint and multiple secondary outcomes, including progression-free survival, overall survival, response duration, stable disease duration, clinical benefit rate, pharmacokinetics, and adverse events. It does not report a multiplicity-adjustment procedure or explain how interpretation across these outcomes was controlled. In general, examining multiple outcomes can increase the chance of at least one apparently notable result when each is assessed separately. Whether and how that issue was addressed is not reported in the registry record.

The primary endpoint population is defined as all participants who received at least one dose. That definition identifies who is intended to contribute, but the record does not report the number treated, the number with response assessments, or how missing assessments were handled. It does not describe imputation, exclusion rules, sensitivity analyses, or the treatment of participants who discontinued before assessment. Missing-data assumptions and their effects on the response estimate therefore cannot be evaluated.

The posted record lists 9 outcome measures and does not report analysis results for them. The reason that outcome results are absent is not reported in the registry record. In particular, the absence of a numerical primary result should not be interpreted as evidence of no response or as evidence of a particular response rate.

The analysis population definition is given for the primary endpoint, but analysis populations for the secondary outcomes are not reported in the registry record. The record also does not state whether any interim analyses were conducted or describe a statistical analysis plan. These gaps limit evaluation of selective reporting, missingness, and consistency between planned and reported analyses.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

ArmParticipants with serious adverse eventsParticipants at riskPercentage
Target Cmax 420 µg/mL215339.6%
Target Cmax 360 μg/mL51827.8%
Albumin-Tailored Dose153246.9%
Participants with at least one serious adverse event
Serious adverse events by armTarget Cmax 420 µg/mL39.6%Target Cmax 360 μg/mL27.8%Albumin-Tailored Dose46.9%% of participants with at least one serious adverse event

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

ArmParticipants affected of at risk
Target Cmax 420 µg/mL47 of 53
Target Cmax 360 μg/mL18 of 18
Albumin-Tailored Dose30 of 32

Most frequent serious adverse event terms

Event termOrgan systemTarget Cmax 420 µg/mLTarget Cmax 360 μg/mLAlbumin-Tailored Dose
ThrombocytopeniaBlood and lymphatic system disorders7 of 532 of 187 of 32
AnaemiaBlood and lymphatic system disorders5 of 532 of 184 of 32
NeutropeniaBlood and lymphatic system disorders4 of 532 of 185 of 32
Abdominal painGastrointestinal disorders4 of 531 of 183 of 32
Small intestinal obstructionGastrointestinal disorders2 of 531 of 184 of 32
Intestinal obstructionGastrointestinal disorders2 of 531 of 183 of 32
VomitingGastrointestinal disorders3 of 530 of 182 of 32
Renal failure acuteRenal and urinary disorders2 of 531 of 182 of 32
DehydrationMetabolism and nutrition disorders2 of 530 of 182 of 32
AscitesGastrointestinal disorders1 of 530 of 182 of 32

Most frequent non-serious adverse event terms

Event termOrgan systemTarget Cmax 420 µg/mLTarget Cmax 360 μg/mLAlbumin-Tailored Dose
FatigueGeneral disorders25 of 535 of 184 of 32
NauseaGastrointestinal disorders16 of 534 of 1812 of 32
DiarrhoeaGastrointestinal disorders12 of 537 of 187 of 32
ThrombocytopeniaBlood and lymphatic system disorders18 of 534 of 183 of 32
AnaemiaBlood and lymphatic system disorders10 of 535 of 184 of 32
NeutropeniaBlood and lymphatic system disorders12 of 532 of 183 of 32
RashSkin and subcutaneous tissue disorders14 of 530 of 183 of 32
Abdominal painGastrointestinal disorders10 of 531 of 185 of 32
VomitingGastrointestinal disorders5 of 534 of 187 of 32
ConstipationGastrointestinal disorders7 of 532 of 186 of 32

Serious events with the highest arm-level rate: thrombocytopenia (21.9%), neutropenia (15.6%), anaemia (12.5%), small intestinal obstruction (12.5%), abdominal pain (9.4%).

Do not overextend the safety comparison. Serious-adverse-event counts are safety observations, not efficacy outcomes, and should not be combined with the primary result into a single benefit-risk number.

The safety record names three groups: Target Cmax 420 µg/mL, Target Cmax 360 μg/mL, and Albumin-Tailored Dose. For serious adverse events, it lists 21 affected among 53 at risk in the first group, 5 among 18 in the second, and 15 among 32 in the third. For other adverse events, it lists 47 among 53, 18 among 18, and 30 among 32, respectively. These are group-level counts; they are not evidence of a randomized comparison.

The registry record also lists serious adverse-event terms with percentages: thrombocytopenia, 21.9%; neutropenia, 15.6%; anaemia, 12.5%; small intestinal obstruction, 12.5%; abdominal pain, 9.4%; and intestinal obstruction, 9.4%. The denominator and method underlying these percentages are not reported in the registry record. The terms should not be interpreted as mutually exclusive categories or added together.

In general, adverse-event counts and percentages describe events recorded under a study’s safety reporting process. They do not, by themselves, establish that the study drug caused an event. Death figures are not reported in the registry record. The safety entries do not replace the missing primary response result or provide a controlled safety contrast.

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

The registry record establishes the study’s question and the way its primary endpoint was defined: the percentage of treated participants with an investigator-classified complete or partial response under RECIST. It also records a phase 2, single-group design and a treatment regimen of an intravenous infusion once every 28 days. These details make clear what the study set out to measure and how the endpoint was intended to be categorized.

The record does not report the observed primary endpoint percentage, response count, or 90% confidence interval. It therefore does not allow a reader to assess the observed frequency of response or the precision of that estimate. The lack of a numerical result is not a zero result and should not be interpreted as proof for or against treatment activity.

Even if a response estimate were available, this design would describe outcomes in a single treated group rather than compare outcomes against a randomized control group. General statistical reasoning distinguishes an outcome observed during treatment from a treatment effect established by a direct comparison. The registry record does not provide a controlled estimate, so it cannot support a causal contrast against an alternative.

The listed enrollment is not interchangeable with the endpoint denominator. The endpoint population includes participants who received at least one dose, but the number treated and the number with evaluable assessments are not reported. The record also does not explain missing response data or provide numerical results for the secondary outcomes.

The serious adverse-event counts and terms add descriptive safety information, but their denominators, attribution, and comparative interpretation are limited by what is recorded. The dose-group labels do not establish randomized assignment. Overall, the registry record documents the planned clinical question, regimen, endpoint definition, and some safety summaries; it does not provide enough numerical outcome information to determine the primary endpoint’s observed magnitude or statistical precision.

14. Why This Trial Matters Statistically

This study illustrates why a clearly defined endpoint and a reported numerical result are both important. The registry record specifies objective response using RECIST categories and defines the treated population for the primary analysis. Those definitions make the intended measure interpretable in principle. Without the response count, denominator, estimate, and confidence interval, however, readers cannot evaluate what the study observed or how uncertain that observation was.

The single-group structure is also important to statistical interpretation. A response proportion can describe outcomes among treated participants, but it is not a direct estimate of the difference between treatment strategies. This distinction is relevant whenever an uncontrolled study is read alongside evidence from controlled studies or used to motivate further research. The design determines which questions the data can answer.

The record further shows that safety descriptions and efficacy outcomes require separate attention. It lists serious adverse-event counts and terms, but the primary response result and several secondary results are not numerically reported. A safety list cannot stand in for an efficacy estimate, and event percentages should be interpreted with awareness of their denominators and reporting definitions.

Finally, the endpoint population, enrollment, and safety group counts are different kinds of information. Keeping those quantities distinct helps avoid treating the registered enrollment as the number analyzed for every outcome. In general, transparent reporting of analysis populations, missing-data handling, confidence intervals, and multiplicity procedures allows a more complete appraisal. Those methodological details are not reported in the registry record, making this study a useful example of how registration details can clarify design while leaving key outcome interpretation unresolved.

15. Limitations

A central limitation of the available registry information is that the primary outcome is defined but its numerical result is not reported. There is no response count, treated denominator, observed percentage, or numerical 90% confidence interval. As a result, neither the magnitude nor the precision of the primary endpoint can be evaluated. The registry record does not explain why these results are absent.

The enrollment figure is 103, but the primary endpoint population is participants who received at least one dose. The number treated and the number with an evaluable response are not reported. The endpoint’s stated timeframe is baseline to measured progressive disease, up to 12.68 months, but the record does not provide participant-level follow-up or the number assessed at each time.

The single-group design offers no concurrent randomized control comparison. The record does not describe masking, and it identifies the study as unmasked. Investigator assessment under RECIST is specified, but independent review and adjudication procedures are not reported in the registry record. The study summary mentions CT scans and CA-125 tests, without further detail on missed or indeterminate assessments.

There are no reported details about missing-data methods, covariate adjustment, interim analyses, multiplicity control, or the trial-specific statistical plan. Numerical results for the listed secondary outcomes are also not reported. Safety information includes group-level counts and serious-event terms, but denominators for the term percentages and death figures are not reported. These limitations restrict both outcome interpretation and evaluation of the analysis process.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

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Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.

19. Record Summary

The registry record describes a completed phase 2, single-group study of LY573636-sodium in platinum-resistant ovarian cancer, with listed enrollment of 103. Treatment was an intravenous infusion once every 28 days until disease progression or other discontinuation criteria. The primary endpoint was the percentage of treated participants with complete or partial response under RECIST, with a stated 90% confidence interval and a timeframe up to 12.68 months.

The record does not report the numerical primary endpoint result, its confidence interval, or numerical results for the listed secondary outcomes. Safety information includes serious adverse-event group counts and a list of serious-event terms with percentages. The absence of a randomized comparator, outcome results, and several analysis details limits statistical interpretation of efficacy and safety.

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