Combination Chemotherapy and Pegfilgrastim in Treating Patients With Previously Untreated Germ Cell Tumors: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Combination Chemotherapy and Pegfilgrastim in Treating Patients With Previously Untreated Germ Cell Tumors (NCT00470366), a na phase 2 study. The primary outcome is Rate of Complete Response.

2. Clinical Question

The trial asked whether a combination of paclitaxel, ifosfamide, and cisplatin, given with pegfilgrastim, could produce complete responses in patients with previously untreated intermediate- and poor-risk germ cell tumors. The registry identifies the primary outcome as the rate of complete response, measured as a count of participants and assessed at 3 years. It also lists progression-free survival, the percentage of participants with progression-free survival, and treatment-related toxicity among the secondary outcomes.

The clinical question is therefore descriptive within the enrolled group: it concerns the observed response count under this regimen. Without a control group, the design cannot directly estimate how outcomes would have differed under another treatment or under no treatment. The registry record does not report the complete-response count or a corresponding response-rate estimate, so the endpoint's observed result cannot be.

3. Trial Design

This was a Phase II, single-group trial sponsored by Memorial Sloan Kettering Cancer Center. The registry lists enrollment of 60 and a completed status. The recorded start is 2007-03 and primary completion is 2016-06. These dates describe the registry entry and do not, by themselves, explain how long an individual participant was followed.

The intervention group is described as receiving paclitaxel, ifosfamide, and cisplatin, with pegfilgrastim listed as a biological intervention. The available arm description says paclitaxel was given first on days 1 and 2 every three weeks for four cycles, and cisplatin was administered daily for five days every three weeks for four courses. It begins an ifosfamide dosing description but ends before the regimen is complete. The full ifosfamide schedule and the pegfilgrastim schedule are not reported in the registry record excerpt.

The study has no listed allocation to multiple arms and no masking. The registry identifies its model as single group and masking as none. Accordingly, there is no concurrent control arm in the described design, and the listed enrollment should not be mistaken for the number analyzed for the primary endpoint. The primary analysis population and endpoint denominator are not reported in the registry record.

The primary outcome is a count of participants with complete response, assessed at 3 years. Secondary outcomes include progression-free survival, the percentage of participants with progression-free survival, and treatment-related toxicity. Although the record lists four outcome measures, the available details do not include estimates for these efficacy outcomes. The trial's protocol, the rationale for its planned enrollment, and any interim-analysis procedures 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.

Overall Study

Reasons for not completing this period:

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.

6. Primary Endpoint

The registry lists the primary outcome as Rate of Complete Response, measured over 3 years.

The primary endpoint is the rate of complete response, expressed in the registry as a count of participants and assessed at 3 years. The stated assessment uses MRI and RECIST v1.0 criteria for target lesions. Under the definition in the record, complete response means disappearance of all target lesions. The description also gives the partial-response criterion as a >=30% decrease in the sum of the longest diameter of target lesions; that criterion distinguishes partial response from complete response and is not the primary endpoint itself.

A complete-response endpoint gives a clinically interpretable summary of whether target lesions were no longer detectable under the specified assessment criteria. In general, a response category can be useful in an early-phase study because it describes tumor change over a defined assessment period. It is not interchangeable with progression-free survival: a response assessment is a status at an evaluation, whereas a time-to-event outcome concerns the timing of progression or another defined event. The registry lists both types of outcomes, but the available record does not give their observed results.

The endpoint's assessment schedule beyond the stated 3-year timeframe, the handling of missing or unevaluable scans, and whether response was independently reviewed are not reported in the registry record. No complete-response count, response estimate, uncertainty interval, or analysis population is given. Thus, the endpoint can be defined from the registry description, but its result and precision cannot be evaluated from the information available.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies a single-group model, no masking, and no allocation to a separate comparison arm. These design features shape what statistical conclusions are possible. A single-group analysis can summarize the observed response count in the treated group. It cannot directly estimate a between-group treatment contrast because there is no concurrent control group in the listed design. The record gives no randomized or otherwise assigned comparison.

What does a participant count convey?

The primary measure is a count of participants meeting the complete-response definition. A count is an absolute description of the observed outcome in an analysis population. To interpret it as a rate, a denominator is also needed: the number of participants included in the endpoint assessment. Although the registry lists 60 enrolled participants, enrollment is not automatically the endpoint denominator. Participants may have missing assessments or may not be included in a particular analysis, and the analysis population is not reported in the registry record.

In general, a confidence interval expresses the uncertainty around an estimated quantity under the assumptions of the statistical method. It helps distinguish a relatively precise estimate from one compatible with a broad range of values. No confidence interval for complete response is reported, so the statistical precision of the primary endpoint cannot be assessed from this record.

Why does the study design matter?

With a single group, the response findings, if reported, would be observed outcomes in participants treated on the study. They would not isolate the effect of the regimen from all other influences. A control group can support a direct comparison by showing outcomes under an alternative strategy in a comparable group; this trial's listed design has no such group. The absence of masking also means the registry describes an unmasked study. The record does not explain how this feature was addressed in outcome assessment.

In general, outcome assessment rules matter because classification depends on how and when measurements are made. Here, the registry specifies MRI, RECIST v1.0, target lesions, and disappearance of all target lesions for complete response. It does not report the full scan schedule, review procedures, or rules for unevaluable assessments. Those details would help readers understand how consistently the endpoint was applied.

What can the sample-size illustrations tell us?

The page includes a sample-size section described as planning illustrations based on the observed effect, not the trial's own design. The stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the target effect is described as a fraction of the observed effect. These hypothetical two-arm planning assumptions do not change the fact that this registry entry describes a single-group trial. Such calculations are planning illustrations, not observed power, and they do not establish that the original trial was designed or powered using those assumptions.

Generally, sample-size planning asks how many participants would be needed under specified assumptions to detect a defined effect with a chosen statistical operating characteristic. Its answer depends on those assumptions and on the outcome model. A planning estimate is not a finding about the current participants and does not demonstrate that a treatment effect is present. The numerical planning results are not included in the registry information, so they cannot be interpreted in detail.

Why can over-dispersion matter?

General statistical context: over-dispersion occurs when observed variability exceeds what a model assumes. If that issue is present and not accommodated, standard errors and uncertainty estimates can be misleading. It is not possible to determine from this registry entry whether over-dispersion was assessed or relevant to any analysis; the statistical analysis plan and reported model details are not reported in the registry record.

What analyses are documented?

The record lists no analyses for the outcomes in the information. It does not provide a test statistic, p-value, adjusted estimate, or confidence interval for the primary endpoint. It also does not report whether covariate adjustment, subgroup analyses, or sensitivity analyses were used. These omissions do not prove that analyses were not conducted; they mean the analyses are not reported in the registry record excerpt. Without those details, the endpoint definition and design can be discussed, but the primary statistical result cannot be independently appraised.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome and several secondary outcomes, including progression-free survival, the percentage of participants with progression-free survival, and treatment-related toxicity. When a study examines multiple outcomes or multiple statistical comparisons, there can be more than one opportunity to observe a result that appears notable by chance. General statistical practice may address this through a prespecified hierarchy, adjustment, or careful distinction between primary and exploratory analyses. The registry information does not state whether multiplicity was addressed or how the outcomes were prioritized beyond identifying the primary outcome.

The record does not report a statistical analysis plan, hypothesis-testing strategy, or analysis population for the primary endpoint. It also does not explain how missing response assessments were handled, whether participants without an assessment were counted as nonresponders, or how any unevaluable cases were treated. These are important details for interpreting a participant count, because the denominator and classification of incomplete observations can affect the reported result. None of these procedures should be inferred from the endpoint description alone.

The record lists four outcome measures but gives no outcome analyses in the information. It therefore does not permit an assessment of whether secondary outcomes were analyzed as planned, whether any analyses were adjusted, or whether any outcome definitions changed. The missing detail is a limit on interpretation, not evidence that a particular method was or was not used. Readers should distinguish outcomes that are named in the registry from results and analysis decisions that are actually reported.

11. Safety Results

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

Deaths

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: nausea (21.7%), vomiting (21.7%), neutrophils/granulocytes (16.7%), febrile neutropenia (15.0%), leukocytes (10.0%).

The safety summary lists one group, Paclitaxel, Ifosfamide, and Cisplatin. It records 60 participants at risk for serious adverse events and 34 affected, alongside 60 at risk for other adverse events and 60 affected. The registry also records 5 deaths. These are counts attached to the safety record; they should not be read as an efficacy result or as proof that an event was caused by the study treatment.

The listed serious adverse-event terms include Nausea and Vomiting, each at 21.7%; Neutrophils/granulocytes at 16.7%; Febrile Neutropenia at 15.0%; Leukocytes at 10.0%; and Hypotension at 8.3%. These percentages are shown as registry values and should not be recomputed or treated as a complete list of all events. The record excerpt does not provide event-level counts for each term, timing, duration, recurrence, or detailed criteria for attribution.

In general, a participant count indicates how many people were recorded with an event, while an event count can include repeated events in the same person. The summary is phrased in terms of affected participants, but it does not provide enough detail to assess recurrent events or exposure-adjusted rates. The recorded deaths are a descriptive count; cause and relationship to treatment are not reported in the registry record. The listed secondary outcome of treatment-related toxicity is not accompanied by a separate analysis.

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

This registry entry describes a Phase II, single-group study of paclitaxel, ifosfamide, and cisplatin with pegfilgrastim in previously untreated germ cell tumors. It defines complete response using MRI and RECIST v1.0 and states a 3-year timeframe. Those details identify the clinical question and the intended primary measure, but they do not supply the primary result. The complete-response count and the population used to calculate it are not reported in the registry record excerpt.

Consequently, this record cannot support a numerical summary of the regimen's response result or its precision. It also cannot establish whether the observed outcomes differed from those under another treatment, because no comparator group is listed. Even a reported response in a single group would need to be interpreted in light of patient selection, follow-up, assessment procedures, and other design features. Details of those matters are limited or not reported.

The safety summary documents serious and other adverse-event counts and records deaths, with several serious-event terms and percentages listed. These entries are useful descriptive information, but the record excerpt does not establish treatment causality, event timing, or the full clinical context. They should not be converted into a benefit-risk conclusion from these figures alone.

The registry also names progression-free survival and treatment-related toxicity as secondary outcomes. Their presence indicates what was to be assessed; no numerical estimates for these outcomes appear in the information. The sample-size section on the page is described as a planning illustration, not an analysis of observed power and not a reconstruction of the trial's original design. Overall, the available record supports a description of the study design, endpoint definitions, and listed safety counts, but not a conclusion about comparative efficacy or the certainty of the primary result.

13. Why This Trial Matters Statistically

This trial illustrates a recurring statistical distinction between defining an outcome and reporting its result. The registry gives a precise primary endpoint concept: a count of participants with complete response, assessed by MRI under RECIST v1.0 at the stated 3-year timeframe. Yet the response count and analysis denominator are not reported in the registry information. Without both, readers cannot evaluate the observed response result or its precision.

The single-group design also makes the distinction between describing outcomes and estimating a comparative effect especially important. A response count in one treated group can characterize what was observed in that group, but there is no concurrent comparator in this design to anchor a treatment contrast. That affects the scope of inference regardless of how clearly the outcome is defined.

The record shows why statistical interpretation requires more than an enrollment figure and a list of outcomes. Missing details about analysis populations, incomplete assessments, and uncertainty estimates affect how much can be concluded from a response measure. Similarly, safety counts and event percentages are informative descriptions, but they do not by themselves explain causality, timing, or comparative risk.

Finally, planning calculations should not be confused with trial results or design documentation. The described calculations use hypothetical two-arm assumptions, while the registry describes a single-group study. Keeping those purposes distinct prevents planning illustrations from being misread as observed power or evidence about efficacy. The statistical lesson is to match each conclusion to the design and information actually reported.

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 most important limitation for interpreting efficacy is that the registry information does not report the primary complete-response count, its denominator, or an uncertainty estimate. It therefore does not show the magnitude or precision of the primary outcome. Although 60 participants are listed as enrolled, the record does not state how many were included in the primary analysis or had an evaluable assessment.

The study is single-group, with no listed comparator and no masking. This design can describe outcomes in the treated group but cannot supply a direct randomized comparison. The registry record does not report the statistical analysis plan, interim-analysis procedures, sample-size justification, analysis population, or handling of missing assessments. The absence of these details in the record should not be taken as evidence about what was done outside the information recorded there.

The intervention description is incomplete: it ends partway through the ifosfamide schedule, and the pegfilgrastim schedule is not described in the excerpt. The record states MRI and RECIST v1.0 for response assessment, but does not give the full assessment schedule, review process, or rules for unevaluable scans. These omissions limit assessment of treatment delivery and endpoint implementation.

The safety summary provides affected-participant counts and selected serious-event terms, but not event timing, recurrence, detailed attribution, or causes of the recorded deaths. The registry also lists secondary outcomes without giving their estimates. Finally, the planning illustrations are not the original trial design and should not be treated as observed power. These limitations leave the design and selected safety entries describable, while restricting conclusions about efficacy, precision, and comparative safety.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Combination Chemotherapy and Pegfilgrastim in Treating Patients With Previously Untreated Germ Cell Tumors — NCT00470366.
• Registry record last updated 2017-11-28; status last verified 2016-06.
• Results first posted 2017-10-24.
• 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.

18. Record Summary

The registry describes a completed Phase II, single-group study sponsored by Memorial Sloan Kettering Cancer Center, with 60 participants enrolled. The intervention is paclitaxel, ifosfamide, and cisplatin with pegfilgrastim for previously untreated intermediate- and poor-risk germ cell tumors. The primary outcome is the count of participants with complete response at the stated 3-year timeframe, assessed by MRI using RECIST v1.0.

No separate control group is listed. The registry information does not report the primary response count, its analysis denominator, or an efficacy estimate with uncertainty. Safety entries include 34 participants with serious adverse events among 60 at risk, 60 with other adverse events among 60 at risk, and 5 deaths. The listed secondary outcomes include progression-free survival and treatment-related toxicity, but their results are not reported in the available record.