Study of Nab-Paclitaxel and Ramucirumab as Second-line Treatment for Patients With Metastatic Gastroesophageal Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study of Nab-Paclitaxel and Ramucirumab as Second-line Treatment for Patients With Metastatic Gastroesophageal Cancer (NCT02317991), a na phase 2 study. The primary outcome is Progression-Free Survival (PFS).

2. Clinical Question

3. Trial Design

This completed Phase II study evaluated nab-paclitaxel and ramucirumab together as second-line treatment for patients with metastatic gastroesophageal cancer. Enrollment was 65. The study began on 2015-05-05, and primary completion was recorded as 2021-05-21. The sponsor was SCRI Development Innovations, LLC.

The registry describes a single-group design, with allocation recorded as NA and masking as none. Everyone in the described treatment group received the combination; there was no separate control group. The schedule specified intravenous nab-paclitaxel at 125 mg/m^2 on Days 1, 8, and 15 of each 28-day cycle, with a week of rest after the three weekly doses. Ramucirumab was given intravenously at 8mg/kg on Days 1 and 15 of the cycle.

The primary endpoint was progression-free survival (PFS), with assessment described for up to 1 year. Secondary outcomes were overall response rate, time to progression, and overall survival. Although the record lists the outcomes, their numerical results are not reported in the registry record. The full analysis set for PFS is defined as enrolled patients who received at least one dose and had a baseline tumor assessment; its actual size is not reported.

A single-group Phase II study can describe outcomes among people treated under the study conditions. Without a concurrent comparison group, however, differences from another treatment or from the natural course of disease cannot be separated from treatment effects using this design alone. The registry record does not report the protocol’s sample-size justification or a detailed statistical analysis plan.

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:

Analysis population for the primary outcome, as defined in the registry: Full analysis set. All enrolled patients who have received at least one dose of study treatment and have a baseline tumor assessment.

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 Progression-Free Survival (PFS), measured over up to 1 year.

Progression-free survival measures the time from a defined starting point until disease progression or death, whichever occurs first. In this study, the starting point was Day 1 of study drug administration. Progression was defined using RECIST v1.1: the appearance of one or more new lesions or unequivocal progression of existing non-target lesions. Death from any cause while on study was also counted as an event.

The registry lists median PFS and a 95% confidence interval as the primary outcome, with assessment described as up to 1 year. The median is a time-to-event summary: it identifies the time by which half of the relevant population is estimated to have experienced the event, subject to the analysis and censoring rules. A confidence interval conveys uncertainty around that estimate; a wider interval indicates less precision than a narrower one.

Participants who were alive and had no recorded progression were censored at their last adequate tumor assessment. If there was no adequate post-treatment tumor assessment, the record says PFS was censored on Day 1. Censoring means that an event time was not observed during the relevant follow-up; it is not itself evidence that progression did or did not occur later.

The registry record does not report the PFS median or its confidence interval. Therefore, it does not support a numerical description of the observed PFS result or its precision.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Time-to-event methods are used when the outcome is the time until an event, such as progression or death, and some participants have no observed event by the end of follow-up. In general, these methods can use information from participants who were followed for different lengths of time, provided the analysis handles censoring according to its assumptions. The registry defines PFS as the time from Day 1 of study drug administration until progression under RECIST v1.1 or death from any cause on study.

What does the median describe?

The median time-to-event estimate marks the point at which the estimated event-free proportion reaches half. It is a summary of the distribution of event times, not a statement that every participant experienced the event at that time. It also does not describe the experience of every individual participant. When follow-up is incomplete, the estimate depends on the observed event and censoring information and on the statistical method used.

The registry names the median as the PFS parameter and a 95% confidence interval as its measure of uncertainty. In general, a confidence interval gives a range of values compatible with the observed data under the model and procedure used. Its width reflects precision, while its endpoints should not be treated as the range in which most individual event times fall. Here, neither the median nor its interval is reported in the registry record, so the precision of the primary result cannot be evaluated.

How does censoring affect the analysis?

Censoring occurs when the event time is not observed during the available follow-up. The registry says participants who were alive and progression-free were censored at their last adequate tumor assessment. It also says that participants with no adequate post-treatment tumor assessment were censored on Day 1. A censored observation contributes information up to the censoring time, but it does not establish what happened after that point.

Time-to-event analyses generally rely on assumptions about how censoring relates to the event process. If participants who are censored differ systematically in their future event risk from those who remain under observation, the estimate can be affected. The registry record gives censoring rules, but details about reasons for censoring, follow-up completeness, and checks of assumptions are not reported.

What is the role of the analysis population?

The primary outcome is defined for the full analysis set: all enrolled patients who received at least one dose of study treatment and had a baseline tumor assessment. This description determines eligibility for the stated PFS analysis. It is not enough to infer the number analyzed: the count meeting the criteria is not reported in the registry record. The enrollment count of 65 should therefore not automatically be read as the primary analysis denominator.

Analysis populations matter because excluding participants can change which experience the estimate represents. A baseline assessment supports evaluation of tumor status over time, while receipt of at least one dose ensures participants started study treatment. The record does not describe any additional analysis populations or give a participant flow showing how many were excluded from the primary analysis.

What can a single-group result establish?

This is a single-group study, not a randomized comparison. A time-to-event estimate can summarize the course observed among participants receiving the combination, but it cannot by itself estimate the difference that would have occurred under a comparator treatment. A comparison with historical or external data can be influenced by differences in eligibility, assessment schedules, supportive care, and follow-up. The registry record does not identify a control group or report a comparative treatment-effect estimate.

General statistical interpretation also distinguishes an estimate from evidence of a causal effect. Even if a median and confidence interval were available, they would describe the study population and analysis under the stated design. They would not remove the limitations of having no concurrent randomized comparator. The absence of the numerical PFS result adds a separate limitation: even a descriptive interpretation of the primary result is not possible from the posted record.

How should the planning illustration be understood?

The study’s sample-size material is described as a planning illustration computed from the observed effect, not as the trial’s own design. Its assumptions include a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. For time-to-event planning, the displayed quantity is the total number of events; other planning quantities are participants per arm. The illustration considers detecting a stated fraction of the observed effect.

These assumptions are not a description of the actual trial design, which was single-group. The illustration must not be interpreted as observed power or as evidence that the enrolled study had a particular probability of detecting an effect. Planning calculations depend on their chosen assumptions, including the effect to detect. The protocol’s sample-size justification and any original design assumptions are not reported in the registry record.

In general, over-dispersion refers to variability greater than expected under a model that assumes a specific variance structure. When present, it can make standard errors too small and confidence intervals too narrow if the model does not account for it. The registry record does not report a count model, an over-dispersion assessment, or a corresponding adjustment for the primary time-to-event outcome. This general concept should not be taken as a claim that over-dispersion applies to this study.

10. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when an analysis tests or estimates several outcomes, groups, time points, or hypotheses. In general, conducting many statistical tests can increase the chance of at least one apparently notable result unless the analysis plan addresses that issue. The registry lists PFS as the primary outcome and overall response rate, time to progression, and overall survival as secondary outcomes. It does not report a multiplicity adjustment or a hierarchy for interpreting those outcomes. The detailed statistical plan is not reported in the registry record, so it is not possible to determine whether multiplicity was addressed elsewhere.

The record lists five outcome measures and no analysis entries. The endpoint descriptions do not supply numerical results for PFS or the named secondary outcomes. This absence limits assessment of both the findings and how multiple outcomes were handled. A listed endpoint is not equivalent to a posted estimate, and an absence of a posted estimate does not establish that the endpoint was never analyzed.

Missing data and censoring are related but distinct. For PFS, the record specifies censoring at the last adequate tumor assessment for participants alive and progression-free, and censoring on Day 1 if no adequate post-treatment tumor assessment was obtained. It does not report how many participants were censored under either rule, the reasons for missing assessments, or any sensitivity analyses. Therefore, the extent to which incomplete assessment could affect the PFS estimate cannot be evaluated.

The full analysis set includes enrolled participants who received at least one dose and had a baseline tumor assessment. Its size is not reported. The registry record also does not report a participant flow, the number excluded from this population, or details of any additional analysis sets. Without those counts, it is not possible to reconcile enrollment with the analyzed population. The record does not report an interim-analysis plan or describe interim efficacy analyses.

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 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: pneumonia (9.2%), sepsis (7.7%), febrile neutropenia (4.6%), septic shock (4.6%), dysphagia (3.1%).

For the nab-paclitaxel and ramucirumab group, 65 participants were listed as at risk for serious adverse events, and 30 were listed as affected. The same group had 65 participants at risk for other adverse events, with 62 affected. The record also lists 51 deaths. These are safety counts recorded for the study group; they should not be read as a comparison between treatments because the study had no control group.

The serious adverse event terms with the highest listed percentages were pneumonia at 9.2%, sepsis at 7.7%, febrile neutropenia at 4.6%, septic shock at 4.6%, dysphagia at 3.1%, and nausea at 3.1%. These percentages are reported as listed; the record does not give additional detail about event timing, recurrence, or the number of events per participant. The safety summary also does not state in this listing whether each event was assessed as related to study treatment.

The 51 deaths are reported as a count, but the record does not provide their causes or timing in this safety listing. The PFS definition separately treats death from any cause on study as an event, but that definition does not explain the circumstances of the deaths. Serious adverse events, other adverse events, and deaths are distinct safety summaries and should not be combined into a single measure.

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

The registry record establishes that a completed Phase II, single-group study evaluated nab-paclitaxel with ramucirumab in metastatic gastroesophageal cancer. It identifies a primary endpoint, defines progression and censoring for that endpoint, and reports selected safety counts and serious adverse event terms. These details describe the study’s intended question and some of the recorded safety experience.

The record does not report the PFS median or its 95% confidence interval. It also does not report numerical results for the listed secondary outcomes. As a result, readers cannot use the registry record to quantify the primary outcome, assess its precision, or compare the listed secondary outcomes. Describing an endpoint’s definition is not a substitute for reporting its estimate.

The design also sets a limit on what the findings could establish. Because there was no randomized comparison group, outcomes in the treated group cannot show what would have happened to comparable participants under another treatment. The study can describe observations in its own participants, but it cannot establish a comparative treatment effect on its own. Comparisons with other studies would need to account for differences in populations, treatment context, and outcome assessment, and would remain less direct than a randomized comparison.

The safety figures describe events among participants in the combination group. Without a control group or detailed event context, they do not establish how much risk is attributable to either drug or how the event frequency compares with another regimen. The death count is reported without the causes and timing needed for a fuller interpretation.

Accordingly, the registry record supports a description of the trial design and its posted safety summaries, but not a numerical conclusion about the primary efficacy endpoint or a causal comparison of treatments. The absence of numerical endpoint results is a substantive limit on interpretation, not evidence that the result was favorable or unfavorable.

13. Why This Trial Matters Statistically

This trial raises several important statistical questions for readers of Phase II research. First, it illustrates why a clearly defined endpoint and a reported estimate are both needed. The registry defines PFS, gives the event criteria, and specifies censoring rules. However, without the median and confidence interval, readers cannot assess the observed time-to-event result or how precisely it was estimated.

Second, the study’s single-group design is central to interpretation. A single-group study can provide descriptive information about participants who received the regimen, but it does not create a concurrent counterfactual. That distinction matters whenever a reader is tempted to interpret an observed outcome as a treatment effect. The design does not support a like-for-like estimate against another treatment.

Third, the analysis population needs to be distinguished from enrollment. The registry reports enrollment of 65 and defines the PFS full analysis set by treatment exposure and baseline assessment. The actual number in that analysis set is not reported. Reporting participant flow and analysis denominators would help readers understand which participants contributed to each endpoint.

Finally, the safety summary shows why counts, definitions, and context matter together. The record gives counts for serious and other adverse events and lists selected serious event terms, but does not supply a comparison group or fuller event-level context. These data can be read as descriptive safety information, not as a comparative risk estimate. The planning illustration also needs to be kept separate from the actual single-group design; planning assumptions do not turn a descriptive study into a randomized comparison or represent observed power.

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.

A central limitation of the posted record is that it does not report the numerical primary PFS result or its 95% confidence interval. The description of the endpoint and its censoring rules does not allow the observed result or its precision to be assessed. Numerical results for the listed secondary outcomes are also not reported in the registry record.

The single-group design has no concurrent comparator. This limits causal interpretation and prevents a direct estimate of how outcomes differ from those under another treatment. Any cross-study comparison would be indirect and potentially affected by differences in eligibility, care, assessment, and follow-up.

Although enrollment was 65, the number included in the defined full analysis set is not reported. The record also does not report the number of PFS events, follow-up distribution, counts censored under each rule, or reasons for incomplete assessment. Those details would help readers assess how much information supports the time-to-event analysis and how missing assessments may affect interpretation.

The registry lists five outcome measures and no analysis entries. It does not report a detailed statistical analysis plan, multiplicity procedures, interim analyses, or the protocol’s sample-size justification. The planning illustration is not the trial’s design and should not be treated as observed power. For safety, the record provides selected counts and percentages but lacks a control group and does not give fuller information on timing, recurrence, or treatment relationship for the listed events. These gaps constrain both efficacy and safety interpretation.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Study of Nab-Paclitaxel and Ramucirumab as Second-line Treatment for Patients With Metastatic Gastroesophageal Cancer — NCT02317991.
• Registry record last updated 2022-07-01; status last verified 2022-06.
• Results first posted 2022-07-01.
• 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

This completed Phase II study enrolled 65 participants with metastatic gastroesophageal cancer and evaluated nab-paclitaxel plus ramucirumab as second-line treatment. It used a single-group design without masking or a separate comparator. Nab-paclitaxel was scheduled on Days 1, 8, and 15 of a 28-day cycle, and ramucirumab on Days 1 and 15.

The primary outcome was median PFS, defined from Day 1 of study drug administration to RECIST v1.1 progression or death from any cause on study. The full analysis set required at least one dose and a baseline tumor assessment. The registry record does not report the PFS median, its 95% confidence interval, or numerical results for the listed secondary outcomes.

Safety reporting includes 30 participants with serious adverse events, 62 with other adverse events, and 51 deaths among the group listed as 65 at risk. The single-group design and missing numerical primary endpoint result limit interpretation of efficacy and comparative safety.