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 Anti-gp100 Cells Plus ALVAC gp100 Vaccine to Treat Advanced Melanoma (NCT00610311), a na phase 2 study. The primary outcome is Number of Participants With Metastatic Melanoma Who Develop Clinical Tumor Regression (CR or PR).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00610311 |
| Phase | Phase 2 |
| Condition | Metastatic Melanoma, Skin Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 3 |
| Arms in the primary outcome | n/a |
| Lead sponsor | National Cancer Institute (NCI) |
| Results posted | Yes |
2. Clinical Question
Population
Patients with metastatic melanoma for whom standard treatments had not been effective. The registry lists metastatic melanoma and skin cancer as conditions.
Intervention
The treatment approach combined ALVAC gp100 vaccine, anti-gp100:154-162 TCR-engineered peripheral blood lymphocytes and interleukin-2. The brief description also reports lymphodepleting chemotherapy before the cell infusion.
Comparator
There was no concurrent comparator: the trial is recorded as single-group, with allocation listed as not applicable. Its treatment experience is not a randomized comparison against another regimen or a control group.
Primary question
How many participants with metastatic melanoma developed complete or partial clinical tumor regression, assessed using RECIST v.1.0 after treatment? The registry lists assessment 4-6 weeks after treatment and then monthly for approximately 3 to 4 months or until off-study criteria were met.
The clinical question concerns a multi-component treatment strategy, rather than the separate contribution of each component. Because the intervention combined conditioning chemotherapy, engineered cells, vaccine and interleukin-2, a single-group observation cannot isolate which component might be associated with a tumor response or adverse event. The registry describes the treatment objective as evaluating safety and effectiveness in advanced melanoma; it does not report a comparative objective against an alternative treatment.
The trial enrolled 3 participants and is listed as terminated. The registry record does not report why it was terminated, nor does it provide a count of participants who met the primary endpoint. That absence matters: the stated clinical question can be described from the endpoint definition, but the registry record does not allow a reader to determine the observed response result or its precision.
3. Trial Design
This was a Phase II, single-group study with masking listed as none and allocation listed as not applicable. The registry lists enrollment of 3 and status as terminated. The record gives a start of 2008-01 and primary completion of 2011-02. It does not report the reason for termination or give a detailed account of enrollment and follow-up for each participant.
The intervention combined ALVAC gp100 vaccine with anti-gp100:154-162 TCR-engineered peripheral blood lymphocytes and high-dose interleukin-2. The brief description says patients underwent 7 days of chemotherapy to prepare the immune system before receiving the engineered cells. It describes vaccine administration just before the cell infusion and again 2 weeks later. Cyclophosphamide, fludarabine phosphate and aldesleukin are among the listed interventions. Further dosing details are not reported in the registry record.
The design does not include a like-for-like control group. Therefore, observed outcomes in the treated group, if reported, could describe what happened during this treatment strategy, but would not by themselves estimate how outcomes compare with another treatment or with no treatment. The design also cannot separate the effects of the regimen's components.
The registry lists four outcome measures, including the primary tumor-response measure and secondary measures relating to survival of engineered cells, adverse events and anti-mouse TCR antibodies. It reports no analyses. Details such as the protocol's sample-size justification, interim analyses, prespecified statistical plan, analysis populations and handling of missing outcome data are not reported in the registry record. The status of terminated does not, by itself, explain why the study ended or establish whether the planned follow-up was completed.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | ALVAC Plus Anti-gp100:154-162 TCR PBL + HD IL-2 |
|---|---|
| STARTED | 3 |
| COMPLETED | 3 |
| NOT COMPLETED | 0 |
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.
| Characteristic | Unit | ALVAC Plus Anti-gp100:154-162 TCR PBL + HD IL-2 |
|---|---|---|
| Participants analysed | 3 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 3 |
| Age, Categorical: >=65 years | Participants | 0 |
| Age, Continuous | years | 33.3 (SD 6.0) |
| Sex: Female, Male: Female | Participants | 2 |
| Sex: Female, Male: Male | Participants | 1 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 3 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 3 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 3 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Metastatic Melanoma Who Develop Clinical Tumor Regression (CR or PR), measured over 4-6 weeks after treatment and then monthly for approximately 3 to 4 months or until off study criteria are met.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with metastatic melanoma who developed clinical tumor regression, defined as complete response (CR) or partial response (PR). Response was assessed using Response Evaluation Criteria in Solid Tumors (RECIST) v.1.0. Under the registry's definition, CR means disappearance of all target lesions. PR means a 30% decrease in lesions, using the baseline sum longest diameter as the reference.
A response endpoint can be useful in a Phase II study because it records whether participants meet a stated clinical tumor-response criterion during follow-up. The RECIST definitions give a common framework for classifying changes in target lesions, rather than relying only on an unstructured description of change. This endpoint is a participant count; it is not a time-to-event measure or a measure of how long a response lasts.
The listed assessment schedule begins 4-6 weeks after treatment and continues monthly for approximately 3 to 4 months or until off-study criteria are met. The registry record does not report the observed number meeting CR or PR, separate counts for CR and PR, or an estimate of uncertainty around the primary endpoint. It also does not report participant-level assessment timing or details of how unevaluable assessments were handled. Consequently, the endpoint definition is available, but its observed result cannot be interpreted from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry describes a small, single-group Phase II study of a multi-component treatment for metastatic melanoma. Enrollment was 3, and the study status is terminated. The primary endpoint is clearly defined as the number of participants with clinical tumor regression, combining complete and partial response under RECIST v.1.0. However, the registry record does not report the number who met that endpoint. No primary endpoint estimate, confidence interval, p-value or analysis is reported.
That missing result prevents a direct statistical reading of the primary question. Without an observed response count, it is not possible to describe the frequency of response, its uncertainty, or how the result compares with a benchmark. No such benchmark is reported either. The endpoint definition alone specifies what would count as a response; it does not establish that any participant did or did not meet the definition.
The safety information is also limited. The record lists 3 participants at risk for serious adverse events and 1 affected, and identifies intracranial hemorrhage as a top serious term at 33.3%. It separately lists 3 participants at risk and 3 affected for other adverse events. These entries should be read as registry counts for this small trial, not as a precise estimate of how frequently an event would occur in a broader population. The record does not provide the timing, severity grading details or participant-level context needed to interpret the events fully.
In general, a confidence interval communicates the range of effect values reasonably compatible with the observed data under a statistical model. It is useful for judging precision, not just whether an estimate is above or below a threshold. No confidence interval for the primary endpoint is reported in the registry record. With only the endpoint definition and no observed result, the precision of the tumor-response estimate cannot be assessed.
The absence of a comparator is another central constraint. Even if a response result were available, a single-group study could describe outcomes among participants receiving this regimen but could not establish a causal difference versus another treatment. This is particularly important for a regimen with several components: the design cannot determine the separate contribution of chemotherapy, vaccine, engineered cells or interleukin-2.
Overall, the posted information supports a description of the design, endpoint and limited safety counts, but not a conclusion about the observed primary outcome or comparative treatment effect. The record does not report why the trial was terminated, and that status should not be interpreted as evidence for any particular clinical outcome.
9. Statistical Methods Explained
What does the primary endpoint count?
The primary outcome is a binary participant-level classification: a participant either met the stated clinical tumor-regression definition or did not. The registry defines the event as complete response or partial response according to RECIST v.1.0. Complete response is disappearance of all target lesions; partial response is a 30% decrease in lesions from the baseline sum longest diameter. The endpoint is reported as a number of participants, rather than as a continuous change in tumor size.
In general, binary outcomes are straightforward to describe as counts, but statistical interpretation depends on both the count and the number of participants assessed. A count without its assessment context does not show how precise an estimated response frequency would be. The registry record does not state the primary endpoint count or an analysis of that count. No response proportion or interval should therefore be inferred from the endpoint definition.
What can a single-group design estimate?
A single-group study records outcomes among people receiving the study regimen. In general, it can describe observed outcomes within that treated group, subject to how participants were selected, followed and assessed. It does not directly estimate a treatment contrast against a concurrent control group. Without a control group, differences attributable to treatment cannot be separated from other explanations, such as the course of disease, patient selection or other care.
The design is especially limited for a regimen containing several components. Even a complete response count would pertain to the combined strategy; it would not identify the separate effect of ALVAC vaccine, engineered cells, chemotherapy or interleukin-2. The record's allocation is listed as not applicable and its model as single-group, so a randomized comparison is not reported.
How should uncertainty be assessed?
In general, a point estimate is the value calculated from observed data, while a confidence interval expresses statistical uncertainty around that estimate under a specified method. A narrow interval generally indicates more precision than a wide interval, although interpretation also depends on the design and assumptions. A p-value, when calculated, addresses compatibility between data and a specified statistical null hypothesis; it is not a measure of clinical importance or the probability that a treatment works.
The registry record reports no analyses. It therefore does not give a primary endpoint estimate, confidence interval or p-value. These absent quantities should not be reconstructed from enrollment alone. No assumptions or analysis plan for such an estimate are reported in the registry record.
What do the sample-size illustrations mean?
In general, a sample-size calculation is a planning exercise: it describes how many participants might be needed under specified assumptions about an effect, significance level, allocation and statistical method. It does not describe the number of outcomes observed, and it is not evidence that a study had a particular probability of finding a result after the fact. Planning illustrations are not observed power.
The planning approach associated with this record uses a two-sided significance level of 0.05, equal allocation between two arms and a normal approximation, with the effect to detect set as a stated fraction of the observed effect. Such assumptions describe a hypothetical two-arm planning comparison, not the actual single-group design recorded for this trial. The registry record does not report the primary endpoint effect needed to assess those illustrations or the trial's own sample-size justification. Any planning number should therefore not be read as a protocol target or as a result of the trial.
Why can over-dispersion matter?
In general, over-dispersion occurs when outcome variability is greater than a statistical model assumes. If ignored, it can make standard errors too small and uncertainty appear narrower than warranted. This issue can arise in some count-data settings; it does not change the observed count itself. The primary outcome in this trial is a participant count meeting a binary response definition. The registry record does not report a model for the endpoint or any over-dispersion assessment, so no claim about its relevance to the trial's analysis can be made.
What can be inferred from the safety counts?
Safety counts are descriptive summaries of participants recorded as affected among those at risk, as reported for the trial. They do not by themselves establish that the treatment caused an event. Causal assessment typically depends on factors such as timing, clinical context, event definitions and alternative explanations; these details are not reported in sufficient form for that assessment. The serious-event count and the listed serious term should therefore be interpreted as registry safety reporting, not a comparative risk estimate.
The registry lists four outcome measures and no analyses. It does not report whether multiplicity adjustments were used, how missing observations were handled, which analysis populations were defined, or whether the listed measures were analyzed according to a prespecified plan. In general, these choices affect how estimates and uncertainty should be interpreted. Their absence limits reproducibility and prevents readers from evaluating the statistical procedures behind a primary endpoint result.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists four outcome measures: the primary clinical tumor-response count and secondary measures concerning in vivo survival of engineered cells, adverse events and anti-mouse TCR antibodies. Considering multiple outcomes can raise multiplicity concerns. In general, if many statistical hypotheses are tested, the chance of at least one apparently notable result can increase unless the analysis plan addresses that issue. The registry record reports no analyses and does not state whether any multiplicity adjustment or testing hierarchy was planned.
The record does not report a primary endpoint result, so there is no reported estimate to assess for selection among outcomes. It also does not report whether secondary outcomes were intended to support formal hypothesis tests or descriptive reporting only. The protocol's statistical plan is not reported in the registry record.
Missing-data methods and analysis populations are also not reported. The registry does not specify how participants with missing or unevaluable tumor assessments were handled, whether all enrolled participants were included in each outcome summary, or how withdrawals and off-study criteria affected follow-up. These details matter because a count of responders depends on who was assessed and how missing assessments are treated.
General statistical practice distinguishes an intention-to-treat population, a treated population and an outcome-evaluable population, but the record does not identify which, if any, was used for the primary endpoint. No assumptions about missing outcomes should be imposed. Without the endpoint result and analysis-population details, readers cannot judge the impact of missingness or reproduce the analysis.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| ALVAC Plus Anti-gp100:154-162 TCR PBL + HD IL-2 | 1 | 3 | 33.3% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| ALVAC Plus Anti-gp100:154-162 TCR PBL + HD IL-2 | 3 of 3 |
Most frequent serious adverse event terms
| Event term | Organ system | ALVAC Plus Anti-gp100:154-162 TCR PBL + HD IL-2 |
|---|---|---|
| Intracranial hemorrhage | Blood and lymphatic system disorders | 1 of 3 |
Most frequent non-serious adverse event terms
| Event term | Organ system | ALVAC Plus Anti-gp100:154-162 TCR PBL + HD IL-2 |
|---|---|---|
| Leukocyte count decreased | Blood and lymphatic system disorders | 3 of 3 |
| Lymphocyte count decreased | Blood and lymphatic system disorders | 3 of 3 |
| Neutrophil count decreased | Blood and lymphatic system disorders | 3 of 3 |
| Platelet count decreased | Blood and lymphatic system disorders | 3 of 3 |
| Rash desquamating | Skin and subcutaneous tissue disorders | 3 of 3 |
| Febrile neutropenia | Infections and infestations | 3 of 3 |
| Hemoglobin decreased | Blood and lymphatic system disorders | 2 of 3 |
| Skin hypopigmentation | Skin and subcutaneous tissue disorders | 2 of 3 |
| Serum phosphate decreased | Metabolism and nutrition disorders | 2 of 3 |
| Vision blurred | Eye disorders | 2 of 3 |
Serious events with the highest arm-level rate: intracranial hemorrhage (33.3%).
The registry reports 3 participants at risk for serious adverse events and 1 affected. Intracranial hemorrhage is listed among the top serious terms at 33.3%. The record separately lists 3 participants at risk and 3 affected for other adverse events. These are descriptive safety entries, not a comparison of the regimen with a control group.
A serious adverse event count is not equivalent to a claim that treatment caused the event. In general, causality requires clinical assessment of timing and context, among other considerations. The registry record does not provide enough participant-level detail to make that assessment. Nor does it report the event's timing, outcome or severity grading details in the information available for this analysis.
The small enrollment makes the safety figures especially limited as estimates of event frequency beyond this trial. A percentage such as 33.3% can look exact, but it does not remove uncertainty from the small underlying group. The posted counts should be read as what the registry records for this trial, not as a stable estimate for a broader patient population or as proof of a causal relationship.
12. What the Result Does, and Does Not, Mean
The record establishes that a Phase II, single-group trial evaluated a combination of ALVAC gp100 vaccine, anti-gp100:154-162 TCR-engineered peripheral blood lymphocytes and interleukin-2, with chemotherapy conditioning described in the treatment summary. It defines clinical tumor regression as complete or partial response under RECIST v.1.0 and lists the timing for response assessment. It also records limited adverse-event counts.
The record does not report the primary endpoint result. Therefore it does not establish how many participants developed tumor regression, whether any participants had complete versus partial response, or how precisely a response frequency could be estimated. It also does not report an inferential analysis or a comparison with another treatment.
Even if a tumor-response count were available, the single-group design would support description of outcomes in the treated group, not a causal claim about what would have happened under a different treatment. Because the intervention is a combination, the design would not identify the independent contribution of its separate components. The registry record also does not report why the trial was terminated, so that status cannot be used to infer a response or safety conclusion.
The safety entries show what the registry records for participants at risk, including the serious-event count and intracranial hemorrhage term. They do not establish causation, provide a controlled risk comparison or determine how the regimen's overall safety compares with alternatives. In general, interpretation of safety requires the event definitions, clinical context, follow-up and ascertainment details; these are not fully reported in the registry record.
Accordingly, the posted information supports a careful account of the trial's design, endpoint definitions and limited safety reporting. It does not support a conclusion that the treatment works or does not work, nor a comparative benefit-harm judgment. Those limits follow from the missing primary result, absence of a comparator and limited enrollment reported for this study.
13. Why This Trial Matters Statistically
This trial illustrates the difference between a clearly defined endpoint and a reported endpoint result. RECIST v.1.0 gives operational criteria for complete and partial tumor response, and the registry specifies when assessments were intended to occur. Those definitions help readers understand what the study set out to count. But without the observed response count or an analysis, the clinical question remains unanswered by the registry record.
It also demonstrates why design determines the scope of statistical conclusions. A single-group study can document outcomes in participants receiving a regimen, but it does not provide a concurrent counterfactual for estimating a treatment contrast. That matters even more when several treatments are administered as a package: the design cannot disentangle their individual effects.
The limited enrollment and safety counts further show why descriptive figures need context. A percentage can appear precise while still carrying substantial uncertainty when based on a small group. Counts are useful for recording what occurred in a study, but they are not automatically generalizable estimates, and without a comparator they do not describe relative risk.
Finally, the record highlights the importance of reporting analysis methods and participant flow. Information about analysis populations, missing outcomes, multiplicity, uncertainty and the reason for termination is not reported. Those details allow readers to assess how robust an estimate is and whether conclusions follow from the planned analysis. Their absence limits interpretation, regardless of how clinically important the research question may be.
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 central limitation is that the registry record does not report the primary tumor-response result or any statistical analyses. The endpoint is defined, but the number meeting it, its uncertainty and any inferential test are absent. The clinical objective therefore cannot be assessed from the posted results.
The study is recorded as single-group, with no concurrent comparator. Any observed outcome would be descriptive of participants treated under the regimen and would not establish a comparative effect. The regimen includes multiple components, so the design also cannot attribute an outcome to an individual component.
Enrollment is listed as 3, limiting the amount of information available for estimating response or characterizing safety. Safety reporting includes counts and a serious-event term, but the record does not provide full event-level context, timing or causal assessment. The study status is terminated, but the reason is not reported in the registry record.
Other relevant details are absent: the sample-size justification, statistical analysis plan, analysis populations, handling of missing or unevaluable tumor assessments, and any multiplicity approach. The record lists four outcome measures but reports no analyses. These gaps limit reproducibility and make it impossible to judge how outcomes would have been summarized or whether planned analyses were completed. The intervention description also does not give all dosing details in the registry information available for this analysis.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Anti-gp100 Cells Plus ALVAC gp100 Vaccine to Treat Advanced Melanoma — NCT00610311.
- Registry record last updated 2015-10-28; status last verified 2015-09.
- Results first posted 2012-04-10.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
NCT00610311 is listed as a Phase II, single-group study of treatment for advanced or metastatic melanoma. The intervention combined ALVAC gp100 vaccine and anti-gp100:154-162 TCR-engineered peripheral blood lymphocytes with interleukin-2; the brief description also includes lymphodepleting chemotherapy. The registry lists enrollment of 3, a start of 2008-01, primary completion of 2011-02 and status as terminated.
The primary outcome is the number of participants with complete or partial clinical tumor regression under RECIST v.1.0, with assessment beginning 4-6 weeks after treatment and continuing monthly for approximately 3 to 4 months or until off-study criteria were met. The primary outcome result and any statistical analyses are not reported in the registry record. Safety entries include 1 affected among 3 at risk for serious adverse events and intracranial hemorrhage listed at 33.3%; other adverse events are listed for 3 affected among 3 at risk. The record does not report the reason for termination or a concurrent control comparison.