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 Sorafenib in Treating Patients With Metastatic or Unresectable Kidney Cancer (NCT00496756), a na phase 2 study. The primary outcome is Toxicity of Intrapatient Dose Escalation of Sorafenib Tosylate.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00496756 |
| Phase | Phase 2 |
| Condition | Kidney Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 14 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Nebraska |
| Results posted | Yes |
2. Clinical Question
The study asked whether patients with metastatic or unresectable kidney cancer could tolerate escalating doses of sorafenib, and also listed response rate as a secondary outcome. The record describes a phase II, single-group study sponsored by the University of Nebraska. It lists 14 enrolled participants and indicates that the study was terminated.
Population
Patients with metastatic or unresectable kidney cancer; the official title specifies metastatic renal cell carcinoma. The registry record lists 14 enrolled participants.
Intervention
Sorafenib, described as starting at 400 mg twice a day, with planned intrapatient dose escalation if dose-limiting toxicity was not observed.
Comparator
There was no separate comparator group. The study is listed as single-group, with no allocation to different arms.
Primary question
How tolerable was dose escalation, assessed by estimating the percentage of patients unable to tolerate escalated doses?
The registry record also lists response rate as a secondary outcome, but reports no response-rate result. It does not report a completed estimate for the primary toxicity outcome. The clinical question is therefore framed by the study’s planned assessment, rather than by a posted estimate of tolerability or tumor response.
3. Trial Design
This was a phase II, single-group study of sorafenib in patients with metastatic renal cell carcinoma. The record lists kidney cancer as the condition and describes the intended population as patients with metastatic or unresectable disease. Enrollment was 14. The study began on 2007-03-01, had a listed primary completion date of 2009-10-31, and is marked terminated.
Because the model is single-group and allocation is listed as not applicable, the design does not provide a concurrent control group for a treatment comparison. The masking field is none. These design features mean that the study was not organized as a blinded, randomized comparison between sorafenib and another treatment or control.
The intervention description gives an initial oral dose of 400 mg twice a day, daily. It describes intrapatient escalation every 4 weeks, conditional on the absence of grade 3 or 4 dose-limiting toxicity, toward a maximum dose of 800 mg BID. The record also mentions delay and dose modification if grade 3 or 4 toxicity occurred, but the posted arm description does not fully specify those adjustments.
The primary outcome was toxicity of intrapatient dose escalation, with the planned measure being an estimate of the percentage unable to tolerate escalated doses. Response rate was listed as a secondary outcome. The registry record does not report the completed analysis for the primary outcome, a response-rate result, or the statistical analysis plan. It also does not report a sample-size justification.
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 | Sorafenib |
|---|---|
| STARTED | 14 |
| COMPLETED | 11 |
| NOT COMPLETED | 3 |
Analysis population for the primary outcome, as defined in the registry: Evaluation of this data is not possible as the investigator performing the analysis has left the study center prior to completing the analysis and data was not provided.
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 | Sorafenib |
|---|---|---|
| Participants analysed | 14 | |
| Age, Customized: Patients greater than or equal to 19 years of age | Participants | 14 |
| Sex: Female, Male: Female | Participants | 3 |
| Sex: Female, Male: Male | Participants | 11 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 14 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 14 |
6. Primary Endpoint
The registry lists the primary outcome as Toxicity of Intrapatient Dose Escalation of Sorafenib Tosylate, measured over Study completion.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint was intended to assess toxicity during intrapatient dose escalation of sorafenib. The registry describes the planned measure as an estimate of the percentage of patients unable to tolerate the escalated doses. Participants were intended to increase dose every 4 weeks until a maximum dose of 800 mg BID was reached, with escalation conditional on the absence of grade 3 or 4 dose-limiting toxicity.
This endpoint addresses tolerability under the study’s escalation approach: it asks whether participants could proceed to higher doses without unacceptable toxicity. Such an endpoint is distinct from an efficacy endpoint. A toxicity estimate would describe the experience of participants under the dosing approach; it would not, by itself, establish whether tumor outcomes improved.
The primary outcome’s timeframe is listed as study completion. However, the registry record states that evaluation was not possible because the investigator performing the analysis left the study center before completing it and data were not provided. No endpoint estimate, uncertainty interval, or detailed analysis method is reported in the registry record. Response rate is listed as a secondary outcome, but no result for it is reported.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The main interpretive fact is that the planned primary toxicity analysis is unavailable. The record says that the analysis was not completed after the investigator left the study center and that data were not provided. Consequently, the posted record does not give an estimate of the percentage unable to tolerate dose escalation. It also gives no uncertainty interval or completed analysis for response rate.
The study enrolled 14 participants and is marked terminated. That enrollment describes the size of the study group, but it does not supply a result for either outcome. Without the completed outcome data, readers cannot determine from this record how many participants reached higher doses, how many could not tolerate escalation, or how the result was estimated. Those details are not reported in the registry record.
Serious adverse events are listed for the sorafenib group: 2 of 14 participants at risk were affected. The record separately lists other adverse events affecting 11 of 14 participants at risk, and lists 6 deaths. It does not establish whether the serious and other adverse-event counts overlap, provide event timing, or state whether deaths were attributed to treatment. These counts should therefore be read as descriptive safety information, not as a complete causal assessment.
The record’s list of serious-event terms includes pleural effusion, weakness, shortness of breath, and extremities tingling or numbness, each reported as 7.1%. The percentages are registry entries; no additional risk period or event-level detail is given to clarify their interpretation.
In general, an estimate is more informative when paired with a measure of uncertainty, because the estimate alone does not show how much the result could vary. Here, the missing primary analysis means neither the toxicity estimate nor its precision can be assessed from the registry record. The single-group design also does not support a direct comparison against a control group. These limitations restrict interpretation to the study’s design, its listed enrollment, and the adverse-event counts actually reported.
9. Statistical Methods Explained
The statistical information in this record is limited. It identifies a single-group phase II study, a planned toxicity endpoint, a secondary response-rate outcome, and adverse-event counts. It does not report a completed primary outcome analysis or a detailed statistical plan. General statistical concepts can help explain what such an analysis would ordinarily convey, but they should not be mistaken for methods documented for this study.
What does the primary endpoint estimate?
The planned primary measure is a percentage: the proportion of participants unable to tolerate escalated doses. In general, a proportion describes how often a defined outcome occurs in a defined group. To interpret it, readers need a clear outcome definition, a denominator, and a specified observation period. In this study, the registry identifies the intended endpoint and describes dose escalation, but does not provide the completed estimate or the underlying analysis data. The detailed rules used to classify inability to tolerate escalation are not reported in the registry record.
A confidence interval is a statistical range used to express uncertainty around an estimate. In general, wider intervals indicate less precision, while narrower intervals indicate more precision under the assumptions of the analysis. No confidence interval for the primary toxicity endpoint is reported in the registry record. It is therefore not possible to assess the precision of that planned estimate.
What can a single-group design establish?
A single-group study describes outcomes among participants receiving the study intervention. It does not directly estimate how those outcomes would have differed under a separate control condition. A comparison with an external or historical group would require additional information and assumptions; such a comparison is not described in this record. The absence of a control group does not prevent descriptive reporting, but it limits causal and comparative interpretation.
Masking is listed as none. In general, masking can reduce the influence of knowledge about treatment assignment on some aspects of care, outcome assessment, or reporting. The registry record does not describe a masked assessment process. It also does not report whether the outcome assessor used a standardized procedure independent of treatment knowledge.
Why does analysis detail matter?
A statistical analysis plan specifies how outcomes are defined and analyzed, how missing observations are handled, and which participants are included. Such choices can affect the estimate and its interpretation. The statistical analysis plan is not reported in the registry record. Nor are the analysis population, exclusions, handling of participants who stopped escalation, or details of any sensitivity analyses reported.
The record reports no analyses. It therefore does not provide a model, test, estimation procedure, p-value, or uncertainty interval for the primary endpoint or response rate. No inferential result should be inferred from the fact that the study was phase II or from its enrollment alone.
How should planning calculations be understood?
General sample-size calculations are planning tools. They depend on assumptions about the target effect, variability, significance level, allocation, and statistical method. A planning illustration based on an observed effect does not become an observed result, and it is not observed power. The registry record does not report the trial’s own sample-size justification. Any planning illustration should be understood as hypothetical, not as evidence that the study had a particular probability of detecting an effect.
In general, over-dispersion means that observed variability is greater than a statistical model assumes. If a model ignores over-dispersion, its uncertainty estimates may be too small. The registry record does not report an over-dispersion assessment or a model for these outcomes, so this concept cannot be tied to a specific analysis in this study.
Likewise, a p-value, when reported, measures how compatible data are with a specified null model under the assumptions used; it is not the probability that a treatment works or that the null hypothesis is true. No p-value is reported for the primary outcome or response rate. The principal statistical conclusion is therefore not a positive or negative test result, but the absence of a completed outcome analysis in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists toxicity of intrapatient dose escalation as the primary outcome and response rate as a secondary outcome. It does not report a multiplicity strategy addressing the possibility of interpreting more than one outcome. In general, multiplicity concerns arise when several outcomes or analyses are tested, because repeated testing can increase the chance of a seemingly notable result arising by chance. The record does not say whether any adjustment or hierarchy was planned.
The record lists two outcome measures but reports no completed analyses. It does not provide a primary toxicity estimate, response-rate result, p-value, or confidence interval. The primary outcome description specifically says that evaluation was not possible because the investigator performing the analysis left the study center before completing it and data were not provided. The analysis population and the amount or pattern of missing outcome data are not reported in the registry record.
In general, missing data can affect interpretation if participants with unavailable outcomes differ from those whose outcomes are observed. The extent and direction of any such effect depend on why data are missing and on the analysis approach. Here, the registry does not describe participant-level missingness, an imputation method, or sensitivity analyses. It is not possible to assess how missing information might have affected the intended endpoint.
The record also does not report whether all enrolled participants were included in an analysis population, whether participants who discontinued escalation remained under observation, or how deaths were handled for the planned toxicity endpoint. These details matter because the denominator and follow-up rules define what an endpoint estimate represents. Without them, no completed analysis population or missing-data strategy can be reconstructed from the registry record.
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 |
|---|---|---|---|
| Sorafenib | 2 | 14 | 14.3% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Sorafenib | 6 of 14 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Sorafenib | 11 of 14 |
Most frequent serious adverse event terms
| Event term | Organ system | Sorafenib |
|---|---|---|
| Pleural effusion | Respiratory, thoracic and mediastinal disorders | 1 of 14 |
| Other, weakness | General disorders | 1 of 14 |
| Other, shortness of breath | Respiratory, thoracic and mediastinal disorders | 1 of 14 |
| Other, extremities tingling, numbness | General disorders | 1 of 14 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Sorafenib |
|---|---|---|
| Diarrhea | Gastrointestinal disorders | 8 of 14 |
| Other, hand foot syndrome | Skin and subcutaneous tissue disorders | 7 of 14 |
| Hypertension | Vascular disorders | 6 of 14 |
| Other, pain | General disorders | 5 of 14 |
| Fatigue | General disorders | 5 of 14 |
| Other- rash | Skin and subcutaneous tissue disorders | 4 of 14 |
| Alopecia | Skin and subcutaneous tissue disorders | 4 of 14 |
| Nausea | Gastrointestinal disorders | 4 of 14 |
| Vomiting | Gastrointestinal disorders | 3 of 14 |
| Proteinuria | Renal and urinary disorders | 3 of 14 |
Serious events with the highest arm-level rate: pleural effusion (7.1%), other, weakness (7.1%), other, shortness of breath (7.1%), other, extremities tingling, numbness (7.1%).
The registry lists 14 participants at risk for serious adverse events in the sorafenib group, with 2 affected. It lists 14 at risk for other adverse events, with 11 affected. These are descriptive counts as recorded; they do not by themselves establish that sorafenib caused the events. The record does not state whether the participants counted in the serious-event group are also included among those with other adverse events.
Six deaths are listed for the group. The registry entry does not provide timing, causes, or an attribution of deaths to treatment. It also does not specify the observation period used for these counts, or provide details that would distinguish events occurring during treatment from those occurring later.
The listed serious-event terms are pleural effusion, other—weakness, other—shortness of breath, and other—extremities tingling or numbness. Each is reported as 7.1%. The record does not provide further information about event duration, recurrence, severity beyond the serious-event listing, or how terms were coded. These entries should be read as reported safety descriptions, not as comparative rates or causal findings.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a phase II, single-group study of sorafenib was conducted in a population described as having metastatic or unresectable kidney cancer, with 14 participants enrolled. It records the study as terminated and identifies toxicity during dose escalation as the primary outcome. It also lists response rate as a secondary outcome and provides adverse-event counts.
It does not establish a completed estimate of dose-escalation tolerability. The primary analysis was not completed, according to the registry, and the data were not provided. No response-rate result is reported. The available record therefore does not show how often participants tolerated escalation, how precisely that outcome could be estimated, or what tumor-response outcome was observed.
The safety counts provide a limited descriptive account of events among the study group. They do not provide a comparison with people receiving another treatment or no study treatment. The record also does not establish whether the listed deaths were related to treatment. The design and reporting do not support attributing differences to sorafenib, because no concurrent comparison group is listed and the relevant completed outcome analyses are absent.
In general, a missing result is not evidence that an outcome did or did not occur. It means that the outcome cannot be characterized from the reported analysis. Similarly, the enrollment count is not itself evidence of treatment benefit or harm, and sample-size calculations are not observed outcomes. The appropriate reading is narrow: the registry documents the study design and certain safety counts, while leaving the planned primary toxicity estimate and secondary response result unavailable.
13. Why This Trial Matters Statistically
This study illustrates why the distinction between a planned endpoint and a reported result matters. The registry identifies a clinically relevant statistical target: the percentage of participants unable to tolerate dose escalation. But without the completed estimate, the denominator used in analysis, and a measure of uncertainty, readers cannot quantify the endpoint or its precision.
The single-group design also makes clear what a study can and cannot answer. It can describe outcomes among participants in the group, if those outcomes are analyzed and reported. It cannot make a direct controlled comparison when no comparator group is present. This is important when interpreting safety counts: counts among enrolled participants are not comparative evidence and do not by themselves establish causation.
The record also demonstrates that registry fields can preserve useful information even when an analysis is unavailable. The intervention, planned escalation, primary endpoint, secondary outcome, enrollment, study status, and adverse-event counts provide context. At the same time, absent outcome estimates, analysis methods, and missing-data details constrain the conclusions that can be drawn.
For biostatistical interpretation, the central lesson is to separate design, data, and inference. The design states what investigators intended to evaluate; the data describe what was observed; inference requires a documented analysis and appropriate uncertainty assessment. In this record, the intended toxicity analysis is described, but its result is not reported. That distinction prevents a study’s purpose or planning assumptions from being mistaken for evidence about its outcomes.
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.
Several limitations are specific to this record. The study is listed as terminated, and the primary toxicity analysis is explicitly described as not possible because the investigator performing it left the study center before completion and data were not provided. As a result, the primary outcome estimate and its precision are unavailable.
The enrollment was 14, and the study had a single group with no comparator. The record therefore offers no concurrent basis for estimating how outcomes might differ under another treatment or control condition. The absence of a comparator is particularly relevant to interpreting adverse-event counts and deaths, for which attribution and comparative context are not given.
The registry does not report the detailed analysis population, participant-level outcome data, the handling of missing observations, or the statistical analysis plan. It also does not report a sample-size justification, completed response-rate analysis, or the time period and methods used for the reported safety counts. These omissions limit assessment of the endpoint definitions, follow-up, missingness, and statistical uncertainty.
The arm description gives a starting dose and broad escalation conditions, but the posted description of dose delay and modification is incomplete. The record does not give participant-level dose histories or explain how inability to tolerate escalation was classified. Consequently, the intended endpoint cannot be reconstructed from the description alone.
Finally, the listed safety terms and deaths lack timing and causal attribution. The registry record supports descriptive reading of those entries but does not support conclusions about why the events occurred or how risks compare with another group.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Sorafenib in Treating Patients With Metastatic or Unresectable Kidney Cancer — NCT00496756.
- Registry record last updated 2023-10-26; status last verified 2023-10.
- Results first posted 2019-02-15.
- 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
NCT00496756 is a phase II, single-group study of sorafenib in patients with metastatic or unresectable kidney cancer, with 14 participants enrolled. The registry lists toxicity of intrapatient dose escalation as the primary outcome and response rate as a secondary outcome. The study is marked terminated.
The primary toxicity analysis was not completed, and data were not provided, according to the registry record. No response-rate result is reported. The safety listing records 2 participants affected by serious adverse events, 11 affected by other adverse events, and 6 deaths; the record does not establish causal attribution or whether the adverse-event counts overlap. The single-group design and unavailable outcome analyses limit comparative and inferential conclusions.