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 CP-751,871 In Combination With Docetaxel In Advance Non-hematologic Malignancies (NCT01653158), a na phase 1 study. The primary outcome is Maximum Tolerated Dose (MTD).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01653158 |
| Phase | Phase 1 |
| Condition | Advanced Non-Hematologic Malignancies |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 46 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Pfizer |
| Results posted | Yes |
2. Clinical Question
Population
The study enrolled patients with advanced non-hematologic malignancies for whom docetaxel was considered a reasonable treatment option. The registry record reports total enrollment of 46 participants. It does not give further eligibility details or describe the enrolled participants’ disease mix in the information reported for this trial.
Intervention
Participants received CP-751,871 in combination with docetaxel. The study evaluated escalating CP-751,871 doses, with recorded dose groups ranging from 0.1 mg/kg through 20 mg/kg. The registry describes the study as open-label, so treatment masking was not used.
Comparator
There was no separate control or comparator group. The registry identifies the study as single-group and its allocation as not applicable. Dose groups should therefore be understood as groups receiving different CP-751,871 doses alongside docetaxel, not as randomized treatment arms for a like-for-like efficacy comparison.
Primary question
The primary outcome was maximum tolerated dose (MTD), measured in mg/kg over Cycle 1 Day 1 through Cycle 1 Day 21. The broader study objective was to evaluate safety, tolerability, pharmacokinetics and pharmacodynamic effects of escalating CP-751,871 doses with docetaxel. The numeric MTD result and the operational rule used to define it are not reported in the registry record.
In statistical terms, this is a dose-escalation question rather than a treatment-versus-control question. The central aim is to characterize how dose relates to tolerability during the specified first-cycle period. The secondary outcomes listed in the registry include objective response, time to tumor progression, antibody response, circulating cell measures, and pharmacokinetic measures. Those outcomes broaden the study’s description of treatment exposure and observed events, but the registry record does not report their results in the information available for this analysis.
3. Trial Design
This was a phase 1b, open-label, single-group dose-escalation study of CP-751,871 combined with docetaxel in advanced non-hematologic malignancies. The registry record lists allocation as not applicable and masking as none. Enrollment was 46. The study is recorded as completed, with a start date of 2005-03 and primary completion in 2009-02.
The intervention was a combination of CP-751,871 and docetaxel. Recorded dose groups were CP-751,871 0.1 mg/kg, 0.4 mg/kg, 0.8 mg/kg, 1.5 mg/kg, 3 mg/kg, 6 mg/kg, 10 mg/kg and 20 mg/kg, each with docetaxel. The number at risk differs across these groups in the adverse-event record. These dose groups are not described as randomized groups, and the record cautions against treating them as a like-for-like control comparison.
The primary outcome was MTD in mg/kg over Cycle 1 Day 1 through Cycle 1 Day 21. Its specified analysis population was the safety analysis set: enrolled participants who started treatment, excluding those enrolled in the expansion cohort. The record does not report how many participants met that population definition, nor does it give the numeric MTD result.
Secondary outcomes included human anti-human antibody response to CP-751,871, objective response, time to tumor progression, circulating tumor cells and related cell measures, and CP-751,871 clearance and maximum plasma concentration in Cycle 1 and Cycle 4. The record lists 45 outcome measures overall. It does not report an analysis count or detailed statistical procedures. The dose-escalation rules, cohort decision criteria, and any protocol amendments are not reported in the registry record, so the design should not be reconstructed beyond the details stated.
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.
Only the first 6 of 8 groups are shown.
Overall Study
| Stage | CP-751,871 0.1 mg/kg + Docetaxel | CP-751,871 0.4 mg/kg + Docetaxel | CP-751,871 0.8 mg/kg + Docetaxel | CP-751,871 1.5 mg/kg + Docetaxel | CP-751,871 3 mg/kg + Docetaxel | CP-751,871 6 mg/kg + Docetaxel |
|---|---|---|---|---|---|---|
| STARTED | 3 | 3 | 3 | 3 | 3 | 3 |
| COMPLETED | 2 | 3 | 3 | 1 | 2 | 2 |
| NOT COMPLETED | 1 | 0 | 0 | 2 | 1 | 1 |
Reasons for not completing this period:
| Reason | CP-751,871 0.1 mg/kg + Docetaxel | CP-751,871 0.4 mg/kg + Docetaxel | CP-751,871 0.8 mg/kg + Docetaxel | CP-751,871 1.5 mg/kg + Docetaxel | CP-751,871 3 mg/kg + Docetaxel | CP-751,871 6 mg/kg + Docetaxel |
|---|---|---|---|---|---|---|
| Death | 0 | 0 | 0 | 1 | 0 | 0 |
| Adverse Event | 0 | 0 | 0 | 1 | 0 | 0 |
| Other | 0 | 0 | 0 | 0 | 0 | 0 |
| Progressive disease | 0 | 0 | 0 | 0 | 1 | 1 |
| Withdrawal by Subject | 1 | 0 | 0 | 0 | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: Safety analysis set: all enrolled participants who started treatment, but excluding those who were enrolled in the expansion cohort.
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 | Entire Study Population |
|---|---|---|
| Participants analysed | 46 | |
| Age Continuous | Years | 59.4 (SD 11.4) |
| Sex: Female, Male: Female | Participants | 6 |
| Sex: Female, Male: Male | Participants | 40 |
6. Primary Endpoint
The registry lists the primary outcome as Maximum Tolerated Dose (MTD), measured over Cycle 1 Day 1 through Cycle 1 Day 21.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | mg/kg |
| Endpoint classification | not reduced to a single comparison |
Maximum tolerated dose is the primary outcome. It is expressed in mg/kg and applies to Cycle 1 Day 1 through Cycle 1 Day 21. The defined safety analysis set includes all enrolled participants who started treatment, except participants enrolled in the expansion cohort. The registry record does not report a numeric MTD result, the number of participants included in this analysis set, or an operational definition of what level or pattern of toxicity constituted the dose-limiting boundary.
In general, MTD is used in early-phase dose escalation to summarize dose tolerability over a specified observation period. It can help describe the dose level identified under a study’s particular escalation rules. It is not, by itself, a measure of comparative efficacy, and it does not establish how a dose performs relative to an untreated or alternative-treatment group. Its interpretation depends on the toxicity definitions, observation window, dose-escalation procedure and analysis population specified by the protocol.
Here, the stated observation window is Cycle 1 Day 1 through Cycle 1 Day 21. The registry record does not state the escalation algorithm or the criteria for identifying MTD, so the meaning of the endpoint can be described only at this general level. The result cannot be interpreted as a particular tolerated dose because no result value is reported in the registry record.
The registry also lists safety, pharmacokinetic, pharmacodynamic and tumor-related secondary outcomes. These can provide distinct kinds of information: adverse events describe observed safety events; pharmacokinetic outcomes describe drug concentration or clearance; and tumor outcomes describe response or progression. They do not substitute for the missing primary MTD result, and their individual results are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The study addresses dose and tolerability in a single-group combination regimen. The registry record gives the primary outcome name, unit, assessment window and analysis-population definition, but not the numeric MTD finding. As a result, no specific CP-751,871 dose can be identified from the posted primary outcome information as the study’s MTD. The dose groups listed in the adverse-event record show which dose levels were represented; their presence alone does not establish which level met the study’s MTD criteria.
The adverse-event record gives counts at risk and counts affected by serious and other adverse events at each dose level. These are descriptive counts from groups of different sizes. For example, the 0.1 mg/kg group lists 2 participants affected by serious adverse events among 3 at risk, while the 20 mg/kg group lists 11 among 19 at risk. The record does not provide a randomized comparison, and these groups should not be interpreted as equivalent comparison arms. Differences in their counts cannot be attributed to dose alone from these data.
All dose groups list participants affected in the other adverse-event category. The listed counts are 3 of 3 at each dose from 0.1 mg/kg through 6 mg/kg, 9 of 9 at 10 mg/kg, and 19 of 19 at 20 mg/kg. The record does not clarify in this summary how the other category is defined. These counts do not describe event severity, duration, recurrence or causal attribution; those details are not reported in the registry record.
Several serious adverse-event terms are listed with 33.3%: febrile neutropenia, neutropenia, abdominal pain, constipation, diarrhoea and intestinal obstruction. The denominator and the dose-group distribution for these percentages are not given in the record information, so they should be read as listed term percentages without inferring a group-specific rate. Death counts are not reported in the registry record.
The trial’s stated purpose also included pharmacokinetics and pharmacodynamic effects, with secondary measures such as CP-751,871 clearance and maximum plasma concentration in Cycle 1 and Cycle 4. Objective response and time to tumor progression were also listed. However, numeric results for these outcomes are not reported in the registry record. The study’s status is completed, but completion does not itself supply evidence about the size or precision of any clinical effect.
In general, confidence intervals express uncertainty around an estimated quantity, while a p-value assesses compatibility of data with a specified statistical model and null hypothesis. No confidence interval, p-value or numeric estimate for the primary outcome is reported in the registry record. Consequently, the precision of the MTD estimate cannot be assessed from the posted result information. The absence of a reported estimate is not evidence for either a particular dose or a particular safety profile.
9. Statistical Methods Explained
The registry describes a phase 1b, open-label, single-group dose-escalation study. This design differs from a randomized comparative trial: there is no separate control group, and allocation is listed as not applicable. Participants were grouped according to the CP-751,871 dose received with docetaxel. The recorded dose groups range from 0.1 mg/kg to 20 mg/kg. Since dose groups can differ in size and are not presented as randomized comparators, a direct contrast between their observed counts would not have the same interpretation as a randomized treatment effect.
What does dose escalation estimate?
In general, dose-escalation studies investigate tolerability across dose levels and use prespecified rules to guide whether escalation, continuation or stopping is appropriate. MTD is one possible summary of the dose level identified under those rules. The rules matter: toxicity definitions, the observation window, how participants are counted, and the decision algorithm all affect the interpretation. The registry record gives the primary assessment window as Cycle 1 Day 1 through Cycle 1 Day 21, but the dose-escalation algorithm and operational MTD criteria are not reported in the registry record. A reader therefore cannot infer how the study moved between doses or what exact threshold defined MTD.
What does the primary analysis population mean?
The primary outcome population is described as a safety analysis set. It includes enrolled participants who started treatment and excludes those enrolled in the expansion cohort. In general, defining an analysis population clarifies which participants contribute to an estimate and supports consistent interpretation. The record does not give the number included in this set, or explain participant-level exclusions beyond the expansion-cohort exclusion stated. Total enrollment is 46, but that total should not be taken as the primary outcome denominator because the stated analysis-set definition is narrower and its size is not reported.
How should the adverse-event counts be read?
The adverse-event record reports, by dose group, the number at risk and the number affected by serious and other adverse events. These are counts, not adjusted comparisons. The dose groups have different counts at risk, and the study is not a randomized comparison. In general, a count is most interpretable alongside its denominator, outcome definition and observation period. The listed counts provide the at-risk totals, but the registry information does not give all details needed to characterize event timing, repeated events, duration or attribution. Serious adverse events and the other adverse-event category should be kept distinct; the record does not define the other category in the summary information.
What do the listed outcome measures imply?
The registry lists 45 outcome measures, including MTD, antibody response, objective response, time to tumor progression, circulating tumor and endothelial cell measures, clearance and maximum plasma concentration. These are different endpoints with different measurement scales and interpretations. A pharmacokinetic measure such as clearance describes drug disposition; an objective response outcome concerns tumor response; and an adverse-event count describes reported events. They cannot be treated as interchangeable evidence. The registry record lists 0 analyses. Results and analytic details for the secondary outcomes are not reported in the registry record.
How should planning calculations be interpreted?
In general, sample-size planning calculations describe the number of participants or events that would be needed under stated assumptions to detect a specified effect with a chosen error rate and power. They are planning illustrations, not observed power and not a description of what the trial achieved. The planning assumptions stated for the illustrations are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect defined as a fraction of an observed effect. For time-to-event outcomes, the stated calculation concerns total events; for other outcomes, it concerns participants per arm. These assumptions describe a hypothetical two-arm calculation and do not change this study’s single-group design. Numeric planning results are not reported in the registry record. The observed effect needed to anchor such illustrations is also not reported in the registry record, so no planning quantity should be inferred from the study’s enrollment alone.
More generally, confidence intervals communicate the range of values compatible with an estimate under an analysis, while estimates and their intervals depend on the statistical model and available observations. Over-dispersion, in general, means observed variability exceeds what a simpler model assumes; accounting for it can affect uncertainty estimates. The registry record does not report a model, confidence intervals, p-values, an over-dispersion assessment, interim analyses or a detailed statistical analysis plan. None should be presumed for this study.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists 45 outcome measures, including the primary MTD outcome and a range of secondary safety, pharmacokinetic, pharmacodynamic and tumor-related outcomes. When a study assesses multiple outcomes or conducts multiple analyses, multiplicity can arise: in general, repeated statistical testing can increase the chance of at least one apparently notable result even when there is no underlying effect. A prespecified testing hierarchy or adjustment can address some multiplicity concerns. The registry record does not report a multiplicity strategy, a testing hierarchy or an adjustment procedure. It also lists 0 analyses, so no outcome-specific analytic results are available in the record information.
The primary outcome’s analysis population is defined as enrolled participants who started treatment, excluding expansion-cohort participants. The number in that set and the handling of missing primary-outcome information are not reported in the registry record. Missing-data methods, reasons for missingness, and the completeness of outcome follow-up are also not reported in the registry record. For the secondary outcomes, participant denominators and missing-data handling are not reported in the registry record.
In general, missing data can affect an estimate when the participants with recorded outcomes differ in relevant ways from those without them. The direction and size of any effect depend on why data are missing and on the analysis approach. Without counts of missing observations and details about their handling, the impact cannot be assessed. No assumptions about imputation, exclusion, censoring or follow-up completeness should be made from the registry summary alone.
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 |
|---|---|---|---|
| CP-751,871 0.1 mg/kg + Docetaxel | 2 | 3 | 66.7% |
| CP-751,871 0.4 mg/kg + Docetaxel | 2 | 3 | 66.7% |
| CP-751,871 0.8 mg/kg + Docetaxel | 2 | 3 | 66.7% |
| CP-751,871 1.5 mg/kg + Docetaxel | 2 | 3 | 66.7% |
| CP-751,871 3 mg/kg + Docetaxel | 1 | 3 | 33.3% |
| CP-751,871 6 mg/kg + Docetaxel | 2 | 3 | 66.7% |
| CP-751,871 10 mg/kg + Docetaxel | 7 | 9 | 77.8% |
| CP-751,871 20 mg/kg + Docetaxel | 11 | 19 | 57.9% |
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 |
|---|---|
| CP-751,871 0.1 mg/kg + Docetaxel | 3 of 3 |
| CP-751,871 0.4 mg/kg + Docetaxel | 3 of 3 |
| CP-751,871 0.8 mg/kg + Docetaxel | 3 of 3 |
| CP-751,871 1.5 mg/kg + Docetaxel | 3 of 3 |
| CP-751,871 3 mg/kg + Docetaxel | 3 of 3 |
| CP-751,871 6 mg/kg + Docetaxel | 3 of 3 |
Most frequent serious adverse event terms
| Event term | Organ system | CP-751,871 0.1 mg/kg + Docetaxel | CP-751,871 0.4 mg/kg + Docetaxel | CP-751,871 0.8 mg/kg + Docetaxel | CP-751,871 1.5 mg/kg + Docetaxel | CP-751,871 3 mg/kg + Docetaxel | CP-751,871 6 mg/kg + Docetaxel |
|---|---|---|---|---|---|---|---|
| Febrile neutropenia | Blood and lymphatic system disorders | 1 of 3 | 0 of 3 | 0 of 3 | 0 of 3 | 0 of 3 | 1 of 3 |
| Neutropenia | Blood and lymphatic system disorders | 0 of 3 | 1 of 3 | 0 of 3 | 1 of 3 | 0 of 3 | 0 of 3 |
| Hypotension | Vascular disorders | 0 of 3 | 1 of 3 | 0 of 3 | 0 of 3 | 1 of 3 | 0 of 3 |
| Abdominal pain | Gastrointestinal disorders | 0 of 3 | 0 of 3 | 0 of 3 | 1 of 3 | 0 of 3 | 0 of 3 |
| Constipation | Gastrointestinal disorders | 0 of 3 | 0 of 3 | 0 of 3 | 1 of 3 | 0 of 3 | 0 of 3 |
| Diarrhoea | Gastrointestinal disorders | 0 of 3 | 0 of 3 | 0 of 3 | 1 of 3 | 0 of 3 | 0 of 3 |
| Intestinal obstruction | Gastrointestinal disorders | 0 of 3 | 0 of 3 | 0 of 3 | 1 of 3 | 0 of 3 | 0 of 3 |
| Vomiting | Gastrointestinal disorders | 0 of 3 | 0 of 3 | 0 of 3 | 1 of 3 | 0 of 3 | 0 of 3 |
| Disease progression | General disorders | 0 of 3 | 0 of 3 | 0 of 3 | 1 of 3 | 0 of 3 | 0 of 3 |
| Pyrexia | General disorders | 0 of 3 | 1 of 3 | 0 of 3 | 0 of 3 | 0 of 3 | 0 of 3 |
Most frequent non-serious adverse event terms
| Event term | Organ system | CP-751,871 0.1 mg/kg + Docetaxel | CP-751,871 0.4 mg/kg + Docetaxel | CP-751,871 0.8 mg/kg + Docetaxel | CP-751,871 1.5 mg/kg + Docetaxel | CP-751,871 3 mg/kg + Docetaxel | CP-751,871 6 mg/kg + Docetaxel |
|---|---|---|---|---|---|---|---|
| Fatigue | General disorders | 3 of 3 | 3 of 3 | 3 of 3 | 3 of 3 | 1 of 3 | 3 of 3 |
| Neutropenia | Blood and lymphatic system disorders | 3 of 3 | 3 of 3 | 1 of 3 | 2 of 3 | 3 of 3 | 3 of 3 |
| Diarrhoea | Gastrointestinal disorders | 2 of 3 | 3 of 3 | 3 of 3 | 2 of 3 | 2 of 3 | 2 of 3 |
| Dysgeusia | Nervous system disorders | 2 of 3 | 3 of 3 | 3 of 3 | 2 of 3 | 2 of 3 | 1 of 3 |
| White blood cell count decreased | Investigations | 3 of 3 | 3 of 3 | 1 of 3 | 1 of 3 | 1 of 3 | 3 of 3 |
| Nausea | Gastrointestinal disorders | 2 of 3 | 2 of 3 | 1 of 3 | 3 of 3 | 2 of 3 | 1 of 3 |
| Anorexia | Metabolism and nutrition disorders | 2 of 3 | 2 of 3 | 1 of 3 | 1 of 3 | 2 of 3 | 2 of 3 |
| Alopecia | Skin and subcutaneous tissue disorders | 3 of 3 | 2 of 3 | 0 of 3 | 2 of 3 | 1 of 3 | 2 of 3 |
| Mucosal inflammation | General disorders | 2 of 3 | 2 of 3 | 2 of 3 | 1 of 3 | 1 of 3 | 1 of 3 |
| Dyspepsia | Gastrointestinal disorders | 1 of 3 | 3 of 3 | 1 of 3 | 0 of 3 | 0 of 3 | 3 of 3 |
Serious events with the highest arm-level rate: febrile neutropenia (33.3%), neutropenia (33.3%), abdominal pain (33.3%), constipation (33.3%), diarrhoea (33.3%).
The adverse-event record gives group-level counts at risk and counts affected by serious and other adverse events. For serious adverse events, the listed counts are 2 of 3 at 0.1 mg/kg, 2 of 3 at 0.4 mg/kg, 2 of 3 at 0.8 mg/kg, 2 of 3 at 1.5 mg/kg, 1 of 3 at 3 mg/kg, 2 of 3 at 6 mg/kg, 7 of 9 at 10 mg/kg, and 11 of 19 at 20 mg/kg. These are descriptive counts, not evidence from a randomized comparison. Group sizes differ, and the record does not describe these dose groups as like-for-like controls.
For the other adverse-event category, the recorded affected counts are 3 of 3 at each dose from 0.1 mg/kg through 6 mg/kg, 9 of 9 at 10 mg/kg, and 19 of 19 at 20 mg/kg. The summary does not specify the event-level definition or the details of repeated events. The serious adverse-event terms listed with 33.3% are febrile neutropenia, neutropenia, abdominal pain, constipation, diarrhoea and intestinal obstruction. Their denominators and dose-specific distributions are not reported in the registry record.
In general, safety counts describe events observed in the recorded groups; they do not by themselves establish causality or quantify comparative risk. Death counts are not reported in the registry record.
12. What the Result Does, and Does Not, Mean
The record describes a completed phase 1b dose-escalation study of CP-751,871 combined with docetaxel in advanced non-hematologic malignancies. It identifies MTD as the primary outcome and specifies the first-cycle assessment window and a safety analysis-set definition. It also records adverse-event counts across CP-751,871 dose groups and lists several secondary outcomes related to safety, pharmacokinetics, pharmacodynamics and tumor response.
The numeric MTD result is not reported in the registry record. Therefore, the posted information does not identify a particular dose as the MTD, nor does it show how precisely an MTD was estimated. The registry also does not report numeric results for the listed secondary outcomes, confidence intervals, p-values or detailed analysis methods. The fact that a study is marked completed does not resolve those gaps.
The adverse-event counts show that serious and other adverse events were recorded in the listed dose groups. They are descriptive, and the groups are not randomized comparator arms. The counts do not isolate the contribution of CP-751,871 from docetaxel or other factors, and they do not establish a dose-related pattern. The serious-event term percentages are listed without the denominator or dose distribution needed to interpret them as group-specific rates.
In general, an early-phase dose-escalation study can provide information about observed tolerability under its own protocol and observation window. It does not, by itself, establish comparative efficacy or show how a regimen performs against another treatment. This record’s stated outcomes include objective response and time to tumor progression, but their results are not reported in the registry record. No conclusion about treatment benefit or lack of benefit follows from the information reported.
The appropriate statistical reading is therefore limited: the record documents the design, outcome definitions and some adverse-event counts, but leaves the primary estimate and much of the analytic detail unreported. Interpretation beyond those descriptive details would require results and methods not reported in the registry record.
13. Why This Trial Matters Statistically
This study illustrates a common statistical distinction between dose-finding and treatment comparison. Its single-group, open-label dose-escalation design focuses on MTD over Cycle 1 Day 1 through Cycle 1 Day 21, rather than estimating a randomized difference against a control group. That distinction matters when interpreting both the dose groups and the adverse-event counts: different dose levels do not automatically constitute equivalent comparison arms.
The registry record identifies a primary safety-oriented endpoint and a defined analysis population, but does not report the MTD estimate or the size of the primary analysis set. This makes the boundary between a clearly specified endpoint and a usable result especially important. Naming an endpoint tells readers what the study intended to assess; a reported estimate and its uncertainty are needed to understand what was observed and how precisely it was assessed.
The list of secondary outcomes also shows why early-phase studies can collect several types of data. Safety events, drug clearance, maximum plasma concentration, circulating cell measures, tumor response and progression each address different questions. Statistical interpretation depends on keeping these outcomes distinct and knowing which analyses were planned and reported. The registry lists 45 outcome measures and 0 analyses, while detailed results and a multiplicity strategy are not reported in the registry record.
Finally, the adverse-event summaries demonstrate the limits of descriptive counts. They record events among groups of varying sizes, without a randomized comparator. Such counts can characterize what was recorded in the study, but do not by themselves establish causation or comparative safety. This trial is statistically informative as an example of the importance of design, endpoint definitions, analysis populations and complete result reporting in early-phase research.
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 principal limitation for interpreting the primary endpoint is that the numeric MTD result is not reported in the registry record. Although the endpoint unit, observation window and safety analysis-set definition are stated, the number analyzed and the operational MTD criteria are not. The dose-escalation rules and cohort decision procedures are also not reported in the registry record, limiting reconstruction of how the study arrived at any dose decision.
The single-group design has no randomized control group. Dose groups are not a like-for-like comparison, and their observed event counts cannot establish a causal effect of dose or separate the combination’s components. The registry’s adverse-event information lists group counts, but does not give event timing, duration, recurrence, attribution or detailed definitions for the other adverse-event category. The serious-event term percentages are listed without their denominator or dose-specific distribution. Death counts are not reported in the registry record.
The registry lists multiple secondary outcomes, but their results are not reported in the registry record. Statistical methods, uncertainty estimates, handling of missing data, multiplicity procedures, interim analyses and a detailed analysis plan are also not reported in the registry record. The analysis population excludes expansion-cohort participants, but its resulting size is not stated. Enrollment of 46 should not be substituted for the size of that primary analysis set.
These limitations mean that the record supports a description of the planned endpoint, study structure and recorded adverse-event counts, but not a detailed assessment of the primary estimate’s precision or the secondary outcome findings. No conclusions beyond those reported elements can be established from this registry information.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: CP-751,871 In Combination With Docetaxel In Advance Non-hematologic Malignancies — NCT01653158.
- Registry record last updated 2013-10-30; status last verified 2013-10.
- Results first posted 2013-08-27.
- 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
This completed phase 1b study evaluated escalating CP-751,871 doses combined with docetaxel in advanced non-hematologic malignancies. It was open-label, single-group and had no separate comparator. Enrollment was 46, with study dates recorded as 2005-03 to 2009-02.
The primary outcome was MTD in mg/kg over Cycle 1 Day 1 through Cycle 1 Day 21. The primary safety analysis set included enrolled participants who started treatment and excluded expansion-cohort participants. The numeric MTD result, size of that analysis set, and dose-escalation criteria are not reported in the registry record.
The registry lists 45 outcome measures and 0 analyses. Adverse-event counts are recorded by dose group; secondary outcomes include antibody response, objective response, time to tumor progression, circulating cell measures, and pharmacokinetic measures. Detailed results for those outcomes, missing-data methods and multiplicity procedures are not reported in the registry record.