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 A Study of Rebastinib (DCC-2036) in Combination With Carboplatin in Patients With Advanced or Metastatic Solid Tumors (NCT03717415), a randomized phase 1, phase 2 study. The primary outcome is Number of Participants With Adverse Events.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03717415 |
| Phase | Phase 1, Phase 2 |
| Condition | Locally Advanced or Metastatic Solid Tumor |
| Allocation | Randomized |
| Design model | Sequential |
| Masking | None (open label) |
| Enrollment | 70 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Deciphera Pharmaceuticals, LLC |
| Results posted | Yes |
2. Clinical Question
Population
The study enrolled participants with advanced or metastatic solid tumors. Expansion cohorts focused on triple-negative breast cancer, platinum-sensitive ovarian cancer, and mesothelioma. The primary outcome population was all participants who received any study drug.
Intervention
Participants received rebastinib with carboplatin. Rebastinib was given by mouth twice daily, with dose levels of 50 mg or 100 mg in the listed cohorts. Carboplatin was given by intravenous infusion on Day 1 of each 21-day cycle. The listed carboplatin levels were AUC5 or, in one dose-escalation cohort, AUC6.
Comparator
The registry describes rebastinib and carboplatin combination cohorts, not a separate untreated or active-control arm. It records randomized allocation, but the randomization procedure and the allocation comparisons are not reported in the registry record. Dose groups and tumor-specific cohorts should not automatically be read as randomized comparisons.
Primary question
The primary outcome counts participants who experienced serious adverse events and adverse events, from baseline up to 2.32 years. The question is descriptive: how many participants in each listed cohort had these events? The registry does not report a single comparative estimate of safety between the regimens or a statistical test for the primary outcome.
3. Trial Design
This was an open-label, multicenter Phase 1b/2 study of rebastinib combined with carboplatin in participants with advanced or metastatic solid tumors. The registry lists randomized allocation, no masking, and a sequential model. Details of how allocation was randomized, what was randomized, and how the sequence of study parts was governed are not reported in the registry record.
The study included dose escalation and dose expansion. In the escalation cohorts, rebastinib was listed at 50 mg with carboplatin AUC5, 100 mg with carboplatin AUC5, or 100 mg with carboplatin AUC6. Expansion cohorts covered triple-negative breast cancer, platinum-sensitive ovarian cancer, and mesothelioma. Within each tumor-specific expansion, the listed rebastinib doses were 50 mg and 100 mg, each combined with carboplatin AUC5. Regimens were administered in 21-day cycles, with carboplatin on Day 1.
The registry records enrollment of 70 and a status of terminated. The study started on 2019-01-02, and the primary completion date is recorded as 2022-05-01. The reason for termination, the number completing treatment or follow-up, and the timing of termination are not reported in the registry record.
The stated purpose was to assess safety, tolerability, and pharmacokinetics. Secondary outcomes also included objective response rate in dose escalation, duration of response, time to progression, progression-free survival, overall survival, and pharmacokinetic measures. No comparator-specific efficacy conclusions can be drawn from those outcome names alone.
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 9 groups are shown.
Overall Study
| Stage | Part 1 Cohort 1 Escalation Rebastinib 50 mg + Carboplatin AUC5 | Part 1 Cohort 2 Escalation Rebastinib 100 mg + Carboplatin AUC5 | Part 1 Cohort 3 Escalation Rebastinib 100 mg + Carboplatin AUC6 | Part 2 Cohort 1 Expansion Rebastinib 50 mg + Carboplatin AUC5 | Part 2 Cohort 1 Expansion Rebastinib 100 mg + Carboplatin AUC5 | Part 2 Cohort 2 Expansion Rebastinib 50 mg + Carboplatin AUC5 |
|---|---|---|---|---|---|---|
| STARTED | 3 | 14 | 5 | 9 | 2 | 18 |
| mITT Population | 3 | 12 | 5 | 9 | 2 | 18 |
| COMPLETED | 3 | 7 | 0 | 4 | 0 | 12 |
| NOT COMPLETED | 0 | 7 | 5 | 5 | 2 | 6 |
Analysis population for the primary outcome, as defined in the registry: All participants who received any study drug.
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.
Only the first 6 of 10 groups are shown.
| Characteristic | Unit | Part 1 Cohort 1 Escalation Rebastinib 50 mg + Carboplatin AUC5 | Part 1 Cohort 2 Escalation Rebastinib 100 mg + Carboplatin AUC5 | Part 1 Cohort 3 Escalation Rebastinib 100 mg + Carboplatin AUC6 | Part 2 Cohort 1 Expansion Rebastinib 50 mg + Carboplatin AUC5 | Part 2 Cohort 1 Expansion Rebastinib 100 mg + Carboplatin AUC5 | Part 2 Cohort 2 Expansion Rebastinib 50 mg + Carboplatin AUC5 |
|---|---|---|---|---|---|---|---|
| Participants analysed | 3 | 14 | 5 | 9 | 2 | 18 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 3 | 9 | 4 | 7 | 2 | 9 |
| Age, Categorical: >=65 years | Participants | 0 | 5 | 1 | 2 | 0 | 9 |
| Sex: Female, Male: Female | Participants | 3 | 8 | 4 | 9 | 2 | 18 |
| Sex: Female, Male: Male | Participants | 0 | 6 | 1 | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 2 | 2 | 0 | 0 | 1 | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 1 | 11 | 5 | 9 | 1 | 18 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 1 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 0 | 0 | 1 | 0 | 1 |
| Race (NIH/OMB): White | Participants | 3 | 13 | 5 | 8 | 1 | 17 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 1 | 0 | 0 | 1 | 0 |
| Region of Enrollment: United States | participants | 3 | 14 | 5 | 9 | 2 | 18 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Adverse Events, measured over Baseline up to 2.32 years.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary outcome is the number of participants who experienced serious adverse events and adverse events. It applies to all participants who received any study drug, and its observation period is listed as baseline up to 2.32 years. Results are presented as counts of participants with events within each cohort.
A participant count is a descriptive measure of how many people in a defined group had at least one event meeting the outcome definition. It is not a count of all event episodes, and it does not indicate how many times an event occurred in an individual. The registry description does not give event-level detail, severity grading beyond the serious-event distinction, or a separate definition of which events were included as adverse events.
Safety outcomes are appropriate in a study designed to assess safety and tolerability, particularly across dose levels and tumor-specific cohorts. The counts can show whether adverse events were reported among treated participants. Interpreting them comparatively requires caution: the cohorts differ in dose and cancer type, and some are small. Counts alone do not adjust for differences in follow-up, exposure to treatment, or participant characteristics.
The registry presents the primary measure as a count rather than a comparative effect estimate. It does not report a statistical test, confidence interval, adjusted analysis, or a prespecified threshold for interpreting the number of events. The primary outcome therefore describes reported safety events; it does not by itself establish a causal difference between regimens.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary results are organized by treatment cohort. Serious adverse events were reported in every listed cohort except the Part 2 expansion cohorts using rebastinib 100 mg with carboplatin AUC5 in triple-negative breast cancer and platinum-sensitive ovarian cancer, where the reported counts were 0 of 2 in each cohort. The other reported serious-event counts were 2 of 3 in Part 1 Cohort 1; 4 of 14 in Part 1 Cohort 2; 1 of 5 in Part 1 Cohort 3; 5 of 9 in Part 2 Cohort 1 at 50 mg; 6 of 18 in Part 2 Cohort 2 at 50 mg; 2 of 6 in Part 2 Cohort 3 at 50 mg; and 6 of 11 in Part 2 Cohort 3 at 100 mg. These are cohort-specific counts, not an adjusted comparison.
The registry also reports participants with adverse events other than the serious-event count. Those counts were 3 of 3 in Part 1 Cohort 1, 13 of 14 in Part 1 Cohort 2, 5 of 5 in Part 1 Cohort 3, 9 of 9 in Part 2 Cohort 1 at 50 mg, 2 of 2 in Part 2 Cohort 1 at 100 mg, 18 of 18 in Part 2 Cohort 2 at 50 mg, 2 of 2 in Part 2 Cohort 2 at 100 mg, 6 of 6 in Part 2 Cohort 3 at 50 mg, and 11 of 11 in Part 2 Cohort 3 at 100 mg. The record does not provide a statistical comparison of these counts.
Small cohort sizes mean that an individual participant represents a substantial part of a cohort's reported count. A count of 0 in a small cohort does not establish that the event cannot occur, while counts in other cohorts do not show that the regimen caused the events. The cohorts differ by dose and cancer type, and the record does not describe adjustments that would make them directly comparable.
The listed serious-event terms include retinal vascular disorder, small intestinal obstruction, malignant pleural effusion, death, cardiac failure, and pericardial effusion, with reported percentages of 33.3%, 33.3%, 33.3%, 20.0%, 11.1%, and 11.1%, respectively. The denominator and method used for these percentages are not reported in the registry record, so the percentages should not be translated into participant counts or interpreted as comparative risks.
Death counts are reported in the Part 1 Cohort 3 and Part 2 Cohort 3 at 100 mg cohorts. The registry does not report whether these deaths were considered treatment-related. The outcome data do not support a conclusion about comparative efficacy or a treatment effect.
9. Statistical Methods Explained
What does a participant count represent?
A count records the number of participants meeting an event definition during the stated observation period. For this primary outcome, the registry identifies participants with serious adverse events and adverse events, rather than the total number of event episodes. If one participant experienced multiple events, a participant-level count would not convey that event frequency. The registry does not provide enough detail to determine the handling of repeated events or the exact event-coding rules.
Counts are easiest to interpret alongside the number of participants at risk in the same cohort. The cohort-specific reporting includes both the count with an event and the cohort size used for that outcome. A count on its own can be misleading: the same count can represent different proportions in groups of different sizes. No overall event proportion or pooled estimate is reported in the registry record, and pooling these cohorts would require a clear rationale because their tumor types and dose groups differ.
Why is a comparative estimate not available?
A comparative analysis needs a defined contrast, such as an outcome difference between prespecified groups, and a method for accounting for uncertainty. Although randomized allocation is recorded, the registry does not describe the allocation procedure or identify a control regimen for the primary safety outcome. The posted results give cohort-level counts and record 0 analyses. They do not provide an effect estimate, confidence interval, or test of a difference.
In general, a confidence interval describes the range of values reasonably compatible with the data under a specified statistical model. It is useful because a point estimate alone does not show its precision. No confidence interval for the primary outcome is reported in the registry record. With small groups, estimates based on event counts can be imprecise; the observed count should not be mistaken for a precise estimate of an underlying event frequency.
Why does cohort structure matter?
The escalation and expansion groups are not interchangeable. The dose-escalation part includes different rebastinib and carboplatin dose combinations. The expansion part separates participants by cancer type and includes two rebastinib doses within each listed disease cohort. Differences in the observed counts could reflect dose, tumor type, treatment exposure, follow-up, or participant characteristics. The registry record does not report an analysis that separates these influences.
In general, over-dispersion occurs when outcomes vary more across groups than a simple statistical model expects. It can arise when participants or cohorts differ in ways the model does not capture. Such variation can make standard errors too small if ignored. This is a general consideration for clustered or heterogeneous data, not a finding reported for this study; the registry does not report a model for over-dispersion or clustering.
What do the planning illustrations mean?
The study's planning illustration is described as a recalculation based on the observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Its effect to detect is a stated fraction of the observed effect. These are planning assumptions, not a description of the original trial's design. For non-time-to-event outcomes, the stated planning quantity is participants per arm for 80% power or another specified power level; for time-to-event outcomes, the stated quantity is the total number of events.
Sample-size illustrations are hypothetical calculations under their assumptions. They do not show that the trial had a particular probability of detecting an effect, and they are not observed power. The original sample-size justification, its assumptions, and whether the study used these methods are not reported in the registry record. A planning calculation based on an observed effect can be especially sensitive to the observed estimate, which may be unstable in small cohorts. It should not be treated as confirmation that a future study will reproduce that effect.
Which statistical details are absent?
The registry does not report a statistical analysis plan for the primary safety outcome, a model or test, an adjustment strategy, or confidence intervals. It does not report interim-analysis methods or explain how any planned analyses were changed after the study was terminated. The purpose and precise interpretation of the recorded randomized allocation are also not described sufficiently to reconstruct an inferential comparison. Consequently, the available outcome data support descriptive reading of the cohort counts, not a formal test of regimen differences.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists multiple outcomes, including safety, response, duration of response, time to progression, progression-free survival, overall survival, and pharmacokinetic measures. Considering several outcomes can increase the chance of a false-positive finding if many statistical tests are performed without an appropriate plan. In general, multiplicity methods may control that risk by defining a primary comparison or adjusting interpretation across tests. The registry record does not report a multiplicity strategy, a hierarchy of hypotheses beyond identifying the primary outcome, or statistical analyses for the listed outcomes.
The primary outcome is presented as cohort-level counts, and the record lists 0 analyses. No inferential test or confidence interval is available to evaluate evidence across cohorts. The reason that the primary outcome was not reduced to a single comparison is not reported in the registry record.
The primary outcome population includes all participants who received any study drug. The registry does not report details about missing outcome data, participants without complete follow-up, exclusions from the safety population, or how missingness was handled. It also does not describe the analysis population used for each secondary outcome. These omissions limit assessment of whether follow-up and outcome ascertainment were consistent across cohorts.
In general, missing data can affect interpretation when the chance of missingness is related to health status, treatment exposure, or the event being measured. The direction and size of that effect cannot be determined without information about missingness and the analysis approach. No assumptions for handling missing observations are reported in 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 |
|---|---|---|---|
| Part 1 Cohort 1 Escalation Rebastinib 50 mg + Carboplatin AUC5 | 2 | 3 | 66.7% |
| Part 1 Cohort 2 Escalation Rebastinib 100 mg + Carboplatin AUC5 | 4 | 14 | 28.6% |
| Part 1 Cohort 3 Escalation Rebastinib 100 mg + Carboplatin AUC6 | 1 | 5 | 20.0% |
| Part 2 Cohort 1 Expansion Rebastinib 50 mg + Carboplatin AUC5 | 5 | 9 | 55.6% |
| Part 2 Cohort 1 Expansion Rebastinib 100 mg + Carboplatin AUC5 | 0 | 2 | 0.0% |
| Part 2 Cohort 2 Expansion Rebastinib 50 mg + Carboplatin AUC5 | 6 | 18 | 33.3% |
| Part 2 Cohort 2 Expansion Rebastinib 100 mg + Carboplatin AUC5 | 0 | 2 | 0.0% |
| Part 2 Cohort 3 Expansion Rebastinib 50 mg + Carboplatin AUC5 | 2 | 6 | 33.3% |
| Part 2 Cohort 3 Expansion Rebastinib 100 mg + Carboplatin AUC5 | 6 | 11 | 54.5% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Part 1 Cohort 1 Escalation Rebastinib 50 mg + Carboplatin AUC5 | 0 of 3 |
| Part 1 Cohort 2 Escalation Rebastinib 100 mg + Carboplatin AUC5 | 0 of 14 |
| Part 1 Cohort 3 Escalation Rebastinib 100 mg + Carboplatin AUC6 | 1 of 5 |
| Part 2 Cohort 1 Expansion Rebastinib 50 mg + Carboplatin AUC5 | 0 of 9 |
| Part 2 Cohort 1 Expansion Rebastinib 100 mg + Carboplatin AUC5 | 0 of 2 |
| Part 2 Cohort 2 Expansion Rebastinib 50 mg + Carboplatin AUC5 | 0 of 18 |
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 |
|---|---|
| Part 1 Cohort 1 Escalation Rebastinib 50 mg + Carboplatin AUC5 | 3 of 3 |
| Part 1 Cohort 2 Escalation Rebastinib 100 mg + Carboplatin AUC5 | 13 of 14 |
| Part 1 Cohort 3 Escalation Rebastinib 100 mg + Carboplatin AUC6 | 5 of 5 |
| Part 2 Cohort 1 Expansion Rebastinib 50 mg + Carboplatin AUC5 | 9 of 9 |
| Part 2 Cohort 1 Expansion Rebastinib 100 mg + Carboplatin AUC5 | 2 of 2 |
| Part 2 Cohort 2 Expansion Rebastinib 50 mg + Carboplatin AUC5 | 18 of 18 |
Most frequent serious adverse event terms
| Event term | Organ system | Part 1 Cohort 1 Escalation Rebastinib 50 mg + Carboplatin AUC5 | Part 1 Cohort 2 Escalation Rebastinib 100 mg + Carboplatin AUC5 | Part 1 Cohort 3 Escalation Rebastinib 100 mg + Carboplatin AUC6 | Part 2 Cohort 1 Expansion Rebastinib 50 mg + Carboplatin AUC5 | Part 2 Cohort 1 Expansion Rebastinib 100 mg + Carboplatin AUC5 | Part 2 Cohort 2 Expansion Rebastinib 50 mg + Carboplatin AUC5 |
|---|---|---|---|---|---|---|---|
| Small intestinal obstruction | Gastrointestinal disorders | 0 of 3 | 1 of 14 | 0 of 5 | 0 of 9 | 0 of 2 | 2 of 18 |
| Pleural effusion | Respiratory, thoracic and mediastinal disorders | 0 of 3 | 1 of 14 | 0 of 5 | 1 of 9 | 0 of 2 | 1 of 18 |
| Malignant pleural effusion | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 1 of 3 | 1 of 14 | 0 of 5 | 0 of 9 | 0 of 2 | 0 of 18 |
| Cardiac failure | Cardiac disorders | 0 of 3 | 0 of 14 | 0 of 5 | 1 of 9 | 0 of 2 | 0 of 18 |
| Myocardial infarction | Cardiac disorders | 0 of 3 | 0 of 14 | 0 of 5 | 0 of 9 | 0 of 2 | 1 of 18 |
| Pericardial effusion | Cardiac disorders | 0 of 3 | 0 of 14 | 0 of 5 | 1 of 9 | 0 of 2 | 0 of 18 |
| Retinal vascular disorder | Eye disorders | 1 of 3 | 0 of 14 | 0 of 5 | 0 of 9 | 0 of 2 | 0 of 18 |
| Constipation | Gastrointestinal disorders | 0 of 3 | 1 of 14 | 0 of 5 | 0 of 9 | 0 of 2 | 0 of 18 |
| Gastric stenosis | Gastrointestinal disorders | 0 of 3 | 0 of 14 | 0 of 5 | 0 of 9 | 0 of 2 | 1 of 18 |
| Nausea | Gastrointestinal disorders | 0 of 3 | 0 of 14 | 0 of 5 | 1 of 9 | 0 of 2 | 0 of 18 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Part 1 Cohort 1 Escalation Rebastinib 50 mg + Carboplatin AUC5 | Part 1 Cohort 2 Escalation Rebastinib 100 mg + Carboplatin AUC5 | Part 1 Cohort 3 Escalation Rebastinib 100 mg + Carboplatin AUC6 | Part 2 Cohort 1 Expansion Rebastinib 50 mg + Carboplatin AUC5 | Part 2 Cohort 1 Expansion Rebastinib 100 mg + Carboplatin AUC5 | Part 2 Cohort 2 Expansion Rebastinib 50 mg + Carboplatin AUC5 |
|---|---|---|---|---|---|---|---|
| Fatigue | General disorders | 1 of 3 | 3 of 14 | 2 of 5 | 6 of 9 | 0 of 2 | 11 of 18 |
| Constipation | Gastrointestinal disorders | 0 of 3 | 5 of 14 | 1 of 5 | 1 of 9 | 1 of 2 | 9 of 18 |
| Nausea | Gastrointestinal disorders | 0 of 3 | 3 of 14 | 2 of 5 | 1 of 9 | 0 of 2 | 7 of 18 |
| Platelet count decreased | Investigations | 0 of 3 | 1 of 14 | 1 of 5 | 1 of 9 | 0 of 2 | 9 of 18 |
| Thrombocytopenia | Blood and lymphatic system disorders | 1 of 3 | 5 of 14 | 2 of 5 | 1 of 9 | 0 of 2 | 1 of 18 |
| Dry mouth | Gastrointestinal disorders | 0 of 3 | 1 of 14 | 1 of 5 | 1 of 9 | 1 of 2 | 6 of 18 |
| Vomiting | Gastrointestinal disorders | 0 of 3 | 1 of 14 | 1 of 5 | 0 of 9 | 0 of 2 | 7 of 18 |
| Intraocular pressure increased | Investigations | 0 of 3 | 2 of 14 | 0 of 5 | 1 of 9 | 0 of 2 | 6 of 18 |
| Dyspnoea | Respiratory, thoracic and mediastinal disorders | 1 of 3 | 1 of 14 | 0 of 5 | 1 of 9 | 1 of 2 | 5 of 18 |
| Anaemia | Blood and lymphatic system disorders | 1 of 3 | 3 of 14 | 0 of 5 | 1 of 9 | 0 of 2 | 3 of 18 |
Serious events with the highest arm-level rate: retinal vascular disorder (33.3%), small intestinal obstruction (33.3%), malignant pleural effusion (33.3%), death (20.0%), cardiac failure (11.1%).
Each safety count is specific to a cohort and distinguishes participants with serious adverse events from participants with adverse events. Read the count together with its cohort size, dose combination, and tumor-specific group. The counts do not represent event episodes or establish that an event was caused by study treatment.
The reported serious-event counts range across cohorts, including 0 of 2 in two expansion cohorts and 6 of 11 in the Part 2 Cohort 3 expansion at rebastinib 100 mg with carboplatin AUC5. These figures describe the participants recorded in those groups. The small group sizes make the counts sensitive to the outcomes of individual participants, and they do not supply a precise estimate of risk for a broader population.
For the serious-event terms, the registry lists percentages for retinal vascular disorder, small intestinal obstruction, malignant pleural effusion, death, cardiac failure, and pericardial effusion. The record does not report the denominator or clarify whether the listed percentages refer to participants, event reports, or another basis. Do not interpret these percentages as directly comparable cohort rates.
The recorded deaths are not identified as treatment-related or unrelated in the registry record. The listed safety results therefore describe reported events, without establishing causation or comparative safety.
12. What the Result Does, and Does Not, Mean
The results show that adverse events were reported in the treated cohorts, with cohort-specific counts for serious adverse events and other adverse events. They also show that the number of participants with serious events varied across the dose-escalation and expansion groups. These observations are descriptive and apply to the participants represented in the registry results.
They do not establish that rebastinib with carboplatin caused a particular event, nor do they identify which dose or tumor-specific group has the lower underlying risk. The groups differ in both treatment details and cancer type, and the registry does not report an adjusted comparison. A zero count in a small cohort cannot demonstrate absence of risk, just as a larger count in another cohort does not by itself demonstrate a treatment effect.
The record's randomized-allocation label does not, on its own, establish that the posted cohorts form a valid randomized comparison. The randomization procedure, comparison groups, and analysis of allocation are not reported in the registry record. Without these details and an inferential analysis, the counts should not be interpreted as evidence that one regimen is safer than another.
The study's stated aims included safety, tolerability, and pharmacokinetics, and the registry lists additional response and survival outcomes. Outcome names alone do not provide results. The registry entries do not support conclusions about efficacy, survival benefit, or the magnitude of a treatment effect. The record also does not explain why the study was terminated, so termination should not be taken as evidence about safety or efficacy.
The appropriate interpretation is limited: the registry records adverse-event counts across the listed cohorts during the stated observation period. Generalization beyond those cohorts, causal attribution, and comparative conclusions require methods and details that are not reported in the registry record.
13. Why This Trial Matters Statistically
This trial is statistically instructive because its results combine dose escalation with tumor-specific expansion cohorts. The same drug combination appears at different doses, and the expansion groups also differ by cancer type. This structure makes it important to keep each count attached to its cohort rather than treating all participants as one homogeneous group.
The primary outcome is a count of participants with adverse events, an accessible summary that can describe the observed safety experience. But a count has limits: it does not express precision, account for follow-up differences, distinguish all event episodes, or establish causation. Interpretation depends on the event definition, observation period, population, and denominator.
The registry records randomized allocation, yet reports no inferential analyses and does not explain how randomization relates to the listed cohorts. This illustrates why a design label is not a substitute for details about the actual comparison and analysis. Without those details, the posted safety results remain descriptive.
The record also highlights the difference between statistical planning and observed evidence. Planning illustrations based on an observed effect can help explore assumptions for future research, but they are not observed power and do not repair limitations in a small or heterogeneous set of cohorts. The registry does not report the original sample-size justification or a statistical analysis plan.
For clinical researchers and biostatisticians, the central lesson is to separate what the registry documents from what a statistical comparison would require. Cohort-specific safety counts are useful information, but their meaning depends on the design, follow-up, analysis population, and uncertainty—all of which need to be reported clearly for stronger conclusions.
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 study status is recorded as terminated, but the reason for termination and its timing are not reported in the registry record. Without that context, termination cannot be connected to the safety counts, treatment activity, recruitment, or operational considerations.
The cohort sizes are small, and the groups differ in dose and tumor type. The registry does not provide an analysis adjusting for these differences or establishing that the groups are directly comparable. While randomized allocation is recorded, the randomization procedure and its relationship to the reported cohorts are not described.
The primary outcome description combines serious adverse events and adverse events, while results present separate counts. The registry does not provide detailed event definitions, severity grading, event-level records, treatment relatedness, or information about repeated events. The denominator for the percentages reported for serious-event terms is also not reported.
Follow-up is stated as baseline up to 2.32 years, but cohort-specific exposure and follow-up distributions are not reported. Nor are missing outcome data, losses to follow-up, or the handling of incomplete observation described. These gaps make it difficult to judge whether the cohorts had comparable opportunity for events to be detected.
No statistical analysis of the primary outcome is listed, and the record does not report confidence intervals, tests, or an adjustment approach. The reason for the recorded absence of analyses is not reported in the registry record. The registry also does not report the original sample-size justification, interim analyses, or statistical plan. These limitations constrain interpretation to descriptive cohort-level reporting.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Study of Rebastinib (DCC-2036) in Combination With Carboplatin in Patients With Advanced or Metastatic Solid Tumors — NCT03717415.
- Registry record last updated 2024-12-27; status last verified 2024-12.
- Results first posted 2024-12-27.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT03717415 is an open-label, multicenter Phase 1b/2 study of rebastinib with carboplatin in advanced or metastatic solid tumors. The registry records randomized allocation, no masking, a sequential model, enrollment of 70, and a terminated status. Dose escalation and tumor-specific expansion cohorts used the listed rebastinib and carboplatin regimens.
The primary outcome counts participants with serious adverse events and adverse events from baseline up to 2.32 years among participants who received any study drug. Results are given by cohort; the registry lists 0 analyses. Secondary outcomes include response, time-to-event, survival, and pharmacokinetic measures. The available safety counts are descriptive and do not establish causation or comparative effects. The reason for termination and key details of the statistical analysis are not reported in the registry record.