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 Pilot Study of Veliparib (ABT-888) and Lapatinib (Tykerb) in Patients With Metastatic, Triple Negative Breast Cancer (NCT02158507), a na na study. The primary outcome is Number of Subjects Experiencing Study-related Toxicities When Taking Veliparib in Combination With Lapatinib.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02158507 |
| Phase | NA |
| Condition | Metastatic Triple Negative Breast Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 20 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Alabama at Birmingham |
| Results posted | Yes |
2. Clinical Question
The registry describes a pilot study of veliparib and lapatinib in people with metastatic triple-negative breast cancer who had undergone previous treatment. It asks a safety-focused question: how many participants experienced study-related toxicities while taking the combination, from baseline to 4 years? The record also lists secondary questions about objective response, progression-free survival, biological markers, circulating tumor cells, and drug concentration.
Population
Participants with metastatic triple-negative breast cancer after previous treatment. The registry lists an enrollment of 20. The adverse-event record separately reports 17 participants at risk for the listed events.
Intervention
Veliparib in combination with lapatinib. The arm description gives lapatinib as a tablet at 1250 mg/day continuously for 28 days from Day 1 of each cycle, and veliparib as a capsule at 200 mg every 12 hours for 28 days from Day 2.
Comparator
There is no comparator arm described. The study is listed as single-group, with allocation and masking recorded as NA and none, respectively. All eligible participants were to receive the study medications rather than placebo.
Primary question
How many participants had toxicity meeting the study’s safety definition during the stated baseline-to-4-years timeframe? The definition uses specified severe toxicities, delayed recovery, and blood-count-related criteria. The primary endpoint result is not reported in the registry record.
The key interpretive distinction is between the question the study set out to assess and the results available in the registry. The endpoint is defined, and adverse-event counts are recorded, but the record does not give the number who met the primary endpoint’s specific toxicity definition. Nor does it report numerical results for the listed secondary questions. Consequently, the record supports a description of the design and the posted safety counts, but not a conclusion about the combination’s effectiveness or a comparison with another treatment.
3. Trial Design
This was an open-label, single-group pilot study sponsored by the University of Alabama at Birmingham. The registry lists the phase as NA, allocation as NA, and masking as none. It records enrollment of 20 and status as completed. The listed start date is 2014-09-04 and primary completion date is 2021-07-22. No comparator arm is described; therefore, the study does not provide a randomized or concurrent control comparison.
The intervention was the combination of veliparib and lapatinib. The arm description states that lapatinib was to be given as a tablet at 1250 mg/day continuously for 28 days starting on Day 1 of each cycle. Veliparib was to be given as a capsule at 200 mg every 12 hours for 28 days starting on Day 2. A cycle was defined as 28 days. The remaining arm-description text is incomplete in the registry record, so further treatment details are not reported there.
The study summary says the combination was to be evaluated for effectiveness and safety in participants with metastatic triple-negative breast cancer after previous treatment. It describes veliparib as investigational and lapatinib as approved for another type of breast cancer. These statements describe the study’s rationale and context, not evidence of benefit from this trial.
The primary outcome is a count of participants experiencing study-related toxicities, with a stated timeframe from baseline to 4 years. Secondary outcomes include counts related to objective response and progression-free survival at 4 years, comparisons of DNA methylation and RNA transcriptome patterns before and after therapy, circulating tumor-cell measurements, and peak plasma concentrations of the drugs. The registry lists six outcome measures, but numerical findings for these outcomes are not reported in the registry record.
Because all participants received the combination and there is no control group, changes over time or observed events cannot be separated from other influences using a between-group comparison. The record does not report a statistical analysis plan, a sample-size justification, or interim analyses.
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 | Combination of Veliparib + Lapatinib |
|---|---|
| STARTED | 20 |
| COMPLETED | 20 |
| 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 | Combination of Veliparib + Lapatinib |
|---|---|---|
| Participants analysed | 20 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 20 |
| Age, Categorical: >=65 years | Participants | 0 |
| Age, Continuous | years | 50 (37 to 63) |
| Sex: Female, Male: Female | Participants | 20 |
| Sex: Female, Male: Male | Participants | 0 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 1 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 19 |
| 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 | 9 |
| Race (NIH/OMB): White | Participants | 11 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 20 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Subjects Experiencing Study-related Toxicities When Taking Veliparib in Combination With Lapatinib, measured over baseline to 4 years.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | count of participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants experiencing study-related toxicities while taking veliparib with lapatinib. Its stated timeframe is baseline to 4 years. The registry defines qualifying toxicity using several criteria: grade 3 or 4 non-hematologic toxicity, with stated exceptions; failure to recover to baseline after delaying the next dose by more than 14 days; specified severe neutropenia; or specified severe thrombocytopenia. Toxicity evaluation was to use the NCI Common Toxicity Criteria.
A toxicity endpoint is used to capture harms that meet a prespecified clinical severity or treatment-management threshold, rather than simply counting every symptom or laboratory change as equivalent. In general, defining the endpoint in advance makes clear which events contribute to the outcome and supports consistent assessment. The registry definition includes both toxicity grades and consequences such as delayed dosing or complications.
The endpoint is a participant count, not a comparison of treatment groups or a measure of how often each person experienced an event. The registry record does not report the observed count meeting this specific definition. The separate adverse-event figures list serious and other adverse events, but those categories cannot be assumed to match the primary endpoint’s qualifying-toxicity definition. The record therefore does not establish how many participants met the primary endpoint.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The study’s design and the registry’s posted results need to be read separately. The design is a completed, open-label, single-group pilot study of veliparib plus lapatinib. The registry lists an enrollment of 20, but the adverse-event figures use 17 participants at risk. These figures have different roles in the record and should not be treated as interchangeable denominators.
For the adverse-event group, the registry reports 0 participants affected by serious adverse events among 17 at risk. It reports 17 participants affected by other adverse events among 17 at risk. The registry also reports 0 deaths in this group. These are counts in the posted adverse-event record. They do not, by themselves, show how many participants met the primary endpoint’s detailed definition of study-related toxicity. The term “other adverse events” should not be read as synonymous with the endpoint’s qualifying toxicities.
The primary endpoint is explicitly defined as a count of participants with study-related toxicities from baseline to 4 years. However, its observed result is not reported in the registry record. The record also names secondary outcomes, including objective response and progression-free survival, without giving their numerical findings in the registry record for this analysis. No effect estimate, confidence interval, or p-value for these outcomes is reported. The registry lists no analysis entries.
In general, a confidence interval communicates the range of effect values compatible with a statistical analysis and indicates the precision of an estimate. No confidence interval for this study’s primary endpoint or secondary outcomes is reported in the registry record, so their precision cannot be assessed from the available information. Likewise, the absence of a reported hypothesis test means there is no p-value to interpret.
There is no concurrent comparison group. As a result, these records cannot establish how the posted counts differ from what would have occurred under another treatment or without the study combination. The single-group design can describe events recorded among participants who received the combination, but it does not isolate a treatment effect from other explanations. The study’s pilot designation also does not itself establish the strength or direction of any effect.
Accordingly, the registry supports a limited descriptive reading: it records the study design and the adverse-event counts above, while leaving the primary endpoint result and numerical efficacy outcomes unreported. This is not evidence that qualifying toxicity did or did not occur, and it is not a basis for claiming that the combination is effective or ineffective. The missing endpoint-specific result and lack of a comparison arm constrain the conclusions that can be drawn.
9. Statistical Methods Explained
The statistical information in the registry is sparse. It identifies a single-group design and a count-based primary endpoint but does not report an analysis plan or statistical results for that endpoint. The following concepts explain how such information is generally interpreted; they do not imply that a particular unreported method was used in this study.
What does a single-group design allow?
In a single-group study, participants receive the same study intervention and outcomes are described within that group. This can document events and outcomes observed during the study. Without a comparator group, however, it cannot directly estimate a difference between the combination and another treatment or control condition. Observed changes may also reflect factors other than the intervention. This is a design limitation, not a defect that can be corrected by a more elaborate description of the same group.
The registry records allocation as NA and masking as none. It does not describe random allocation or blinding. Open-label assessment can be relevant to the interpretation of outcomes, especially when identifying or grading events involves judgment. The registry does not state how the study addressed possible assessment differences, so further safeguards are not reported in the registry record.
What does a participant count represent?
The primary endpoint is a count of participants who experienced toxicity meeting the stated criteria. A count is descriptive: it tells how many participants were recorded as meeting a definition. It is not a treatment-effect estimate on its own. Interpretation also depends on the relevant denominator, event definition, observation period, and completeness of outcome assessment. The registry specifies the endpoint timeframe and definition but does not report the primary endpoint count or its analysis population.
The separate adverse-event record gives participants at risk and participants affected for serious and other events. Those figures describe the recorded adverse-event categories. They do not supply a crosswalk between those categories and the primary endpoint criteria. In general, an adverse-event category and a study-specific endpoint can overlap without being identical; the record does not establish that they are equivalent.
Why does uncertainty matter?
In general, a point estimate describes a result calculated from observed data, while a confidence interval expresses uncertainty around that estimate under the assumptions of the analysis. Wider intervals generally indicate less precision, and narrower intervals more precision. An interval does not resolve limitations such as lack of a comparator or incomplete outcome reporting. No primary endpoint estimate or confidence interval is reported in the registry record, so it is not possible to characterize the statistical precision of that outcome.
A p-value, in general, summarizes how unusual data would be under a specified null model and assumptions. It does not measure the probability that a treatment works, and it does not communicate the size or clinical importance of an effect. No p-value or other inferential analysis for the outcomes is reported in the registry record. There is therefore no hypothesis-test result to interpret.
How should planning illustrations be read?
General sample-size calculations ask how many participants might be needed under stated assumptions to detect a specified effect with a chosen error rate and power. The registry’s planning assumptions describe a hypothetical two-arm calculation, with equal allocation, a two-sided significance level of 0.05, a normal approximation, and effect sizes expressed as fractions of an observed effect. These are planning illustrations, not the design used in this single-group study. They do not represent observed power and cannot be read as evidence about the precision or success of this trial. The registry record does not report the study’s own sample-size justification.
For time-to-event outcomes, planning can be based on the number of events rather than simply the number of participants; the registry’s planning note distinguishes that approach from participant-per-arm calculations for other outcomes. In general, event-driven planning depends on assumptions about event occurrence and follow-up. The record does not provide enough study-specific planning details to evaluate such assumptions or to infer that a planned event target was reached.
What does the absence of analysis entries imply?
The registry lists no analysis entries. This means no statistical analysis results are available in the registry record; it does not establish why results are absent or whether analyses were conducted outside the record. No adjusted model, subgroup analysis, interim analysis, or sensitivity analysis is described. Those methods should not be inferred from the outcome list or the design.
In general, any recalculation from posted summary statistics would be an unadjusted analysis and could differ from a sponsor’s own analysis. No such recalculated treatment comparison is relevant to the registry entries because a comparator and endpoint-specific result are not reported. A statistical method cannot recover an unreported outcome or remove the limitations of the single-group design.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary outcome and several secondary outcomes. When multiple outcomes are assessed, general statistical practice considers whether the analysis plan accounts for the chance of false-positive findings across repeated tests. The registry record does not report a multiplicity strategy, such as an adjustment procedure or a hierarchy for interpreting outcomes. It also does not report outcome-level hypothesis tests or p-values, so the implications of multiple testing cannot be evaluated from numerical results.
Missing-data methods are not reported in the registry record. The posted information does not explain whether outcome data were incomplete, how missing observations were handled, or whether any sensitivity analyses assessed their effect. The enrollment figure and the adverse-event denominator do not, by themselves, explain the difference between those counts; reasons are not reported in the registry record. No assumptions about withdrawal, follow-up completion, or missing outcomes should be inferred.
The registry does not identify analysis populations, such as an intention-to-treat or per-protocol population, for the primary endpoint. It also does not state how participants who did not complete treatment or follow-up were handled. The adverse-event group reports 17 participants at risk, but that figure does not establish the population used for the primary toxicity endpoint.
In general, these details matter because results can depend on which participants are included, how missing observations are treated, and how multiple outcomes are interpreted. With no endpoint-specific analysis result, missing-data description, or analysis-population definition, the registry record does not support assessment of these choices.
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 |
|---|---|---|---|
| Combination of Veliparib + Lapatinib | 0 | 17 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Combination of Veliparib + Lapatinib | 0 of 17 |
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 |
|---|---|
| Combination of Veliparib + Lapatinib | 17 of 17 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Combination of Veliparib + Lapatinib |
|---|---|---|
| fatigue | Nervous system disorders | 17 of 17 |
| diarrhea | Gastrointestinal disorders | 17 of 17 |
The adverse-event record lists one group, the combination of veliparib and lapatinib. It reports 17 participants at risk for serious adverse events and 0 affected. For other adverse events, it reports 17 at risk and 17 affected. Deaths are recorded as 0. These are the posted counts; they are not a comparison with another group.
The serious-adverse-event count is distinct from the primary endpoint. The primary endpoint uses a specific study-related toxicity definition involving severity grades, treatment delay, recovery, and blood-count-related criteria. The adverse-event record does not state how its serious or other event categories map to those criteria. Thus, the serious-event figure cannot be substituted for the primary endpoint result, and the other-event count cannot be assumed to represent qualifying endpoint toxicities.
The record does not provide event descriptions in the listed serious-event terms, nor does it report event timing or an endpoint-specific participant count. The adverse-event counts describe what was recorded in those categories; they do not show comparative risk or establish whether an event was caused by study treatment. The primary endpoint result is not reported in the registry record.
12. What the Result Does, and Does Not, Mean
The registry describes a completed pilot study in which participants with metastatic triple-negative breast cancer received veliparib plus lapatinib. It records an enrollment of 20 and posts adverse-event figures for a group with 17 participants at risk. The posted figures include 0 affected by serious adverse events, 17 affected by other adverse events, and 0 deaths. Those counts are descriptive and should be interpreted within the categories and denominators recorded.
The principal safety outcome asks for the number of participants meeting a more specific definition of study-related toxicity. That endpoint result is not reported in the registry record. Because the definitions may not coincide, the other adverse-event count cannot fill that gap. Numerical findings for the listed secondary outcomes are also not reported in the registry record.
The record does not establish a treatment effect. A single-group study has no concurrent comparator, so it cannot estimate how outcomes under the combination compare with outcomes under another treatment or control condition. No statistical analysis results, confidence intervals, or p-values are reported to quantify an effect or its precision. The sample-size assumptions describe planning illustrations, not observed power or the study’s own design.
These limits do not negate the descriptive information that is available. They define its scope: the design, treatment schedule, endpoint definition, and adverse-event counts can be described, but the registry does not provide enough endpoint-specific results to judge the primary safety question or the listed efficacy questions. The findings should not be treated as evidence that the combination does or does not work, or that it is safer or less safe than an alternative.
13. Why This Trial Matters Statistically
This study is statistically notable for the gap between a clearly specified primary safety endpoint and the results available in the registry record. The endpoint sets out a detailed definition of qualifying toxicity and a baseline-to-4-years timeframe, but its observed participant count is not reported. That makes it impossible to connect the endpoint definition to a numerical result in the record.
The study also illustrates why design matters when interpreting counts. A single-group study can report events among participants receiving an intervention, but there is no concurrent comparison group to distinguish treatment-associated differences from other influences. The adverse-event figures are useful as descriptive records, yet they do not provide a comparative estimate or substitute for the defined primary endpoint.
The registry lists multiple outcome questions, including response, progression-free survival, biological measures, circulating tumor cells, and drug concentration. Without numerical findings or an analysis plan, readers cannot assess how these outcomes were analyzed, how uncertainty was quantified, or how multiple outcomes were handled. In general, transparent reporting of denominators, missing-data handling, analysis populations, and uncertainty estimates helps readers judge both the result and its limitations; those details are not reported in the registry record.
The planning assumptions also illustrate a separate statistical point: a hypothetical two-arm sample-size calculation is not the same as the design of a single-group study, and planning power is not observed power. Keeping those ideas separate prevents planning illustrations from being mistaken for evidence about the trial’s actual results.
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 most consequential limitation in the registry record is that the observed primary endpoint result is not reported. The adverse-event counts do not state how many participants met the study-specific definition of study-related toxicity. Numerical results for the secondary outcomes are also not reported, limiting interpretation of the study’s response, progression-free survival, and biomarker questions.
The single-group design has no comparator arm, so the record cannot support a between-treatment estimate. The study is open-label, and the registry does not describe masking or other procedures for limiting assessment differences. It does not report the analysis plan, statistical models, confidence intervals, p-values, interim analyses, or a sample-size justification.
The record does not explain why the adverse-event at-risk count is 17 while listed enrollment is 20, nor does it report missing-data handling, follow-up completeness, or analysis populations. These omissions should not be filled with assumptions about withdrawals or data availability. The adverse-event categories are also not explicitly linked to the primary endpoint’s toxicity criteria.
The registry’s treatment description is incomplete after the listed dosing schedule, so additional regimen details are not reported in the registry record. Overall, these limitations restrict the available interpretation to the design and posted descriptive counts; they prevent assessment of the primary endpoint’s result, its precision, or a comparative treatment effect.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Pilot Study of Veliparib (ABT-888) and Lapatinib (Tykerb) in Patients With Metastatic, Triple Negative Breast Cancer — NCT02158507.
- Registry record last updated 2026-01-22; status last verified 2025-12.
- Results first posted 2026-01-22.
- 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
The registry describes a completed, open-label, single-group pilot study of veliparib plus lapatinib in metastatic triple-negative breast cancer after previous treatment. It lists enrollment of 20, with a start date of 2014-09-04 and primary completion date of 2021-07-22. The primary outcome is a count of participants experiencing study-related toxicities from baseline to 4 years, defined using specified toxicity criteria.
The adverse-event record lists 17 participants at risk, 0 affected by serious adverse events, 17 affected by other adverse events, and 0 deaths. The primary endpoint result and numerical results for the listed secondary outcomes are not reported in the registry record. No analysis entries are listed. With no comparator group and no endpoint-specific result, the record supports descriptive reporting but not a comparative treatment-effect conclusion.