Implantable Microdevice for In Vivo Drug Sensitivity Testing in Patients With Early Stage, HER2-Positive or Triple Negative Breast Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Implantable Microdevice for In Vivo Drug Sensitivity Testing in Patients With Early Stage, HER2-Positive or Triple Negative Breast Cancer (NCT02521363), a non-randomized na study. The primary outcome is Number of Participants With Implantable Devices.

2. Clinical Question

The study's broader rationale was that measurements from a device placed in a tumor might help predict how different treatments affect an individual's cancer and inform personalized treatment choices. That rationale is distinct from the registered primary question. The primary endpoint concerns whether participant data can be collected in the device study; it is not a direct measure of whether a treatment controls cancer or improves a clinical outcome.

The record identifies anthracycline and taxane based chemotherapy as a drug intervention and describes neoadjuvant chemotherapy before definitive surgery in the neoadjuvant therapy arm. It does not report a treatment-effect estimate comparing chemotherapy with another regimen, nor does it establish that the device predicts treatment response. The design and endpoint are best read as an early feasibility investigation.

3. Trial Design

The registry record describes a completed, non-randomized, unmasked, parallel-group pilot study sponsored by Memorial Sloan Kettering Cancer Center. The registered enrollment was 11, and the study status is completed. The phase is not reported in the registry record. The study started on 2015-07-24, with primary completion on 2024-08-01.

Participants were assigned to one of two treatment pathways, but allocation was not randomized. In the Upfront Breast Surgery arm, the microdevice was implanted before breast surgery in the absence of neoadjuvant chemotherapy. In the Neoadjuvant Therapy arm, the device was placed and retrieved on a core biopsy the following day, followed by neoadjuvant chemotherapy before definitive breast surgery. These pathways differ in their clinical sequence and chemotherapy exposure, so the arms should not be treated as equivalent groups differing only in device use.

Masking was listed as none. The registry record does not report a random allocation procedure, and it explicitly identifies the study as non-randomized. Thus, any contrast between the arms would be vulnerable to differences in who entered each pathway and in their treatment context. The study is not structured as a randomized comparison capable of isolating the effect of one pathway versus the other.

The main stated aim was to assess the safety and feasibility of device placement and removal. The primary measure was a count of participants with implantable devices, with data collection from at least 6 out of the 12 patients described as the criterion for considering a larger cohort. This is a pilot feasibility objective, rather than a confirmatory test of treatment efficacy.

The registry record lists one outcome measure and zero analyses. Detailed eligibility criteria, allocation rationale, sample-size justification, statistical analysis plan, and any interim analysis plan are not reported in the registry record. The stated sample-size assumptions for planning illustrations are not the trial's own design assumptions.

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

Reasons for not completing this period:

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.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Implantable Devices, measured over Up to 1 year.

The primary outcome is titled “Number of Participants With Implantable Devices,” uses participants as its unit, and has a timeframe of up to 1 year. It is a count-based endpoint. The accompanying description frames feasibility in terms of collecting data from at least 6 out of the 12 patients; reaching that criterion would support conducting a larger cohort.

A feasibility endpoint is used to assess whether key study procedures can be carried out and whether the intended data can be collected. In general, such an endpoint can help determine whether a larger study is practicable. It does not, by itself, establish that a device predicts treatment response or that a treatment improves a health outcome. Those questions require relevant clinical outcomes and an analysis designed to address them.

The endpoint title refers to participants with implantable devices, while the description refers to collecting data. The registry record does not clarify how these concepts were operationally defined, what counted as usable data, or how missing or incomplete device data would be handled. The observed endpoint count and the result against the stated feasibility criterion are not reported in the registry record.

Because the measure is a count of participants rather than a continuous measurement or time-to-event outcome, an analysis would ordinarily describe how many participants met the endpoint definition. The record does not provide an endpoint estimate, confidence interval, or test result. It therefore does not support a quantitative conclusion about the degree of feasibility achieved.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registered primary measure is a participant count. In general, a count endpoint records how many people satisfy a defined condition, rather than the size of a continuous change or the time until an event. Here, the endpoint title refers to participants with implantable devices, and its description emphasizes collecting data. The record does not provide a more detailed operational definition or the observed count.

What a feasibility threshold means

The registry record states that collecting data from at least 6 out of the 12 patients would lead investigators to deem the study feasible to conduct in a larger cohort. This is a prespecified-looking decision rule as described in the outcome text, but the registry record does not report the observed data collection count or whether the rule was satisfied. A threshold is a decision criterion; it is not itself an outcome result. It also does not quantify the precision of a future estimate or demonstrate a treatment effect.

In general, feasibility studies assess whether the practical elements of research can be completed, such as carrying out a procedure and obtaining usable measurements. Success on a feasibility measure can justify further study, but it is not proof that the intervention has clinical benefit. The present record does not report what specific types of data counted toward the rule, whether all planned device procedures were completed, or how incomplete records were classified.

Why a confidence interval can matter

In general, a confidence interval describes uncertainty around an estimated quantity. For a count-based feasibility outcome, an interval around a proportion or another defined summary can convey how much uncertainty remains about feasibility beyond the participants observed. A narrow interval generally indicates greater precision than a wide interval, while neither interval width nor interval location should be interpreted without the study question and analysis assumptions. The registry record posts no confidence interval or endpoint estimate, so the precision of the primary result is not reported in the registry record.

For a small pilot, observed counts can be especially sensitive to the experience of individual participants. General statistical interpretation therefore distinguishes the observed result from the underlying rate or likelihood in a broader population. The record's enrollment of 11 is not enough to determine the endpoint result, and no uncertainty estimate is posted. No additional estimate can be inferred from enrollment alone.

What non-random allocation changes

Random allocation, in general, is used to make treatment groups comparable on average with respect to measured and unmeasured participant characteristics. This study was non-randomized. Its two arms also followed distinct treatment sequences: one involved upfront surgery without neoadjuvant chemotherapy, and the other involved neoadjuvant chemotherapy before definitive surgery. As a result, group differences would not automatically be attributable to the device or to one treatment pathway. The record does not report a comparative analysis, covariate adjustment, or method for addressing confounding.

Unmasked design means that masking was listed as none. In general, masking can reduce the influence of expectations or knowledge of treatment assignment on subjective assessments, but it does not address every source of bias. The registry record does not describe whether outcome assessment involved subjective judgment, so the implications of the unmasked design for measurement cannot be specified more narrowly.

How to read the planning assumptions

The stated sample-size assumptions describe planning illustrations computed from the observed effect, not the trial's own design. They specify a two-sided significance level of 0.05, equal allocation between arms, a normal approximation, and an effect to detect expressed as a stated fraction of the observed effect. These assumptions are not evidence that the trial was designed around that model, and they do not supply a trial result.

In general, a sample-size calculation depends on the target effect, variability or event frequency, significance level, power target, allocation, and analysis method. Changing those assumptions changes the planning result. A calculation based on an observed effect is a retrospective illustration and can be unstable, especially when the estimate comes from a small study. It should not be described as observed power. The registry record does not report the original sample-size justification or provide the inputs needed to evaluate it.

The stated normal approximation is a modeling assumption for the planning illustration. In general, approximations can be less dependable when data are sparse or when the outcome distribution does not fit the assumed model well. The registry record does not provide enough endpoint data to assess whether that approximation is appropriate for this study's observed outcome. The record also does not report an analysis model for the primary endpoint.

What the posted analysis status permits

The registry record lists one outcome measure and zero analyses. That means no statistical analysis results are posted in the registry information. It does not reveal whether analyses were conducted outside the registry, whether there were protocol deviations, or why results are absent. Those matters are not reported in the registry record. Statistical interpretation should therefore remain descriptive and should not supply estimates, tests, or conclusions that are not posted.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists one outcome measure and zero analyses. It identifies the primary endpoint as the number of participants with implantable devices, but does not post a statistical result for it. The record does not report additional endpoint analyses, secondary outcome results, or an analysis plan specifying which comparisons or outcomes were considered confirmatory.

In general, multiplicity arises when several hypotheses or outcomes are tested. With multiple tests, the chance of obtaining at least one apparently notable result by chance can increase unless the analysis plan accounts for the testing structure. The registry record does not describe a multiplicity adjustment or a strategy for controlling false-positive findings. Because no analyses are posted, it is not possible to assess how multiplicity was handled in any results analysis.

The registry record also does not describe missing-data counts, reasons for missingness, imputation methods, or sensitivity analyses. These details matter because incomplete endpoint information can affect a feasibility estimate. Enrollment is listed as 11, while the feasibility description refers to collecting data from at least 6 out of the 12 patients. The record does not explain this relationship or report how many participants contributed evaluable endpoint data. The missing-data approach is not reported in the registry record.

Analysis populations are not described. In general, an analysis population defines which participants are included in a particular analysis and how exclusions or incomplete data are handled. The record does not specify whether the primary endpoint was intended to include all enrolled participants, only those who received a device, or another group. It also does not report a protocol-defined intention-to-treat or per-protocol population. These omissions limit interpretation of the planned endpoint and any potential comparison between arms.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The adverse-event figures are descriptive counts by study group. For Upfront Breast Surgery, the registry record lists 4 participants at risk, 0 participants with serious adverse events, 0 with other adverse events, and 0 deaths. For Neoadjuvant Therapy, it lists 7 participants at risk, 0 with serious adverse events, 0 with other adverse events, and 0 deaths. No top serious adverse-event terms are listed.

These figures show that no serious adverse events, other adverse events, or deaths were recorded in the listed groups in the registry record. They do not establish that the device or chemotherapy has no safety risks. In general, a zero count in a small study does not rule out events that could occur in a larger or different group, and it does not describe how completely events were monitored or reported.

The listed at-risk counts are group-specific. The record does not provide event timing, severity details beyond the serious/other categories, attribution to device or treatment, or a narrative of safety monitoring. It also does not explain how these denominators relate to the registered enrollment. Safety interpretation should therefore stay within the posted counts and should not treat them as a comparative risk analysis.

12. What the Result Does, and Does Not, Mean

The study addresses whether an implantable microdevice can be used in a clinical research setting to collect information about drug sensitivity in breast tumors. The registry record describes a pilot study intended to assess safety and feasibility and states a criterion for considering a larger cohort. It does not report the observed primary endpoint count or whether that criterion was achieved.

The posted record does not establish that the device predicts which treatment will work best for an individual. The stated scientific rationale is that device measurements may help predict treatment sensitivity and personalize choices. A rationale is not evidence of predictive accuracy. Evaluating prediction would require reported comparisons between device findings and relevant treatment-response outcomes, along with an analysis of how well those predictions perform. Such results are not reported in the registry record.

The study also does not establish that one treatment pathway is superior to another. The arms were not randomized, and they differed in whether participants received neoadjuvant chemotherapy before surgery. Their outcomes would not constitute a clean causal comparison, even if group-level results were posted. The registry record lists no analyses, and no comparative treatment-effect estimate is reported.

The safety counts are reassuring only in the narrow descriptive sense that the record lists zero serious adverse events, zero other adverse events, and zero deaths in each group. They cannot rule out uncommon events or characterize safety outside the participants and monitoring represented by this pilot. Further details of event ascertainment and attribution are not reported in the registry record.

In general, pilot studies can inform whether a research procedure and data collection plan warrant further study. They are not ordinarily sufficient on their own to establish clinical effectiveness or broad safety. For this study, the available registry information supports describing its design, intended feasibility threshold, and posted safety counts. It does not support concluding that the device met the feasibility rule, predicts response, changes treatment decisions, or improves outcomes.

13. Why This Trial Matters Statistically

This trial is statistically notable because its main question is feasibility rather than treatment efficacy. That distinction determines what kind of evidence the endpoint can provide. A count of participants with implantable devices, linked to a data-collection threshold, concerns whether a research process can be undertaken and whether information can be obtained. It is not an efficacy endpoint.

The study also illustrates why a pilot's decision rule should be separated from its observed outcome. The registry record states that collecting data from at least 6 out of the 12 patients would support deeming a larger cohort feasible. But the outcome count is not posted. Without that count, a reader cannot determine whether the stated rule was reached or how precisely feasibility was estimated.

Design matters as much as the endpoint. The non-randomized arms reflect different clinical sequences, including whether neoadjuvant chemotherapy preceded surgery. A comparison between such groups could reflect participant selection or treatment context as well as any device-related differences. The record's lack of posted analyses means there is no reported estimate to evaluate, but even a descriptive contrast would require cautious interpretation.

Finally, the record makes clear that safety counts and feasibility answer different questions. The listed event counts describe what was recorded among participants at risk; they do not show whether device-related data were successfully collected. Conversely, meeting a feasibility threshold would not establish that the device is safe or clinically useful. Keeping these questions separate is essential when interpreting early-stage device 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.

Several trial-specific limitations follow from the registry information. The study was non-randomized, and its arms followed different care pathways. Consequently, an arm-to-arm comparison would not provide a like-for-like estimate of a device effect. The record does not report methods for adjusting for differences between participants or treatment contexts.

The registered enrollment was 11, while the feasibility description refers to data collection from at least 6 out of the 12 patients. The registry record does not explain the relationship between these figures or report the actual number of participants whose device data were collected. The primary endpoint result and whether the feasibility rule was met are not reported.

The endpoint wording does not fully specify how “participants with implantable devices” relates to successful data collection, what constituted usable data, or how incomplete data were treated. Eligibility details and participant characteristics are also not reported in the registry record. These omissions make it difficult to assess who the findings would represent or how the endpoint should be interpreted operationally.

The registry record lists zero analyses and does not provide a statistical analysis plan, original sample-size justification, interim analysis plan, or details of missing-data handling and analysis populations. It also does not provide a comparative estimate of device performance or treatment response. The sample-size assumptions described for planning illustrations should not be mistaken for the original trial design or for a result.

Safety reporting is limited to group-level counts of participants at risk, adverse events, and deaths. Event timing, attribution, monitoring procedures, and detailed descriptions are not reported. These limitations constrain both the assessment of feasibility and the interpretation of safety or clinical utility.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Implantable Microdevice for In Vivo Drug Sensitivity Testing in Patients With Early Stage, HER2-Positive or Triple Negative Breast Cancer — NCT02521363.
• Registry record last updated 2025-08-22; status last verified 2024-08.
• Results first posted 2025-08-22.
• 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.

18. Record Summary

This completed pilot study evaluated an implantable microdevice for in vivo drug sensitivity testing in patients with early-stage, HER2-positive or triple-negative breast cancer. The registry record lists a non-randomized, unmasked, parallel design and an enrollment of 11. The study started on 2015-07-24, and primary completion was 2024-08-01. The phase is not reported in the registry record.

The primary outcome was the number of participants with implantable devices, with a timeframe of up to 1 year. The stated feasibility criterion was collecting data from at least 6 out of the 12 patients. The observed endpoint result and whether the criterion was met are not reported in the registry record. One outcome measure and zero analyses are listed.

For Upfront Breast Surgery, 4 participants were listed at risk, with 0 serious adverse events, 0 other adverse events, and 0 deaths. For Neoadjuvant Therapy, 7 were listed at risk, with 0 serious adverse events, 0 other adverse events, and 0 deaths. These descriptive safety counts do not establish efficacy or rule out risk.