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 Effects of Evolocumab on Platelet Reactivity in Patients With Diabetes Mellitus (NCT03258281), a randomized phase 4 study. The primary outcome is Change From Baseline in Adenosine Diphosphate (ADP) Stimulated P-selectin Expression.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03258281 |
| Phase | Phase 4 |
| Condition | Diabetes Mellitus, Type 2, Dyslipidemia Associated With Type II Diabetes Mellitus, Percutaneous Coronary Intervention |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 4 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Inova Health Care Services |
| Results posted | Yes |
2. Clinical Question
The study asked whether platelet reactivity, measured by ADP-stimulated P-selectin expression, changed from baseline after 30 days of evolocumab treatment compared with placebo in patients with diabetes undergoing elective percutaneous coronary intervention (PCI). The outcome was defined as the change in the percentage of positive cells, measured by flow cytometry. The registry describes a study population with diabetes mellitus and a treatment context involving PCI; its brief summary also describes participants with atherosclerotic cardiovascular disease receiving optimal statin therapy.
Population
Patients with diabetes undergoing elective PCI. The brief summary describes the intended population as 150 subjects with atherosclerotic cardiovascular disease on optimal statin therapy and diabetes. Actual registry enrollment was 4.
Intervention
Evolocumab 420 mg, described as a 30-day treatment in the brief summary.
Comparator
Placebo, with both groups described as receiving optimal statin therapy in the arm descriptions.
Primary question
How did ADP-stimulated P-selectin expression change from baseline after 30 days, and how did that change compare between evolocumab and placebo?
This is a pharmacodynamic question: it concerns a laboratory measure of platelet response rather than a clinical event outcome. The registry record does not report numerical results for the stated comparison, so it does not establish the direction or size of any difference in change. Nor does it report enough information to determine how representative the enrolled participants were of the population described in the study summary.
3. Trial Design
The registry identifies this as a Phase 4, randomized, triple-masked, parallel-group study. Its brief summary characterizes it as a prospective, single-center, double-blind, randomized pharmacodynamic experimental study. Randomization assigns participants to treatment groups by chance, while a parallel-group design means participants receive one assigned treatment rather than crossing between the treatments. The registry does not report who was masked; the wording of the brief summary and the triple-masked designation are both part of the record.
The planned treatment comparison was evolocumab 420 mg versus placebo over 30 days. The arm descriptions specify 75 subjects in each group, receiving treatment alongside optimal statin therapy and undergoing elective PCI. Separately, the brief summary describes planned enrollment of 150 subjects. The registry's actual enrollment is 4, so the planned counts should not be read as the number who enrolled or completed treatment.
The study start date is 2018-05-01 and the primary completion date is 2019-09-01. Its status is TERMINATED. The reason for termination, the actual allocation by treatment arm, and participant disposition after enrollment are not reported in the registry record. The safety summaries list participants at risk separately by group, but those figures alone do not establish how many participants were randomized, treated, or included in the primary endpoint analysis.
The primary outcome is described as a change from baseline in ADP-stimulated P-selectin expression, measured by flow cytometry, with baseline and after 30 days of treatment as the timeframe. The record also lists three secondary outcomes concerning P-selectin expression, lectin-like oxLDL receptor-1 mean fluorescence intensity, and CD-147 mean fluorescence intensity. Numerical results for these outcomes are not reported in the registry record.
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.
Before assignment: A total of 31 participants were screened, 4 met eligibility and were randomized to the study treatment.
Overall Study
| Stage | Evolocumab 420mg | Placebo |
|---|---|---|
| STARTED | 3 | 1 |
| COMPLETED | 3 | 1 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: Instrument malfunction with flow cytometer. Unable to collect data from subject (n=1) in placebo group.
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 | Evolocumab 420mg | Placebo | Total |
|---|---|---|---|---|
| Participants analysed | 3 | 1 | 4 | |
| Age, Continuous | years | 70 (SD 8) | 67 (SD 0) | 69 (SD 7) |
| Sex: Female, Male: Female | Participants | 1 | 0 | 1 |
| Sex: Female, Male: Male | Participants | 2 | 1 | 3 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): White | Participants | 3 | 1 | 4 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Change From Baseline in Adenosine Diphosphate (ADP) Stimulated P-selectin Expression, measured over Baseline and after 30 days of treatment.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | % Positive Cells |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is change from baseline in adenosine diphosphate (ADP)-stimulated P-selectin expression. It is measured as the percentage of positive cells using flow cytometry, with measurements specified at baseline and after 30 days of treatment. The intended comparison is between the evolocumab 420 mg group and the placebo group.
General statistical context: an endpoint defines what is measured and the time or conditions under which it is assessed. A change-from-baseline endpoint represents the difference between a participant's later measurement and their initial measurement. Comparing changes between randomized groups can describe whether the measured response differed between the assigned treatment strategies, subject to the quality and completeness of the measurements and the analysis.
P-selectin expression is used as a laboratory measure of platelet reactivity. ADP-stimulation specifies the condition under which the platelet response is assessed; flow cytometry measures cell characteristics in a sample. The endpoint is therefore a pharmacodynamic marker, not a direct measure of a clinical event. The record does not report a numerical mean change, standard deviation, treatment contrast, confidence interval, or test result. It also notes that flow-cytometer malfunction prevented collection of data for one subject in the placebo group. Accordingly, the registry record does not show what the observed endpoint values were or how precisely any group comparison was estimated.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The record establishes the study's intended comparison but does not provide numerical results for the primary endpoint. It reports enrollment of 4 and a primary outcome defined as change in ADP-stimulated P-selectin expression between baseline and after 30 days. It does not report group means, standard deviations, a difference between groups, a confidence interval, or a p-value for that outcome. The direction, magnitude, and precision of the treatment comparison therefore cannot be described from the registry record.
The registry identifies the study as TERMINATED. That status is relevant context for interpreting the difference between the planned enrollment and the recorded enrollment: the brief summary describes a plan for 150 subjects, while actual enrollment is listed as 4. The record does not explain why the study was terminated, whether enrollment stopped before or after treatment began, or how many participants contributed usable primary endpoint data. It would be inappropriate to treat the planned group sizes as observed sample sizes.
One specific data-collection problem is documented: a flow-cytometer malfunction prevented collection of data for one subject in the placebo group. This indicates missing primary endpoint data for that subject, but the registry does not report the analysis approach for the missing measurement or whether any other data were missing. The effect of the equipment failure on the reported findings cannot be assessed because numerical findings and analysis details are not reported in the registry record.
General statistical context: estimates from a comparison are more informative when accompanied by measures of uncertainty. A confidence interval describes a range of values compatible with the data and analysis assumptions; a p-value addresses compatibility with a specified null hypothesis, but does not express the size or clinical importance of an effect. Neither can be interpreted for this endpoint because neither is reported. The record lists zero analyses, so there is no registered numerical analysis to use as a basis for a statistical conclusion.
The safety summary is a separate source of information and should not be treated as evidence about the primary pharmacodynamic endpoint. It lists adverse-event counts for small group-specific populations, but those counts do not provide a treatment-effect estimate for platelet reactivity. Overall, the registry record documents a randomized study question and some safety counts, but it does not support a conclusion about the observed primary endpoint comparison.
9. Statistical Methods Explained
The study is described as randomized and parallel-group, with evolocumab compared with placebo. General statistical context: random assignment is intended to make treatment groups comparable, on average, with respect to factors that could influence outcomes. In a parallel-group study, the comparison is between groups assigned to different treatments. These design features do not guarantee that a small enrolled sample will be balanced, and the registry does not report the actual allocation or baseline characteristics by group.
What does a change-from-baseline comparison represent?
The stated endpoint measures ADP-stimulated P-selectin expression as a percentage of positive cells. It records the change between baseline and after 30 days of treatment, then compares the change between the treatment groups. General statistical context: a group mean summarizes the average observed value or change in a group, while a standard deviation describes the spread of individual values around that mean. The endpoint is designated as a mean of a continuous measure, with standard deviation as its dispersion measure. However, the registry does not report the actual means or standard deviations for the primary outcome.
A comparison of changes can be reported as a contrast between the groups' mean changes. Its interpretation depends on the measurement scale, the data available, and the analysis method. The registry record does not report a numerical contrast or the model or test used for the primary endpoint. It also does not report whether the analysis adjusted for baseline values or any other variables. Those details cannot be inferred from the randomized design alone.
How should uncertainty be read?
General statistical context: a confidence interval describes uncertainty around an estimated quantity under the assumptions of the method used. A narrow interval indicates more precise estimation than a wide interval, while an interval that spans values on both sides of a null contrast may be compatible with a range of possible effects. A p-value summarizes how unusual data would be under a specified null hypothesis and analysis assumptions; it is not a measure of the probability that a treatment works. No confidence interval or p-value for the primary endpoint is reported in the registry record, so there is no basis for interpreting statistical precision or testing results.
The record lists zero analyses. This means the registry does not include a numerical analysis entry to interpret. It should not be replaced by a calculation based on presumed participant-level data, because participant-level values and sufficient summary statistics are not reported. The outcome description also was not reduced to one comparison because it involves several categories or time points, according to the record's note. Thus, a single outcome contrast should not be reconstructed from the description.
What is the role of the planning assumptions?
The registry includes a description of a planning illustration based on the observed effect, using a two-sided significance level of 0.05, equal allocation, and a normal approximation. It describes the target effect as a stated fraction of the observed effect. General statistical context: such an illustration explores how sample size might depend on assumptions about the effect to be detected and the analysis method. It is not evidence that the trial achieved a particular power, and it is not an observed result. The registry record does not provide a sample-size justification for the study's original design. The enrollment of 4 should not be interpreted as a target or as proof of the adequacy of the design.
When the outcome is continuous, planning calculations may depend on assumptions about the variability of measurements as well as the effect size. If the data are highly variable, the estimated effect can be less precise. General statistical context: a normal approximation treats the sampling distribution of an estimate as approximately normal under the calculation's assumptions. Whether that approximation is appropriate for a particular dataset depends on information not reported, including the observed outcome distribution and the analysis details. No new planning estimate can be derived from the registry description alone.
Why do missing measurements and small enrollment matter?
The registry specifically reports that a flow-cytometer malfunction prevented collection of primary outcome data for one placebo-group subject. Missing outcome data can affect a comparison if the participants with unavailable measurements differ systematically from those with observed measurements. General statistical context: methods for handling missing data rely on assumptions about why values are absent and how the missingness relates to observed or unobserved measurements. The registry does not report a missing-data method or enough information to assess those assumptions.
The recorded enrollment is 4, whereas the study summary describes a plan to enroll 150 subjects. With no primary outcome estimates, uncertainty intervals, or analysis details reported, the magnitude and precision of the intended treatment comparison are unknown. No observed-power claim should be made from the enrollment figure. A sample-size illustration, where reported, is a planning exercise under stated assumptions and is not a substitute for the observed result or its uncertainty.
10. Multiplicity, Missing Data and Analysis Populations
The registry describes one primary endpoint and three secondary outcomes. The secondary outcomes concern change in ADP-unstimulated P-selectin expression, change in ADP-stimulated lectin-like oxLDL receptor-1 mean fluorescence intensity, and change in ADP-stimulated CD-147 mean fluorescence intensity. The primary outcome is described at baseline and after 30 days, and the record notes that it has several categories or time points and is not reduced to one comparison. Numerical results for the primary and secondary outcomes are not reported in the registry record.
Multiplicity arises when several outcomes, time points, or statistical comparisons are examined. General statistical context: the more comparisons considered, the greater the chance that at least one may appear notable by chance if each is tested independently without accounting for the set of tests. Researchers may address this through prespecified outcome priorities or statistical adjustments. The registry does not report a multiplicity strategy, a hierarchy among secondary outcomes, or an adjustment method. It also does not report interim analyses; no interim-analysis plan is reported in the registry record.
The record reports a flow-cytometer malfunction that prevented collection of primary endpoint data for one participant in the placebo group. It does not describe how this missing measurement was handled, whether other measurements were missing, or whether any imputation or sensitivity analysis was performed. A missing-data method is not reported in the registry record.
The registry does not specify the analysis population, such as whether the primary comparison was intended to include all randomized participants or only those with observed measurements. The actual allocation, treatment receipt, exclusions, and participant flow are also not reported in the registry record. The listed safety populations should not be assumed to be identical to the population used for the primary endpoint analysis.
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 |
|---|---|---|---|
| Evolocumab 420mg | 1 | 3 | 33.3% |
| Placebo | 0 | 1 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Evolocumab 420mg | 0 of 3 |
| Placebo | 0 of 1 |
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 |
|---|---|
| Evolocumab 420mg | 1 of 3 |
| Placebo | 0 of 1 |
Most frequent serious adverse event terms
| Event term | Organ system | Evolocumab 420mg | Placebo |
|---|---|---|---|
| Chest pain | Cardiac disorders | 1 of 3 | 0 of 1 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Evolocumab 420mg | Placebo |
|---|---|---|---|
| rash | Skin and subcutaneous tissue disorders | 1 of 3 | 0 of 1 |
Serious events with the highest arm-level rate: chest pain (33.3%).
The safety summary lists adverse-event counts by group. For evolocumab 420mg, 3 participants are listed as at risk, 1 as having a serious adverse event, 1 as having another adverse event, and 0 deaths. For placebo, 1 participant is listed as at risk, 0 as having a serious adverse event, 0 as having another adverse event, and 0 deaths. These are the counts recorded in the registry; they are not an estimate of the comparative safety of the treatments.
The registry lists chest pain at 33.3% as the top serious adverse-event term. It does not specify an arm attribution for that listed term in the information recorded. The count of participants at risk is the denominator context for the group summaries, but the safety populations should not be presumed to be the same as the randomized population or the primary endpoint analysis population.
General statistical context: safety counts based on very small groups are descriptive and imprecise. A count alone does not establish that an event was caused by a treatment, and a count of zero does not establish that an event cannot occur. The registry record does not report event timing, duration, severity details beyond the serious/non-serious categories, or an adjusted comparison. No deaths are listed in either group.
12. What the Result Does, and Does Not, Mean
The registry record shows that the study was designed to compare evolocumab 420 mg with placebo for change in ADP-stimulated P-selectin expression after 30 days in patients with diabetes undergoing elective PCI. It identifies the randomized, triple-masked, parallel-group design and reports enrollment of 4. It also records that a flow-cytometer malfunction prevented collection of the primary endpoint measurement for one subject in the placebo group.
Those details describe the question, design, and a data-collection limitation; they do not show the result of the treatment comparison. The record does not report the observed mean changes, a between-group estimate, a confidence interval, or a p-value. Thus, it cannot establish whether the measured platelet response differed between groups, by how much, or with what precision. A result cannot be inferred from the planned group sizes, the study's status, or the safety counts.
The brief summary and arm descriptions describe a planned study of 150 subjects, with 75 subjects in each treatment group. These are plans, not the observed enrollment. The registry lists the actual enrollment as 4 and the study status as TERMINATED. The reason for termination and the disposition of enrolled participants are not reported in the registry record. Consequently, the information available does not clarify why the planned and recorded enrollment differ or how many participants contributed usable endpoint measurements.
General statistical context: a laboratory endpoint can describe a biological response under the specified measurement conditions, but it is not automatically equivalent to a patient-centered clinical outcome. The registry's primary endpoint is a flow-cytometry measure of P-selectin expression, not a reported measure of clinical events. The record therefore does not establish a clinical benefit or harm, nor does it establish a conclusion about treatment efficacy. It documents a pharmacodynamic research question whose numerical outcome results are not reported.
13. Why This Trial Matters Statistically
This study is statistically notable because its registry record juxtaposes a detailed randomized design with very limited recorded enrollment and no numerical results for the primary endpoint. The brief summary describes a plan for 150 subjects, and the arm descriptions give planned groups of 75 each, while the enrollment entry is 4. That distinction is important: planned counts are design intentions, whereas enrollment records the number entered in the study.
The study also illustrates why outcome definitions and data availability matter. The primary endpoint is specified as change from baseline in ADP-stimulated P-selectin expression, with flow cytometry as the measurement method. The record documents a flow-cytometer malfunction that prevented collection for one placebo-group subject. Even a clearly described endpoint cannot support a comparison without usable measurements and reported analysis results.
General statistical context: randomized allocation is valuable for structuring a comparison, but randomization alone does not provide an effect estimate. Interpretation requires observed outcome data, a defined analysis, and an account of missing measurements. Precision also depends on the amount and variability of data. With no reported primary endpoint estimates or uncertainty measures, readers cannot assess how informative the comparison is.
The record's status is TERMINATED, but the reason and the timing of termination are not reported in the registry record. This highlights the difference between a trial's planned design and the information available from its posted results. Statistical interpretation must follow the actual reported evidence rather than the intended sample size or protocol description. Here, the design and measurement question can be described, but the treatment comparison itself cannot be evaluated from numerical endpoint 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 main trial-specific limitation is that the registry records enrollment of 4, far below the planned 150 subjects described in the brief summary. The planned arm descriptions list 75 subjects per group, but those counts are not actual enrollment figures. The study is marked TERMINATED, while the reason for termination and participant disposition are not reported in the registry record. The actual number randomized to each group and the number completing the 30-day treatment period are also not reported.
The primary endpoint is not accompanied by numerical results. Group means, standard deviations, a treatment contrast, confidence intervals, and p-values are not reported in the registry record. The record lists zero analyses, so there is no reported numerical endpoint analysis on which to base an estimate or assess precision. The outcome description also was not reduced to a single comparison because it has several categories or time points.
The registry documents one missing primary measurement due to flow-cytometer malfunction in a placebo-group subject. It does not report how that missing value was handled, whether any other endpoint data were missing, or whether a sensitivity analysis was conducted. The analysis population and statistical model are not reported in the registry record.
Finally, the study's single-center description may limit how broadly its design and findings can be generalized, although the absence of numerical endpoint results prevents assessment of the findings themselves. The record describes patients with diabetes undergoing elective PCI and, in its brief summary, participants with atherosclerotic cardiovascular disease on optimal statin therapy. Detailed eligibility criteria and group characteristics are not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Effects of Evolocumab on Platelet Reactivity in Patients With Diabetes Mellitus — NCT03258281.
- Registry record last updated 2023-01-19; status last verified 2022-12.
- Results first posted 2023-01-19.
- 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
NCT03258281 is a Phase 4 randomized, triple-masked, parallel-group study comparing evolocumab 420 mg with placebo in patients with diabetes undergoing elective PCI. The primary endpoint is change from baseline in ADP-stimulated P-selectin expression, measured as percentage of positive cells by flow cytometry at baseline and after 30 days. The registry describes intended enrollment of 150 subjects, with 75 per group in the arm descriptions, and records actual enrollment of 4. The study status is TERMINATED. The record notes that a flow-cytometer malfunction prevented collection of primary outcome data for one placebo-group subject. Numerical primary endpoint results and analysis details are not reported in the registry record. Safety summaries list 3 participants at risk in the evolocumab group and 1 in the placebo group, with 0 deaths listed in each group.