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 Pilot Study Investigating Apixaban and Dexamethasone InterAction in Multiple Myeloma (NCT02749617), a na phase 2 study. The primary outcome is Anti Xa Activity.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02749617 |
| Phase | Phase 2 |
| Condition | Anti-Xa Activity |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 2 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of British Columbia |
| Results posted | Yes |
2. Clinical Question
Population
The proposed population was people with multiple myeloma for whom a lenalidomide-dexamethasone (LEN-DEX)-based regimen was indicated. The brief summary described a prospective cohort of 24 participants, but the registry records enrollment of 2. The registry does not report an analyzed primary-outcome population or participant-level endpoint results.
Intervention
Participants were to take apixaban 2.5 mg by mouth twice a day for thromboprophylaxis. The proposed schedule began before the DEX-containing regimen and continued until the end of cycle 3. Anti-Xa activity was to be measured serially; D-dimer and plasma drug concentration were also identified for measurement in the study description.
Comparator
This was a single-group study, with allocation recorded as not applicable and no masking. It was not a randomized comparison and had no separate control arm. The brief summary frames the primary outcome as a change from baseline, but the registry does not report the details of an analyzed baseline-to-follow-up comparison.
Primary question
The study sought to investigate whether dexamethasone was associated with a change in anti-Xa activity among participants taking apixaban. Its brief summary states a planned primary outcome of a reduction of at least 50% in peak anti-Xa levels from baseline. The primary outcome record describes serial anti-Xa activity over 3 months, but provides no analyzed result. The clinical question therefore remains unanswered by the posted results.
3. Trial Design
This was a Phase 2 pilot study with a single-group model. The registry lists apixaban as the intervention and describes the dose as 2.5 mg by mouth twice a day. Allocation is recorded as not applicable, and masking is listed as none. There was no randomized control group, so the design does not support a direct comparison between treatment arms.
The brief summary describes a prospective cohort of 24 people with multiple myeloma who were expected to begin a LEN-DEX regimen. Apixaban was to start before the dexamethasone-containing regimen and continue until the end of cycle 3. The stated measurement period was 3 months. The study description identifies serial anti-Xa activity as the primary outcome and also describes measuring D-dimer and plasma drug concentration. It mentions symptomatic venous thromboembolism and bleeding as secondary outcomes during the treatment period.
The registry records actual enrollment of 2 and a status of terminated. The recorded start date is 2016-08-09, and the primary completion date is 2018-01-03. The registry record does not report why the study was terminated, whether the planned follow-up was completed, or how many participants contributed endpoint measurements. It lists two outcome measures and no analyses. These record features distinguish the proposed pilot design from the limited posted results: the planned cohort and outcome aims should not be treated as evidence that those outcomes were analyzed.
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 | Apixaban |
|---|---|
| STARTED | 2 |
| COMPLETED | 2 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: Lack of data.
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 | Apixaban |
|---|---|---|
| Participants analysed | 2 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 |
| Age, Categorical: >=65 years | Participants | 2 |
| Sex: Female, Male: Female | Participants | 1 |
| Sex: Female, Male: Male | Participants | 1 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 2 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 1 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 1 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: Canada | Participants | 2 |
6. Primary Endpoint
The registry lists the primary outcome as Anti Xa Activity, measured over 3 months.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is titled “Anti Xa Activity.” The registry describes serial anti-Xa activity over 3 months, but does not specify a unit, parameter, or dispersion measure. Its population description says “Lack of data.” The brief summary gives more context about the intended question: the investigators planned to examine whether peak anti-Xa levels fell by at least 50% from baseline during dexamethasone-containing treatment.
As a general measurement concept, an endpoint is chosen to represent the quantity that a study is designed to assess. Serial measurements can describe how a measured quantity changes over time, while a baseline comparison can place follow-up values in the context of each participant’s earlier value. That general rationale does not establish which specific summary or comparison was used in this study; the analysis method is not reported in the registry record.
Anti-Xa activity was the primary measurement because the study was investigating a possible interaction involving apixaban and dexamethasone. However, the posted results do not give anti-Xa values, a change estimate, or an uncertainty interval. The endpoint’s intended role can be described, but its observed behavior and precision cannot be assessed from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central interpretive fact is that the registry records enrollment of 2, while no primary endpoint analysis or anti-Xa result is posted. The study’s brief summary states an intended question about a reduction in peak anti-Xa levels from baseline, but an intended outcome is not an observed result. No estimate of change, confidence interval, test statistic, or p-value is reported. Accordingly, the posted record does not establish whether anti-Xa activity changed during the study.
The study is described as a pilot and a single-group prospective cohort, not a randomized comparison. Even if a within-participant change had been reported, that design would describe change over time in the enrolled group rather than isolate the effect of dexamethasone from other possible influences. General statistical reasoning: a control group can help distinguish changes associated with a study exposure from changes that may occur for other reasons. This study has no separate control arm in the registry design.
The brief summary proposed a cohort of 24 and described a planned target of detecting a reduction of at least 50% in peak anti-Xa levels from baseline with 90% power. Those are planning statements, not results from the 2 participants recorded as enrolled. They do not show that the target was reached, that the intended sample was enrolled, or that the study had a particular degree of power after enrollment. The registry does not report why enrollment was lower than the proposed cohort or why the study was terminated.
The safety entries should also be read as registry counts, not as an efficacy finding or a causal assessment. The Apixaban group lists 0 serious adverse events among 2 participants at risk, 2 affected by other adverse events among 2 at risk, and 2 deaths. The record does not provide event descriptions, timing, causes, or attribution. These entries therefore do not establish whether any event was related to apixaban, dexamethasone, the underlying condition, or another factor.
Overall, the posted record provides design and enrollment information and sparse adverse-event counts, but no evaluable primary outcome result. It cannot support a conclusion about the size, direction, or precision of an anti-Xa change. Nor does the absence of a posted endpoint analysis establish that no change occurred; it means the result is not reported in the registry record.
9. Statistical Methods Explained
The registry describes a single-group study, with allocation recorded as not applicable and masking listed as none. This matters for interpretation: the design is not a randomized comparison of apixaban with a separate control treatment. The study description instead places the primary question in a longitudinal setting, with participants taking apixaban before and during a dexamethasone-containing regimen and anti-Xa activity measured serially. The specific statistical method used to analyze those repeated measurements is not reported in the registry record.
As a general statistical concept, repeated measurements can be summarized in several ways. An analysis might focus on change from baseline, the pattern of values across visits, or a particular peak value. These approaches answer related but distinct questions and depend on prespecified definitions, measurement timing, and a method for handling observations that are not available. The brief summary refers to peak anti-Xa levels and a reduction from baseline, while the primary outcome record says “serial anti Xa activity.” It does not define the peak calculation, identify the analysis time point, or state how repeated measurements were to be combined.
The brief summary describes a planned sample of 24 and states 90% power to detect a primary outcome of at least a 50% reduction in peak anti-Xa levels from baseline. This is a design statement, not an observed result. The registry records enrollment of 2, and no endpoint analysis is posted. A planned power calculation concerns the chance that a specified analysis would detect an assumed effect under its planning conditions; it does not show what an incomplete or terminated study actually found. Sample-size illustrations are planning aids, not observed power.
General statistical explanation: power depends on assumptions such as the effect size being targeted, variability in measurements, the significance level, the analysis design, and the number of observations. If those assumptions differ from the data or design ultimately available, a planning calculation may not describe the study’s ability to answer its question. The registry does not report the detailed assumptions or calculation supporting the stated power claim, beyond the planned cohort and target outcome in the brief summary. It also does not report a variance estimate or observed effect for anti-Xa activity.
A generic planning illustration described for the posted material uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a fraction of an observed effect. Those assumptions are not the registry’s stated single-group trial design: there are no two randomized arms to allocate equally. Such a calculation should therefore be read as a hypothetical planning illustration rather than as the study’s own design, a trial result, or evidence of observed power. No numerical planning outputs are reported in the registry record.
Confidence intervals are a general way to express uncertainty around an estimated effect. A narrow interval indicates greater precision under the method’s assumptions, while a wide interval indicates less precision. Here, no effect estimate or confidence interval for the primary endpoint is reported, so its precision cannot be evaluated. The lack of a reported estimate is not equivalent to a confidence interval centered on no change; it leaves the magnitude and direction unquantified.
General statistical explanation: small samples can make estimates sensitive to the observations contributed by individual participants, and may leave substantial uncertainty about the population effect. With 2 participants enrolled, the record offers little basis for estimating how representative any measured pattern might be. This observation is about the limits of the available sample, not a calculation of power or a claim about an unreported result.
Over-dispersion is a general concern when observed variability exceeds the assumptions of a statistical model. If a model assumes less variation than the data contain, uncertainty can be understated and inferential conclusions can be too confident. The registry does not report a model, a dispersion estimate, or enough endpoint results to assess over-dispersion in this study. It would therefore be inappropriate to attribute any particular modeling issue to the investigators.
The structured record lists no analyses. It does not report the statistical test or model, whether estimates were adjusted, how within-participant dependence was handled, how missing measurements were treated, or whether any analysis was prespecified. These omissions prevent a statistical reconstruction of the primary outcome. The planned objective can be described from the brief summary, but the analysis and its result cannot be inferred from that objective.
10. Multiplicity, Missing Data and Analysis Populations
The brief summary names several outcomes: anti-Xa activity as the primary outcome, and changes in plasma apixaban levels, D-dimer, symptomatic venous thromboembolism, and bleeding as secondary outcomes. The structured registry record lists Plasma Apixaban Levels as a secondary outcome. The record does not explain the difference in scope between that listing and the outcomes mentioned in the brief summary, or report results for these measures.
Multiplicity is a general statistical issue that arises when several outcomes or hypotheses are evaluated. Repeated testing can increase the chance of finding an apparently notable result by chance. A prespecified hierarchy, adjustment method, or distinction between confirmatory and exploratory outcomes can help readers understand how multiple results are interpreted. No multiplicity plan, testing hierarchy, or adjustment method is reported in the registry record. Since no analyses are listed, the record also does not show whether any multiplicity procedure was applied.
Missing-data methods and analysis populations are not reported. The record does not say which enrolled participants had usable endpoint measurements, how incomplete follow-up was handled, or whether all enrolled participants were included in any analysis. General statistical reasoning: missing measurements can affect both the amount of information available and the interpretation of a change over time, particularly if the reasons for missingness are related to outcomes. Without participant-level follow-up information or a stated method, the impact cannot be assessed.
The study is terminated and enrollment is recorded as 2, but the registry does not report the termination reason or the endpoint availability for those participants. No imputation approach, exclusion rule, or analysis-population definition is reported. These gaps limit interpretation of both the planned outcomes and the adverse-event counts.
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 |
|---|---|---|---|
| Apixaban | 0 | 2 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Apixaban | 2 of 2 |
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 |
|---|---|
| Apixaban | 2 of 2 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Apixaban |
|---|---|---|
| Nose Bleed | Blood and lymphatic system disorders | 1 of 2 |
| Nausea | General disorders | 1 of 2 |
| Flu-like Symptoms | General disorders | 1 of 2 |
| Diarrhea | General disorders | 1 of 2 |
| Pseudomonas aerugionosa | General disorders | 1 of 2 |
| Skin Itchiness | General disorders | 1 of 2 |
| Low Energy | General disorders | 1 of 2 |
| Back right-sided buttock pain | General disorders | 1 of 2 |
The Apixaban group records 2 participants at risk for serious adverse events and 0 affected by serious adverse events. It records 2 participants at risk for other adverse events and 2 affected. The record also lists 2 deaths. No serious adverse-event terms are listed.
These entries are counts, not a complete account of event type, timing, severity beyond the registry categories, or clinical course. In particular, the record does not state when the deaths occurred or their causes. It does not report whether the adverse events or deaths were considered related to apixaban, dexamethasone, the underlying disease, or another factor. The counts should therefore not be interpreted as establishing causation or as a comparative safety estimate.
The serious-event count of 0 is specific to the registry’s serious adverse-event category and the 2 participants recorded as at risk. It does not imply that no adverse events of any kind were recorded: the other-adverse-event category lists 2 affected participants. Because the study has a single group and enrollment of 2, these entries provide limited descriptive information and do not support a reliable comparison with another treatment or population.
12. What the Result Does, and Does Not, Mean
The registry record documents a pilot study intended to investigate anti-Xa activity during apixaban use and dexamethasone-containing treatment for multiple myeloma. It describes a planned cohort of 24 and an intended primary outcome involving peak anti-Xa levels from baseline. Actual enrollment is recorded as 2, the status is terminated, and no primary endpoint analysis is listed.
What the posted record does show is the study design, the stated measurement period, the proposed outcome, and a small set of adverse-event counts. It does not show participant-level anti-Xa measurements, an estimated change, or uncertainty around an effect. Therefore, the record cannot indicate the direction or size of any change, or how precisely such a change was estimated. It also cannot answer whether the planned threshold was met.
What the record does not mean is that anti-Xa activity did not change, that the planned outcome was reached, or that any adverse event was caused by a particular treatment. Absence of a reported analysis is not evidence of no effect. Similarly, a planned power statement is not a result, and it does not describe the achieved information from the enrolled participants.
The single-group design also limits causal interpretation. A change over time, if measured and analyzed, would not by itself distinguish the influence of dexamethasone from other factors that could coincide with treatment or follow-up. The registry does not report a control group, a causal analysis, or an adjusted estimate. The sound conclusion is therefore narrow: the registry records an intended pharmacodynamic pilot question, but does not report the outcome analysis needed to resolve it.
13. Why This Trial Matters Statistically
This study matters statistically because its stated objective and its posted evidence are different things. The brief summary describes a specific planned question about a substantial reduction in peak anti-Xa activity from baseline. The registry, however, records 2 participants, a terminated status, and no primary endpoint analysis. Recognizing that distinction prevents a planned target or power statement from being mistaken for an observed finding.
The design also makes the intended comparison important to interpret carefully. The study is single-group, not randomized, and has no separate control arm. A baseline-to-follow-up description can be informative about change within participants, but a single-group design does not independently separate treatment-associated change from other changes over time. That distinction is a general feature of study design, not a claim about what happened to these participants.
The record further illustrates how precision and completeness matter. Without an outcome estimate, interval, or analysis description, readers cannot assess the magnitude, uncertainty, or robustness of the primary result. The adverse-event entries are likewise descriptive counts without event details or attribution. They should not be expanded into a broader safety conclusion.
Finally, the difference between the proposed cohort of 24 and recorded enrollment of 2 is relevant to the scope of the evidence, but the reason for that difference is not reported. A transparent reading preserves both details without guessing why the study ended. That approach keeps the scientific question distinct from the information the registry actually documents.
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 direct limitation is the absence of posted primary endpoint results. The registry describes serial anti-Xa activity but reports no values, change estimate, confidence interval, or analysis. Consequently, the main research question cannot be evaluated statistically from the record. The primary outcome’s population field states “Lack of data,” and its unit, parameter, and dispersion are not specified.
Enrollment is recorded as 2, although the brief summary describes a planned cohort of 24. The registry status is terminated, but the reason for termination and the extent of follow-up are not reported. It is unknown from the record whether endpoint measurements were available for either participant, whether all planned assessments occurred, or whether other data were collected but not posted.
The single-group design has no separate control arm and is not randomized. Therefore, it cannot provide a like-for-like treatment-arm contrast. The registry also does not report the analysis method, the handling of repeated measurements, missing-data rules, analysis populations, or any multiplicity plan. These omissions prevent assessment of whether the stated endpoint was analyzed as intended.
The safety information is limited to category counts. Event descriptions, timing, causes, and attribution are not reported, and the record lists 2 deaths without further context. These limitations mean the counts cannot establish a causal relationship or support a detailed safety profile. The reason for termination, the status of the intended secondary outcomes, and any protocol deviations are also not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Pilot Study Investigating Apixaban and Dexamethasone InterAction in Multiple Myeloma — NCT02749617.
- Registry record last updated 2021-08-23; status last verified 2021-07.
- Results first posted 2021-08-23.
- 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 identifies NCT02749617 as a Phase 2 pilot study of apixaban and dexamethasone interaction in multiple myeloma. It describes a single-group, unmasked design with allocation not applicable. Apixaban was listed at 2.5 mg by mouth twice a day. The brief summary proposed a prospective cohort of 24 and described serial anti-Xa activity over a 3-month period as the primary outcome.
The registry records enrollment of 2, status terminated, a start date of 2016-08-09, and a primary completion date of 2018-01-03. It lists two outcome measures and no analyses. The posted record does not include a primary endpoint result, an analysis method, or the reason for termination. It records 0 serious adverse events among 2 at risk, 2 affected by other adverse events among 2 at risk, and 2 deaths, without event details or attribution.