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 Maraviroc Efficacy for Hepatitis C (NCT02881762), a randomized phase 4 study. The primary outcome is The Change in Hepatitis C Viral Load From Baseline to 4 Weeks of Maraviroc or No Maraviroc.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02881762 |
| Phase | Phase 4 |
| Condition | Hepatitis C, Human Immunodeficiency Virus |
| Allocation | Randomized |
| Design model | Crossover |
| Masking | None (open label) |
| Enrollment | 10 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Maryland, Baltimore |
| Results posted | Yes |
2. Clinical Question
Population
People co-infected with hepatitis C and HIV who were taking antiretroviral therapy for HIV. The registry record lists an enrollment of 10, but does not report the number included in the final analysis.
Intervention
Maraviroc, an intervention being evaluated for its effect on hepatitis C viral levels. In the immediate-start group, maraviroc began after randomization; the delayed-start group began it 8 weeks after enrollment.
Comparator
The comparison was between periods with maraviroc and periods without maraviroc in a randomized crossover study. The registry record describes immediate and delayed starts, but does not report the detailed sequence or period-specific analysis.
Primary question
The registered primary outcome concerns change in hepatitis C viral load from baseline to 4 weeks of maraviroc or no maraviroc, measured in International Units/ml. The numerical results for that outcome are not reported in the registry record.
The study was intended to evaluate whether viral levels changed during maraviroc exposure in participants who also had HIV and were receiving HIV antiretroviral therapy. The crossover design means that participants could contribute observations under both maraviroc and no-maraviroc conditions, rather than belonging to only one treatment condition throughout the study. Such a design can make within-person comparisons possible, but interpretation also depends on the timing of measurements, treatment order, and whether effects from one period could persist into another. Those details are not reported in the registry record.
The registry describes a pilot study, not a large confirmatory trial. Its primary question is therefore best read as an evaluation of a registered viral-load outcome in a small enrolled group, rather than as a definitive estimate of an effect. The outcome result itself, including its direction, magnitude, and precision, is not reported in the registry record.
3. Trial Design
This was a phase 4, randomized, open-label, single-site, longitudinal interventional study. Its stated focus was the effect of maraviroc on hepatitis C viral levels in people co-infected with HIV and hepatitis C who were taking HIV antiretroviral therapy. The registry lists an enrollment of 10 and a completed status. The study start was 2017-06-01, and primary completion was 2019-03-27.
The study used a crossover model. The immediate-start group was to begin maraviroc after randomization, while the delayed-start group was to begin maraviroc 8 weeks after enrollment. These descriptions establish a difference in timing, but do not fully specify the treatment sequence, the duration of every period, or the timing of all measurements. Those details are not reported in the registry record. The record also does not report the randomization method or the allocation ratio.
Masking was none, so the study was open-label. Participants and study personnel were not described as blinded to the treatment condition. Open-label conduct does not by itself determine the direction or size of bias, but it can matter for outcomes influenced by decisions, expectations, or measurement procedures. The primary outcome is a laboratory measure, but the registry record does not describe laboratory masking or quality-control procedures.
The primary analysis population was defined as participants who received at least one dose of each intervention and completed all study visits. This definition is narrower than simply being enrolled or randomized. The number meeting those criteria is not reported in the registry record, so the extent of any difference between enrollment and final analysis cannot be assessed. The protocol, sample-size justification, and details of the statistical analysis plan 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.
First Intervention (4 Weeks)
| Stage | Maraviroc First, Then No Maraviroc | No Maraviroc First, Then Maraviroc |
|---|---|---|
| STARTED | 5 | 5 |
| COMPLETED | 5 | 4 |
| NOT COMPLETED | 0 | 1 |
Reasons for not completing this period:
| Reason | Maraviroc First, Then No Maraviroc | No Maraviroc First, Then Maraviroc |
|---|---|---|
| Withdrawal by Subject | 0 | 1 |
Washout (4 Weeks)
| Stage | Maraviroc First, Then No Maraviroc | No Maraviroc First, Then Maraviroc |
|---|---|---|
| STARTED | 5 | 4 |
| COMPLETED | 5 | 4 |
| NOT COMPLETED | 0 | 0 |
Second Intervention (4 Weeks)
| Stage | Maraviroc First, Then No Maraviroc | No Maraviroc First, Then Maraviroc |
|---|---|---|
| STARTED | 5 | 4 |
| COMPLETED | 5 | 4 |
| NOT COMPLETED | 0 | 0 |
Followup No Maraviroc First Only (4 Wks)
| Stage | Maraviroc First, Then No Maraviroc | No Maraviroc First, Then Maraviroc |
|---|---|---|
| STARTED | 5 | 4 |
| COMPLETED | 5 | 4 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: All participants who received at least one dose of each intervention and completed all study visits were included in the final analysis
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 | Maraviroc First, Then no Maraviroc | No Maraviroc First, Then Maraviroc | Total |
|---|---|---|---|---|
| Participants analysed | 5 | 4 | 9 | |
| Age, Continuous | Years | 56.6 (SD 3.1) | 55.8 (SD 9.7) | 56.2 (SD 6.8) |
| Sex: Female, Male: Female | Participants | 2 | 2 | 4 |
| Sex: Female, Male: Male | Participants | 3 | 2 | 5 |
| 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 | 5 | 4 | 9 |
| Race (NIH/OMB): White | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | participants | 5 | 4 | 9 |
| Hepatitis C viral load | International Units/ml | 1734274 (SD 949012) | 2411068 (SD 1093469) | 2035071 (SD 1012880) |
| Alanine transaminase | International Units/ml | 39.6 (SD 21.2) | 31.8 (SD 2.6) | 36.1 (SD 15.7) |
6. Primary Endpoint
The registry lists the primary outcome as The Change in Hepatitis C Viral Load From Baseline to 4 Weeks of Maraviroc or No Maraviroc, measured over Baseline to 4 weeks.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | International Units/ml |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is described as change in hepatitis C viral load from baseline to 4 weeks of maraviroc or no maraviroc. Viral load is expressed in International Units/ml. The registry identifies the summary measure as a mean and the dispersion measure as a standard deviation. It also states that viral load was measured before starting maraviroc and at 4 weeks of maraviroc. However, the registry does not report a numerical mean change, standard deviation, confidence interval, or statistical test result for the primary outcome.
A continuous viral-load measure can capture the amount of virus at a measurement time, while a change score describes how that measure differs between specified times. Change from baseline is often used to make the follow-up measurement interpretable relative to participants’ starting values. In a crossover study, measurements during maraviroc and no-maraviroc periods may also allow within-person comparisons. These are general statistical reasons for using such an endpoint; the registry record does not explain the endpoint’s rationale or the exact calculation used for each participant’s change.
The registry indicates that the primary outcome has several categories or time points and is not reduced to one comparison. As a result, it is not possible to identify a single numerical primary contrast from the posted registry information. The outcome should therefore be understood through its stated measurement and timeframe, while recognizing that its analysis and numerical findings are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies a primary viral-load outcome and a final-analysis population, but it does not report the numerical primary outcome results. In particular, no mean change, standard deviation, confidence interval, or p-value for the primary outcome is reported in the registry record. The size, direction, and statistical precision of any difference between maraviroc and no-maraviroc conditions therefore cannot be assessed from the posted outcome information.
The design matters for interpretation. Because this was a crossover study, participants could experience both intervention conditions. That structure may allow a participant’s measurements under one condition to be compared with that same participant’s measurements under another condition. In general, within-person comparisons can account for stable differences between participants. They also require attention to treatment order, time effects, and possible carryover between periods. The registry record does not report how these issues were handled or whether any carryover assessment was undertaken.
The registry lists an enrollment of 10, but the primary analysis included only participants who received at least one dose of each intervention and completed all study visits. The number satisfying that definition is not reported. Thus, the enrolled count cannot be treated as the analyzed count, and the possible effect of exclusions or incomplete follow-up cannot be evaluated. The registry record does not report the extent or reasons for missing outcome measurements.
The record lists 2 outcome measures and 2 analyses. It does not describe a hierarchy among outcomes, a multiplicity adjustment, or which analysis should be treated as confirmatory. Those omissions matter because results across multiple outcomes or analyses can be difficult to interpret as a single test of a primary hypothesis. The registry’s description of several primary-outcome categories or time points also means that a lone summary comparison cannot be reconstructed from the information reported.
Accordingly, the registry record supports a description of the study question, design, and outcome definition, but not a conclusion about the magnitude or precision of the observed viral-load changes. The absence of reported numerical results is not evidence that the outcome was unchanged, nor does it show that a particular effect was present. It means the result cannot be judged from this record. Any planning illustrations based on an observed effect should be read only as planning calculations under stated assumptions, not as evidence about the reliability of a treatment effect or as observed power.
9. Statistical Methods Explained
What does a mean and standard deviation describe?
The registered primary outcome is continuous and is summarized using a mean and standard deviation. In general, a mean represents the average value across the observations included in a particular summary. A standard deviation describes how spread out those observations are around their mean. These summaries answer different questions: the mean describes the center of the observations, while the standard deviation describes their variability.
For a change outcome, the specific observations being averaged matter. A mean change could be calculated for each treatment condition and then compared, or individual within-person changes could be contrasted. In a crossover study, the latter kind of comparison may use information from both conditions for the same participant. The registry record does not report the precise calculation, the period-specific summaries, or the numerical mean and standard deviation. Those statistics therefore cannot be interpreted quantitatively.
Why is crossover structure relevant?
In general, crossover trials assign treatment conditions in a sequence so that participants contribute measurements during more than one condition. A potential advantage is that each participant can serve as their own comparator, reducing the influence of stable between-person differences on the contrast. This advantage depends on appropriate design and analysis. Outcomes can vary with time even without a treatment effect, and exposure in one period may affect measurements in a later period. These are general concerns, not findings about this trial.
The record identifies immediate and delayed maraviroc starts and a crossover model, but does not report the full sequence, period length, washout arrangements, or statistical handling of period and carryover effects. It is therefore not possible to determine from the registry record how the analysis used the crossover structure or how well it addressed these design considerations.
What would a confidence interval add?
In general, a confidence interval gives a range of values compatible with the data and the assumptions of a statistical method. Its width communicates precision: a narrower interval indicates more precise estimation, while a wider interval indicates more uncertainty. A confidence interval is not a guarantee that the true effect lies within the particular interval, and it does not by itself settle whether an effect is clinically important.
No confidence interval for the primary viral-load outcome is reported in the registry record. Without one, readers cannot assess the precision of the estimated change from the posted outcome results. A p-value is also not reported for that primary outcome. General interpretation of a p-value depends on the statistical test and its assumptions, and a p-value alone does not describe the size of an effect. No such test result can be inferred from the outcome description.
Why can dispersion and distribution matter?
Standard deviation is a familiar measure of spread for continuous data. If observations have an unusual distribution or influential extreme values, the mean and standard deviation may not fully convey the data pattern. In general, graphical or robust summaries can help assess whether the mean is a useful description. The registry record does not report distributional diagnostics, transformations, or alternative summaries for this endpoint.
Over-dispersion is a concern most often discussed for count data, where variability exceeds what a simple model assumes. The registered primary outcome is continuous and summarized as a mean with standard deviation, so the registry record does not establish that a count-data model or an over-dispersion adjustment was used. More broadly, model assumptions should match the data structure; the specific statistical model for this trial is not reported in the registry record.
What do the planning assumptions mean?
The registry material describes a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It states that the effect to detect is a specified fraction of the observed effect. Such a calculation is a scenario for planning future sample sizes under assumptions; it is not the trial’s observed effect and is not evidence that the trial had a particular probability of detecting an effect.
The illustration’s numerical sample-size outputs and the observed effect used for it are not reported in the registry record. The record also does not report the trial’s own sample-size justification. Consequently, the planning assumptions should not be mistaken for the design rationale or for the actual statistical analysis plan. No sample-size figure can be recovered from the information reported.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 2 outcome measures and 2 analyses, but does not report how the analyses relate to one another, whether one outcome was designated as the sole confirmatory outcome, or whether any adjustment for multiple testing was planned or used. When several outcomes, time points, or analyses are examined, the chance of at least one apparently notable result can increase. This is a general issue; the registry record does not report enough detail to determine its practical effect in this study.
The primary outcome is described as involving several categories or time points and is not reduced to one comparison. That makes it especially important to know which contrast was prespecified and how results were interpreted across the full set of measurements. The registry record does not report an analysis hierarchy, a family of tests, or a multiplicity procedure. It also does not report the statistical analysis plan or interim analyses.
The primary analysis population required participants to receive at least one dose of each intervention and complete all study visits. This criterion identifies who was eligible for the final analysis, but it does not explain how missing measurements were handled among those participants or what happened to participants who did not meet the criterion. The number analyzed, number with missing outcome data, and reasons for missingness are not reported in the registry record.
In general, excluding participants with incomplete visits can change the composition of the analyzed group if completion is related to outcome or treatment experience. Imputation, likelihood-based methods, and complete-observation analyses each rely on assumptions about missingness and the data structure. The registry record does not identify which missing-data method, if any, was used. It also does not report sensitivity analyses assessing the effect of missing data or changes in the analysis population.
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 |
|---|---|---|---|
| Maraviroc | 1 | 9 | 11.1% |
| No Maraviroc | 0 | 9 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Maraviroc | 0 of 9 |
| No Maraviroc | 0 of 9 |
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 |
|---|---|
| Maraviroc | 3 of 9 |
| No Maraviroc | 1 of 9 |
Most frequent serious adverse event terms
| Event term | Organ system | Maraviroc | No Maraviroc |
|---|---|---|---|
| Tibial plateau fracture | Musculoskeletal and connective tissue disorders | 1 of 9 | 0 of 9 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Maraviroc | No Maraviroc |
|---|---|---|---|
| Vomiting | Gastrointestinal disorders | 1 of 9 | 0 of 9 |
| Presyncope | Nervous system disorders | 1 of 9 | 0 of 9 |
| Soft tissue injury | Musculoskeletal and connective tissue disorders | 1 of 9 | 0 of 9 |
| Bruise | Skin and subcutaneous tissue disorders | 0 of 9 | 1 of 9 |
Serious events with the highest arm-level rate: tibial plateau fracture (11.1%).
The registry reports serious adverse events for 9 participants at risk during the maraviroc condition and 9 during the no-maraviroc condition. One participant was reported with a serious adverse event during maraviroc, compared with 0 during no maraviroc. Other adverse events were reported for 3 of the 9 at risk during maraviroc and 1 of the 9 at risk during no maraviroc. Deaths were 0 in both conditions.
The top listed serious event term was tibial plateau fracture, reported as 11.1%. The record does not explain the event’s relationship to study treatment, its timing, or whether it occurred in the participant counted among serious events for the maraviroc condition. The figures should therefore be read as registry event counts and listed terms, not as proof that an event was caused by or unrelated to maraviroc.
Because the study used a crossover design, participants may contribute to both treatment conditions. The two groups of 9 at risk should not automatically be treated as independent sets of people. The registry record does not report participant-level event overlap or a comparative safety analysis. These counts are descriptive and do not, by themselves, establish a difference in safety between conditions.
12. What the Result Does, and Does Not, Mean
The record establishes that a randomized, open-label crossover pilot study was conducted to evaluate maraviroc in people co-infected with hepatitis C and HIV who were taking antiretroviral therapy for HIV. It identifies the registered primary outcome as change in hepatitis C viral load over the stated timeframe and defines a final-analysis population based on exposure to both interventions and completion of all study visits.
What the posted record does not establish is the numerical result for that primary outcome. It does not report a mean change, a standard deviation, a confidence interval, or a p-value. Without those results, the direction and magnitude of the viral-load change, and the precision of any comparison, cannot be assessed. The missing numerical result cannot be interpreted as evidence of no change, just as the study’s stated purpose cannot be interpreted as evidence that a change occurred.
The enrollment of 10 signals that the study was small, but the analyzed number is not reported. The registry labels the study as a pilot; it does not report the sample-size justification or establish that the study was designed to provide a precise estimate. Small studies can produce uncertain estimates, but the actual precision in this study cannot be judged without the outcome data and their uncertainty measures.
The crossover design can support within-person comparisons in general, but the posted information does not detail the analysis of sequence, period, or carryover effects. The open-label design and the defined final-analysis population also warrant attention when interpreting any future reported result. The record provides a basis for understanding the question and some design features, not a basis for declaring a treatment effect or lack of effect.
Any sample-size planning illustration should be kept separate from trial findings. It is a calculation under assumptions based on an observed effect, not a result of a new trial and not observed power. The registry’s outcome, analysis, and missing-data details are insufficient to draw stronger statistical conclusions.
13. Why This Trial Matters Statistically
This trial is statistically informative as an example of how a crossover design can be used to study a continuous laboratory outcome in a small clinical setting. The immediate and delayed starts create treatment timing contrasts, while the crossover model indicates that the comparison may involve participants measured under both maraviroc and no-maraviroc conditions. This structure raises useful questions about within-person analysis, period effects, and carryover.
The registry also illustrates why an endpoint definition is not a substitute for outcome reporting. It specifies hepatitis C viral load, the unit, the mean and standard deviation as summary measures, and the baseline-to-4-week timeframe. But it does not report the resulting values or an inferential comparison. Readers can identify what was intended to be measured without being able to estimate the result or its precision.
The final-analysis criterion is another important statistical feature. Requiring exposure to both interventions and completion of all visits may be relevant to a crossover comparison, but the analyzed number and the handling of incomplete data are not reported. That distinction matters because an enrollment total alone does not reveal how many participants contributed to the primary analysis.
Finally, the record contains safety counts and planning assumptions that require careful interpretation. Crossover exposure means that event counts in the two conditions need not represent independent groups, and descriptive counts do not establish causality. Sample-size planning based on an observed effect is an illustration rather than an observed-power result or a substitute for the trial’s own design justification. The case underscores the value of reporting analysis populations, numerical outcome estimates, uncertainty, and missing-data methods together.
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 details needed to interpret the primary outcome are not reported in the registry record. The numerical viral-load results, including the mean change, standard deviation, confidence interval, and test result, are absent. The primary outcome is described as having several categories or time points and is not reduced to a single comparison, so the principal numerical contrast cannot be identified from the record.
The study is listed as randomized and crossover, but the randomization method, allocation ratio, treatment sequence, period durations, and any washout procedure are not reported. The record does not describe how the statistical analysis accounted for period, sequence, or carryover effects. It also does not report whether laboratory assessment was masked despite the overall open-label design.
Although enrollment is listed as 10, the number meeting the final-analysis definition is not reported. The record does not give counts or reasons for incomplete visits, missing outcome measurements, or exclusions from analysis. It does not specify a missing-data method or sensitivity analysis. These omissions prevent assessment of whether the final analysis population differed in important ways from those enrolled.
The registry lists 2 outcome measures and 2 analyses but does not describe multiplicity handling, outcome hierarchy, or a statistical analysis plan. The sample-size justification is not reported, and numerical outputs for the planning illustration are not available in the record. Finally, the single-site setting and small listed enrollment limit how much can be inferred about the breadth and precision of results, even if numerical results were available. These are limits on interpretation, not evidence for any particular outcome.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Maraviroc Efficacy for Hepatitis C — NCT02881762.
- Registry record last updated 2024-05-01; status last verified 2023-10.
- Results first posted 2024-05-01.
- 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
NCT02881762 is a completed phase 4, randomized, open-label, single-site crossover study sponsored by the University of Maryland, Baltimore. It evaluated maraviroc in people co-infected with hepatitis C and HIV who were taking antiretroviral therapy for HIV. The record lists an enrollment of 10 and study dates from 2017-06-01 to primary completion on 2019-03-27.
The primary outcome concerned change in hepatitis C viral load from baseline to 4 weeks of maraviroc or no maraviroc, measured in International Units/ml and summarized by a mean and standard deviation. The final-analysis population was defined by receiving at least one dose of each intervention and completing all study visits. Numerical primary-outcome results and the final analyzed count are not reported in the registry record.
The record lists serious and other adverse-event counts for each condition, with no deaths reported. It does not provide enough detail to attribute events to treatment or to assess a comparative safety effect. Statistical analysis details, including missing-data and multiplicity methods, are not reported in the registry record.