Evaluating the Role of Immune Responses in the Emergence of Protease Inhibitor Mutations: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluating the Role of Immune Responses in the Emergence of Protease Inhibitor Mutations (NCT01517529), a registered phase not stated study. The primary outcome is Number of Participants Who Completed Standard Treatment.

2. Clinical Question

The question is therefore exploratory and concerns biological processes during treatment, rather than a treatment-versus-control effect. The registry identifies HCV NS3 resistance mutations in the official title and describes blood sampling during treatment. It also lists a secondary outcome, the number of participants who cleared the virus. However, it does not report the results for viral clearance, the emergence of resistance mutations, viral load, or immune responses. Without those results, the record does not establish how often any outcome occurred or how immune responses related to mutation emergence.

3. Trial Design

This is a completed study sponsored by the University of Cincinnati. The registry lists a start date of 2012-01, a primary completion date of 2014-07, and enrollment of 10. The described arm consists of 10 chronically HCV-infected participants who had failed standard peg-IFN and Ribavirin therapy and were eligible for combined protease inhibitor therapy.

The record does not describe a randomized allocation. It explicitly characterizes the study as not a randomized comparison and notes that the arms are not a like-for-like control comparison. No control arm is described in the arm information. Consequently, the posted design does not support interpreting a difference between treatment groups, and the record does not establish a separate untreated or alternative-treatment group for comparison.

The project goal is to examine the role of immune responses in the emergence of protease inhibitor mutants during therapy. The primary outcome timeframe is 9 months. Its description says blood samples will be drawn while a participant is on treatment to measure viral load and HCV-specific immune responses. The primary outcome title, however, refers to participants who completed standard treatment. The registry does not report the protocol details needed to reconcile these descriptions, including the specific treatment regimen, sampling schedule, or operational definition of completion.

The record lists two outcome measures and identifies viral clearance as a secondary outcome. Although the study status is COMPLETED, numerical outcome results and analysis results are not reported in the registry record. The planned sample size and rationale, allocation procedures, eligibility details beyond those in the arm description, and analysis plan are not reported in the registry record. The small enrolled cohort and absence of a described control mean that the record chiefly documents a treatment-associated observational question, not a controlled estimate of treatment effect.

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

Analysis population for the primary outcome, as defined in the registry: Measure HCV viral load and HCV-specific immune responses at baseline

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.

Population: chronically HCV-infected patients who fail the standard peg-IFN and Ribavirin (RBV) therapy (NR)

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants Who Completed Standard Treatment, measured over 9 months.

The primary outcome is titled “Number of Participants Who Completed Standard Treatment,” with participants as the unit and a timeframe of 9 months. The record describes a binary outcome, meaning participants with an event are counted, but does not define the criteria for treatment completion or report the number who completed treatment.

The accompanying outcome description says blood samples are to be drawn during treatment to measure viral load and HCV-specific immune responses. The population description refers to measuring viral load and immune responses at baseline. These descriptions point to biological measurements, whereas the title specifies treatment completion. The registry does not explain how those measurements relate to the primary endpoint, whether they are separate measures, or how completion was determined.

In general, a clearly defined endpoint gives readers a consistent rule for deciding which observations count as events. Treatment completion can describe whether participants remained on a regimen through its defined course, while viral load and immune-response measurements describe biological characteristics. Those concepts are not interchangeable. Without an operational definition and posted results, the endpoint title alone cannot show how many participants completed treatment or what their measurements indicated.

The endpoint may be useful for describing treatment participation, but the registry record does not establish that completion is a measure of resistance mutation emergence. The goal of studying HCV NS3 mutations is stated in the study title and summary; the endpoint description does not specify a mutation outcome or a method for linking immune responses to mutation emergence.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a binary outcome as participants with an event, counted as a number. For the primary outcome, the named event is completion of standard treatment. In general, binary outcomes require an explicit rule for classifying each participant as having or not having the event. That rule should identify the relevant treatment course and what qualifies as completion. The operational definition is not reported in the registry record, and no event count is reported.

What can a participant count show?

A count can describe how many participants met an endpoint definition in the enrolled group. It is not, by itself, an estimate of a difference between treatments. To interpret a count fully, readers need its denominator, endpoint definition, time period, and the way missing observations were handled. The record gives enrollment of 10 and a primary timeframe of 9 months, but does not report the number completing treatment or the analysis population used for that outcome. The secondary outcome, viral clearance, is also named as a participant count, but its result is not reported.

What does the study design allow?

In general, random allocation can help balance measured and unmeasured participant characteristics between comparison groups. This record does not describe randomized allocation and states that it is not a randomized comparison. It also notes that the arms are not a like-for-like control comparison. No control arm is specified in the arm description. Thus, there is no registered randomized contrast to interpret as an estimate of the effect of protease inhibitor therapy relative to a comparator.

Within-participant measurements during treatment can be used to describe changes or associations over time, if a measurement schedule and analysis are defined. The record says blood samples will be drawn while participants are on treatment to measure viral load and HCV-specific immune responses, and its population description refers to baseline measurement. The sampling schedule, analysis methods, and numerical measurements are not reported in the registry record. The description also does not specify how measurements would be connected to the emergence of HCV NS3 resistance mutations.

How should uncertainty be understood?

In general, a point estimate is a single summary of an observed result, while a confidence interval communicates uncertainty around that estimate under the chosen model and assumptions. A p-value, if reported, measures how compatible the data are with a specified null model; it does not describe the probability that a hypothesis is true. Neither an estimate, a confidence interval, nor a p-value for the study outcomes is reported in the registry record. With no posted analyses, statistical significance and precision cannot be evaluated.

General planning calculations can estimate how many participants would be needed under specified assumptions to detect an effect at a chosen significance level and power. The planning illustration associated with this study assumes a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the target effect is a stated fraction of the observed effect. For time-to-event illustrations, the quantity is total events; other illustrations use participants per arm. These are planning assumptions, not evidence that the trial used that design. The record does not report the trial’s sample-size justification, and no observed effect is reported from which to assess the illustration. Such a calculation is not observed power and cannot show whether this completed cohort had adequate precision.

Why can over-dispersion matter?

General explanation: when count data vary more than a statistical model expects, standard errors can be underestimated and confidence intervals can be too narrow. A model that accounts for over-dispersion may better reflect the observed variability. This study’s primary endpoint is described as a binary participant count, not a rate or repeated event count, and the registry does not report an over-dispersion assessment or a model. No specific model choice can therefore be attributed to the study.

For an exploratory biological question, analysis also needs to distinguish descriptive measurement from a prespecified association test. The record states a goal of examining immune responses and mutation emergence but does not report the statistical plan, mutation outcome definition, covariates, or analysis population. Those details are necessary to judge whether a reported relationship would be descriptive, adjusted, or intended as a causal estimate. They are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The record lists two outcome measures: the primary outcome concerning completion of standard treatment and a secondary outcome concerning viral clearance. It does not report a statistical analysis plan, a testing hierarchy, or a method for accounting for multiple outcome tests. It also does not report outcome analyses or numerical results. Therefore, the registry does not establish which comparisons, if any, were treated as confirmatory or how the interpretation of multiple tests was handled.

In general, testing several outcomes can increase the chance of finding at least one apparently unusual result by chance. A prespecified hierarchy or multiplicity adjustment can address that issue, but the appropriate approach depends on the study objectives and analysis plan. No such approach is reported in the registry record, so it should not be assumed that an adjustment was or was not used.

Missing-data handling is also not reported in the registry record. The record does not state whether all 10 enrolled participants contributed endpoint data, whether any discontinued treatment, or how unavailable measurements would be handled. The enrollment count cannot be treated as the denominator for every outcome without those details. Likewise, the analysis population—such as whether the analysis included all enrolled participants or a subset—is not reported.

In general, missing measurements can affect both the estimated outcome and its uncertainty, especially if missingness is related to treatment completion, illness, or the measured response. The registry does not describe the extent or reasons for missing data, so their effect cannot be assessed. The record lists 0 analyses; this is an absence of posted analysis results, not a finding that there were no events or no missing observations.

11. Safety Results

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

Other (non-serious) adverse events

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

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: infection (10.0%).

The registry lists 10 participants at risk for serious adverse events and 1 participant affected. It separately lists 10 participants at risk for other adverse events and 0 affected. The most frequent serious adverse event term shown is “Infection,” with 10.0%. These are descriptive registry figures; they do not establish that an event was caused by the treatment.

The safety counts should be interpreted within the limits of the posted record. It does not provide event narratives, severity grades beyond the serious-event classification, timing, exposure details, or a comparison group. The listed serious-event term does not by itself establish the relationship between that event and protease inhibitor therapy. No comparative safety estimate can be derived from the described single arm.

The death count is null in the record. A null entry is not the same as a reported count of zero, so the number of deaths is not reported in the registry record. More generally, safety summaries can count participants, events, or both; the posted figures identify participants affected for the listed groups. They do not give a fuller account of repeated events or of how event collection was conducted.

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

The registry record documents a completed study enrolling 10 people with chronic HCV infection who had failed standard peg-IFN and Ribavirin therapy and were eligible for combined protease inhibitor therapy. Its stated scientific aim was to examine how immune responses relate to the emergence of protease inhibitor mutants during therapy. It also describes sampling to measure viral load and HCV-specific immune responses and lists viral clearance as a secondary outcome.

Those details establish the topic and broad population, but not the findings. Numerical results for treatment completion, viral clearance, viral load, immune responses, and resistance mutation emergence are not reported in the registry record. The listed primary outcome and its description do not provide an operational definition linking treatment completion with biological response. No analysis results are posted, so no estimate of association or its precision can be interpreted.

The record also does not describe a randomized comparison or a like-for-like control group. It therefore cannot support a causal conclusion about the effect of protease inhibitor therapy compared with another treatment. The enrolled cohort and the stated objective alone do not demonstrate that an immune response caused, prevented, or predicted resistance mutations.

General interpretation distinguishes a study’s rationale from its empirical result. A biologically important question can motivate data collection, but evidence about the question depends on clearly defined outcomes, available observations, and an analysis that connects those observations to the question. Here, the registry provides the rationale and some outcome descriptions, while the numerical findings and analysis details needed for that interpretation are not reported. The record should therefore be read as documentation of a small completed study and its intended inquiry, not as evidence for a particular treatment or biological effect.

13. Why This Trial Matters Statistically

This study matters statistically because its central question links several types of information: treatment completion, viral load, immune responses, and the emergence of HCV NS3 resistance mutations. These are related scientific concepts, but they are not interchangeable endpoints. A clear analysis would need to specify which measurement is the outcome, when it is assessed, and how immune responses are related to mutation emergence. The registry states the project goal and sampling intent, but does not report these analytic details or numerical results.

The record also illustrates why a participant count should not automatically be read as a treatment effect. The primary outcome title is a count of participants completing treatment, and the study does not describe randomized allocation or a comparable control group. A count can describe the enrolled group, but cannot by itself identify what would have happened to those participants under an alternative treatment.

Small exploratory studies can be valuable for describing feasibility and generating biological questions, but their estimates may be imprecise. In general, uncertainty should be evaluated with estimates and confidence intervals, alongside the endpoint definition and analysis population. Those outcome estimates are not reported in the registry record. The enrollment of 10 is not a substitute for an effect estimate, and planning illustrations do not establish observed power or the adequacy of the study’s design.

The record’s limitations are therefore relevant to how readers distinguish a research objective from a supported conclusion. It identifies a focused question about immune responses and resistance, but the posted registry information does not show the empirical relationship. Clear endpoint alignment, transparent missing-data handling, and reported analysis results would be necessary to make the question statistically interpretable.

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 registry’s outcome descriptions do not fully align. The primary outcome title concerns the number of participants who completed standard treatment, whereas the description concerns blood sampling for viral load and HCV-specific immune responses. The population description refers to baseline measurements. The record does not explain how these elements fit together or define treatment completion, limiting interpretation of what the primary outcome was intended to capture.

Although the official title and project goal concern HCV NS3 resistance mutations, no mutation outcome definition or numerical mutation results are reported in the registry record. The relationship between immune-response measurements and mutation emergence is also not specified. The secondary outcome of viral clearance is named, but its result is not reported.

Enrollment was 10, and no randomized comparison or like-for-like control is described. The registry does not report allocation details, treatment specifics, analysis populations, missing-data procedures, or the study’s sample-size justification. These omissions constrain assessment of bias, precision, and the scope of any possible inference. The status is COMPLETED, but completion status does not supply missing outcome results.

The record lists 1 participant affected by a serious adverse event and identifies Infection at 10.0% among the top serious terms, but it does not describe attribution or provide a comparator. The death entry is null rather than a stated zero. These safety details cannot support a comparative risk conclusion. Overall, the registry record offers limited descriptive information and does not provide enough outcome or analysis detail to assess the study’s biological or clinical findings.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Evaluating the Role of Immune Responses in the Emergence of Protease Inhibitor Mutations — NCT01517529.
• Registry record last updated 2015-11-20; status last verified 2015-10.
• Results first posted 2015-09-30.
• 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

NCT01517529 is a completed University of Cincinnati study with enrollment of 10 and a study start of 2012-01 and primary completion of 2014-07. It concerns chronic hepatitis C in participants who had failed standard peg-IFN and Ribavirin therapy and were eligible for combined protease inhibitor therapy.

The project aimed to examine immune responses in the emergence of protease inhibitor mutants during therapy. The primary outcome is titled as the number of participants who completed standard treatment, with a 9 months timeframe; its description refers to viral-load and HCV-specific immune-response measurements. Viral clearance is listed as a secondary outcome. Numerical outcome results and analysis results are not reported in the registry record. The record does not describe a randomized control comparison, and it does not provide the analysis plan or outcome definitions needed to assess an association between immune responses and resistance mutations.