Efficacy and Safety of Elbasvir (MK-8742) + Grazoprevir (MK-5172) in Treatment-Naïve/Treatment-Experienced (TN/TE) French Participants With Hepatitis C Virus (HCV) Genotype 4 (GT4) Infection (MK-5172-096): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Efficacy and Safety of Elbasvir (MK-8742) + Grazoprevir (MK-5172) in Treatment-Naïve/Treatment-Experienced (TN/TE) French Participants With Hepatitis C Virus (HCV) Genotype 4 (GT4) Infection (MK-5172-096) (NCT03111108), a randomized phase 4 study. The primary outcome is Percentage of Participants Achieving Sustained Virologic Response 12 Weeks After End of Treatment (SVR12).

2. Clinical Question

3. Trial Design

This was a completed, Phase 4, multi-site, open-label, parallel-group trial listed as randomized in the registry. Its official title describes it as partially randomized. The registry reports enrollment of 117 participants and identifies the condition as hepatitis C virus infection. The study took place in French participants with genotype 4 infection, including treatment-naïve and treatment-experienced participants. The start date was 2017-06-20, and primary completion was 2018-10-15.

The tested treatment was a fixed-dose combination of elbasvir and grazoprevir at 50 mg/100 mg. One arm received the regimen for 8 weeks and the other for 12 weeks. The 8-week arm was for treatment-naïve participants with F0-F2 fibrosis. The 12-week arm included treatment-naïve participants with F0-F2 or F3-F4 fibrosis and treatment-experienced participants with F0-F4 fibrosis. Each arm had 24 weeks of follow-up. The primary response was assessed 12 weeks after treatment ended, corresponding to Arm 1: Week 20 / Arm 2: Week 24.

Because eligibility differed between arms, the comparison should be read in light of the enrolled populations as well as the treatment durations. The registry does not report the specific randomization process, the allocation ratio, or how the partially randomized design operated. It also does not report the trial's original sample-size justification, interim analysis plan, or detailed statistical analysis plan. Those omissions limit what can be inferred about the intended design assumptions and the planned handling of the data.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All randomized participants who received ≥1 dose of study treatment are included.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants Achieving Sustained Virologic Response 12 Weeks After End of Treatment (SVR12), measured over 12 weeks after completing study treatment (Arm 1: Week 20 / Arm 2: Week 24).

The primary endpoint was the percentage of participants achieving sustained virologic response 12 weeks after completing study treatment, or SVR12. The registry defines SVR12 as HCV ribonucleic acid (RNA) below the lower limit of quantification at that post-treatment assessment. RNA was measured using the COBAS™ AmpliPrep/COBAS™ TaqMan HCV Test, v2.0®, with a lower limit of quantification of 15 IU/mL.

In general, a virologic response endpoint records whether the laboratory result meets a prespecified threshold at a defined time. It converts a measurement into a response classification: each participant either meets the SVR12 definition or does not. The reported percentage is therefore a proportion of participants, rather than an average change in RNA concentration. The registry states that the primary analysis population included all randomized participants who received at least one dose of study treatment.

SVR12 is used in this trial to assess whether the defined virologic response was present after treatment had ended, rather than only while participants were taking study therapy. It is a time-specific endpoint: it describes response at the stated follow-up assessment and does not, on its own, describe every later outcome. The registry also lists SVR24 as a secondary outcome. Neither endpoint alone conveys the full clinical course or establishes a comparative treatment effect without considering the design, population, uncertainty, and analysis methods.

7. Results Posted in the Registry

• Arm 2: EBR/GZR for 12 Weeks: 95.3% (61/64) versus 94.3% (50/53) on control; risk difference 1.0 percentage points (95% CI -7.1 to 9.1), risk ratio 1.01 (0.93–1.10); unadjusted two-proportion z-test p = 0.812.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Percentage of Participants Achieving Sustained Virologic Response 24 Weeks After End of Treatment (SVR24)

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Arm 2: EBR/GZR for 12 Weeks: 93.8% (60/64) versus 94.3% (50/53) on control; risk difference -0.6 percentage points (95% CI -9.2 to 8.0), risk ratio 0.99 (0.91–1.09); unadjusted two-proportion z-test p = 0.894.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Arm 2: EBR/GZR for 12 Weeks and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists SVR24 and baseline resistance-associated substitutions as secondary outcomes. The posted SVR24 results show a similar broad pattern to the primary outcome: response percentages in both arms are high, and the arm estimates are close relative to the uncertainty around the comparison. This provides a later-timepoint description alongside the SVR12 endpoint, rather than an independent confirmation that removes the limitations of the primary comparison.

The other listed secondary outcomes concern the prevalence of baseline NS3 and NS5A resistance-associated substitutions to elbasvir or grazoprevir. These describe baseline viral characteristics, not post-treatment response. They address a different question from whether participants meet the SVR endpoint and should not be combined conceptually with response proportions as if they measured the same outcome.

In general, secondary outcomes can add context about durability or baseline characteristics, but their interpretation depends on how they were prespecified, how many were examined, and how results were analyzed. The registry record lists six outcome measures and reports no analysis records. It does not report a multiplicity strategy or detailed plans for secondary analyses. When many outcomes are considered, unadjusted results carry less weight as confirmatory evidence because the chance of seeing an apparently notable result can increase across repeated testing.

The secondary findings should therefore be treated as supportive descriptions rather than as a substitute for the primary endpoint or a separate basis for asserting a treatment difference. Their relevance is best judged alongside the primary results, the different eligibility criteria, the uncertainty in the estimates, and the incomplete reporting of analysis methods. No claim about an adjusted secondary comparison can be made from the registry record.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Percentage of Participants Achieving Sustained Virologic Response 24 Weeks After End of Treatment (SVR24)
• Prevalence of Baseline NS3 Resistance-Associated Substitutions (RASs) to EBR or GZR
• Prevalence of Baseline NS5A RASs to EBR or GZR

9. Statistical Interpretation

10. Statistical Methods Explained

Several statistical ideas help explain how to read the response estimates and their comparison. General explanations are identified as such; the trial-specific values are those reported in the registry record.

What does a response percentage represent?

General: For a binary endpoint, each participant is classified according to whether the specified event occurred. The response percentage estimates the proportion meeting that definition in the analysis group. It is an estimate rather than a guarantee that the same proportion would be seen in another sample from a similar population. The registry's primary endpoint is the percentage with SVR12, and the response definition is based on HCV RNA below the stated lower limit of quantification at the specified follow-up.

The posted SVR12 estimates are 94.3% for the 8-week arm and 95.3% for the 12-week arm. Their denominators are 53 and 64, respectively. The registry defines the primary analysis population as randomized participants who received at least one dose of study treatment. The record does not describe the number of participants with missing endpoint data or the method, if any, used to address missingness.

What do confidence intervals communicate?

General: A confidence interval conveys uncertainty around an estimate under the method used to calculate it. Wider intervals indicate less precision than narrower intervals. An interval is not a range that guarantees the true value lies within its endpoints; rather, it reflects the variability expected from the estimation procedure under its assumptions. For proportions, precision depends in part on the number of observations and on the observed response pattern.

The registry reports a 95% confidence interval for each arm's response proportion. It also reports an interval for the risk difference. The risk-difference interval runs from -0.071 to 0.091. Because it crosses zero, it is compatible with no difference as well as with differences in either direction. The confidence interval is important alongside the point estimate: a point estimate alone can make a small or uncertain comparison appear more definite than it is.

How should the arm comparison be read?

General: A risk difference compares the response proportions by subtraction on the probability scale. A risk ratio compares them as a ratio, while an odds ratio compares the odds of response. These measures express related but distinct aspects of a binary outcome and can have different numerical scales. The registry's posted comparison gives a risk difference of 0.010, a risk ratio of 1.01, and an odds ratio of 1.22. Each measure has its own confidence interval, and none should be interpreted without attention to its scale and uncertainty.

The reported p-value for the primary comparison is unadjusted and equals 0.812. General: A p-value measures how surprising data at least as incompatible with a stated null hypothesis would be under a statistical model, assuming that model and hypothesis. It is not the probability that the null hypothesis is true, nor a measure of clinical importance. An unadjusted p-value also does not account for testing multiple outcomes or comparisons. The registry record does not report a multiplicity adjustment plan.

Why does the design matter to the estimate?

General: A randomized comparison can support causal interpretation when assignment is implemented as intended, relevant groups are comparable at baseline, and analysis follows a suitable plan. Open-label status means treatment assignment was not masked. The trial is described as partially randomized, but the registry does not explain the allocation process or which participants were randomized. In addition, the arms had different eligibility criteria. These details make it especially important not to attribute the observed contrast solely to treatment duration without more information about assignment and population composition.

The primary population is described as all randomized participants who received at least one dose, rather than all randomized participants regardless of treatment receipt. The registry does not report further analysis-population definitions, deviations from assigned treatment, or missing-data procedures. Such information can affect how robustly the posted proportions represent the randomized groups.

What does the endpoint timing mean?

General: An endpoint is tied to a definition and an assessment time. SVR12 refers to meeting the RNA threshold 12 weeks after treatment ends. It is not interchangeable with an assessment during therapy or at a later follow-up point. The registry also reports SVR24 as a secondary outcome. Comparing the two timepoints can describe response at separate assessments, but it does not replace a prespecified longitudinal analysis, which is not reported in the registry record.

The registry identifies 6 outcome measures and 0 reported analyses. That means the record presents outcome results but does not provide reported analysis records detailing modeling choices, adjustments, or other inferential procedures. The posted estimates are therefore best read as registry-reported proportions and unadjusted comparisons, with their stated intervals, rather than as a complete account of every planned statistical analysis.

11. Confidence Intervals and Precision

The SVR12 estimates are 94.3% for the 8-week regimen and 95.3% for the 12-week regimen. Their 95% confidence intervals are 84.3% to 98.8% and 86.9% to 99.0%, respectively. Although the point estimates are close, the intervals cover a wider span of possible response proportions. This indicates that the percentages are not highly precise estimates of the underlying response rates.

The comparison is less precise than a single arm estimate might suggest from its point estimate alone. The risk difference is 0.010, with a 95% confidence interval from -0.071 to 0.091. In general, a confidence interval for a difference shows which values remain compatible with the data and the calculation method. Here, the interval includes zero and extends in both directions, so the data do not pin down the direction or size of the difference. The unadjusted p-value is 0.812, which likewise does not establish equivalence.

Precision is affected by the available sample size and by the amount of outcome variation. The arm denominators were 53 and 64. With modest groups, a few outcome classifications can influence the estimated proportions, and uncertainty can remain appreciable even when the observed percentages are high. In general, more observations can improve precision, but the degree of improvement depends on design and outcome variability; this is not a claim about what the trial would have found with a larger enrollment.

Interpretation also requires acknowledging that the populations were not defined identically across arms. Confidence intervals quantify sampling uncertainty under their calculation assumptions; they do not resolve differences in eligibility, the partially randomized design, possible missing outcomes, or unreported analysis choices. The intervals therefore describe statistical precision for the posted estimates, not every source of uncertainty about the comparison.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size figures are planning illustrations based on the observed effect, not the trial's own original design assumptions. The registry's stated planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is the stated fraction of the observed effect. The figures are participants per arm, not total enrollment or total events; the note about total events applies to time-to-event outcomes, whereas these response outcomes are not time-to-event outcomes.

The 80% power column gives the number of participants per arm that the planning calculation associates with an 80% chance of detecting the specified effect under those assumptions, if that effect and model assumptions were true. The 90% power column makes the same calculation for a higher target chance of detection, and therefore calls for more participants per arm. These are conditional planning quantities, not guarantees about the result of a future trial.

For the primary comparison, planning for 100% of the observed effect gives 8,136 participants per arm for 80% power and 10,892 participants per arm for 90% power. Planning for 75% of the observed effect gives 14,786 participants per arm for 80% power and 19,794 participants per arm for 90% power. Planning for 50% of the observed effect gives 33,990 participants per arm for 80% power and 45,503 participants per arm for 90% power. The pattern illustrates the general principle that smaller effects require more participants to detect with a given power target. This is not observed power.

These projections use the observed effect as their starting point, so they should not be read as a reconstruction of the original trial's target or design. The original sample-size justification is not reported in the registry record. The planning calculations also assume equal allocation, while the posted outcome denominators are 53 and 64; the planning assumptions and the observed trial enrollment answer different questions.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.943; treatment proportion p₁ = 0.953; average p̄ = 0.948.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.3132 = 0.6140.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.3132 = 0.2636.
4. n = (0.6140 + 0.2636)² / (0.0097)² = 8,135.9, rounded up to 8,136 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
p0 <- 0.943396226415094                          # control proportion
p1 <- 0.953125                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(3111108)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 8,136 (80% power), 10,892 (90% power)
 75% of observed effect: n per arm = 14,786 (80% power), 19,794 (90% power)
 50% of observed effect: n per arm = 33,990 (80% power), 45,503 (90% power)
power.prop.test: 8135.9 
Simulated power at n = 8,136 per arm: 0.804 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

The registry identifies a primary endpoint and several secondary outcomes, but does not report a multiplicity strategy. Multiplicity arises when statistical tests are conducted for multiple endpoints, timepoints, groups, or comparisons. In general, the more tests considered, the greater the chance that at least one unadjusted result will appear noteworthy by chance alone. Adjustments or a prespecified hierarchy can help control how results are interpreted, but neither an adjustment nor a hierarchy is reported in the registry record.

The primary comparison includes an unadjusted p-value of 0.812. The registry lists 0 reported analyses, so it does not provide a fuller inferential record describing model choices, adjustment procedures, or planned testing order. The reported p-value should be read as an unadjusted result, not as evidence that multiplicity was addressed. The specific statistical analysis plan and interim analysis approach are not reported in the registry record.

Missing-data handling is also not reported in the registry record. The endpoint is assessed after treatment, and the primary population is defined as all randomized participants who received at least one dose. However, the record does not state how many endpoint measurements were missing, whether any participants were excluded after randomization, or how missing results were classified or imputed. It is therefore not possible to determine from the posted information whether missingness could have affected the response estimates.

The stated analysis population is not identical in wording to an all-randomized population because receipt of at least one dose is part of the definition. The record does not explain whether the analysis followed assigned treatment, how protocol deviations were handled, or whether other analysis populations were used. These are important distinctions for interpreting a randomized trial, especially one described as partially randomized and open-label.

These reporting gaps do not show that a particular method was or was not used; they mean the details are not reported in the registry record. Consequently, interpretation should remain centered on the posted estimates, their confidence intervals, the stated outcome definitions, and the known limits of the documented design.

15. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: post procedural infection (1.9%), diabetes mellitus (1.9%), osteoarthritis (1.6%), cerebellar stroke (1.6%).

The registry reports serious adverse events for 2 of 53 participants in the 8-week arm and 2 of 64 participants in the 12-week arm. Deaths were 0 in the 8-week arm and 1 in the 12-week arm. Other adverse events were reported for 27 of 53 and 38 of 64 participants, respectively. These counts describe what was recorded in the two arms; they do not establish that the regimens caused or prevented an event.

The registry also lists serious adverse event terms and their reported percentages: Post procedural infection, 1.9%; Diabetes mellitus, 1.9%; Osteoarthritis, 1.6%; and Cerebellar stroke, 1.6%. The record does not make clear in this listing how those terms map to individual arms, so they should not be assigned to one arm from this information alone.

In general, adverse-event counts need context about event definitions, follow-up, severity, relatedness assessment, and how repeated events are counted. Those details are not reported in the registry record. The posted counts are useful for describing the recorded safety experience, but the group sizes and limited reporting do not support a broad comparative safety conclusion.

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

The posted results describe the proportion of participants meeting a laboratory-defined SVR12 threshold in each arm, as well as a later SVR24 outcome. They show high response percentages in both groups and a small observed risk difference for the primary comparison. The confidence interval around that difference is wide enough to include values favoring either arm as well as no difference. The result therefore gives an estimate with substantial uncertainty rather than a precise account of how the regimens compare.

These data do not establish equivalence or non-inferiority. Such conclusions require a suitable design, a prespecified margin, and an analysis capable of addressing that question; a margin is not reported in the registry record. A non-significant unadjusted p-value also does not show that two regimens have identical effects. It indicates only that the posted comparison did not produce strong evidence against the tested null under the calculation used.

The comparison should not be interpreted as isolating treatment duration alone. The 8-week group comprised treatment-naïve participants with F0-F2 fibrosis. The 12-week group included a broader range of fibrosis stages and treatment histories. The registry calls the trial partially randomized but does not describe how assignment worked. Those features limit causal interpretation of the contrast as a direct duration comparison.

The findings describe participants in the registry's defined analysis population who received at least one dose, with outcome denominators of 53 and 64. The record does not provide detailed missing-data methods or a complete account of analysis populations. It also does not report the original sample-size justification or a detailed analysis plan. Results should therefore be understood as registry-posted estimates, not as a complete statistical report.

The findings do not determine an individual's outcome, provide a treatment recommendation, or establish how results would generalize beyond the trial's French genotype 4 population and eligibility groups. They are one part of the evidence about response and recorded adverse events. Their statistical meaning is bounded by the endpoint definitions, study design, sample size, and uncertainty described in the registry record.

17. Why This Trial Matters Statistically

This trial is statistically informative because its point estimates appear close, while the uncertainty around the comparison remains broad. That combination is a useful reminder that similarity between observed percentages does not automatically mean the underlying effects are known to be similar. Confidence intervals help show what the data can and cannot distinguish; the risk-difference interval spans zero and possible differences in either direction.

The arm populations also illustrate why the comparison must be interpreted as a design question, not only as a numerical contrast. The groups had different eligibility criteria, and the registry describes the study as partially randomized without explaining the allocation process. Those features matter when asking whether a difference in outcomes can be attributed to treatment duration. Clear reporting of randomization, analysis populations, missing data, and prespecified comparisons is essential for evaluating that question.

The planning illustrations highlight a further statistical issue: small observed differences can imply large sample-size requirements when a study is designed to detect a similar or smaller effect under the stated assumptions. Such calculations are forward-looking planning tools and not evidence that the original study had adequate power or that an effect is absent. The original design justification is not reported in the registry record.

Finally, the registry record lists multiple outcomes but no reported analyses or multiplicity strategy. This underscores the distinction between descriptive outcome reporting and a prespecified inferential framework. Statistical interpretation depends not just on the reported percentages and p-value, but also on the design, uncertainty, testing plan, and transparency of analysis choices.

18. 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.
• Participant counts were reconstructed from posted percentages and arm sizes, so small rounding differences are possible.

Several trial-specific limitations constrain interpretation. The registry describes the trial as partially randomized, but does not report which participants were randomized, how assignment was conducted, or whether allocation differed by eligibility group. The study was open-label, and the record does not describe any safeguards for outcome assessment. These missing design details make it difficult to assess the strength of the between-arm comparison.

The eligibility criteria differed by arm. The 8-week group included treatment-naïve participants with F0-F2 fibrosis, whereas the 12-week group included treatment-naïve participants with F0-F2 or F3-F4 fibrosis and treatment-experienced participants with F0-F4 fibrosis. Consequently, the groups cannot be assumed to represent the same population. The posted contrast should not be read as a duration-only comparison without more detail about allocation and participant characteristics.

The outcome groups were limited in size, with 53 and 64 participants contributing to the primary estimates. The confidence intervals reflect substantial uncertainty. Although total enrollment was 117, the record does not explain the relationship between enrollment and the primary analysis population beyond the stated requirement of at least one dose.

The registry does not report the original sample-size justification, detailed analysis plan, interim analyses, multiplicity approach, or methods for handling missing outcomes. It also does not report a non-inferiority margin or equivalence framework. The record lists 0 reported analyses, which limits the ability to evaluate statistical modeling and sensitivity analyses. These are reporting limitations; they do not establish that a particular procedure was not performed.

Finally, the findings apply directly to the listed French participants with genotype 4 infection and the eligibility groups in this study. The registry information alone does not establish how well the results generalize to other populations or settings.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Efficacy and Safety of Elbasvir (MK-8742) + Grazoprevir (MK-5172) in Treatment-Naïve/Treatment-Experienced (TN/TE) French Participants With Hepatitis C Virus (HCV) Genotype 4 (GT4) Infection (MK-5172-096) — NCT03111108.
• Registry record last updated 2020-06-09; status last verified 2020-05.
• Results first posted 2019-11-12.
• 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.

22. Record Summary

NCT03111108 is a completed Phase 4, open-label, parallel-group trial of fixed-dose elbasvir/grazoprevir in French participants with hepatitis C virus genotype 4 infection. The registry reports randomized allocation and describes the study as partially randomized. Enrollment was 117. The arms evaluated 8 weeks in treatment-naïve participants with F0-F2 fibrosis and 12 weeks in a broader group that included treatment-experienced participants and additional fibrosis stages.

The primary endpoint was SVR12, defined as HCV RNA below the lower limit of quantification 12 weeks after treatment ended. The posted response estimates were 94.3% and 95.3%, with overlapping 95% confidence intervals; the unadjusted risk difference was 0.010, with a 95% confidence interval from -0.071 to 0.091. The record also reports SVR24 and safety outcomes.

Interpretation is limited by different arm eligibility criteria, incomplete detail about partial randomization, and the absence of reported analysis, missing-data, multiplicity, and original sample-size planning methods.