Pharmacokinetics of JULUCA in Hemodialysis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Pharmacokinetics of JULUCA in Hemodialysis (NCT04431518), a non-randomized phase 4 study. The primary outcome is Dolutegravir (DTG) Ctau.

2. Clinical Question

In statistical terms, the study asks whether dolutegravir exposure at the specified Ctau measurement differs between participants receiving hemodialysis and those with normal renal function after both groups have received the same combination tablet. The stated study objective also concerns pharmacokinetics of both component drugs. Secondary outcomes include dolutegravir AUC and Cmax, as well as safety of DTG.

The design can describe pharmacokinetic measurements in these groups, but it does not isolate the effect of hemodialysis in the way a randomized comparison might isolate an assigned intervention. Group membership was not randomized, and treatment was the same in both groups. The registry record does not report adjustment for differences between the groups, a detailed eligibility definition, or numeric pharmacokinetic results. Consequently, the clinical question is clear, but the record does not contain the endpoint estimates needed to judge the size or precision of any observed group difference.

3. Trial Design

This is a Phase 4, non-randomized, unmasked, parallel-group study. The registry reports enrollment of 8. Participants were assigned to a hemodialysis group or a normal renal function group; the record does not describe random allocation. Both groups received JULUCA 50Mg-25Mg Tablet, one pill per day for up to 14 days.

The brief study description says the investigators compare pharmacokinetics of the component drugs in JULUCA in HIV-negative patients requiring hemodialysis with those with normal renal function. The formal title identifies dolutegravir/rilpivirine fixed-dose combination and patients with end stage renal disease requiring hemodialysis. The registry lists HIV/AIDS and end stage renal disease as conditions. Additional inclusion and exclusion criteria are not reported in the registry record.

The primary outcome is dolutegravir Ctau, described as steady-state plasma Ctau at an intensive study visit occurring between days 11 and 14. The measurement timeframe is 0 to 24 hours post-dose on that visit. The record lists five outcome measures in total and identifies DTG safety, DTG AUC, and DTG Cmax among the secondary outcomes. The full set of other outcome details is not reported in the registry record.

The study status is completed. The record gives a start date of 2021-04-23 and a primary completion date of 2023-07-31. These dates describe the registry timeline; they do not provide information about the timing or conduct of interim analyses. Interim analyses and the detailed statistical plan are not reported in the registry record.

Because the groups were not randomized and both received the same drug regimen, this is a comparison of pharmacokinetic observations across renal-function groups, not a randomized test of JULUCA against an untreated or alternative-treatment control. The design can be informative about observed exposure in the studied groups, while leaving potential group differences and confounding unresolved. The registry record does not state how the investigators addressed such differences in analysis.

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

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 Dolutegravir (DTG) Ctau, measured over 0 to 24 hours post-dose on the intensive study visit.

The primary endpoint is dolutegravir Ctau, reported in ng/mL. The record defines it as steady-state plasma Ctau at the intensive study visit, which occurred between days 11 and 14. The measurement timeframe is 0 to 24 hours post-dose on that visit. The endpoint is specified as a mean with standard deviation as its dispersion measure.

In general pharmacokinetic usage, Ctau refers to a drug concentration associated with the dosing interval. A concentration measurement can help describe how much drug is present in plasma at a specified point in dosing, complementing other exposure measures. The registry also lists DTG AUC and DTG Cmax as secondary outcomes: generally, AUC describes exposure over time, while Cmax refers to the maximum measured concentration. Those general definitions do not substitute for the study's actual measurement results.

Pharmacokinetic endpoints are used to characterize drug exposure, rather than directly to measure a clinical outcome such as symptom change or disease progression. Comparing Ctau between the two groups could describe whether the observed concentration distributions differ under the study conditions. However, the registry record does not report group means, standard deviations, confidence intervals, or a test of the primary endpoint. It therefore does not show the magnitude or precision of the observed Ctau measurements. The primary endpoint population and any exclusions from that population are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a continuous primary outcome summarized by a mean and standard deviation. These measures answer different descriptive questions. The mean represents the arithmetic average of observed measurements, while the standard deviation describes how spread out the measurements are around that average. A mean without a measure of spread gives an incomplete picture of the data, particularly when observations vary substantially.

What does a continuous endpoint mean?

As a general statistical concept, a continuous outcome can take values along a measurement scale rather than being limited to event categories. Dolutegravir Ctau is specified in ng/mL, so the endpoint is a concentration measurement. The registry calls for a group mean and standard deviation. It does not report the individual measurements or the resulting group summaries, so the distribution, variability, and possible influence of unusual observations cannot be assessed.

What does the measurement window tell the reader?

The record defines the primary measurement as steady-state plasma Ctau at the intensive study visit, between days 11 and 14, with a timeframe of 0 to 24 hours post-dose. The timing is important because concentration depends on when a sample is taken relative to dosing. A defined window makes the intended measurement interpretable, but it does not disclose the exact sampling schedule, participant-level timing, or any deviations from the intended schedule; those details are not reported in the registry record.

In general, pharmacokinetic endpoints describe drug exposure through measurements such as concentration at a specified time, exposure over time, or peak concentration. The registry identifies DTG AUC and DTG Cmax as secondary outcomes in addition to DTG safety. It does not report the numeric results for these measures. AUC and Cmax address different aspects of exposure, so one cannot be substituted for another or used to infer an unreported Ctau result.

How should uncertainty be understood?

General statistical interpretation considers both an estimate and its uncertainty. Standard deviation describes the observed spread among measurements; it is not the same as the uncertainty in a group mean. A confidence interval is a method-based range intended to convey uncertainty about an estimated quantity. Its width depends on factors including variability and the amount of usable information. No confidence interval for the primary endpoint is reported in the registry record, and no endpoint estimate is available from which to describe its precision.

A hypothesis test can assess compatibility between data and a stated null hypothesis under specified assumptions. A p-value is not the probability that a hypothesis is true, nor does it measure clinical importance. The registry record lists zero analyses and does not report a primary-endpoint test, a p-value, or a detailed statistical plan. No claim about statistical significance can be made from the endpoint definition or enrollment information.

Why does the allocation approach matter?

Allocation was non-randomized. In general, randomization helps balance measured and unmeasured characteristics across groups on average, although it does not guarantee identical groups. Without random allocation, group membership may be associated with other characteristics that also relate to the endpoint. A comparison of observed means can still describe the enrolled groups, but causal interpretation requires appropriate design and analysis assumptions. The registry does not report adjusted estimates or covariates used in an analysis.

Both groups received JULUCA, so the study is not described as a drug-versus-no-drug comparison. The scientific contrast is between pharmacokinetic measurements in the hemodialysis and normal renal function groups. The record does not provide enough information to determine whether other group characteristics were comparable.

What are the sample-size illustrations?

The registry describes planning illustrations computed from the observed effect, with a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. The illustrations are for detecting a stated fraction of the observed effect. The registry's general description distinguishes participant counts per arm for non-time-to-event outcomes from total event counts for time-to-event outcomes. These calculations are planning illustrations, not observed power. Their numerical results are not reported in the registry record, and the record does not state that these assumptions formed the original trial design or sample-size justification.

General statistical planning uses assumptions about an effect size, variability, significance level, power, and allocation to estimate the information needed for a future study. A calculation based on an effect observed in a small study may be unstable, and a planning calculation does not show that the original study had adequate power. The actual trial's sample-size justification is not reported in the registry record. No planning illustration can replace a reported estimate and uncertainty interval for the primary endpoint.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Hemodialysis Group", "Normal Renal Function Group")
n   <- c(4, 4)
m   <- c(1259, 1666)
sp  <- c(447, 415)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Hemodialysis Group  4  1259.000  447.000  547.723  1970.277
CARM  Normal Renal Function Group  4  1666.000  415.000  1005.642  2326.358

11. Multiplicity, Missing Data and Analysis Populations

The registry lists five outcome measures and identifies dolutegravir Ctau as primary. It names DTG safety, DTG AUC, and DTG Cmax among the secondary outcomes. The details for the remaining outcome measures are not reported in the registry record. The record lists zero analyses, so it does not provide outcome estimates or inferential results for these endpoints.

Multiplicity arises when several outcomes or comparisons are tested. In general, performing multiple tests can increase the chance of at least one apparently unusual result under a collection of null hypotheses. Statistical plans may identify a primary outcome, set a testing order, or use an adjustment procedure. The registry record does not report a multiplicity strategy, a testing hierarchy, or an adjustment method. It is therefore not possible to determine how the family of outcomes was handled statistically.

The record does not report missing-data counts, reasons for missing measurements, or a method for handling missing outcome data. The number enrolled should not be treated as the number analyzed for every endpoint. The primary endpoint population is not specified, and no account of exclusions or unavailable pharmacokinetic measurements is reported in the registry record.

Analysis populations can differ depending on whether they include all enrolled participants, those who received treatment, or those with an evaluable measurement. These are general distinctions; the registry does not say which population was used for the primary endpoint. Nor does it describe whether any protocol deviations or missing data affected analysis. Without these details and the numeric results, both multiplicity and missing-data handling remain unclear.

12. 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 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry reports serious adverse event counts by group. In the hemodialysis group, 4 were at risk for serious adverse events and 0 were affected. In the normal renal function group, 4 were at risk and 0 were affected. Deaths are recorded as 0 in each group. No serious adverse event terms are listed.

For other adverse events, the registry records 2 affected among 4 at risk in the hemodialysis group and 1 affected among 4 at risk in the normal renal function group. These are descriptive counts from the registry record. They are distinct from serious adverse event counts and should not be combined with them.

In general, adverse event counts describe events recorded under the study's reporting definitions; they do not by themselves establish that a drug caused an event. A group comparison based on these small counts would be imprecise, and no comparative safety analysis is reported. The record does not provide event details for the other adverse events, duration, severity, or a statistical assessment. The figures therefore describe what was recorded, not a complete estimate of safety or a causal contrast between groups.

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

The result that can be read directly from the registry is the study question and its measurement framework. It compares dolutegravir Ctau in a hemodialysis group and a normal renal function group, with both groups receiving JULUCA. Ctau is specified as a steady-state plasma concentration measured during an intensive visit between days 11 and 14, in a 0 to 24 hours post-dose timeframe.

The registry record does not report numeric Ctau results. There is no reported group mean, standard deviation, confidence interval, or statistical test for the primary endpoint. Accordingly, the record does not show whether concentrations were higher, lower, or similar between groups, nor does it show how precisely any difference was estimated. The same limitation applies to the numeric results for the listed secondary pharmacokinetic outcomes.

The design also limits what a group comparison could establish. Because allocation was non-randomized, an observed difference would be an association between group membership and measured exposure in the enrolled participants. It would not, without additional assumptions and analysis, show that hemodialysis itself caused a difference. Both groups received JULUCA, so the study does not estimate a treatment effect against a control regimen.

The safety counts are descriptive. The record reports no serious adverse events or deaths in either group and reports other adverse events in both groups. These entries do not establish comparative safety, and they should not be treated as evidence that an event was or was not caused by treatment.

General statistical interpretation separates the existence of a study from evidence about its result. A registered endpoint and completed status do not substitute for reported estimates, uncertainty, and analysis methods. The available record gives useful context about the planned comparison, but it does not provide the quantitative evidence needed to judge the primary pharmacokinetic question. It also does not report the actual sample-size justification, missing-data approach, or multiplicity plan. Conclusions should therefore remain limited to the study design and the reported safety counts.

14. Why This Trial Matters Statistically

This study illustrates why a pharmacokinetic question should be read separately from a clinical efficacy question. Its primary endpoint is a plasma concentration measure, not a reported clinical outcome. Pharmacokinetic measurements can describe drug exposure in groups with different renal status, but their interpretation depends on the timing and methods of sampling as well as on the uncertainty around the resulting estimates.

The non-randomized design is also statistically important. When groups are formed by clinical or physiological characteristics rather than random assignment, differences in observed outcomes can reflect those characteristics and other group differences. A descriptive comparison may still be useful, but the distinction between association and causation must be maintained. Here, both groups received the same regimen, so the central comparison is between groups, not between assigned treatments.

The registry record also shows the importance of complete results reporting. It specifies a primary endpoint and secondary outcomes, but lists zero analyses and does not report the primary endpoint values. Without estimates and uncertainty, readers cannot assess the size or precision of the pharmacokinetic comparison. Enrollment and endpoint definitions alone cannot answer that question.

Finally, small group counts make cautious interpretation of the reported safety entries especially important. Counts can describe events recorded during the study, but they do not provide a stable comparative estimate by themselves. The statistical value of the record lies in its description of the study question, design, endpoint, and recorded adverse events, while its absence of outcome analyses limits further inference.

15. 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 central limitation is that the registry record does not report numeric results for the primary endpoint. Group means, standard deviations, confidence intervals, and inferential tests are not reported. The record lists zero analyses, preventing an assessment of the magnitude, direction, or precision of the pharmacokinetic comparison.

The non-randomized allocation means the groups are not a like-for-like control comparison. Both received JULUCA, and the record does not report adjustment for group differences or identify covariates included in any analysis. The available details therefore do not support a causal interpretation of a potential difference in Ctau.

Enrollment is reported as 8, but the number of participants contributing to each endpoint is not reported in the registry record. The primary endpoint population, missing measurement counts, reasons for missing data, and handling of missing observations are also not reported. These omissions prevent assessment of how complete the endpoint data were.

The record identifies five outcome measures but does not report a multiplicity strategy or a detailed statistical plan. It names DTG safety, AUC, and Cmax among secondary outcomes, but does not report their numeric results. The stated sample-size illustrations are planning calculations; their numerical outputs and the trial's own sample-size justification are not reported in the registry record.

Further details that would help interpret the pharmacokinetic measurements, including individual concentration data, exact sampling schedules, and endpoint-specific analysis decisions, are not reported in the registry record. The safety entries provide counts, but not further event descriptions or a comparative analysis. These limitations restrict conclusions to the design and the adverse-event counts that are recorded.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Pharmacokinetics of JULUCA in Hemodialysis — NCT04431518.
• Registry record last updated 2024-06-05; status last verified 2024-05.
• Results first posted 2024-05-21.
• 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.

19. Record Summary

NCT04431518 is a completed Phase 4, non-randomized, unmasked, parallel-group study sponsored by Indiana University. It enrolled 8 and compared a hemodialysis group with a normal renal function group. Both groups received JULUCA 50Mg-25Mg Tablet, one pill per day for up to 14 days.

The primary outcome is steady-state dolutegravir Ctau in ng/mL, measured at an intensive visit between days 11 and 14, with a stated timeframe of 0 to 24 hours post-dose. The registry record does not report the primary endpoint values or a statistical analysis; it lists zero analyses. It identifies DTG safety, DTG AUC, and DTG Cmax among the secondary outcomes.

Serious adverse events and deaths are recorded as 0 in both groups. Other adverse events are recorded in both groups. The primary endpoint population, missing-data handling, multiplicity approach, and detailed statistical plan are not reported in the registry record.