Switch to Bictegravir/Emtricitabine/Tenofovir Alafenamide (BIC/F/TAF) After Renal Transplant: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Switch to Bictegravir/Emtricitabine/Tenofovir Alafenamide (BIC/F/TAF) After Renal Transplant (NCT04530630), a na phase 4 study. The primary outcome is Number of Subjects With Plasma HIV-1 Ribonucleic Acid (RNA) <50 Copies/ml.

2. Clinical Question

3. Trial Design

This was a Phase 4, open-label, single-group study of switching to BIC/F/TAF after renal transplant. The registry lists enrollment of 20 and a completed status. Participants moved from their current HIV medication to the study regimen; there was no randomized allocation and no concurrent control group. Consequently, the design can describe outcomes observed after the switch, but it cannot by itself distinguish a treatment effect from other explanations for change over time.

The study drug was a BIC/F/TAF tablet taken orally once daily, with or without food. Participants were to be followed for 48 weeks to monitor efficacy, safety, and tolerability. Since both participants and investigators knew the treatment, outcome assessment was not masked. For the primary endpoint, the description says HIV viral loads would be obtained from laboratory reports.

The primary outcome was the number of subjects with plasma HIV-1 RNA below 50 copies/ml up to week 48. Secondary outcomes listed changes in CD4+ T lymphocyte numbers and percentages, kidney transplant rejection, and participant satisfaction with reduced pill burden and adverse events. The registry lists 13 outcome measures, but the results for these measures are not reported in the registry record.

One subject was excluded from data analysis because of early study withdrawal. The registry does not report the exact analysis denominator for the primary endpoint or how unavailable measurements were handled. Nor does it report a statistical analysis plan or an inferential analysis for the outcome. The single-group structure and the missing endpoint result are important when interpreting the study: neither a comparative effect estimate nor the precision of an observed outcome can be assessed from 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.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: One subject was excluded from data analysis due to early study withdrawal.

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 Number of Subjects With Plasma HIV-1 Ribonucleic Acid (RNA) <50 Copies/ml, measured over Up to week 48 (End of Study).

The primary endpoint is a count: the number of participants with plasma HIV-1 RNA below 50 copies/ml by the end of the study, up to week 48. The threshold defines the endpoint’s criterion for viral suppression; the intended measurement comes from laboratory viral-load reports. A count is a direct way to describe how many participants met a specified outcome, but interpreting it also requires knowing the analysis denominator and how missing measurements were handled.

For a single-group switch study, the count can describe the endpoint status observed after the treatment change. It does not, by itself, establish what would have happened to the same participants under another regimen or without switching. That distinction matters because a controlled comparison is needed to separate treatment-related differences from background changes and other influences.

The registry does not report the number who met the endpoint, a corresponding denominator, or an uncertainty interval. It therefore does not permit an assessment of the observed endpoint result or its precision. The stated laboratory source identifies the intended measurement method, but the registry does not report further details about the timing or completeness of those laboratory measurements.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a single-group design tell us?

In a single-group study, participants receive the intervention under study and outcomes are observed afterward. This can document what happened in the enrolled group, but there is no concurrent group assigned to a different treatment or to continue another regimen. Without such a comparator, the observed outcome cannot isolate the effect of the intervention from other changes that occur over time. This is a general limitation of non-comparative designs, not a claim about what happened to these participants.

Here, the registry describes a switch from current HIV medication to BIC/F/TAF and labels the model single-group. Allocation is recorded as not applicable. The existing medication is part of the participants’ treatment history, not a randomized control arm. The design therefore does not support a randomized between-group treatment contrast.

How should a count endpoint be understood?

The primary outcome is a count of participants meeting a binary criterion: plasma HIV-1 RNA below 50 copies/ml by the end of follow-up. A binary outcome classifies each assessed participant as meeting or not meeting the criterion. Counts can be easy to understand, but a count alone is not enough to interpret the frequency of an outcome. The denominator, measurement availability, and analysis population are also needed.

In general, a proportion expresses a count relative to its denominator, and a confidence interval conveys the precision of that estimate under the chosen statistical method. Neither can be reconstructed responsibly without the underlying outcome count and denominator. The registry record does not report the primary count, denominator, or confidence interval. No such estimate can be stated from the information recorded.

What does open-label mean for interpretation?

Open-label means participants and investigators know the treatment being given. That feature does not automatically invalidate measured outcomes, but it can matter for outcomes affected by expectations, reporting, or clinical decisions. The primary endpoint is based on laboratory viral-load reports, as described in the registry. The registry does not report whether endpoint assessment was otherwise blinded or whether any procedures were used to reduce assessment bias.

Several secondary outcomes include satisfaction and tolerability, which involve participant experience. In general, awareness of treatment can influence how such experiences are reported. The record does not provide the results or analysis details for these measures, so their direction, size, and precision cannot be assessed.

What can be learned from the planning assumptions?

The registry’s sample-size assumptions describe a planning illustration using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. These are planning assumptions, not evidence that the completed study used a two-arm design. The actual study is listed as single-group, so the hypothetical two-arm framework should not be mistaken for the trial’s allocation or analysis.

In general, a sample-size calculation estimates how many participants a hypothetical study might need under specified assumptions. Such calculations depend on the effect size, variability or event frequency, statistical test, and desired power. Changing assumptions changes the planning result. A planning illustration is not observed power: it does not measure the probability that a completed study found a true effect, and it cannot make an unreported endpoint result available. The record does not report the trial’s own sample-size justification or statistical analysis plan.

Why do event distributions matter?

The primary outcome is binary, so methods for counts or proportions are generally relevant. In a controlled study, an analysis might compare proportions between groups; in a single-group study, a descriptive count or proportion may be reported. The choice of inferential method depends on the design and the question. The registry does not report an analysis method or inferential result for this endpoint.

Over-dispersion is a general issue for some count models when observed variability exceeds what a model assumes. It can make standard errors too small if ignored. That issue is not established for this endpoint: the primary outcome is described as a count of participants meeting a binary threshold, and no count-model analysis is reported. There is no basis in the registry record for asserting that over-dispersion was assessed or that a particular model was used.

Likewise, an uncertainty interval would require an estimate and a specified method. Different methods may be appropriate for different designs and outcome distributions. Because the primary result and analysis are absent, the interval and its assumptions are not available for interpretation. General statistical principles explain what those quantities would mean, but they do not supply missing trial results.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Bictegravir/Emtricitabine/Tenofovir Alafenamide (B")
n      <- c(19)
events <- c(19)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Bictegravir/Emtricitabine/Tenofovir Alafenamide (B  19  19  100.0  82.4  100.0  83.2  100.0  83.2  99.9

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 13 outcome measures, including the primary viral-load count and secondary measures related to CD4+ T lymphocytes, kidney transplant rejection, satisfaction, pill burden, and adverse events. When a study assesses multiple outcomes, the chance of at least one apparently notable result can increase if many statistical tests are conducted. General approaches to this issue include defining a primary outcome in advance and adjusting or otherwise planning interpretation across multiple tests. The registry record does not report a multiplicity strategy or a statistical analysis plan, so it is not possible to determine how multiple outcomes were handled.

No analysis records are reported, and the registry does not provide inferential results for the listed outcomes. Thus, there are no reported hypothesis tests or confidence intervals to assess for multiplicity. The absence of reported analyses should not be interpreted as evidence that no analyses were performed outside the registry; it means the registry record does not document them.

For missing data, the primary endpoint description says viral loads would be obtained from laboratory reports. The record notes that one subject was excluded from data analysis because of early study withdrawal. It does not report the primary endpoint denominator, whether that subject had an available viral-load measurement, or how any missing endpoint data were handled. It also does not report whether the analysis followed an intention-to-treat, per-protocol, or other population definition. These omissions prevent assessment of how exclusions or missing measurements may affect the endpoint result.

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 serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: anaphylaxis (5.0%).

The registry reports 1 participant with a serious adverse event among 20 at risk, 5 participants with other adverse events among 20 at risk, and 0 deaths. These are recorded counts for the BIC/F/TAF group. They describe the safety information in the registry, not a comparison with another treatment, because the study had no concurrent control group.

Anaphylaxis is listed among the top serious terms, with 5.0% reported. This term-level entry should be read as the registry’s reported listing; the record excerpt does not provide further details that reconcile it with the aggregate serious-event count. It does not state timing, duration, severity details beyond the serious classification, or whether events were judged related to the study drug. The counts also do not indicate whether one participant experienced more than one event, so event counts and participant counts should not be treated as interchangeable.

These figures are descriptive. Without a comparator and fuller event-level information, they cannot establish whether the treatment caused an event or whether the recorded frequency differs from another regimen. The registry does not report additional safety analyses or uncertainty estimates.

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

The record establishes that a completed, open-label, single-group study evaluated switching virally suppressed HIV-positive renal transplant recipients to once-daily BIC/F/TAF, with follow-up planned for 48 weeks. It identifies a primary endpoint based on plasma HIV-1 RNA below 50 copies/ml and lists secondary outcomes that include CD4+ T lymphocyte measures, kidney transplant rejection, and satisfaction and tolerability measures. It also records aggregate adverse-event counts.

However, the primary endpoint result is not reported in the registry record. The number meeting the viral-load criterion, the analysis denominator, and any estimate of uncertainty are not available. Consequently, the record does not establish how many participants met the endpoint or how precisely an outcome was estimated. Completion status and a defined endpoint are not substitutes for a reported result.

The single-group design also means the study cannot provide a randomized comparison against another regimen. Any outcome observed after a switch would be descriptive of the study group and would not, on its own, show what would have occurred under a different treatment. The open-label design and the absence of reported analysis details add further limits to interpretation, particularly for outcomes involving participant experience.

The safety entries record serious and other adverse events and deaths, but do not provide a comparative safety estimate or enough event-level detail to attribute an event to treatment. These data can be read as registry-recorded counts, not as proof of a causal relationship.

In short, the registry documents the study question and design but does not report the primary result needed to assess the study’s main outcome. It cannot support a conclusion about whether switching changed viral suppression, transplant outcomes, CD4+ measures, or satisfaction.

14. Why This Trial Matters Statistically

This study raises a clinically specific statistical question: how to describe outcomes after a medication switch among HIV-positive patients following renal transplant. The population and treatment context make clear why a carefully defined endpoint matters. The primary endpoint uses a laboratory-based viral-load threshold, while the listed secondary outcomes span immune measures, transplant rejection, and participant experience.

Statistically, the study illustrates the difference between defining an outcome and reporting its result. The registry specifies a count-based primary endpoint and a follow-up period, but does not report the count, denominator, or uncertainty. Without those elements, readers cannot evaluate either the observed outcome or its precision. This is a reporting limitation rather than evidence for or against a treatment effect.

The single-group design also makes the comparison question important. Observing outcomes after a switch can describe the enrolled group, but it does not provide the counterfactual information available from a concurrent randomized comparison. That limitation should shape the language used for any conclusions, even if descriptive outcomes are reported elsewhere.

Finally, the registry lists several outcomes and safety summaries but does not document multiplicity procedures, missing-data handling, or an analysis plan. These details help readers judge how a result was produced and how robust it may be. Their absence from the registry record makes transparent reporting of the analysis especially important. The record is informative about the study’s intended question and basic design, while leaving the main statistical result unresolved.

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 primary limitation for interpretation is that the registry record does not report the primary endpoint result. It also does not give the endpoint denominator or an uncertainty interval, so the magnitude and precision of the observed outcome cannot be evaluated. The note that one subject was excluded from data analysis because of early withdrawal does not establish the exact analysis population or the handling of other missing measurements.

There was no concurrent comparison group, and the study was open-label. These design features limit causal interpretation and can matter when outcomes are influenced by time, clinical management, or participants’ awareness of treatment. The registry does not report procedures for blinded endpoint assessment or other methods intended to address these concerns.

The record lists 13 outcome measures but does not report a multiplicity approach, analysis plan, or inferential analyses. It also does not provide detailed results for the listed secondary outcomes. For safety, aggregate counts are reported, but event timing, participant-level detail, attribution, and comparative context are not.

The registry’s planning assumptions describe a two-arm, equal-allocation illustration, whereas the actual study is listed as single-group. Such planning assumptions should not be read as the trial’s design or as observed power. The registry does not report the trial’s own sample-size justification. Taken together, the design and reporting gaps restrict assessment of efficacy, safety comparisons, and statistical precision.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Switch to Bictegravir/Emtricitabine/Tenofovir Alafenamide (BIC/F/TAF) After Renal Transplant — NCT04530630.
• Registry record last updated 2025-08-12; status last verified 2025-07.
• Results first posted 2025-08-12.
• 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.

19. Record Summary

The registry describes a completed Phase 4, open-label, single-group study of switching virally suppressed HIV-positive renal transplant recipients to BIC/F/TAF. Enrollment was 20, and follow-up was planned for 48 weeks. The primary endpoint was the count of participants with plasma HIV-1 RNA below 50 copies/ml by the end of the study. The registry notes that one subject was excluded from data analysis because of early withdrawal.

The record lists 13 outcome measures and reports safety counts of 1 participant with a serious adverse event, 5 with other adverse events, and 0 deaths. Anaphylaxis is listed as a top serious term at 5.0%. The primary endpoint result, analysis denominator, missing-data approach, and statistical analysis plan are not reported in the registry record. With no concurrent comparator, the design is non-comparative, and the recorded information does not support a causal treatment estimate.