Efficacy of Switching to DTG/3TC in Virologically-suppressed Adults Currently on B/F/TAF: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Efficacy of Switching to DTG/3TC in Virologically-suppressed Adults Currently on B/F/TAF (NCT04585737), a randomized phase 4 study. The primary outcome is The Primary Outcome Measure is to Evaluate the Efficacy of Switching From B/F/TAF to DTG/3TC Versus Continuing B/F/TAF as Determined by the Proportion of Participants With HIV-1 RNA ≥50 Copies/mL at Week 48.

2. Clinical Question

This is a question about outcomes under two assigned treatment strategies in a particular group: adults whose HIV was already virologically suppressed while taking B/F/TAF. It is not a comparison of starting either regimen in people who were not already taking B/F/TAF, nor is it a comparison in an unselected population living with HIV. The trial also recorded outcomes concerning viral suppression at other time points, adverse events, treatment discontinuation, cholesterol, weight, waist circumference and BMI. Those outcomes add context but do not change the primary question. The registry record describes the study as randomized and open-label. It does not report further details about eligibility criteria, the process used to generate or conceal assignments, or the primary analysis population.

3. Trial Design

The DYAD Study is recorded as a Phase 4, randomized, open-label, parallel-group study. It enrolled 222 participants and is listed as completed. The recorded study start was 2020-10-05, and the primary completion date was 2023-08-03. The sponsor is listed as Charlotte-Paige Rolle, MD. The study compared switching from B/F/TAF to DTG/3TC with staying on B/F/TAF.

The treatment descriptions assign participants to Treatment Group 1, receiving DTG/3TC, or Treatment Group 2, continuing B/F/TAF. The descriptions list group sizes of 148 and 74, respectively. For the posted primary outcome, however, the denominators are 149 for Treatment Group 1 and 73 for Treatment Group 2. The registry record does not explain this difference. The posted results therefore need to be read using their outcome-specific denominators rather than treating the treatment-description counts as the denominators for every result.

Open-label means the record does not describe masking of participants or study personnel to the assigned treatment. The primary outcome is assessed at Week 48, and the registry also lists a Week 24 viral-load outcome and additional outcomes through 48 weeks. The record does not report details of follow-up procedures, adherence measurement, assignment concealment, or the reasons for any differences between treatment-description and outcome denominators. Those omissions limit what can be concluded about trial conduct from the registry entry alone. No further protocol detail should be inferred from the brief study description.

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 The Primary Outcome Measure is to Evaluate the Efficacy of Switching From B/F/TAF to DTG/3TC Versus Continuing B/F/TAF as Determined by the Proportion of Participants With HIV-1 RNA ≥50 Copies/mL at Week 48, measured over 48 weeks.

The primary endpoint is the number and proportion of participants in each treatment group with HIV-1 RNA at least 50 copies/mL at Week 48. The registry describes the measure as the percentage in each arm, while the posted results give counts and denominators. In the switch group, 6 of 149 participants met this endpoint; in the group continuing B/F/TAF, 5 of 73 did.

This threshold-based outcome records whether a participant's viral-load result was at or above the specified level at the assessment time. It is distinct from an outcome defined as HIV-1 RNA below 50 copies/mL: although the thresholds are complementary in concept, the registry lists these as separate outcome measures, and their participant counts need not be simple complements in the posted data. The endpoint is used to assess whether participants experienced the specified level of detectable HIV-1 RNA after the assigned strategy. It does not, by itself, describe the full trajectory of viral load over time, the duration of any result, or other aspects of health.

The interpretation depends on the event definition, the assessment time and which participants contribute data. The registry states the threshold and time point, but does not report the detailed handling of missing Week 48 measurements or the analysis population. The event counts should therefore be understood as the posted endpoint results, not as a complete description of every participant's clinical course.

7. Results Posted in the Registry

• Treatment Group 2: 6.8% (5/73) versus 4.0% (6/149) on control; risk difference 2.8 percentage points (95% CI -3.8 to 9.4), risk ratio 1.70 (0.54–5.39); unadjusted two-proportion z-test p = 0.363.

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.

The Secondary Outcome Measure is to Evaluate the Efficacy of Switching to DTG/3TC From B/F/TAF as Determined by the Proportion of Participants With HIV-1 RNA≥ 50 Copies/mL at Week 24

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Treatment Group 2: 4.1% (3/73) versus 2.0% (3/149) on control; risk difference 2.1 percentage points (95% CI -3.0 to 7.2), risk ratio 2.04 (0.42–9.87); unadjusted two-proportion z-test p = 0.366.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Treatment Group 2 and the control. The interval gives the range of effects that remain compatible with the data.

The Secondary Outcome Measure is to Evaluate the Efficacy of Switching to DTG/3TC From B/F/TAF as Determined by the Proportion of Participants With HIV-1 RNA<50 Copies/mL at Week 48

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Treatment Group 2: 80.8% (59/73) versus 85.2% (127/149) on control; risk difference -4.4 percentage points (95% CI -15.1 to 6.3), risk ratio 0.95 (0.83–1.08); unadjusted two-proportion z-test p = 0.402.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Treatment Group 2 and the control. The interval gives the range of effects that remain compatible with the data.

The secondary viral-load results follow the same broad pattern as the primary outcome: they do not provide a clear, precise separation between the assigned groups in the posted unadjusted comparisons. At Week 24, the counts meeting the threshold of HIV-1 RNA at least 50 copies/mL are the same in each group. At Week 48, the outcome defined as HIV-1 RNA below 50 copies/mL has a point estimate in the opposite direction from the primary endpoint's risk difference. Its uncertainty remains substantial, and the unadjusted comparison does not establish a clear difference.

These secondary measures complement the primary endpoint by looking at a different assessment time or a different threshold definition. They do not cancel out, confirm, or replace the primary result. The registry also lists outcomes concerning adverse events, treatment discontinuation and changes in cholesterol, weight, waist circumference and BMI. The record does not post analysis results for those measures in the secondary outcomes included in the results information, so their direction and precision cannot be assessed from the registry record.

Many outcomes create a multiplicity concern: if numerous comparisons are tested, some may look noteworthy by chance even when there is no underlying effect. The registry does not report whether a multiplicity adjustment, testing hierarchy or other prespecified approach was used. Consequently, unadjusted secondary results carry less weight than a prespecified primary result for confirmatory interpretation. This is not because secondary outcomes are inherently unimportant, but because their statistical role and the chance of selective or chance findings cannot be evaluated without the analysis plan.

Overall, the secondary viral-load findings are compatible with the primary result's uncertainty rather than resolving it. The registry does not report enough detail to combine the endpoints into a single conclusion, and they should be read according to their separate definitions and time points.

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

• The Secondary Outcome Measure is to Evaluate the Efficacy of Switching to DTG/3TC From B/F/TAF as Determined by the Proportion of Participants With HIV-1 RNA≥ 50 Copies/mL at Week 24
• The Secondary Outcome Measure is to Evaluate the Efficacy of Switching to DTG/3TC From B/F/TAF as Determined by the Proportion of Participants With HIV-1 RNA<50 Copies/mL at Week 48
• The Secondary Outcome Measure is to Measure the Incidence and Severity of Grade 2-5 Drug-related Adverse Events and Laboratory Abnormalities (Graded Using DAIDs Grading Scale) Through 48 Weeks
• The Secondary Outcome Measure is to Evaluate the Proportion of Participants That Discontinue Treatment Through 48 Weeks in Each Treatment Arm and Reasons for Discontinuation
• The Secondary Outcome Measure is to Evaluate the Effects of DTG/3TC Once Daily on Fasting Total Cholesterol Over Time Compared to B/F/TAF Through 48 Weeks
• The Secondary Outcome Measure is to Evaluate Changes in Weight (kg) in Those Treated With DTG/3TC vs. B/F/TAF Over Time
• The Secondary Outcome Measure is to Evaluate Changes in Waist Circumference (Inches) in Those Treated With DTG/3TC vs. B/F/TAF Over Time
• The Secondary Outcome Measure is to Evaluate Changes in BMI (kg/m2) in Those Treated With DTG/3TC vs. B/F/TAF Over Time

9. Statistical Interpretation

10. Statistical Methods Explained

The registry describes a randomized, parallel-group comparison. Randomization is intended, in general, to make assigned groups comparable on average at the start of a study, including with respect to factors that may not have been measured. It does not ensure identical groups in every realized trial. The registry record does not report the method used to generate the assignment sequence, whether assignment was concealed, or the analysis population. These details matter when judging how closely the analysis reflects the randomized comparison.

What does the primary outcome count?

The primary outcome is binary at the participant level: a participant either had HIV-1 RNA at least 50 copies/mL at Week 48 or did not meet that event definition. The posted results present event counts alongside the number of participants in each group. A risk, or event proportion, is the number with the event relative to the group denominator. A risk difference compares those proportions by subtraction. Its sign depends on the order of the groups; the posted comparison is for Treatment Group 2 relative to Treatment Group 1. The registry does not describe an adjusted model for this outcome, and the p-value is identified as unadjusted.

How should a confidence interval be read?

A confidence interval describes a range of values compatible with the observed data under the statistical method used. It conveys uncertainty around an estimated contrast rather than a guarantee that the true value lies within the reported bounds. For a risk difference, zero represents no difference in the event proportions. When an interval crosses zero, the data are compatible with both directions of difference as well as no difference. That does not prove equality; it indicates that the estimate is not sufficiently precise to rule out those possibilities under the stated method.

What does the p-value contribute?

A p-value assesses how unusual data at least as discrepant as the observed data would be if the null hypothesis and the test's assumptions held. It is not the probability that the null hypothesis is true, nor does it measure the size or clinical importance of an effect. The unadjusted primary p-value is 0.363. The registry record does not provide the exact statistical test, its full assumptions, or an adjusted analysis. The p-value should therefore be read alongside the event counts and interval, not as a standalone decision rule.

Why do denominators and missing results matter?

The denominator determines which participants contribute to an event proportion. The outcome denominators are 149 and 73, while the treatment descriptions list group sizes of 148 and 74. The record does not explain the difference. It also does not report how missing Week 48 values were handled, whether all randomized participants were included in the primary analysis, or whether participants were analysed according to their assigned groups. Missing outcome data can affect estimates if participants with unavailable measurements differ from those with observed measurements. Without the analysis details, the posted proportions cannot be assumed to represent a particular missing-data strategy.

What can be inferred from the registry analysis information?

The registry lists no posted analysis descriptions for the primary outcome and no reported analyses for the two secondary viral-load outcomes. That absence means the record does not specify such matters as model choice, covariate adjustment, or sensitivity analyses. It does not justify guessing which methods were used. The posted comparisons can be described as unadjusted comparisons, but the original statistical analysis plan and the trial's complete analysis procedures are not reported in the registry record.

How should secondary outcomes be interpreted?

Several outcomes are listed, including virologic measures, adverse events, discontinuation, cholesterol, weight, waist circumference and BMI. When many outcomes are examined, the chance of finding an apparently notable result by chance can increase unless the analysis plan accounts for multiple testing. The registry does not report a multiplicity procedure or a hierarchy for interpreting secondary endpoints. Secondary results should therefore be regarded as exploratory unless the record establishes otherwise. Their interpretation also depends on outcome definitions and analysis details, some of which are not reported.

11. Confidence Intervals and Precision

The primary risk-difference interval crosses zero. This means the posted data do not pin down the direction of the between-group difference: values compatible with the interval include a lower event proportion in either group and no difference. The unadjusted p-value is 0.363. Together, the interval and test indicate that the primary contrast is uncertain; they do not show that the groups are equivalent.

The interval's breadth matters as much as whether it crosses zero. A wide interval allows a range of possible effect sizes, so the estimate is not highly precise. The primary event counts are 6 and 5, and the outcome denominators are 149 and 73. With relatively few recorded events, the estimated contrast can be sensitive to the occurrence or classification of individual events. The posted result is therefore better understood as an imprecise estimate than as a definitive measure of no difference.

Risk ratios and odds ratios are also reported for the comparison, but their confidence intervals likewise span values on both sides of the no-association value. These alternative scales do not remove the uncertainty in the sparse event data. They describe the contrast differently; they do not supply independent evidence that resolves the primary result.

A confidence interval reflects sampling uncertainty under the method used. It does not account automatically for all possible sources of uncertainty, such as missing outcomes, differences in analysis populations, or unreported features of trial conduct. The registry record does not give enough detail to assess those sources fully. Nor does the interval provide a probability that any particular treatment effect is true. It is a range of values compatible with the observed data and the calculation's assumptions.

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 planning figures are participants per arm, not total events. The registry describes them as an illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effects used for planning are fractions of the observed effect: 100%, 75% and 50%. For each assumed effect, the figures give the number of participants per arm for 80% power and for 90% power. The original trial's own design assumptions and sample-size justification are not reported in the registry record.

In general, power is the probability that a study will detect an effect of a specified size under the assumptions used for planning, if that effect is present. The 80% column represents a planning target with an 80% chance of detecting the assumed effect under those assumptions; the 90% column uses a higher target. These are prospective planning quantities, not a description of how likely the completed trial was to produce a statistically significant result. This is not observed power.

The planning illustration uses the observed effect as its reference. It shows that planning to detect a smaller fraction of that effect requires more participants per arm than planning for the full observed effect. For example, the primary-outcome planning figures range from 1,013 participants per arm for 80% power at 100% of the observed effect to 3,553 participants per arm for 80% power at 50% of the observed effect. For 90% power, the corresponding primary-outcome figures are 1,355 and 4,756 participants per arm. These are illustrations under the stated assumptions, not a reconstruction of the trial's original design.

Because the reference effect comes from the observed trial results, the planning values depend on an estimate that is itself uncertain. They should not be read as proof that a future trial of a particular size will achieve a particular result. The registry's planning assumptions also specify equal allocation, whereas the posted outcome denominators are unequal. The record does not explain that difference or report the original design rationale.

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 = 0.040; treatment proportion p₁ = 0.068; average p̄ = 0.054.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.3207 = 0.6286.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.3201 = 0.2694.
4. n = (0.6286 + 0.2694)² / (0.0282)² = 1,012.1, rounded up to 1,013 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 <- 0.0402684563758389                          # control proportion
p1 <- 0.0684931506849315                          # 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(4585737)
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 = 1,013 (80% power), 1,355 (90% power)
 75% of observed effect: n per arm = 1,690 (80% power), 2,262 (90% power)
 50% of observed effect: n per arm = 3,553 (80% power), 4,756 (90% power)
power.prop.test: 1012.1 
Simulated power at n = 1,013 per arm: 0.805 (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 lists a primary outcome and multiple secondary outcomes, but it does not report a statistical analysis plan that explains how the family of outcomes was to be interpreted. In particular, the record does not state whether testing was hierarchical, whether p-values were adjusted for multiple comparisons, or whether any secondary outcomes were intended to support confirmatory conclusions. Without that information, unadjusted secondary p-values should be treated cautiously: repeated testing can increase the chance of apparently notable results arising by chance.

The record also does not report how missing outcome data were handled. It does not describe whether participants without a Week 48 measurement were excluded, counted according to a specified rule, imputed, or addressed in sensitivity analyses. These choices can affect a binary outcome's numerator and denominator. The treatment-description group sizes differ from the outcome denominators, but no explanation is given. The posted results should therefore be interpreted as the reported counts and denominators, without assuming an unreported missing-data method.

The analysis population is not specified in the registry results. The record does not say whether the primary analysis followed intention-to-treat principles, was based on participants who received treatment, or used another population definition. It also does not report per-protocol analyses or sensitivity analyses. These distinctions matter because analysis populations can address different questions and may produce different estimates.

Further details about model specification, covariate adjustment, prespecified subgroup analyses and the handling of protocol deviations are not reported in the registry record. The posted primary comparison is identified as unadjusted, but that does not supply the missing information about the full planned analysis. These reporting gaps limit assessment of multiplicity, robustness and the relationship between the registry outcome and any final analysis.

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 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: covid-19 (4.1%), chest pain (1.4%), asthma (1.3%), pancreatitis (0.7%), drug overdose (0.7%).

The registry records serious adverse events in 12 of 149 participants in the DTG/3TC group and 4 of 73 in the group continuing B/F/TAF. Other adverse events are recorded for 14 of 149 and 1 of 73, respectively. No deaths are recorded in either group. These are counts among the posted group denominators; the registry record does not provide an adjusted comparison or uncertainty intervals for these safety counts.

The listed serious-event terms include COVID-19 at 4.1%, Chest Pain at 1.4%, Asthma at 1.3%, Pancreatitis at 0.7%, Drug Overdose at 0.7% and Bipolar Disorder at 0.7%. The record does not make clear in the posted summary how these term percentages relate to participant counts or whether participants could contribute more than one event. They should not be treated as a complete account of every safety outcome.

Raw counts can help describe what was recorded, but they do not by themselves establish a treatment-related difference. The registry does not report detailed exposure-adjusted rates, event timing, severity breakdowns by group, or a statistical safety analysis. The posted figures therefore provide limited descriptive information about serious and other adverse events.

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

The primary result describes the Week 48 frequency of HIV-1 RNA at least 50 copies/mL in adults who were already virologically suppressed while taking B/F/TAF and were assigned either to switch to DTG/3TC or to continue B/F/TAF. The posted counts are 6 of 149 and 5 of 73, respectively. The unadjusted comparison does not establish a clear difference, and its confidence interval is compatible with more than one direction of effect.

This should not be interpreted as proof that the strategies are equivalent. Equivalence requires a prespecified range of differences considered acceptably small and an analysis designed to assess that range. The registry does not report an equivalence margin. Similarly, the record does not report a non-inferiority margin or a non-inferiority analysis. A non-significant p-value alone cannot establish either conclusion.

The result is also not a statement about every possible outcome. The primary endpoint is a threshold-based measure at a particular follow-up time. It does not summarize viral-load history, all adverse events, discontinuation, metabolic measures, or other aspects of participants' health. Several of those outcomes are listed, but analyses for most are not reported in the registry record.

The findings apply to the trial population and comparison described in the record. They should not automatically be extended to people who were not virologically suppressed at entry, people taking other baseline regimens, or settings not represented by the study. The registry does not report enough detail about eligibility and analysis populations to define broader applicability more precisely.

Overall, the posted data leave substantial uncertainty around the primary between-group contrast. The study's results are descriptive of the reported participants and endpoint; they do not by themselves establish a clinical recommendation or a definitive conclusion about the relative effects of the two strategies.

17. Why This Trial Matters Statistically

The trial is statistically informative because it asks a randomized question about changing treatment in adults who were already virologically suppressed on B/F/TAF. That makes the comparison specifically about switching versus continuing, rather than about initiating treatment in a broader population. Keeping the question and population in view is essential when interpreting the endpoint.

The primary outcome illustrates why a point estimate should not be read alone. The groups had relatively few participants meeting the event definition, and the confidence interval crosses zero. The resulting uncertainty means the observed direction does not settle the direction or size of the underlying difference. A non-significant p-value is not evidence of equivalence, and the registry does not report a design intended to establish equivalence or non-inferiority.

The record also illustrates the importance of denominators and transparent analysis reporting. The treatment descriptions give group sizes that differ from the denominators used for the posted primary outcome. The registry does not explain the difference, describe missing-data handling, or specify the analysis population. Those are not minor details: they affect how readers understand who contributed to the reported proportions and how robust the comparison may be.

Finally, the trial lists a range of secondary outcomes, but the registry does not report analyses for most of them or explain how multiple comparisons were handled. This limits the strength of conclusions that can be drawn from any isolated secondary finding. The statistically responsible reading is therefore focused: describe the posted primary counts and uncertainty, use the secondary outcomes as context, and avoid claims the registry record cannot support.

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.

Several limitations are specific to the posted registry information. First, the treatment-group descriptions list 148 participants in Treatment Group 1 and 74 in Treatment Group 2, while the primary outcome uses denominators of 149 and 73. The record does not explain why these counts differ. This makes it important not to assume that the group-description counts define the population contributing to each outcome.

Second, the primary event counts are small: 6 in one group and 5 in the other. The corresponding confidence interval crosses zero, and the unadjusted p-value does not indicate a clear difference. The estimate is therefore uncertain. The planning illustrations are based on fractions of the observed effect, not on the trial's original sample-size justification, which is not reported.

Third, the record does not report missing-data procedures, the analysis population, the full statistical analysis plan, or sensitivity analyses. It also does not explain whether the listed secondary outcomes were adjusted for multiplicity. These omissions restrict assessment of how participant exclusions, unavailable measurements, or multiple testing might affect interpretation.

Finally, the registry reports limited details about eligibility criteria, allocation procedures, follow-up, adherence, and the safety analysis. Most listed secondary outcomes have no posted analysis results in the results information. These limitations concern what can be assessed from the registry record and should not be taken to imply unreported trial conduct or findings.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Efficacy of Switching to DTG/3TC in Virologically-suppressed Adults Currently on B/F/TAF — NCT04585737.
• Registry record last updated 2024-10-17; status last verified 2024-09.
• Results first posted 2024-10-17.
• 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

The DYAD Study is a completed Phase 4 randomized, open-label, parallel-group trial with enrollment listed as 222. It compared switching virologically suppressed adults living with HIV from B/F/TAF to once-daily DTG/3TC with continuing B/F/TAF. The primary endpoint was HIV-1 RNA at least 50 copies/mL at Week 48.

The posted primary outcome records 6 events among 149 participants in the switch group and 5 among 73 participants continuing B/F/TAF. The unadjusted comparison does not establish a clear difference, and its confidence interval crosses zero. The registry record does not report the original sample-size justification, missing-data methods, analysis population, or a multiplicity strategy. The treatment-description group sizes also differ from the outcome denominators without explanation.

The secondary viral-load outcomes provide context but do not resolve the primary result's uncertainty. Analyses for most other listed secondary outcomes are not reported in the registry record.