Effect of VI-0521 (Qsymia®) on Glomerular Filtration Rate (GFR) in Overweight or Obese Healthy Subjects: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Effect of VI-0521 (Qsymia®) on Glomerular Filtration Rate (GFR) in Overweight or Obese Healthy Subjects (NCT02229214), a randomized phase 4 study. The primary outcome is Change in iGFR (Glomerular Filtration Rate as Measured by Iohexol Clearance) From Baseline to End of Treatment.

2. Clinical Question

3. Trial Design

This was a Phase IV, single-center, randomized, parallel-group study comparing VI-0521 (Qsymia) with placebo. The registry describes the study as double-blind in its official title and lists triple masking in the masking field. Total enrollment was 51, and the record gives the study status as completed. The recorded start was 2014-08 and primary completion was 2014-11.

The intervention lasted 28 days. In the VI-0521 arm, the dose increased in stages: 3.75 mg/23 mg on days 1-3, 7.5 mg/46 mg on days 4-6, 11.25 mg/69 mg on days 7-9, and 15 mg/92 mg on days 10-28. The placebo arm received placebo on days 1-28. The registry summary describes GFR measurements at baseline, after 4 weeks of treatment, and after an additional 4 weeks off treatment.

The primary endpoint compares baseline with end-of-treatment iGFR, measured using iohexol clearance and expressed in mL/min/1.73 m^2. Its analyzed sample included 34 participants in the VI-0521 group and 10 in the placebo group. The registry defines this outcome population as subjects with measurements at both time points. The original sample-size justification, allocation ratio, detailed visit procedures, and operational details beyond the registry description are not reported in the registry record.

Other listed outcomes concern serum creatinine, cystatin C, and the proportion of subjects with a decrease of at least 15% in iohexol clearance, assessed at treatment end or after the off-treatment period. The available posted numeric results include several continuous secondary measures; further details about other outcomes are not reported in 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: The number analyzed in this outcome measure are those subjects who have both baseline and end of treatment iGFR measurements.

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 Change in iGFR (Glomerular Filtration Rate as Measured by Iohexol Clearance) From Baseline to End of Treatment, measured over Baseline, end of treatment.

The primary endpoint is change in iGFR from baseline to the end of treatment. GFR estimates how much fluid the kidneys filter over time. The registry describes this measure as based on iohexol clearance and body surface area, with units of mL/min/1.73 m^2. Iohexol is described in the record as a non-radioactive iodine-containing substance used as a marker for measuring GFR.

Using a change from baseline focuses the comparison on how the measurement moved during the treatment period, rather than on the end value alone. The trial compares the mean change in the VI-0521 and placebo groups. A mean summarizes the average change across the measured participants in each group; it does not imply that every participant had a change of that size or direction.

Iohexol-clearance measurement is used as a direct marker of filtration, while serum creatinine and cystatin C are included among the secondary measures. The primary outcome timeframe is baseline to end of treatment. Although the registry summary also describes measurement after an additional 4 weeks off treatment, that recovery time point is not the primary endpoint reported in the primary results. The registry does not report further details about measurement procedures, the handling of repeat measurements, or the interpretation thresholds used for individual changes.

7. Results Posted in the Registry

• VI-0521 (Qsymia): mean -14.92 versus 1.08 on control; difference -16.00 (95% CI -21.12 to -10.88), standardized effect d = -2.16; z-test p = <0.001.

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.

Change in Serum Creatinine From Baseline to End of Treatment

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard errors.
• Result:
  • Sugar Pill: mean 0.03 versus 0.10 on control; difference -0.07 (95% CI -0.13 to -0.01), standardized effect d = -1.03; z-test p = 0.027.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Sugar Pill than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Change in Serum Creatinine From Baseline to 28 Days After End of Treatment

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard errors.
• Result:
  • Sugar Pill: mean 0.03 versus -0.01 on control; difference 0.04 (95% CI -0.00 to 0.08), standardized effect d = 0.67; z-test p = 0.074.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Sugar Pill and the control. The interval gives the range of effects that remain compatible with the data.

Change in Cystatin C From Baseline to End of Treatment

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard errors.
• Result:
  • VI-0521 (Qsymia): mean 0.04 versus 0.03 on control; difference 0.01 (95% CI -0.03 to 0.05), standardized effect d = 0.17; z-test p = 0.655.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between VI-0521 (Qsymia) and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes broaden the assessment beyond iohexol-clearance GFR. They include serum creatinine and cystatin C changes, as well as the proportion of subjects whose iohexol clearance decreased by at least 15%, with several outcomes specified at end of treatment and after the off-treatment period. These measures address related aspects of kidney function or change over time, but they are not interchangeable with the primary endpoint.

Across the continuous secondary results with posted estimates, the pattern is not uniformly aligned in magnitude or statistical evidence with the primary comparison. Such variation is possible because biomarkers capture different features, outcome time points differ, and the analyzed participants can vary. It does not by itself resolve the primary finding or establish a consistent effect across all measures. The secondary outcomes should be read alongside their estimates and uncertainty rather than reduced to whether an individual p-value crosses a threshold.

The registry lists six secondary outcomes, while detailed numerical summaries are not available for every listed measure in the posted results. Results not included in the reported numerical summaries are not reported in the registry record. In particular, lack of a posted estimate should not be interpreted as no change or as evidence of no difference.

Each additional outcome creates another opportunity for a chance finding. If many tests are considered without an adjustment or a prespecified testing order, the chance that at least one result appears noteworthy can increase. The registry record does not report a multiplicity-control method or hierarchy. For that reason, unadjusted secondary results carry less weight than the primary outcome, especially when considered one by one. They can help describe the broader pattern and identify questions for further study, but should not be treated as independent confirmation of the primary contrast.

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

• Change in Serum Creatinine From Baseline to End of Treatment
• Change in Serum Creatinine From Baseline to 28 Days After End of Treatment
• Change in Cystatin C From Baseline to End of Treatment
• Change in Cystatin C From Baseline to 28 Days After End of Treatment
• Percentage of Subjects With a Decrease of >/= 15% in Iohexol Clearance From Baseline to End of Treatment
• Percentage of Subjects With a Decrease of >/= 15% in Iohexol Clearance From Baseline to 28 Days After End of Treatment

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous, and the registry reports group means with standard errors. The comparison is a mean difference between VI-0521 and placebo. Statistical methods help describe the observed group contrast, its uncertainty, and the assumptions that connect the analysis to a broader population. The original statistical analysis plan is not reported in the registry record.

What does a mean difference represent?

A mean is the arithmetic average of the observed changes in a group. The primary results report mean change of -14.92 mL/min/1.73 m^2 in the VI-0521 group and 1.08 mL/min/1.73 m^2 in the placebo group. The reported mean difference is -16.0 mL/min/1.73 m^2. The sign reflects the ordering of the groups in the comparison: the VI-0521 group’s mean change is lower than the placebo group’s mean change.

A group mean does not describe the spread of individual responses. Participants could have changes both above and below their group average. The registry reports standard errors for the group means, but does not provide the individual observations or a distribution of participant-level changes. Consequently, the posted aggregate results cannot show how consistently individual participants changed.

What does the standard error describe?

The standard error describes the statistical uncertainty in an estimated mean, rather than the range of individual participant values. The reported standard errors for the primary group means are 1.28 and 2.28. A smaller standard error generally indicates a more precisely estimated mean under the analysis assumptions. Standard error depends on both the variability in measurements and the number of observations contributing to the estimate. It should not be read as a standard deviation or as an interval containing most individual changes.

The registry reports no confidence limits for the separate group means, but it does report a confidence interval for the between-group mean difference. That interval is usually more directly relevant to the comparative question because it expresses uncertainty about the contrast, not just uncertainty around each group’s average considered separately.

How should the confidence interval be read?

A confidence interval gives a range of values for the population contrast that are reasonably compatible with the observed data and the procedure’s assumptions. The primary interval is -21.12 to -10.88 mL/min/1.73 m^2. Its endpoints are both below zero, so the interval excludes a zero mean difference under the reported calculation. The interval’s width communicates uncertainty: narrower intervals indicate more precision than wider intervals, all else equal. It does not mean that there is a stated probability that the true effect lies in this particular interval.

What does the p-value add?

The unadjusted p-value is <0.001. In general, a p-value measures how incompatible the observed data are with a specified null model, assuming that model and the analysis assumptions are correct. It does not measure the size or clinical importance of the difference, and it is not the probability that the result occurred by chance. The registry record does not report a multiplicity adjustment for this comparison, so the posted p-value should be treated as unadjusted rather than as a family-wise error-controlled result.

Randomization is intended to make treatment groups comparable on average, while masking can reduce some sources of bias in treatment delivery and outcome assessment. Those design features do not remove uncertainty from a small study, missing measurements, or limitations in reporting. The registry records randomization and masking but does not report the sequence-generation method, concealment procedure, or details of how masking was maintained.

In general, over-dispersion matters when data vary more than a chosen model expects: standard errors and tests based on an inadequate variability model can then be too optimistic. The primary endpoint is reported as a continuous mean, and no over-dispersion analysis is reported in the registry record. Likewise, model details, covariate adjustment, repeated-measure handling, and assumptions about the distribution of changes are not reported. No particular model beyond the posted mean comparison should therefore be inferred.

For secondary continuous outcomes, the same broad distinction applies: estimates describe group contrasts, while standard errors, confidence intervals, and p-values address different aspects of uncertainty. The posted secondary p-values are unadjusted. The record does not report a prespecified hierarchy or a procedure for controlling the chance of false-positive findings across multiple outcomes. Interpretation should therefore give the primary endpoint greater weight and regard secondary findings as less conclusive.

11. Confidence Intervals and Precision

The primary mean difference is -16.0 mL/min/1.73 m^2, with a 95% confidence interval from -21.12 to -10.88. This interval gives a range of values compatible with the observed data under the confidence-interval method and its assumptions. Since both endpoints are below zero, the reported interval does not include no difference. The interval is not a guarantee that the true contrast lies within its bounds, nor does it express the range of individual participant outcomes.

Precision is influenced by the amount of information in the data, including the number of measured participants and variability in the outcome. The primary analyzed groups contained 34 and 10 participants. The imbalance in group sizes means that the smaller group contributes less information to the comparison, all else equal. The standard errors of the group means were 1.28 for VI-0521 and 2.28 for placebo, reflecting different estimated precision for those means.

The confidence interval should be considered alongside the point estimate. The estimate gives one best-fitting value under the analysis, while the interval communicates uncertainty around it. A confidence interval does not show whether the difference is important in a clinical sense; the registry record does not state a threshold for clinical importance. It also does not account automatically for unreported design or analysis choices, such as multiplicity handling or missing-data methods. These should not be assumed.

For secondary results, interval estimates may include values in more than one direction, and their interpretation depends on both the estimate and its uncertainty. The number of outcomes and lack of a reported multiplicity approach make isolated secondary intervals or tests less definitive. Precision concerns statistical uncertainty in the posted estimates, not certainty about generalizing to other populations or longer follow-up.

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 study’s original design calculation. The registry record does not report the trial’s original sample-size assumptions or justification. For continuous outcomes, the figures are participants per arm, not combined totals or event counts.

The stated planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. Each row considers an effect equal to a stated fraction of the observed effect: the full observed effect, 75% of it, or 50% of it. These are hypothetical effects for illustration and should not be mistaken for additional observed results.

The 80% power column gives the number of participants per arm that the planning calculation estimates would be needed for an 80% chance of detecting the chosen effect under those assumptions, if that effect were the true one. The 90% power column gives the corresponding number per arm for a 90% chance. Power is a property of a proposed design under specified assumptions; it does not tell whether the trial’s result is true or clinically important.

Smaller effects are harder to distinguish from random variation and therefore require more participants. The planning figures increase as the assumed effect is reduced. This is not observed power: it is a prospective planning illustration calculated from the observed effect, not a measure of the probability that the completed trial detected a true effect.

These figures also assume equal allocation, whereas the primary analyzed group sizes were 34 and 10. They are not a reconstruction of the original study design and do not establish that the trial was adequately or inadequately sized. The registry does not report whether the original design used different assumptions, endpoints, or methods.

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, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -16.000; pooled standard deviation σ = 7.410.
2. n = 2 × (1.96 + 0.842)² × 7.410² / -16.000² = 3.4, rounded up to 4 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
delta <- -16                      # observed difference in means
sigma <- 7.41000096394827                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^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 (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(2229214)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 4 (80% power), 5 (90% power)
 75% of observed effect: n per arm = 6 (80% power), 9 (90% power)
 50% of observed effect: n per arm = 14 (80% power), 19 (90% power)
power.t.test: 4.6 
Simulated power at n = 4 per arm: 0.723 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-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

Multiplicity arises when several outcomes, time points, or comparisons are tested. Each test can produce a chance-positive result even when there is no true effect, and the overall chance of at least one such result can increase as more tests are considered. This trial lists multiple secondary outcomes, including several biomarkers and assessments at more than one follow-up time. The registry record does not report a strategy for controlling multiplicity, such as an adjustment or a prespecified hierarchy. The posted secondary p-values are therefore unadjusted and warrant caution when interpreted as a group of findings.

The registry records zero reported analyses in its analysis information, and no detailed analysis plan is included. That does not establish that no analysis was performed; it means that the statistical analysis details are not reported in the registry record. Covariate adjustment, the exact testing procedure, handling of repeated measures, and any interim analyses are not reported in the registry record. No such methods should be inferred from the summary statistics alone.

The primary outcome population is defined as subjects with both baseline and end-of-treatment iGFR measurements. The reported primary group sizes are 34 and 10, while total enrollment was 51. The reasons participants may not have contributed to the primary analysis, and the values or outcomes of those without both measurements, are not reported in the registry record. Methods for handling missing data, including imputation or sensitivity analyses, are also not reported.

Other outcome populations have their own reported group sizes, so the number analyzed is not necessarily identical across measures. The registry does not provide enough detail to determine whether the same participants contributed to each endpoint or how incomplete follow-up was handled. These omissions limit assessment of possible selection effects and of how robust results are to missing measurements.

15. Safety Results

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

Other (non-serious) adverse events

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

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: fall (2.4%).

The registry reports serious adverse events among 41 participants at risk in the VI-0521 group and 10 at risk in the placebo group. One participant in the VI-0521 group was affected by a serious adverse event; none were affected in the placebo group. “At risk” is the registry’s stated group denominator, while the affected counts refer to the number of participants recorded with the event category. The registry lists Fall at 2.4% among the top serious adverse-event terms.

For other, non-serious adverse events, 33 of 41 participants were affected in the VI-0521 group and 6 of 10 in the placebo group. These figures describe the recorded safety data and should not be treated as a causal comparison by themselves. The group sizes differ, follow-up was limited to the study period described, and details about event definitions, severity grading, duration, or relatedness assessments are not reported in the registry record.

Deaths are not reported in the registry record. Serious adverse-event counts are not a complete account of all safety considerations and do not establish the likelihood of events in other populations or during longer use. The registry data are descriptive; they do not support medical advice or a broad conclusion about safety.

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

The posted primary result describes a between-group difference in mean change in iohexol-clearance iGFR from baseline to the end of a 28-day treatment period. The estimate is -16.0 mL/min/1.73 m^2, with a 95% confidence interval from -21.12 to -10.88 and an unadjusted p-value of <0.001. In the analyzed sample, the average change was lower in the VI-0521 group than in the placebo group. This is a statistical description of the measured outcome and time period.

It does not mean that every participant in the VI-0521 group experienced the same change, or that the group mean predicts an individual’s outcome. The registry provides group summaries rather than participant-level data. Nor does the result establish a mechanism, a durable effect after treatment stops, or the meaning of the observed change for health outcomes. Those questions are not answered by the primary mean comparison.

The trial was a single-center study in healthy overweight or obese subjects, and the primary analysis included subjects with both required measurements. The result should not automatically be generalized to other populations, care settings, durations, or patterns of use. The study summary describes an additional 4-week off-treatment period, but the primary result is the baseline-to-end-of-treatment comparison. The registry entries do not establish what happens beyond the reported measurements.

The endpoint is a measure of filtration, not a direct report of symptoms or clinical events. The registry’s secondary outcomes include other kidney markers and threshold-based measures, but those outcomes do not replace the primary endpoint and are subject to the limitations of multiple unadjusted analyses. The posted results provide evidence about a defined statistical contrast; they do not, on their own, determine clinical importance, individual risk, or treatment decisions.

17. Why This Trial Matters Statistically

This trial illustrates how a continuous physiological measure can be analyzed as a change from baseline and compared between randomized groups. The distinction between group means, standard errors, confidence intervals, and p-values matters: the mean difference describes the estimated contrast, the interval conveys its precision, and the p-value addresses compatibility with a null model under specified assumptions. These quantities answer related but distinct questions.

It also highlights the importance of the analysis population. Total enrollment was 51, while the primary outcome was analyzed among subjects with both baseline and end-of-treatment measurements, with reported group sizes of 34 and 10. Interpreting a result requires knowing who contributed data and whether missing measurements could affect the comparison. The registry defines the primary population but does not report the reasons for missing outcome data or methods for handling them.

The trial’s several secondary endpoints illustrate the statistical challenge of interpreting many outcomes. Unadjusted findings can be useful descriptively, but without a reported multiplicity strategy they carry less confirmatory weight. A consistent interpretation emphasizes the prespecified primary question while treating secondary patterns as context.

Finally, the sample-size illustrations show how power calculations depend on assumptions about the effect to detect and allocation. They are planning scenarios based on the observed effect, not evidence of what the trial was originally designed to detect. Keeping those distinctions clear prevents retrospective calculations from being mistaken for the actual design rationale or for evidence that a result is true.

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.

The primary outcome is reported for participants with both baseline and end-of-treatment measurements, but reasons for non-inclusion in that analysis and missing-data methods are not reported in the registry record. Total enrollment was 51, whereas the primary analyzed group sizes were 34 and 10. Without further information, the potential effect of incomplete measurements on the estimate cannot be assessed.

The study was single-center and enrolled healthy overweight or obese subjects. The registry record does not establish how results would generalize beyond this population or setting. Treatment and primary measurement covered a short period: the primary endpoint compares baseline with the end of 28 days of treatment. Although the study summary mentions an additional 4 weeks off treatment, the primary result does not answer whether any change persists beyond treatment.

The registry does not report the original sample-size justification, detailed statistical analysis plan, interim analyses, multiplicity procedure, or methods for handling repeated measurements. The primary group sizes were unequal, and the placebo group was smaller. The posted confidence interval reflects statistical uncertainty under the reported analysis, but cannot address unreported design choices or missing-data assumptions.

Secondary outcomes involve several markers and time points, while the registry does not report a multiplicity-control strategy. Some listed outcomes do not have detailed numerical estimates in the posted results. Safety figures are descriptive and include limited group counts; further details about event definitions, severity, relatedness, and duration are not reported in the registry record. These reporting and design limits constrain interpretation without negating the descriptive primary result.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Effect of VI-0521 (Qsymia®) on Glomerular Filtration Rate (GFR) in Overweight or Obese Healthy Subjects — NCT02229214.
• Registry record last updated 2017-11-07; status last verified 2017-10.
• Results first posted 2016-02-09.
• 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

NCT02229214 is a completed Phase IV, randomized, parallel-group, placebo-controlled study of VI-0521 (Qsymia) in healthy overweight or obese subjects. The study was described as double-blind in its official title, with triple masking recorded in the registry. Total enrollment was 51.

The primary outcome was change in iohexol-clearance iGFR from baseline to end of treatment. The reported mean difference between VI-0521 and placebo was -16.0 mL/min/1.73 m^2, with a 95% confidence interval from -21.12 to -10.88 and an unadjusted p-value of <0.001. The primary outcome analysis included 34 participants in the VI-0521 group and 10 in the placebo group.

Secondary outcomes covered additional kidney markers and follow-up measures. The registry also reports serious and other adverse-event counts. Details not recorded, including the original sample-size justification, missing-data methods, and multiplicity strategy, are not reported in the registry record.