Study to Evaluate ARD-101 in Adults With Obesity: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study to Evaluate ARD-101 in Adults With Obesity (NCT05121441), a randomized phase 2 study. The primary outcome is Relative Change in Body Weight (%).

2. Clinical Question

3. Trial Design

This was a Phase 2, randomized, single-masked, parallel study of ARD-101 compared with placebo in adults with obesity. The registry lists an enrollment of 20 participants. The posted primary-outcome summaries include 14.0 participants in the ARD-101 arm and 6.0 in the placebo arm. The record does not explain the difference between the overall enrollment and the numbers contributing to these endpoint summaries.

The active regimen was 200 mg of ARD-101 twice daily for 28 days. The placebo arm is described as matching the active arm. The registry identifies single masking but does not state which participants, investigators, or other personnel were masked. Details of the randomization sequence, allocation concealment, or procedures for maintaining masking are not reported in the registry record.

The primary outcome was relative change in body weight (%) at the end of treatment, with the timeframe given as the run-in visit (baseline) and Day 28. The registry lists secondary outcomes covering treatment-emergent adverse events, total cholesterol, triglycerides, HDL, LDL, waist circumference, and percentage HbA1C. It records eight outcome measures overall and seven posted secondary outcomes.

The study is marked completed. Its listed start date is 2021-11-15, and its primary completion date is 2022-11-09. Further details on the protocol, recruitment, participant flow, and analysis populations are not reported in the registry record. The posted information therefore supports a description of the design and the available endpoint summaries, but not a full reconstruction of how participants moved through the trial or how every outcome was analyzed.

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.

Before assignment: A total of 20 subjects were enrolled and all 20 (100%) subjects completed the study.

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 Relative Change in Body Weight (%), measured over Run-in Visit (baseline), Day 28.

The primary endpoint measures relative change in body weight as a percentage from baseline to the end of treatment. The registry defines the timeframe as the run-in visit (baseline) and Day 28, and describes the measure as percent total weight change at the end of treatment from baseline. A negative mean indicates a decrease from baseline on this scale, while a positive mean indicates an increase.

Body weight is a continuous measure, so the registry reports a mean and standard deviation for each arm. A mean gives the central average change among participants included in that arm’s summary. The standard deviation describes how spread out individual changes are around that mean; it does not itself measure the uncertainty of the mean or the precision of a between-arm comparison.

For this endpoint, the reported mean was -0.33 in the ARD-101 arm and 0.38 in the placebo arm. These values describe the two arm summaries, not an adjusted or unadjusted treatment contrast. The registry record does not report a confidence interval or an estimable two-arm comparison for this continuous endpoint. As a result, the arm means cannot establish the size or precision of the difference attributable to assignment.

Body-weight change is used as a measurable outcome over the stated treatment period. The record does not report a rationale for selecting this particular endpoint, a threshold for judging a change meaningful, or how the endpoint relates to other study outcomes. Its stated role is the primary measure of preliminary efficacy, alongside the study’s assessment of safety and tolerability.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean change describe?

For a continuous outcome, the mean is the arithmetic average of the participant-level values included in an arm summary. In this study, the outcome is relative change in body weight as a percentage from the run-in visit (baseline) to Day 28. The reported means are -0.33 for ARD-101 and 0.38 for placebo. A negative value describes an average decrease on the stated scale; a positive value describes an average increase. These are within-arm summaries and are not, on their own, the estimated effect of assigning ARD-101 rather than placebo.

What does the standard deviation describe?

General statistical explanation: the standard deviation describes the spread of participant values around their arm mean. A larger spread means observations are more dispersed; a smaller spread means they are more closely clustered. It is not the same as a confidence interval, and it is not a direct measure of the uncertainty in a treatment comparison. The reported standard deviations are .94 for ARD-101 and 1.08 for placebo. The registry does not give confidence intervals around the means or around a between-arm contrast.

Why is the direct comparison important?

General statistical explanation: a randomized comparison ordinarily focuses on the difference in outcomes between assigned groups, with an estimate of its uncertainty. That comparison answers a different question from whether the average changed from baseline within either arm. Within-arm changes may reflect many influences, while the randomized contrast is intended to compare outcomes between the assigned groups. The registry record says a two-arm comparison could not be estimated for this continuous endpoint. It therefore does not report a treatment contrast or a test of that contrast.

How should uncertainty be understood?

General statistical explanation: a confidence interval describes a range of values reasonably compatible with the data and the method used to calculate it. Its width reflects uncertainty, including the amount of information available and the variability in observations. A p-value, when reported, measures how unusual the observed data or a more extreme result would be under a specified null model; it does not measure the probability that a treatment works. Neither a confidence interval nor a p-value for the primary two-arm comparison is reported in the registry record. Their absence means the precision and inferential strength of a between-arm estimate cannot be assessed from the posted primary summary.

What does the planning illustration represent?

General statistical explanation: sample-size calculations use assumptions about the effect to be detected, variability, allocation, and a chosen significance level. The registry describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation, a normal approximation, and planning for a specified share of the observed effect. Such calculations are hypothetical planning scenarios; they do not show the power achieved by the completed trial and are not evidence that the trial was designed around those assumptions. The record does not report the trial’s own sample-size justification or design calculations.

The posted planning assumptions specify equal allocation, whereas the endpoint summaries list 14.0 participants in the ARD-101 arm and 6.0 in the placebo arm. The record does not explain this difference. No planning sample-size figures are included in the registry record, so no numerical planning requirement can be stated. In general, planning illustrations can help show how assumptions influence sample-size requirements, but they cannot replace an account of the original design rationale.

Why can over-dispersion matter?

General statistical explanation: over-dispersion occurs when data vary more than a statistical model assumes. If a model understates variability, standard errors may be too small and confidence intervals too narrow; if it accounts for the extra variability, uncertainty estimates may become wider. This concern is especially relevant when the chosen model’s variance assumptions do not match the observed data. The primary endpoint is a continuous measure, and the record reports arm-level standard deviations, but it does not report a fitted model, an over-dispersion assessment, or any model adjustment. No claim about over-dispersion or its effect on the analysis can therefore be made.

Overall, the reported mean and standard deviation are descriptive summaries. They provide information about the observed arm-level values and their spread, but the registry’s note that a two-arm comparison was not estimable limits further inference about the randomized treatment contrast.

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("ARD-101", "Placebo Comparator")
n   <- c(14, 6)
m   <- c(-0.33, 0.38)
sp  <- c(0.94, 1.08)
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  ARD-101  14  -0.330  0.940  -0.873  0.213
CARM  Placebo Comparator  6  0.380  1.080  -0.753  1.513

11. Multiplicity, Missing Data and Analysis Populations

The registry lists the primary endpoint as relative change in body weight (%) and identifies seven secondary outcomes: treatment-emergent adverse events, changes in total cholesterol, triglycerides, HDL, LDL, waist circumference, and percentage HbA1C. It records eight outcome measures overall. Testing several outcomes can raise a multiplicity concern: general statistical explanation, when many hypotheses are tested, the chance of at least one apparently unusual result can increase unless the analysis plan addresses this issue.

The registry record does not report whether the secondary outcomes were treated as confirmatory or exploratory, whether any multiplicity adjustment was planned, or how outcomes were prioritized. It also does not report a complete statistical analysis plan. Accordingly, no conclusion can be made about how the study handled multiplicity.

The record gives primary-endpoint summaries for 14.0 ARD-101 participants and 6.0 placebo participants, against total enrollment of 20. It does not report the analysis population definition, participant-level missingness, reasons for missing data, or the methods used to handle missing outcome values. It notes that a two-arm comparison for the continuous endpoint was not estimable, but does not explain why. It is therefore not possible to determine whether the summaries include all randomized participants or how missing observations may have affected results.

The registry reports zero analysis entries. This indicates that analysis details are not posted in the record; it does not establish that no analyses were conducted. The planned or used approach to analysis populations, missing data, and multiplicity is not reported in the registry record.

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 posted serious adverse-event counts are zero in both arms. The registry lists 14 participants at risk in the ARD-101 arm and 6 in the placebo arm, with zero affected by a serious adverse event in each. Deaths are also listed as zero in both arms. These are counts in the registry record, not estimates of comparative safety with uncertainty intervals.

For other adverse events, the record lists 3 affected participants among 14 at risk in the ARD-101 arm and 1 among 6 at risk in the placebo arm. These counts are distinct from the serious adverse-event counts. The record lists treatment-emergent adverse events as a secondary outcome, but the information does not provide event types, severity details, timing, or an analysis comparing arms.

A zero count means no events of that category were recorded among the listed participants at risk; it does not establish that an event is impossible or that the groups have identical underlying risks. The arm sizes are limited, and the registry does not report uncertainty estimates for these counts. The record also lists no top serious-event terms. These safety figures should therefore be read as descriptive counts rather than a definitive comparison between treatments.

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

The posted results establish that the registry contains arm-level mean relative body-weight changes at Day 28: -0.33 for ARD-101 and 0.38 for placebo. They also give the standard deviations, .94 and 1.08, and the endpoint summary counts, 14.0 and 6.0. These details describe what was observed in the endpoint summaries.

They do not establish the size or precision of a between-arm effect. The registry record states that values were missing or not estimable for a two-arm comparison of the continuous endpoint. Without a reported contrast and uncertainty estimate, the direction of the two means cannot be translated into a reliable estimate of the difference between assigned groups. No statistical significance claim can be made from these summaries.

The record describes a randomized comparison and a 28-day treatment regimen, but the primary endpoint is limited to the stated baseline-to-Day 28 period. Later outcomes are not reported in the information available for this account. The registry lists secondary outcomes, but their results and analysis details are not reported. Conclusions about those outcomes cannot be drawn from the primary weight summaries.

The safety data show no recorded serious adverse events or deaths in either arm, alongside the reported counts for other adverse events. Those counts are descriptive and do not quantify comparative risk precisely. The registry’s overall enrollment is 20, and the endpoint summaries are based on smaller arm-specific counts; explanations for the participant accounting are not reported.

In short, the registry offers a limited descriptive account of body-weight changes and adverse-event counts. It does not report an estimable primary treatment comparison, the associated precision, or enough analysis detail to support broader conclusions. These limitations concern what can be inferred from the posted record, not a claim about results that are absent from it.

14. Why This Trial Matters Statistically

This study is statistically informative as an example of the distinction between descriptive arm summaries and an interpretable randomized comparison. The registry reports mean relative body-weight changes in both arms, but also states that a two-arm comparison for this continuous endpoint was not estimable. The summaries can describe the observed values; they cannot substitute for the contrast that addresses the comparative question.

The endpoint summary counts are 14.0 for ARD-101 and 6.0 for placebo, while overall enrollment is 20. Unequal arm counts can affect the precision of estimates, and the smaller arm may contribute less information. The registry does not explain the participant accounting or provide confidence intervals, so the degree of uncertainty cannot be quantified from the reported primary results.

The record also illustrates why planning assumptions must be kept separate from observed trial evidence. It describes a sample-size planning illustration based on the observed effect and specified assumptions, including equal allocation, a two-sided significance level of 0.05, and a normal approximation. Such planning scenarios do not describe the power achieved in the completed study, nor do they disclose the original sample-size rationale.

Finally, the record lists secondary outcomes and adverse-event counts without reporting a complete analysis plan or inferential results for the primary contrast. Statistical interpretation depends not only on outcome values but also on a clearly described estimand, analysis population, missing-data approach, and uncertainty assessment. Their absence makes restraint important: the posted numbers support descriptive reading, while the comparative strength and precision remain unreported.

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.

Several limitations specific to this trial constrain interpretation. The registry describes a completed Phase 2 study with enrollment of 20 and a 28-day active regimen. The primary outcome summaries list 14.0 participants for ARD-101 and 6.0 for placebo, but the registry does not explain this accounting or report participant flow. It is therefore unclear from the record how many enrolled participants contributed to each endpoint or why the arm summary counts differ.

The primary endpoint is reported through arm means and standard deviations, but the registry states that a two-arm comparison for the continuous endpoint was not estimable. No contrast, confidence interval, or inferential test is reported. This prevents assessment of the magnitude and precision of the randomized comparison. The record does not give participant-level data or another basis for reconstructing that comparison.

Methodological details are also limited. The record identifies randomization, single masking, and a parallel design, but does not say who was masked or describe allocation procedures. It does not report the analysis population, handling of missing data, a detailed statistical analysis plan, or the original sample-size justification. Secondary outcomes are listed, but their results and multiplicity handling are not reported.

The endpoint timeframe is baseline to Day 28. Results beyond that period are not reported in the registry information. The safety counts are descriptive, with no reported uncertainty estimates or detailed event information. These limitations mean that the posted record supports only a bounded account of the available short-term summaries and counts.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Study to Evaluate ARD-101 in Adults With Obesity — NCT05121441.
• Registry record last updated 2025-01-22; status last verified 2025-01.
• Results first posted 2025-01-22.
• 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 record identifies NCT05121441 as a completed Phase 2, randomized, single-masked, parallel study of ARD-101 in adults with obesity, sponsored by Aardvark Therapeutics, Inc. The listed enrollment is 20. The study start date is 2021-11-15, and the primary completion date is 2022-11-09.

ARD-101 was given at 200 mg twice daily for 28 days, with matching placebo as the comparator. The primary outcome was relative body-weight change (%) from the run-in visit (baseline) to Day 28. The reported means were -0.33 for ARD-101 and 0.38 for placebo; the registry notes that a two-arm comparison for this continuous endpoint was not estimable.

Serious adverse events and deaths were recorded as zero in both arms. Other adverse events were reported in 3 participants in the ARD-101 arm and 1 in the placebo arm. The registry lists seven secondary outcomes and records zero analysis entries. Further analysis details, including missing-data methods and the primary comparison, are not reported in the registry record.