Study to Evaluate the Efficacy and Safety of Leronlimab for Mild to Moderate COVID-19: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study to Evaluate the Efficacy and Safety of Leronlimab for Mild to Moderate COVID-19 (NCT04343651), a randomized phase 2 study. The primary outcome is Mean Change From Baseline in Total Symptom Score.

2. Clinical Question

The registry also lists secondary outcomes involving clinical resolution, hospitalization, mechanical ventilation, oxygen use and mortality. Those outcomes address other aspects of the clinical course, but the primary comparison is the change in the symptom score. The central statistical question is whether the observed difference between the randomized groups is sufficiently precise to distinguish a treatment-group difference from variation compatible with no difference. The posted primary summaries and the registry's reported ANCOVA result are both relevant, but they are not the same analysis: one is an unadjusted calculation from group summaries, and the other is the sponsor-reported analysis.

3. Trial Design

This was a phase 2, randomized, double-blind, placebo-controlled, multicenter, parallel-group study of leronlimab for mild to moderate COVID-19. The registry lists quadruple masking. Enrollment was 86, and the study status is completed. The recorded study start was 2020-04-01, and primary completion was 2020-07-21. CytoDyn, Inc. is listed as the sponsor.

Participants were assigned to placebo or 700mg leronlimab. The posted primary outcome summaries include 28 participants in the placebo group and 56 in the leronlimab group. The registry defines the modified intent-to-treat population as subjects who received at least one dose of either study treatment, and reports 84 subjects in that population at the time of the report. The registry record does not explain the difference between total enrollment and the size of this efficacy population.

The primary outcome was mean change from baseline in total symptom score, assessed at baseline and end of treatment at day 14. The record describes four symptoms and a score ranging from 0 to 12 points, with each symptom graded from 0 to 3. It also describes classifying patients as improved, unchanged or worsened. The registry's outcome title emphasizes mean change, while its description includes both the score definition and those clinical-change categories.

The registry reports an ANCOVA analysis for the primary comparison. Its specific covariates, missing-data procedures, allocation sequence details, and original sample-size assumptions are not reported in the registry record. The planning estimates associated with the posted results are illustrative calculations based on the observed effect, not the trial's original design assumptions.

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: 126 patients were screened, 40 were screen failures.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The Modified Intent-to-Treat (mITT) population was defined as the set of subjects who received at least one dose of leronlimab (PRO 140) or placebo. This population was to be used for the analysis of efficacy parameters or measurements. At the time of this report, there were 84 subjects in the mITT population.

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.

Population: The Modified Intent-to-Treat (mITT) population is defined as the set of subjects who have received at least one dose of leronlimab or placebo and is population used for the analysis of efficacy parameters or measurements. The Safety Population includes all subjects who received at least one dose of leronlimab or placebo. This population was used for the analysis of safety parameters or measurements. There were 84 subjects in the MITT and Safety Population.

6. Primary Endpoint

The registry lists the primary outcome as Mean Change From Baseline in Total Symptom Score, measured over Clinical Improvement will be assessed at baseline and at EOT (day 14)..

The primary endpoint is mean change from baseline in total symptom score at end of treatment, identified as day 14. The score combines fever, myalgia, dyspnea and cough. Each symptom is graded from 0 to 3, and the total ranges from 0 to 12 points. Higher scores represent worse symptoms. A negative change from baseline therefore represents a decrease in symptom burden, while a positive change would represent worsening on this scale.

A combined score can summarize several symptoms in a single continuous measure, allowing a comparison of average change between randomized groups. That makes the endpoint useful for assessing the overall direction and magnitude of symptom-score change rather than treating each symptom as a separate primary outcome. However, an average does not show how many individual participants improved, stayed the same or worsened. The registry description mentions those categories, but the primary numerical summaries posted for this comparison are group means and standard deviations.

The recorded placebo mean change was -3.4, and the recorded leronlimab mean change was -3.5. Those group means are close, and the estimated difference is small relative to the variability described by the standard deviations. The endpoint measures change on this symptom scale; it does not by itself establish what happened on every secondary clinical outcome.

7. Results Posted in the Registry

• 700mg Leronlimab: mean -3.50 versus -3.40 on control; difference -0.10 (95% CI -1.52 to 1.32), standardized effect d = -0.03; z-test p = 0.890.

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.

Duration (Days) of Hospitalization

• 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 deviations.
• Result:
  • 700mg Leronlimab: mean 2.10 versus 2.00 on control; difference 0.10 (95% CI -1.45 to 1.65), standardized effect d = 0.03; z-test p = 0.899.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between 700mg Leronlimab and the control. The interval gives the range of effects that remain compatible with the data.

Duration of Mechanical Ventilation Supply

• 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 deviations.
• Result:
  • 700mg Leronlimab: mean 0.20 versus 0.40 on control; difference -0.20 (95% CI -0.97 to 0.57), standardized effect d = -0.14; z-test p = 0.612.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between 700mg Leronlimab and the control. The interval gives the range of effects that remain compatible with the data.

Duration of Oxygen Use

• 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 deviations.
• Result:
  • 700mg Leronlimab: mean 0.90 versus 0.80 on control; difference 0.10 (95% CI -1.20 to 1.40), standardized effect d = 0.03; z-test p = 0.880.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between 700mg Leronlimab and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists 12 secondary outcomes, including clinical resolution, hospitalization, mechanical ventilation, oxygen use and mortality. Detailed numerical summaries in the record include three duration outcomes: hospitalization, mechanical ventilation and oxygen use. Their unadjusted mean differences are small relative to their reported uncertainty, and each posted confidence interval includes zero. These summaries do not establish a clear separation between the randomized groups for those duration measures.

The secondary summaries are broadly consistent with the primary result in that they do not show a precise, clear between-group difference. They should not be treated as independent confirmation of the primary finding: secondary outcomes address different aspects of the clinical course, and only some have detailed numerical results in the record. Results for the other listed secondary outcomes are not reported in the registry record in the material available for these comparisons.

Unadjusted secondary comparisons carry less weight when many outcomes are examined. General statistical explanation: as the number of statistical tests increases, the chance of at least one apparently notable result arising by chance can increase. Adjustment or a prespecified hierarchy can help address this issue, but a multiplicity strategy is not reported in the registry record. Thus, secondary results are best read as exploratory context rather than as multiple independent tests of the primary question. Their interpretation also depends on how the outcomes were defined, analyzed and handled when data were unavailable, details that are not fully reported in the registry record.

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

• Time to Clinical Resolution (TTCR)
• Incidence of Hospitalization
• Duration (Days) of Hospitalization
• Incidence of Mechanical Ventilation
• Duration of Mechanical Ventilation Supply
• Incidence of Oxygen Use
• Duration of Oxygen Use
• Mortality at Day 14

9. Statistical Interpretation

10. Statistical Methods Explained

What does a mean change compare?

A mean is the arithmetic average of observations in a group. Here, the outcome is each participant's change in total symptom score from baseline to end of treatment. A negative group mean indicates an average decrease from baseline on a scale where higher scores are worse. The comparison of interest is the difference between the two group means, rather than either group's change considered alone. The posted means are -3.4 for placebo and -3.5 for 700mg leronlimab; the unadjusted mean difference is -0.1.

What do the standard deviations describe?

A standard deviation describes how spread out individual observations are around a group mean. It is not the uncertainty in the mean itself, and it does not indicate the range of every participant's result. The primary standard deviations are 3.19 for placebo and 3.03 for leronlimab. General statistical interpretation: when the spread among individual observations is large in relation to the difference between group means, the group contrast may be estimated with limited precision, especially when the groups are not large.

What is a confidence interval?

A confidence interval expresses the uncertainty around an estimated effect under the statistical method used. In general, intervals that include zero for a difference in means are compatible with no difference, as well as with the other values inside the interval. The unadjusted primary interval is -1.523 to 1.323. It includes zero, and its width shows that the point estimate of -0.1 should not be interpreted as a precise measurement of the true group difference. The registry does not post an interval for the ANCOVA result.

What does a p-value say?

A p-value describes how compatible the observed data are with a specified null model, under the assumptions of the analysis. 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 p-value is 0.89; the sponsor-reported ANCOVA p-value is 0.818. These values do not, by themselves, identify the range of effects compatible with the data. The confidence interval provides a more direct expression of uncertainty for the unadjusted estimate.

How do the two analyses differ?

The unadjusted recalculation compares the posted group summaries without adjustment for other variables. The sponsor's reported method is ANCOVA. In general, analysis of covariance compares group outcomes while accounting for covariates included in the model; which covariates were used in this trial is not reported in the registry record. The registry reports the ANCOVA p-value but no adjusted estimate, interval or detailed model specification. Because there is no discrepancy flagged between the posted summaries and the reported analysis, the recalculation is best treated as a descriptive, unadjusted check rather than a substitute for the sponsor's analysis.

What does a standardized effect add?

A standardized effect expresses a mean difference relative to a measure of outcome variability, making the contrast less dependent on the original scale's units. The posted standardized effect for the primary comparison is -0.032. This is a compact description of the small estimated separation relative to the pooled variability; it does not replace the original scale, identify clinical importance, or account for every feature of the trial analysis. Its interpretation depends on the direction and definition of the contrast, so the raw mean difference and its interval remain important.

Why can over-dispersion matter?

General statistical explanation: over-dispersion means that outcomes vary more than a statistical model expects. When a model understates variability, standard errors can be too small and intervals can be too narrow. The primary outcome is continuous and reported with standard deviations; the registry record does not identify an over-dispersion adjustment. This concept is especially relevant to models for counts or binary outcomes and should not be assumed to describe this trial's primary analysis.

What can the registry analysis details establish?

The registry identifies the primary reported analysis as ANCOVA and labels it a superiority analysis. It does not report the model covariates, detailed analysis plan, missing-data method, or any interim-analysis procedure. Those omissions limit independent assessment of the exact analysis and its assumptions. General statistical principles can explain the purpose of common methods, but they do not reveal which unreported choices were made in this study.

11. Confidence Intervals and Precision

Precision concerns how tightly the data locate the treatment-group difference, not whether an estimate points in a preferred direction. For the primary unadjusted comparison, the estimated mean difference is -0.1 units, with a confidence interval from -1.523 to 1.323. The interval crosses zero and includes values on either side. It therefore does not isolate a single direction of difference, and it allows differences larger in magnitude than the point estimate.

The interval should be read together with the group means and standard deviations. The means, -3.4 and -3.5, are close, while the group standard deviations are 3.19 and 3.03. The group summaries show that the estimated average separation is small relative to the observed spread. The confidence interval makes the uncertainty about that separation explicit. It is not evidence that every individual outcome was similar, nor does it estimate the range of individual responses.

The sponsor's ANCOVA result is reported as p = 0.818, but its estimate and confidence interval are not reported in the registry record. Consequently, the precision of the adjusted estimate cannot be assessed from that p-value alone. The unadjusted interval is a recalculation from posted summary statistics and should not be mistaken for the interval from the sponsor's model.

Precision is also distinct from clinical importance. The registry record does not state a threshold for a clinically important difference on the symptom scale. Without such a threshold, the interval can describe statistical uncertainty but cannot determine whether values within it would be important to patients. The observed estimate is near zero, yet the interval's breadth means that the data do not pin down the true group contrast closely.

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 estimates describe hypothetical future sample sizes based on the observed effect, not the number enrolled in this trial. For this continuous primary outcome, the figures are participants per arm. The planning assumptions are a two-sided significance level of 0.05, equal allocation between arms, a normal approximation, and an effect to detect set at the stated fraction of the observed effect. The original design assumptions for this trial are not reported in the registry record.

For planning at 100% of the observed primary effect, the estimates are 14,927 participants per arm for 80% power and 19,983 participants per arm for 90% power. At 75% of the observed effect, the estimates are 26,536 participants per arm for 80% power and 35,524 participants per arm for 90% power. At 50% of the observed effect, they are 59,706 participants per arm for 80% power and 79,929 participants per arm for 90% power.

In plain language, 80% power means that, under the stated planning assumptions and if the specified effect were the true effect, the design would have an 80% chance of meeting the chosen statistical significance criterion. The 90% column uses a higher target chance and therefore calls for more participants per arm. Smaller effects are harder to distinguish from random variation, so they require more participants under these assumptions. These figures are planning illustrations, not observed power, and they should not be read as evidence about the probability that the trial's result is correct.

The general convention for time-to-event planning estimates is to report the total number of events, whereas other estimates are reported as participants per arm. The primary outcome is continuous, so its estimates are per arm.

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 = -0.100; pooled standard deviation σ = 3.084.
2. n = 2 × (1.96 + 0.842)² × 3.084² / -0.100² = 14,926.4, rounded up to 14,927 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 <- -0.1                      # observed difference in means
sigma <- 3.08359981269912                     # 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(4343651)
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 = 14,927 (80% power), 19,983 (90% power)
 75% of observed effect: n per arm = 26,536 (80% power), 35,524 (90% power)
 50% of observed effect: n per arm = 59,706 (80% power), 79,929 (90% power)
power.t.test: 14927.3 
Simulated power at n = 14,927 per arm: 0.797 (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. Analyses Reported by the Sponsor

The registry reports the sponsor's primary analysis as ANCOVA, with p = 0.818 for the superiority comparison. It does not report the adjusted mean difference, its confidence interval, the model covariates or additional model details. The p-value indicates the result of that reported analysis but does not show the adjusted effect's size or precision on the symptom-score scale.

The recalculated comparison uses the posted group means and standard deviations without adjustment. It gives a mean difference of -0.1, a confidence interval from -1.523 to 1.323, and an unadjusted p-value of 0.89. This calculation is useful as a transparent check of the group summaries, but it is not the sponsor's ANCOVA analysis and should not replace it. The two p-values are broadly similar in their lack of a clear statistical separation, while only the unadjusted calculation has an estimate and interval available in the posted material.

No discrepancy is flagged between the posted summaries and the registry's reported analysis. Accordingly, the sponsor's own analysis takes precedence as the trial's reported inferential result. The recalculation can supplement that result by making the unadjusted contrast and its uncertainty explicit, but it cannot recover the adjusted result or verify unreported modeling choices.

15. Multiplicity, Missing Data and Analysis Populations

The registry lists 17 outcome measures and identifies 12 secondary outcomes. It reports an ANCOVA superiority analysis for the primary comparison, but a multiplicity procedure or hierarchy for interpreting the several outcomes is not reported in the registry record. When multiple outcomes are tested, general statistical reasoning cautions that the chance of a nominally unusual result somewhere among them can rise. Without a stated approach to multiplicity, secondary p-values, where available, should not be treated as if each were the sole confirmatory test.

The record defines the modified intent-to-treat population as subjects who received at least one dose and states that this population was intended for efficacy parameters or measurements. It reports 84 subjects in that population at the time of the report. The primary arm summaries include 28 placebo participants and 56 leronlimab participants. The registry record does not explain the relationship between the enrolled population and the efficacy population, or report outcome-specific denominators for all endpoints.

Missing-data procedures are not reported in the registry record. The record also does not specify how missing baseline or day-14 scores were handled, whether any imputation was used, or how participants without a measured outcome were treated in each analysis. Those details matter because analyses based on observed outcomes can be affected if missingness is related to symptom severity or treatment group. This is a general concern, not a claim that a particular missing-data pattern occurred in this trial.

The registry does not report interim analyses, stopping rules, or a complete statistical analysis plan. Their absence from the record means these aspects cannot be assessed from the posted information; it does not establish that no such procedures existed. The posted outcome summaries and sponsor p-value should therefore be interpreted with awareness that key analytic details are unavailable.

16. 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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: chest pain (7.1%), atrial fibrillation (3.6%), mitral valve incompetence (3.6%), abdominal pain (3.6%), swelling face (3.6%).

The posted serious adverse event counts are 6 participants in the placebo group, among 28 at risk, and 5 participants in the 700mg leronlimab group, among 56 at risk. These are counts of participants affected, not counts of every serious event. The registry also lists serious-event terms and percentages: Chest Pain, 7.1%; Atrial Fibrillation, 3.6%; Mitral Valve Incompetence, 3.6%; Abdominal Pain, 3.6%; Swelling face, 3.6%; and Dehydration, 3.6%.

Other adverse events are listed for 12 placebo participants and 7 leronlimab participants. The registry reports 0 deaths in the placebo group and 1 in the leronlimab group. These figures are descriptive. The record does not establish whether any event was caused by study treatment, and the counts alone do not support a comparative safety conclusion. The groups differ in size, and interpretation also depends on event definitions, exposure and follow-up, details not fully available in these summaries.

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

The posted primary summaries describe average change in a four-symptom score from baseline to day 14. Both groups had negative mean changes, and the group means were close: -3.4 for placebo and -3.5 for 700mg leronlimab. The unadjusted estimated difference was -0.1, with a confidence interval from -1.523 to 1.323. The interval includes no difference and values in either direction, so the estimate is not precise enough to establish a clear group separation.

The sponsor's reported ANCOVA p-value is 0.818. That result and the unadjusted recalculation are different analyses, with the adjusted estimate and interval not reported in the registry record. Neither the p-value nor the similarity of group means demonstrates that the treatments are identical. Conversely, the numerical direction of the mean difference does not establish a treatment effect. The evidence is best described as an uncertain estimate with no clear statistical separation in the reported primary results.

The outcome is a symptom-score measure and does not summarize every aspect of COVID-19 or every secondary endpoint. The registry lists outcomes such as hospitalization, mechanical ventilation, oxygen use and mortality, but the numerical record available for these comparisons is incomplete across those outcomes. The primary result therefore should not be generalized to all clinical outcomes or to populations beyond the study population described.

The sample-size estimates are hypothetical planning illustrations derived from the observed effect and specified assumptions. They are not a measure of the trial's observed power and do not change the interpretation of the trial's actual data. The record also does not state a threshold for a clinically important change on the symptom scale. Statistical uncertainty can be described, but clinical importance cannot be resolved from the posted summaries alone.

18. Why This Trial Matters Statistically

This trial illustrates the difference between observing improvement within groups and estimating a difference between randomized groups. Both primary group means indicate a decline in symptom score, but the treatment comparison is the contrast between those changes. The estimated contrast is -0.1, not the size of either group's change from baseline. That distinction is central to interpreting randomized trials.

It also shows why a point estimate and its precision belong together. The unadjusted estimate is close to zero, but its confidence interval extends across zero and includes both negative and positive differences. A single estimate cannot capture that uncertainty. Likewise, a p-value alone cannot express the range of effects compatible with the data or their clinical relevance.

The record makes a sponsor-reported ANCOVA result available alongside group summaries that permit a simple unadjusted recalculation. Keeping those analyses distinct is important: the adjusted model result is the sponsor's reported inferential analysis, while the recalculation provides a transparent view of the raw summary contrast. Missing model details limit independent evaluation of the adjustment.

Finally, the planning illustrations demonstrate how assumed effect size influences required sample size under stated assumptions. Since smaller effects require more participants, estimates based on a small observed contrast can become very large. Such calculations are useful for planning scenarios, but they neither explain the trial's original design nor indicate how much power the completed trial actually had.

19. 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 trial-specific limitations affect interpretation of the posted record. The efficacy population is described as 84 subjects, while total enrollment is 86; the registry record does not explain the difference. The arm summaries are unbalanced, with 28 participants in the placebo group and 56 in the leronlimab group. The summaries do not provide participant-level results, so the distribution of individual changes, potential outliers and the number improving, remaining unchanged or worsening cannot be assessed from the means alone.

The primary outcome description combines a mean-change title with a description that also refers to counts of patients showing improvement, no change or worsening. The posted numerical comparison is a mean-based summary. The registry record does not provide enough detail to reconcile those elements or to assess whether additional categorical analyses were conducted.

The sponsor's ANCOVA result is reported only as a p-value. Covariates, adjusted effect estimate, confidence interval and model details are not reported in the registry record. Missing-data handling, interim analyses, multiplicity procedures and the trial's original sample-size assumptions are also not reported. Those omissions make it difficult to assess the full analysis plan and the sensitivity of results to alternative analytic choices.

The secondary outcomes are numerous, but detailed numerical comparisons are not available for all listed outcomes in the record. The adverse-event summaries give counts and selected terms, but they do not by themselves establish causation or provide a complete account of event timing and exposure. These limitations constrain what can be concluded from the registry summaries; they do not indicate that unreported procedures or data were absent.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Study to Evaluate the Efficacy and Safety of Leronlimab for Mild to Moderate COVID-19 — NCT04343651.
• Registry record last updated 2023-01-04; status last verified 2022-12.
• Results first posted 2023-01-04.
• 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.

23. Record Summary

NCT04343651 is a completed randomized, double-blind, placebo-controlled phase 2 study of 700mg leronlimab for mild to moderate COVID-19. The primary outcome was mean change in total symptom score from baseline to day 14. The posted group means were -3.4 for placebo and -3.5 for leronlimab, with an unadjusted mean difference of -0.1 and a confidence interval from -1.523 to 1.323. The registry reports the sponsor's ANCOVA p-value as 0.818.

The primary summaries do not show a clear group separation, and the unadjusted interval indicates substantial uncertainty around the estimated difference. Important analysis details, including the adjusted estimate and interval, missing-data procedures and multiplicity approach, are not reported in the registry record. Secondary and safety summaries offer descriptive context but do not resolve those uncertainties.