A Study of Opaganib in Coronavirus Disease 2019 Pneumonia: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of Opaganib in Coronavirus Disease 2019 Pneumonia (NCT04414618), a randomized phase 2 study. The primary outcome is Measurement of the Change in Oxygen Requirement From Baseline.

2. Clinical Question

3. Trial Design

This was a Phase 2a, randomized, double-blind, placebo-controlled parallel-group trial of opaganib plus standard of care versus matching placebo plus standard of care. The registry lists quadruple masking. The trial is marked completed, with enrollment of 42. Its start date is 2020-07-02 and its primary completion date is 2020-11-26. The brief summary describes a proof-of-concept study conducted in the US and other countries at approximately 15 clinical sites.

The intended population was hospitalized patients with COVID-19 infection, pneumonia, and a need for supplemental oxygen. Participants assigned to opaganib received 500 mg every 12 hours, in addition to standard of care. The placebo arm received matching capsules and standard of care on the same schedule. The brief summary describes 14 days of planned treatment, with drug administration for 10 days in the specified circumstance of discharge without oxygen. Participants were to be followed for 4 weeks after their last dose.

The primary endpoint was assessed over 14 days. The primary analysis population is defined as randomized participants who received at least one dose of study medication. The posted arm sizes for this endpoint are 22.0 in the opaganib group and 18.0 in the placebo group. These are analysis-population counts, not a restatement of the registry enrollment. Safety at-risk counts are reported separately and are not interchangeable with the primary-analysis counts.

The registry lists 13 outcome measures and 8 posted secondary outcomes. Secondary topics include oxygen requirements, oxygen-free status, viral swabs, intubation and mechanical ventilation, fever, and mortality. The registry record does not report a sample-size justification, interim analyses, or a detailed statistical analysis plan. Those omissions limit conclusions about how the study was planned to test hypotheses or how outcome analyses were prespecified.

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: Modified ITT (mITT) population (randomized and treated with at least one dose of study medication).

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 Measurement of the Change in Oxygen Requirement From Baseline, measured over 14 days.

The primary endpoint is the median absolute change from baseline in oxygen requirement, expressed as L/min*day, over 14 days. Maximal oxygen flow was recorded daily. For each participant, the daily values were used to calculate an area under the curve (AUC) by the trapezoidal rule after subtracting baseline oxygen requirement at each day. The median AUC change is then reported separately for each treatment arm.

As a general statistical concept, an AUC can represent accumulated burden over time rather than a measurement at a single visit. This approach can incorporate both the magnitude and duration of changes in oxygen flow during the observation period. It is relevant when a clinical course evolves across repeated daily observations and a single measurement might not capture that trajectory.

The endpoint’s sign depends on the stated change-from-baseline calculation. Negative values indicate that the accumulated oxygen-flow measurements were below the baseline reference under that calculation. The endpoint is not itself a direct comparison between groups, and the arm-specific medians should not be treated as a treatment-effect estimate. The registry record does not report a between-group estimate or test for this primary result. Its confidence intervals describe uncertainty around each arm’s median as posted, not uncertainty around a difference between medians.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is a continuous, repeated-measure-derived summary, but the registry reports its median rather than its mean. Its construction begins with daily maximal oxygen flow over the 14-day treatment period. Baseline oxygen requirement is subtracted from each day’s flow value, and the trapezoidal rule is used to calculate an individual AUC. The median of these individual AUC changes is then reported for each arm. The unit, L/min*day, reflects oxygen flow accumulated across time.

What does an AUC represent?

In general, an area under a curve condenses observations made over time into one summary. It can reflect the combination of how far measurements move from a reference and how long they remain there. The trapezoidal rule estimates the area between observed time points by treating the change between adjacent observations as a straight-line segment. This is a general explanation of the method; the registry does not report additional details about handling missing daily measurements or irregular observation schedules.

The median is the central value after individual results are ordered. In general, a median is less influenced by extreme values than a mean, which may be useful for outcomes with skewed distributions. But reporting a median for each group does not by itself give the median difference between groups. A formal comparison could use an analysis appropriate to the endpoint and its distribution, but the registry record does not report the method, estimate, or test used for a primary between-group comparison.

How should the confidence intervals be read?

The primary arm-specific intervals are identified as 95% confidence intervals. In general, a confidence interval conveys the uncertainty associated with an estimate under the method used to calculate it. A wide interval indicates limited precision: many values remain compatible with the observed data and the interval procedure. Here, the primary intervals are arm-specific. They do not directly quantify uncertainty in the difference between the opaganib and placebo medians. The registry record does not report a confidence interval for that difference.

The posted secondary comparisons use risk differences for binary outcomes. A risk difference expresses the difference between the observed proportions in two groups, with the direction depending on which group is subtracted from which. The posted estimates are labeled as comparisons of opaganib with placebo. For example, a positive estimate for being oxygen-free corresponds to a higher observed proportion in the opaganib group in the posted summary. The risk-difference intervals for the listed secondary outcomes include zero, so they do not rule out no difference under the interval procedure. The registry does not report a formal analysis for these outcomes; the displayed estimates and p-values are unadjusted recalculations from posted counts.

A p-value describes how unusual data at least as discrepant as those observed would be under a specified null model and its assumptions. It is not the probability that the null hypothesis is true, nor a measure of clinical importance. The p-values posted for the secondary comparisons are unadjusted. They do not account for the assessment of multiple outcomes, and they should not be interpreted as confirmatory evidence on their own.

Why does over-dispersion matter?

As a general concept, over-dispersion occurs when observed variation is greater than a statistical model expects. If a model assumes less variability than the data contain, standard errors may be too small and confidence intervals too narrow, making evidence appear more precise than it is. The registry does not report whether over-dispersion was assessed for the primary endpoint or whether a model-based analysis was used. Because the primary result is a median AUC summary with no reported between-group model, no claim about an over-dispersion adjustment can be made.

The sample-size illustrations use the observed secondary effects and specify a two-sided significance level of 0.05, equal allocation, and a normal approximation. They show participants per arm for 80% or 90% power under planning scenarios based on 100%, 75%, or 50% of the observed effect. These are planning illustrations, not observed power, and they are not the trial’s documented design calculation. The registry record does not report the trial’s own sample-size assumptions or justification. Small or uncertain observed effects can yield very large planning estimates; those estimates should not be mistaken for a recommendation or a forecast of a future study’s outcome.

The posted secondary comparisons include confidence limits and p-values, but the record lists no reported analyses for those endpoints. The recalculations use the posted group counts and are unadjusted. In general, recalculation from summary counts cannot reproduce analyses that might rely on participant-level data, prespecified covariates, stratification, censoring rules, or other modeling choices. The registry does not report such details for these results. Where the sponsor’s own analysis is available, it takes precedence over a simple recalculation; no sponsor-reported secondary analyses are listed in this record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 13 outcome measures and 8 posted secondary outcomes, but does not report a multiplicity-adjustment plan. When a study evaluates multiple endpoints, the chance of at least one apparently noteworthy result can increase. Adjustment methods can control specified error rates, but the appropriate approach depends on which outcomes were considered primary, how they were ordered, and what hypotheses were prespecified. Those details are not reported in the registry record. The posted secondary p-values are unadjusted, so they should not be treated as if they controlled the overall chance of false-positive findings across outcomes.

The registry also does not report how missing primary or secondary observations were handled, whether any imputation was used, or whether sensitivity analyses assessed the effect of missing data. This matters because daily oxygen measurements, follow-up, and other outcomes may not be available for every participant at every scheduled time. The primary endpoint description states how the AUC was calculated, but does not specify the handling of incomplete trajectories. No assumptions about the amount, pattern, or impact of missing data can be made from the posted record.

The primary population is described as modified intention-to-treat: randomized participants who received at least one dose of study medication. This definition excludes randomized participants who did not receive a dose by its wording, but the registry does not give a broader accounting of exclusions or a separate intention-to-treat analysis. The primary arm counts are 22.0 and 18.0. Safety at-risk counts are 23 and 18, showing that safety and primary endpoint populations are reported with different denominators. The record does not explain the difference in these analysis sets.

The statistical analysis plan, interim-analysis procedures, and sample-size justification are not reported in the registry record. Consequently, it is not possible to assess from the registry whether the analyses followed a prespecified hierarchy, how multiplicity was intended to be handled, or how the planned enrollment related to a target effect. These gaps limit the strength of conclusions that can be drawn from exploratory secondary comparisons and from the arm-specific primary summaries.

11. 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: acute kidney injury (11.1%), respiratory failure (11.1%), covid-19 pneumonia (5.6%), pneumonia aspiration (5.6%), septic shock (5.6%).

The registry reports serious adverse events in 3 of 23 at-risk participants in the opaganib group and 5 of 18 in the placebo group. Other adverse events are reported in 11 of 23 and 9 of 18, respectively. Deaths are listed as 3 in each group. These are descriptive counts with the stated safety denominators; they are not the same analysis population or outcome as the primary endpoint. The registry record does not provide a formal comparative safety analysis in the registry record, so these counts should not be interpreted as a tested difference between groups.

The serious adverse event terms listed among the top terms include Acute kidney injury and Respiratory failure, each at 11.1%; COVID-19 pneumonia, Pneumonia aspiration, and Septic shock, each at 5.6%; and Sepsis at 4.3%. The record does not assign these listed term percentages to a specific treatment arm in the posted summary. The categories may not be mutually exclusive, and the record does not give enough detail to infer whether any death was associated with a listed event or treatment. Counts and terms describe what was reported, but by themselves do not establish causation, comparative risk, or safety equivalence.

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

The primary findings describe the median accumulated change in oxygen requirement in each arm over 14 days. The opaganib median was -38.8 L/min*day, with a 95% confidence interval from -56.5 to 0.0; the placebo median was -33.0 L/min*day, with a 95% confidence interval from -149.5 to -12.5. These are summaries of each group, not a direct estimate of the treatment contrast. The registry record does not report a primary between-group estimate or test, so the posted medians do not establish whether the groups differed statistically.

The secondary outcomes offer descriptive information on selected clinical events. Their recalculated estimates are uncertain, and the posted intervals include zero. The p-values are unadjusted, and the registry lists no reported secondary analyses. These comparisons therefore do not establish that opaganib has an effect, that it has no effect, or that the groups are equivalent. A non-significant result is not proof of no difference, particularly when estimates are imprecise.

The findings also should not be generalized beyond the study population without further evidence. The intended population was hospitalized adults with SARS-CoV-2-positive pneumonia who needed supplemental oxygen. The record describes a Phase 2a proof-of-concept trial, but it does not provide evidence in other populations or settings. The enrollment and analysis populations differ in definition, and the registry does not provide details of missing-data handling, a multiplicity plan, or a primary between-group analysis.

Overall, the posted information characterizes arm-specific oxygen-change distributions and several secondary event counts, but it does not provide a sufficiently complete inferential account of the primary comparison. The evidence should be read as limited and exploratory. These statistical findings alone are not a treatment recommendation and do not determine individual care.

13. Why This Trial Matters Statistically

This trial illustrates why an endpoint’s summary and its treatment comparison are not the same thing. The primary outcome uses daily oxygen-flow observations to form an individual AUC, then reports a median for each arm. That preserves information about change over time in a compact summary, but separate arm medians do not answer the inferential question of how different the groups are. A between-group estimate and its uncertainty are needed to quantify that contrast directly; the registry record does not report them for the primary endpoint.

It also demonstrates the importance of matching interpretation to the analysis population. The primary endpoint is based on a modified intention-to-treat population defined by treatment receipt, while the safety summaries use their own at-risk denominators. Those populations should not be casually combined or treated as if they were identical. Clear reporting of analysis sets helps readers understand who contributes to each result.

The secondary results show why confidence intervals and multiplicity matter in small proof-of-concept trials. Event counts can be sparse, and estimates can remain compatible with materially different directions or magnitudes. An unadjusted p-value does not resolve that imprecision or account for testing multiple outcomes. Planning illustrations based on observed effects can help show how uncertain estimates translate into potential future study sizes, but they are not observed power and are not evidence that the original design was adequate.

More broadly, the record highlights the value of complete statistical reporting: a prespecified primary contrast, confidence interval, analysis population, missing-data approach, and multiplicity strategy. Without these, even a biologically or clinically relevant endpoint can be difficult to interpret as evidence for a treatment difference. Statistical transparency is essential to distinguish descriptive signals from confirmatory results.

14. 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 principal limitation for interpretation is that the registry reports primary arm-specific medians and confidence intervals but no between-group estimate or test. The primary endpoint is therefore not presented as a direct treatment contrast. Separate confidence intervals cannot substitute for that comparison, and their width indicates uncertainty about each arm’s median.

The modified intention-to-treat population is limited to randomized participants who received at least one dose. The registry enrollment is 42, while the primary endpoint arm counts are 22.0 and 18.0. The record does not explain the population flow or whether other analysis sets were used. Safety denominators differ from the primary endpoint denominators, and the reasons are not reported.

Secondary comparisons are based on relatively sparse event counts and are unadjusted recalculations from posted summary counts. Their intervals are broad and include zero. The registry lists no reported analyses for these endpoints, and the record does not report a multiplicity plan. The additional listed secondary outcomes do not have numerical results in the information.

Important analysis details are also absent: the handling of missing daily oxygen measurements and other missing outcomes, a statistical analysis plan, interim analyses, and the sample-size justification. The planning illustrations use observed effects and are not the trial’s design calculation. These limitations do not show that the results are biased, but they leave uncertainty about analysis choices and the precision and robustness of the findings. The Phase 2a proof-of-concept setting also limits how far these results can be generalized.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Study of Opaganib in Coronavirus Disease 2019 Pneumonia — NCT04414618.
• Registry record last updated 2022-03-21; status last verified 2022-03.
• Results first posted 2022-03-21.
• 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.

18. Record Summary

NCT04414618 is a completed randomized, double-blind, placebo-controlled Phase 2a parallel-group study of opaganib plus standard of care versus placebo plus standard of care in hospitalized adults with COVID-19 pneumonia. The registry lists enrollment of 42, a start date of 2020-07-02, and a primary completion date of 2020-11-26.

The primary endpoint measured median accumulated change in oxygen requirement over 14 days in a modified intention-to-treat population. The registry reports arm-specific medians and 95% confidence intervals, but no primary between-group estimate or test. Secondary posted comparisons are unadjusted and imprecise; the registry record does not report a multiplicity plan, missing-data methods, interim analyses, or a sample-size justification.