SP16 Inflammatory Response Inhibition Trial: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for SP16 Inflammatory Response Inhibition Trial (NCT04225533), a na phase 1, phase 2 study. The primary outcome is Area Under the Curve (AUC) for C-reactive Protein (CRP).

2. Clinical Question

This is a question about an inflammatory biomarker over a defined observation period, rather than a randomized comparison of clinical outcomes. CRP is the measure named for the primary endpoint; the record also lists creatine-kinase myocardial band area under the curve, change in left ventricular ejection fraction at baseline and 365 days, and diagnosis of heart failure as secondary outcomes. Results for these outcomes are not reported in the registry record. Without posted outcome values and a described historical-control analysis, the stated research question remains a planned comparison rather than an interpretable estimate of an effect.

3. Trial Design

The registry classifies the study as Phase 1 and Phase 2, completed, and single-group. It lists enrollment of 10 and describes all patients as receiving a standard dose of SP16. The intervention is a drug, given as a single dose of 0.2 mg/kg by subcutaneous injection. Allocation is recorded as NA and masking as none. These design features mean the registry does not describe random assignment or blinding, nor a concurrent control group receiving another intervention or no intervention.

The listed start date is 2020-02-24, and the primary completion date is 2021-01-04. These dates describe the registered study timeline; they do not by themselves establish when each participant was assessed or whether every planned measurement was available. The registry status is completed, but outcome-level analysis results are not reported in the registry record.

The primary endpoint is CRP area under the curve, with CRP measurements specified at baseline, 72 hours, and 14 days. The description proposes comparison with historical controls. Since the record does not identify the historical-control data, explain how they were selected, or report the comparison, this proposed benchmark cannot be evaluated from the registry entry. Historical controls are not equivalent to a concurrent randomized comparison: differences in participant selection, measurement, care, or timing can affect comparisons. That is a general design consideration, not evidence that any particular difference occurred in this study.

The record lists three secondary outcomes: CK-MB area under the curve, change in left ventricular ejection fraction at baseline and 365 days, and diagnosis of heart failure. It reports four outcome measures overall, including the primary endpoint. Definitions, analysis populations, and results for these outcomes are not reported in the registry record. The design therefore identifies the intended intervention and outcomes, but the posted information is insufficient to assess the estimated effects or their precision.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Area Under the Curve (AUC) for C-reactive Protein (CRP), measured over Baseline, 72 hours, 14 days.

The primary endpoint is the area under the curve (AUC) for C-reactive protein (CRP), with units of mg*day/L. The registry specifies CRP measurements at baseline, 72 hours, and 14 days. It describes calculating the area under the CRP curve as a way to assess the inflammatory response over the observation period, then comparing that measure with historical controls.

In general, an AUC compresses measurements taken over time into a summary that reflects both the level of a measurement and its duration. For a biomarker, this can represent the overall pattern across the specified observation period rather than relying on a single measurement. The interpretation depends on the measurement schedule, the calculation method, and the availability of the underlying values. The registry record does not report the calculation details or the CRP AUC result.

The endpoint is summarized in the record as a median with an interquartile range. In general, the median describes the center of a distribution, while the interquartile range describes the spread of its middle portion. These summaries can be useful when values are skewed or when a small sample makes a mean sensitive to extreme observations. They do not, by themselves, establish a treatment effect. To assess the stated question, readers would need the endpoint values and a clearly described comparison with the historical-control data. Those results are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The endpoint is described as a median and interquartile range for CRP AUC. These are descriptive summaries, not a treatment-effect estimate. The median gives the central value when observations are ordered. The interquartile range conveys the spread of the central portion of the observations. In general, these summaries are less influenced by unusually large or small values than the mean and standard deviation. They can be informative for a small study or for data with an asymmetric distribution, but they do not replace a comparison between groups or a confidence interval for an effect.

What does the AUC represent?

In general, an area under a curve summarizes measurements across time. Here the record specifies CRP at baseline, 72 hours, and 14 days, and gives the unit mg*day/L. The AUC is intended to capture the pattern over the period rather than a single CRP reading. The record does not give the calculation rule used between measurements, whether values were transformed, or how missing measurements would enter the calculation. Those details can affect the resulting summary and are not reported in the registry record.

How should the proposed historical comparison be read?

The endpoint description says the CRP AUC would be compared with historical controls. In general, a concurrent randomized control group helps balance measured and unmeasured factors through random assignment. A historical comparison does not have that feature: the comparison participants were observed in a different context or period, and comparability depends on how they were chosen and measured. Differences in baseline characteristics, clinical practice, eligibility, measurement schedules, and follow-up can influence the contrast. These are general concerns, not claims that any specific imbalance occurred in this study. The registry does not identify the historical-control source, describe matching or adjustment, or report the comparison estimate.

Why does the single-group structure matter?

The registry lists a single-group model, allocation NA, and no masking. The arm description says patients receive SP16. Thus, the posted design does not include a concurrent randomized contrast. A change in a biomarker after treatment, if reported, would describe change over time in the observed group; without an appropriate comparison it would not isolate the effect attributable to SP16. The registry does not report participant-level trajectories or a group-level endpoint result, so even that descriptive change cannot be assessed from the record.

What can an interval or p-value add?

In general, a confidence interval expresses the statistical uncertainty around an estimated quantity under the assumptions of the analysis. A p-value assesses how compatible the data are with a specified null model, also under assumptions. Neither is reported for the primary endpoint in the registry record. Even if they were available, they would need to be read alongside the effect estimate, design, and analysis choices; a p-value alone would not establish clinical importance or eliminate bias from a nonrandomized comparison.

What do the sample-size assumptions mean?

The record includes planning assumptions for an illustrative sample-size calculation: a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. The record describes these as planning illustrations, not the trial's own design. They should not be read as evidence that this single-group study randomized participants between two arms, or as observed power. The registry record does not report a sample-size justification for this trial. No sample-size result or calculation is needed to interpret the outcome results, which are not reported in the registry record.

More generally, power calculations depend on assumptions about the target effect, variability, analysis, and design. If assumptions differ from the eventual data-generating process, a planning calculation may not reflect the study's realized precision. Over-dispersion, in general, means that variability exceeds what a chosen statistical model expects; if a model ignores this, uncertainty can be understated. The registry record does not describe an over-dispersion assessment or a model for the primary endpoint, so such methods cannot be attributed to this trial.

Finally, the record reports no analyses. The endpoint's descriptive summary type is specified, but the inferential model, covariate adjustment, missing-data method, and decision criteria are not reported in the registry record. These omissions limit reproducibility and make it impossible to determine whether the proposed historical comparison was conducted as described.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary CRP AUC endpoint and secondary outcomes for CK-MB AUC, left ventricular ejection fraction change at baseline and 365 days, and heart failure diagnosis. It reports four outcome measures overall. When a study evaluates multiple outcomes, general statistical practice distinguishes the primary question from supporting or exploratory questions. If formal claims are based on several tests, multiplicity can increase the chance of at least one apparently notable result by chance. Prespecified testing order, adjustment methods, or a statement that secondary analyses are exploratory can clarify interpretation. Such a multiplicity strategy is not reported in the registry record, and outcome analysis results are not reported.

The registry does not describe how missing CRP measurements, incomplete follow-up, or unavailable secondary-outcome data were handled. It also does not specify whether the analysis population included all enrolled participants, only participants who received the intervention, or those with evaluable endpoint data. These analysis populations and missing-data methods are not reported in the registry record. This matters because excluding participants with missing measurements can change the composition of the analyzed group, and the direction of any resulting bias cannot be inferred without further information.

The enrollment listed is 10, but that figure does not identify the number with complete data for each endpoint. The registry record does not give endpoint-specific denominators or explain withdrawals and exclusions. It also does not report an interim-analysis plan, stopping rules, or a multiplicity adjustment. These items should therefore be treated as unknown, rather than assumed absent from all study conduct. With no posted endpoint analyses, neither the handling of missing observations nor the control of multiple comparisons can be evaluated.

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 non-serious adverse event terms

For the SP16 group, the registry reports 10 participants at risk for serious adverse events and 0 affected. It reports 10 at risk for other adverse events and 2 affected. The deaths count is 0. These are the counts recorded in the registry entry; the record does not list serious adverse-event terms.

These categories should be kept distinct. The serious-event count is not interchangeable with the count for other adverse events, and the death count is a separate reported figure. The registry does not provide event descriptions for the two participants counted under other adverse events, the timing or duration of events, or an assessment of whether events were attributed to SP16. It also does not describe event-collection methods or provide further detail about follow-up for safety.

Counts from a small, single-group study are descriptive. Without a concurrent comparison group, they cannot show whether the observed events occurred more or less often than they would have without SP16. The registry record does not support a broader estimate of risk or a causal conclusion. These safety figures should be read alongside the limits in event detail and the absence of comparative safety analyses.

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

The record establishes that the SP16 Inflammatory Response Inhibition Trial was registered as a completed Phase 1 and Phase 2, single-group study, with SP16 administered as a single 0.2 mg/kg subcutaneous dose. It specifies a primary CRP AUC endpoint measured at baseline, 72 hours, and 14 days, and says that the measure would be compared with historical controls. These details describe the registered research question and intervention.

They do not establish the result of that question. The primary endpoint value, historical-control comparison, uncertainty estimate, and secondary-outcome results are not reported in the registry record. It is therefore not possible to determine from the posted entry whether CRP AUC differed from the historical benchmark, how large any difference was, or how precisely it was estimated. The record also does not support conclusions about the listed clinical outcomes.

More generally, a biomarker result and a clinical outcome answer different questions. A change in CRP, even if reported, would not by itself establish a change in heart failure, cardiac function, or other patient outcomes. Conversely, a clinical outcome requires its own definition, follow-up information, and analysis. The registry lists these outcomes but does not report their results.

The single-group design and unspecified historical comparison also limit causal interpretation. General statistical reasoning distinguishes an observed association or before-and-after pattern from an effect attributable to an intervention. A concurrent randomized comparison can address some alternative explanations more directly than a historical benchmark. No such concurrent arm is described in the registry record.

The posted safety counts describe events recorded in the SP16 group, but without event details or a control group they do not establish comparative safety. Taken together, the registry entry documents the intended study question and selected design details, but the missing outcome analyses mean it cannot answer whether the planned biomarker or clinical comparisons favored one course of treatment.

13. Why This Trial Matters Statistically

This trial is statistically notable because it asks a biomarker question in a single-group study while proposing a historical-control comparison. That structure makes it important to distinguish a clearly stated endpoint from evidence that answers the endpoint question. The registry specifies CRP AUC and its measurement times, but it does not report the calculated value or the comparison. A well-defined outcome is necessary for interpretation, yet it cannot substitute for posted results.

The study also illustrates why the source of a comparator matters. Historical controls may offer context when a concurrent control is not present, but their usefulness depends on transparent selection, consistent outcome measurement, and careful consideration of differences between groups. Those details are not reported in the registry record. Without them, readers cannot assess whether the historical benchmark offers a credible counterfactual for the participants who received SP16.

Reporting the median and interquartile range indicates a descriptive summary approach for the primary endpoint. In general, distributional summaries help readers understand both the center and spread of observations. For an intervention question, they are most informative alongside a defined comparison, an effect estimate, and uncertainty. Those analysis results are not reported in the registry record.

The listed secondary outcomes further show why prespecification and transparent reporting matter. Multiple endpoints can address different aspects of a clinical question, but interpretation depends on knowing which analyses were planned, how missing data were handled, and whether results are exploratory or confirmatory. Those details are not reported. The record therefore serves as a useful description of the study's planned focus, while its sparse results entry leaves the statistical evidence unavailable for evaluation.

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 main limitation for interpreting this specific record is that outcome results are not reported in the registry record. The primary CRP AUC estimate, its interquartile range, and any comparison with historical controls are unavailable. Results for CK-MB AUC, left ventricular ejection fraction change at baseline and 365 days, and heart failure diagnosis are also not reported. The entry therefore does not permit an assessment of the magnitude, direction, or precision of the intended outcome comparisons.

The design is listed as single-group, with allocation NA and no masking. No concurrent comparator is described, while the primary endpoint description refers to historical controls without identifying their source or methods of selection. This leaves the proposed comparison difficult to evaluate. The record does not report adjustment methods, endpoint calculation details, or the statistical model.

Although enrollment is listed as 10, the registry does not report how many participants contributed data to each outcome, whether measurements were missing, or how missing data were handled. Eligibility criteria, participant characteristics, and withdrawals are not reported in the registry record. The specified measurement times for CRP are baseline, 72 hours, and 14 days, but the record does not say whether all measurements were obtained for every participant.

Safety reporting is also limited: the entry gives counts but no serious-event terms and no detail about the other adverse events or their attribution. Multiplicity procedures and analysis populations are not reported. These record-specific gaps do not prove that the information was never collected or analyzed; they mean it cannot be assessed from the registry entry.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: SP16 Inflammatory Response Inhibition Trial — NCT04225533.
• Registry record last updated 2023-01-30; status last verified 2023-01.
• Results first posted 2023-01-30.
• 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

The SP16 Inflammatory Response Inhibition Trial (NCT04225533) is listed as a completed Phase 1 and Phase 2, single-group study sponsored by Serpin Pharma, LLC. The registry lists enrollment of 10, a start date of 2020-02-24, and primary completion on 2021-01-04. The intervention is a single 0.2 mg/kg subcutaneous dose of SP16.

The primary endpoint is CRP AUC in mg*day/L, with measurements specified at baseline, 72 hours, and 14 days. The endpoint description proposes comparison with historical controls. Three secondary outcomes are listed: CK-MB AUC, change in left ventricular ejection fraction at baseline and 365 days, and diagnosis of heart failure.

Primary and secondary outcome results, the historical-control analysis, and analysis methods are not reported in the registry record. Safety counts include 0 affected for serious adverse events, 2 affected for other adverse events, and 0 deaths.