Phase 1 Study of SL-172154 (SIRPα-Fc-CD40L) in Subjects With Ovarian Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Phase 1 Study of SL-172154 (SIRPα-Fc-CD40L) in Subjects With Ovarian Cancer (NCT04406623), a na phase 1 study. The primary outcome is Safety Profile of SL-172154.

2. Clinical Question

The central statistical question is descriptive: what adverse-event counts are reported for the escalating dose groups, and how much can those counts establish about safety? The study is Phase 1, sequential, and uncontrolled. Its structure is suited to describing observations during early dose escalation, not to estimating a treatment effect against a control condition. Because the registry record does not provide a comparative efficacy analysis, the clinical question should not be reframed as whether SL-172154 is better than another treatment or no treatment.

3. Trial Design

This completed Phase 1 study evaluated SL-172154 in subjects with ovarian cancer. The registry also lists fallopian tube cancer and primary peritoneal carcinoma among the conditions. The study is described as first in human, open label, multicenter, and dose escalation. The intervention was intravenous SL-172154, delivered in sequential groups at 0.1 mg/kg, 0.3 mg/kg, 1.0 mg/kg, 3.0 mg/kg, and 10.0 mg/kg. The registry lists enrollment as 27.

Allocation is marked not applicable, and masking is recorded as none. No control or comparator group is described. The dose groups therefore represent stages of an escalation study rather than randomized treatment arms. Differences between groups cannot be treated as unbiased estimates of dose effects: participants were not allocated to dose groups through a reported randomized comparison, and the groups may differ in ways not documented in the registry record.

The registry reports a study start date of 2020-06-29, a primary completion date of 2023-02-02, and a completed status. Its stated aims include safety, tolerability, pharmacokinetics, anti-tumor activity, and pharmacodynamic effects. Listed secondary outcomes include a recommended Phase 2 dose, preliminary anti-tumor activity, immunogenicity, and measures of serum concentration over time. These aims describe what the study set out to assess; they should not be mistaken for results. The registry record does not report a statistical analysis plan, dose-escalation decision rules, or the rationale used to select enrollment.

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 Safety Profile of SL-172154, measured over From Day 1 to 90 days after Last Dose of SL-172154.

The primary outcome is titled “Safety Profile of SL-172154.” It measures the number of participants with treatment-emergent adverse events from Day 1 to 90 days after the last dose. The unit is participants, and the measure is a count of participants with an event. This is a participant-level summary: it concerns whether participants experienced treatment-emergent adverse events, rather than the total number of event episodes.

In general, early-phase studies use safety outcomes to characterize events observed while participants receive an investigational treatment and during a specified follow-up period. Such descriptions help readers understand the kinds of events recorded and the number of participants affected in the study. They do not, by themselves, establish that treatment caused an event. Events may arise from the underlying illness, other care, or other factors, and causal attribution requires information beyond a count.

The registry record identifies this outcome but does not provide a complete reported result for it in the information available for this analysis. The serious and other adverse-event counts listed by dose group are relevant safety information, but they should not automatically be equated with the primary outcome’s full count of participants with treatment-emergent adverse events. The record does not give a definition linking those summaries to every component of the primary outcome, nor does it provide event-level timing or attribution details. The outcome’s stated timeframe is clear; its complete analysis and handling of missing safety observations are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical interpretation depends on the design and on what the outcome actually counts. This study is described as sequential, open label, and dose escalating. Allocation is recorded as not applicable, masking as none, and no comparator is listed. The dose groups are therefore not randomized arms in a controlled comparison. General statistical principles can clarify the limits of the posted summaries, but they cannot replace analyses that are not reported in the registry record.

What does a participant count represent?

The primary outcome is a count of participants with treatment-emergent adverse events during the stated period, from Day 1 to 90 days after the last dose. A count of participants is different from a count of all event episodes: an individual can experience more than one event, while a participant-level count records whether the participant meets the outcome definition. The registry’s adverse-event summary separately gives counts of participants at risk and affected for serious and other events. The complete primary-outcome result and the precise relationship between these summaries are not reported in the registry record.

In general, participant counts can be useful for describing how many people in a study were affected. The interpretation remains dependent on the outcome definition, follow-up, and completeness of observation. Without a reported analysis population and missing-data handling, readers cannot determine from the record whether every enrolled participant contributed to each outcome summary or how incomplete follow-up was treated.

Why does the sequential design matter?

In a randomized controlled trial, random allocation can help balance participant characteristics between treatment groups, supporting a causal comparison under appropriate conditions. Here, the registry describes sequential dose escalation and does not report random allocation. Participants at different doses may have entered at different stages or differed in unreported ways. Consequently, a difference in adverse-event counts across dose groups cannot be attributed to dose alone. These counts are useful for describing what was recorded in each group, but they are not a controlled test of a dose effect.

The open-label design means masking is absent. In general, knowledge of treatment can influence reporting, assessment, or decisions about whether an event is recorded. That does not establish that reporting was biased in this study; it identifies a design feature that matters when interpreting subjective or investigator-assessed outcomes. Details about event adjudication and assessment procedures are not reported in the registry record.

What can uncertainty estimates add?

In general, a confidence interval describes a range of values compatible with data under a specified statistical method and assumptions. It can show how imprecisely an estimate is measured. Small group counts typically make estimates sensitive to individual observations, so a count alone may not communicate the uncertainty around an underlying event probability. The registry record provides no confidence intervals for the adverse-event counts, and no inferential analyses are listed. No interval should be inferred from the counts without performing a separate analysis and specifying its method.

Likewise, a p-value would address compatibility with a defined statistical model or hypothesis; it would not by itself establish clinical importance or causation. The record does not report a comparative hypothesis test. Because there is no comparator and no reported analysis, the posted safety data should not be presented as a statistical test of treatment versus control or one dose versus another.

How should the sample-size illustrations be read?

The sample-size assumptions describe planning illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The illustrations are not the trial’s own design justification and are not observed power. They do not turn this sequential, uncontrolled study into a randomized two-arm study. The record does not report the study’s sample-size justification or a prospective power calculation. Any planning number should be understood only as an illustration under its stated assumptions, not as evidence that the completed study had a particular probability of detecting an effect.

In general, a planning calculation asks how much information might be needed to detect a chosen effect under specified assumptions. It is distinct from post-study power, which is not a useful substitute for examining the estimate and its uncertainty. The listed assumptions refer to detecting a stated fraction of an observed effect, but the registry record does not provide a statistical analysis plan or a basis for interpreting such an illustration as a design feature of this Phase 1 trial.

What analyses are documented?

The record lists 12 outcome measures and zero analyses. The absence of listed analyses means no inferential procedure, model, or adjusted estimate can be described from this record. It does not establish what analyses may have been conducted outside the registry. The record does not report methods for dose-escalation decisions, covariate adjustment, subgroup analyses, or management of multiple outcomes. Interpretation should remain tied to the information actually documented: a study design, stated outcomes, and descriptive safety summaries.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("SL-172154 (0.1 mg/kg)", "SL-172154 (0.3 mg/kg)", "SL-172154 (1.0 mg/kg)", "SL-172154 (3.0 mg/kg)", "SL-172154 (10.0 mg/kg)")
n      <- c(3, 6, 4, 9, 5)
events <- c(3, 6, 4, 9, 5)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  SL-172154 (0.1 mg/kg)  3  3  100.0  29.2  100.0  43.9  100.0  39.8  99.4
ARM  SL-172154 (0.3 mg/kg)  6  6  100.0  54.1  100.0  61.0  100.0  59.0  99.6
ARM  SL-172154 (1.0 mg/kg)  4  4  100.0  39.8  100.0  51.0  100.0  47.8  99.5
ARM  SL-172154 (3.0 mg/kg)  9  9  100.0  66.4  100.0  70.1  100.0  69.2  99.7
ARM  SL-172154 (10.0 mg/kg)  5  5  100.0  47.8  100.0  56.6  100.0  54.1  99.6

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 12 outcome measures, including safety, recommended dose, preliminary anti-tumor activity, immunogenicity, and pharmacokinetic measures. It does not report a multiplicity strategy for interpreting these outcomes. In general, when many outcomes or comparisons are examined, the chance of observing apparently notable findings can increase; a prespecified approach may help control how evidence is interpreted. Whether such an approach was used in this study is not reported in the registry record.

The record lists zero analyses. It therefore does not document an analysis population, a hierarchy of outcomes, or a plan for confirmatory versus exploratory testing. The listed objectives should not be treated as evidence that every outcome was analyzed or that any result met a prespecified decision threshold. A statistical analysis plan, including any interim analysis approach, is not reported in the registry record.

Missing-data handling is also not reported in the registry record. The record does not explain how participants with incomplete follow-up, unavailable event information, or discontinuation were treated in the primary safety outcome. It does not describe imputation, censoring, or sensitivity analyses. These details matter because an outcome count can depend on how observation periods and incomplete records are handled.

The registry gives enrollment as 27, but the record does not describe which participants were included in each outcome analysis or whether the safety summaries use all enrolled participants. The information does not support assuming an intention-to-treat, per-protocol, or other analysis population. These omissions limit assessment of completeness and of how consistently the outcome definitions were applied across dose groups.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: embolism (33.3%), sepsis (25.0%), large intestine infection (20.0%), lower gastrointestinal haemorrhage (20.0%), small intestinal obstruction (11.1%).

The registry’s safety summary reports, for each dose group, the number at risk and the number affected by serious adverse events and by other adverse events. Serious adverse-event counts are 1 of 3 at 0.1 mg/kg, 0 of 6 at 0.3 mg/kg, 1 of 4 at 1.0 mg/kg, 2 of 9 at 3.0 mg/kg, and 2 of 5 at 10.0 mg/kg. The corresponding other adverse-event counts are 3 of 3, 6 of 6, 4 of 4, 9 of 9, and 5 of 5.

These figures describe recorded events in the study groups. They do not show whether an event was caused by treatment, and they are not comparisons against an untreated or active-control group. The sequential design also means that differences between dose groups should not be interpreted as evidence of a dose-related safety pattern without additional analysis and context.

The record separately lists deaths by group as 2, 5, 3, 2, and 1. It does not report the causes, timing, or treatment relationship for these deaths in the information. The serious-event term percentages are posted as embolism at 33.3%, sepsis at 25.0%, large intestine infection at 20.0%, lower gastrointestinal haemorrhage at 20.0%, and small intestinal obstruction at 11.1%. Their denominator and counting details are not reported in the registry record, so they should be read as term summaries rather than directly comparable event risks.

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

The posted results establish that the registry contains dose-specific summaries of serious and other adverse events, as well as death counts and selected serious-event terms. They provide a descriptive account of safety observations in a Phase 1 study of intravenous SL-172154. The counts are relevant to understanding what was recorded during the study, but their meaning is bounded by the design and by gaps in the reported analysis.

They do not establish that SL-172154 caused any particular event or death. They also do not establish that a higher dose caused more or fewer events: the dose groups were sequential, not randomized comparators, and may differ in unreported participant or study characteristics. No controlled estimate, confidence interval, or hypothesis test is reported in the registry record. A numerical pattern across groups is not, by itself, a dose-response analysis.

The summaries also do not establish the treatment’s anti-tumor activity. Although anti-tumor activity is among the study objectives and preliminary activity is listed as a secondary outcome, the record does not report a complete efficacy result. A safety count cannot answer an efficacy question. Nor can the listed secondary pharmacokinetic and pharmacodynamic objectives be treated as findings without their reported outcome data and methods.

The trial’s first-in-human, dose-escalation setting matters: the study is intended to characterize early observations, not to provide a definitive comparative assessment. The record does not report the protocol’s dose-escalation rules, analysis populations, missing-data methods, or statistical plan. Readers should therefore distinguish the descriptive counts that are posted from broader claims about risk, causation, comparative safety, dose selection, or clinical benefit. Those claims require information and analyses not reported in the registry record.

14. Why This Trial Matters Statistically

This study is statistically notable for the interpretive demands of early dose escalation. A set of dose-specific safety counts can look like a direct comparison, but the registry describes sequential groups without random allocation or a control arm. Recognizing that structure prevents descriptive observations from being mistaken for evidence that dose caused differences in outcomes.

The primary outcome is framed at the participant level and specifies follow-up through 90 days after the last dose. That definition highlights two important questions for readers: whether the recorded event summaries correspond to the full primary outcome, and how participants with incomplete observation were handled. The registry record does not answer those questions. This distinction matters because a clear outcome definition is not the same as a complete outcome analysis.

The study also lists a broad set of objectives, spanning safety, dose selection, anti-tumor activity, immunogenicity, and pharmacokinetics. Multiple objectives can serve different scientific purposes, but interpretation depends on knowing which analyses were planned, which were exploratory, and how uncertainty was assessed. The record lists 12 outcome measures and zero analyses, and does not report a multiplicity strategy. That makes careful separation of stated objectives from reported results especially important.

Finally, the record illustrates why safety data require context beyond counts. The posted serious-event and death summaries are important descriptive information, yet treatment relationship, causes, event timing, and analysis methods are not reported. Statistical restraint is not dismissal of the observations; it is a way to distinguish what the registry documents from what would require additional evidence. The available information supports description, while causal and comparative conclusions remain outside its scope.

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.

The registry record does not provide a comparator arm, randomized allocation, or masking. Because the groups are sequential dose-escalation groups, their observed counts cannot support a like-for-like comparison of dose effects. No adjustment for differences between groups is reported.

The primary safety outcome is identified, but a complete result for the number of participants with treatment-emergent adverse events is not reported in the record. The relationship between that outcome and the separate serious and other adverse-event summaries is not fully specified. The record does not give event-level detail, adjudication procedures, causes of death, or treatment attribution for the deaths listed.

The serious-event term percentages are reported without denominator or counting details in the available record. They should not be interpreted as population risks or compared across groups. The record also does not report confidence intervals, inferential tests, a statistical analysis plan, interim analyses, dose-escalation rules, multiplicity handling, or sample-size justification. Missing-data methods and the analysis populations are not reported in the registry record.

Although the record lists outcomes related to anti-tumor activity, recommended dose, immunogenicity, and pharmacokinetics, their results are not included in the information. The posted safety counts alone cannot establish efficacy, causal relationships, or a recommended dose. These limitations reflect what is and is not documented in the registry record and constrain the strength of conclusions that can be drawn from it.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Phase 1 Study of SL-172154 (SIRPα-Fc-CD40L) in Subjects With Ovarian Cancer — NCT04406623.
• Registry record last updated 2025-01-30; status last verified 2025-01.
• Results first posted 2025-01-30.
• 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.

19. Record Summary

The completed Phase 1 study evaluated intravenous SL-172154 in subjects with ovarian cancer and related conditions. It is described as first in human, open label, multicenter, sequential, and dose escalating, with groups at 0.1 mg/kg, 0.3 mg/kg, 1.0 mg/kg, 3.0 mg/kg, and 10.0 mg/kg. The registry reports enrollment of 27 and dates of 2020-06-29 for study start and 2023-02-02 for primary completion.

The primary outcome is the number of participants with treatment-emergent adverse events from Day 1 to 90 days after the last dose. The posted safety information includes serious and other adverse-event counts, deaths by dose group, and selected serious-event terms. No comparator is described, and the registry lists zero analyses. A complete primary-outcome analysis, statistical plan, missing-data methods, and analysis populations are not reported in the registry record. The available results support descriptive reading of the recorded safety summaries, not causal or comparative conclusions.