Study of CD388 Intramuscular or Subcutaneous Administration in Healthy Subjects: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study of CD388 Intramuscular or Subcutaneous Administration in Healthy Subjects (NCT05285137), a randomized phase 1 study. The primary outcome is Number of Participants With Treatment-Emergent Adverse Events (TEAEs) After a Single Dose of CD388.

2. Clinical Question

The study asks whether CD388, given by intramuscular or subcutaneous injection, has an acceptable safety and tolerability profile in healthy adult subjects compared with saline placebo. The registry describes this as a first-in-human, Phase 1 study. Its primary endpoint counts participants who experienced at least one treatment-emergent adverse event after study treatment.

This is a safety and pharmacokinetics study, not a trial designed in the registry record to establish a clinical benefit. Its randomized, blinded comparisons can describe observed safety counts across dose groups and routes. The record does not report a single pooled treatment-versus-placebo estimate or a statistical test for the primary endpoint. Consequently, the posted counts are best read as descriptive observations within the study groups, rather than as a definitive comparison between treatments.

3. Trial Design

The registry describes a randomized, quadruple-masked, sequential Phase 1 study with dose escalation. It enrolled 77 participants and is listed as completed. Its purpose was to assess the safety, tolerability, and pharmacokinetics of CD388 administered by intramuscular or subcutaneous injection in healthy subjects. Saline placebo was the comparator.

The study used sentinel and main cohorts. In the sentinel cohorts, 2 subjects were randomized at a ratio of 1:1. In the main cohorts, 9 subjects were randomized at a ratio of 7:2. The low-dose groups received 50 mg by either route. The mid-dose groups received 150 mg by either route, and the high-dose groups received 450 mg by either route. The highest-dose groups received 900 mg subcutaneously. The cohort descriptions for the mid- and high-dose groups also describe a further single dose of the same assigned treatment after a washout of 5 effective half-lives. The registry text does not give a complete description of the timing details for those repeat administrations.

These cohort structures matter when interpreting the posted counts. Participants were distributed across dose levels, routes, sentinel and main groups, and placebo groups, rather than assigned to one simple two-arm comparison. The posted adverse-event results pool placebo by route, while the active-treatment results are shown by dose and route. The safety population comprises all randomized participants who received any amount of study drug.

The registry lists study start as 2022-03-14 and primary completion as 2023-10-27. Those dates describe the study record; they do not supply details about the analysis schedule, monitoring decisions, or protocol amendments. The allocation and masking are reported, but the specific people or roles covered by quadruple masking are not reported in the registry record.

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.

Only the first 6 of 9 groups are shown.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The Safety Population included all randomized participants who received any amount of study drug (77 total; 33 \[IM route\], 44 \[SQ route\]).

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 Safety Population included all randomized participants who received any amount of study drug (77 total; 33 \[IM route\], 44 \[SQ route\]).

Only the first 6 of 10 groups are shown.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Treatment-Emergent Adverse Events (TEAEs) After a Single Dose of CD388, measured over Day 1 through Day 120 (±14 days; Cohorts 1A/1B only); Day 1 through Day 374 (±14 days; Cohorts 2A/2B and 3A/3B); or Day 1 through Day 206 (±10 days; Cohort 4B only).

The primary endpoint is the number of participants with at least one treatment-emergent adverse event (TEAE) after study treatment. It is a participant count: a person is counted if one or more qualifying events occur during the specified observation period. It is not a measure of the total number of separate events, the severity of each event, or the duration of symptoms.

The registry’s endpoint description includes adverse events and serious adverse events, systemic reactogenicity or injection-site reactions, hypersensitivity reactions, and events leading to study-drug discontinuation or study withdrawal. It also includes findings based on vital signs, 12-lead electrocardiograms, and clinical laboratory tests, including hematology, coagulation, serum chemistry, and urinalysis. The measure therefore summarizes a broad safety assessment, rather than a single narrowly defined event.

Observation periods differ by cohort. The record specifies Day 1 through Day 120 (±14 days) for Cohorts 1A/1B, Day 1 through Day 374 (±14 days) for Cohorts 2A/2B and 3A/3B, and Day 1 through Day 206 (±10 days) for Cohort 4B. Those differences are important: counts drawn from different follow-up windows do not represent identical observation opportunities.

Counting participants with at least one event is a common descriptive approach in early safety studies. It gives a straightforward summary of how many people experienced an event, while leaving the event’s clinical details and causal relationship to treatment for separate assessment. The registry record does not report an adjusted comparison or a formal inferential analysis of this endpoint.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a randomized, quadruple-masked, sequential study. Randomization assigns participants to treatment groups by chance, which can reduce systematic differences between groups. Masking can reduce the influence of treatment knowledge on participant reports, clinical assessments, and other study processes. The registry does not identify which roles were included in quadruple masking or provide enough detail to assess how randomization and masking were implemented.

What does a participant count represent?

The primary outcome is a count of participants with at least one TEAE. Each participant contributes to that count if at least one qualifying event is recorded in the applicable follow-up period. This approach differs from counting all event episodes: someone with multiple events is still counted as one participant for this endpoint. Participant counts are useful for a broad safety summary, but they do not describe the number, duration, seriousness, or clinical character of all events.

As a general statistical concept, a confidence interval describes a range of values compatible with the data under a specified method and assumptions. It helps show the precision of an estimate. The registry record does not report confidence intervals for the primary endpoint, so readers cannot use the posted counts alone to determine the precision of a formal between-group estimate. In small groups, observed counts can be sensitive to the experience of individual participants; this is one reason descriptive counts should not be mistaken for a precise estimate of risk.

Why do route, dose, and cohort structure matter?

The trial has several active-treatment groups and separate placebo groups for the intramuscular and subcutaneous routes. The active groups are organized by dose, and the cohort descriptions distinguish sentinel and main participants. Some cohorts have a further single administration after a washout. A comparison across any two groups must therefore consider route, dose, cohort, dosing sequence, and follow-up period. The registry record does not report a model that adjusts for these features or a single primary contrast that combines them.

The treatment allocation ratios also differ by cohort type: sentinel cohorts are described with a 1:1 ratio and main cohorts with a 7:2 ratio. This is part of the study design, not a statistical result. The record does not explain the rationale for those ratios or report a sample-size justification.

What does the sequential design imply?

In general, sequential dose escalation means that cohorts proceed through planned dose levels in sequence rather than assigning all participants across all doses at once. Such a structure can support stepwise study of tolerability, but the registry description does not report the decision rules used to move between levels, any review committee, or interim analyses. Those details are not reported in the registry record and should not be inferred from the cohort names.

The repeat-dose descriptions say that another single dose of the same treatment was given after a washout of 5 effective half-lives in specified mid- and high-dose cohorts. The record’s available text does not fully state the timing details that follow this phrase. It also does not explain how events after a repeat administration were attributed or summarized relative to the primary endpoint’s wording, which refers to TEAEs after a single dose.

How should the planning illustrations be read?

Any sample-size figures displayed on the page are planning illustrations, not observed power. The stated assumptions use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is expressed as a fraction of the observed effect. These are planning assumptions, not a description of the actual cohort allocation. They do not establish that the trial was designed or powered to detect a particular safety difference. The registry record does not report its own sample-size justification.

In general, an observed effect can be unstable when based on small groups, and using it as the basis for a planning illustration does not make it a reliable target for a future study. The illustrations should be treated as hypothetical planning aids under their stated assumptions. They are not evidence that a result was statistically significant, nor do they estimate the probability that the trial detected an effect.

What inferential analysis is available?

The registry lists 0 analyses. It does not report a statistical test, model, adjustment method, or confidence interval for the primary safety endpoint. It also does not report an analysis plan for handling multiple dose, route, or outcome comparisons. Without those details, readers can describe the observed counts and their context, but cannot reconstruct an inferential analysis from the registry record alone.

As a general concept, over-dispersion occurs when variability in count data is greater than a model expects. It can make standard errors too small if the chosen model does not account for that extra variability. The posted primary outcome is a participant count with multiple groups, but no model or dispersion assessment is reported. It would therefore be inappropriate to claim that any particular count model was used or that over-dispersion was evaluated.

10. Multiplicity, Missing Data and Analysis Populations

The study reports multiple doses, two administration routes, several cohort types, a primary safety endpoint, and pharmacokinetic secondary outcomes. When many outcomes or group comparisons are examined, the chance of at least one apparently unusual result can increase. Statistical methods can address this issue in different ways, but the registry record does not report a multiplicity strategy or identify a hierarchy of comparisons.

The record lists 32 outcome measures and 0 analyses. The primary outcome is a broad TEAE count, while the secondary outcomes include mean and median pharmacokinetic measures such as peak plasma concentration, time to maximum concentration, terminal elimination half-life, and apparent clearance. The registry does not report which outcomes were treated as confirmatory, whether any adjustments were planned, or how comparisons across dose and route were to be interpreted.

Missing-data handling is also not reported in the registry record. The safety population is defined as randomized participants who received any amount of study drug, but the record does not explain how incomplete follow-up, missing assessments, or participants who discontinued were handled in summaries or analyses. It does not report whether any endpoint data were missing.

The record gives cohort-specific observation windows and describes the safety population, but does not provide a detailed statistical analysis plan. There is no reported account of interim analyses, stopping rules, imputation procedures, or sensitivity analyses. The absence of these details in the registry record does not show that no such procedures existed; it means they cannot be evaluated from the posted information. Interpretations should therefore remain descriptive and tied to the listed group counts and follow-up periods.

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

The serious-adverse-event figures report 0 participants with a serious adverse event in each listed treatment group. The death count is also 0 in each listed group. These are observed counts within the safety population and the study’s reported follow-up periods. They do not imply that the risk is zero outside the study or that a serious event could not occur in a larger or different population.

The posted groups include CD388 50 mg, 150 mg, and 450 mg intramuscularly; CD388 50 mg, 150 mg, 450 mg, and 900 mg subcutaneously; and pooled placebo for each route. The accompanying other-adverse-event counts are not the same as serious-adverse-event counts. For example, the other-event count is 6 of 8 for CD388 450 mg intramuscularly, while the serious-event count in that group is 0 of 8. These are participant counts, not counts of every event episode.

Each group has a limited number of participants, and the follow-up periods vary by cohort. The registry record does not give confidence intervals, a formal comparison, or detailed event-level descriptions in the information. A zero serious-event count should therefore be read narrowly: no serious events were reported for the listed participants in those groups, not as evidence that treatment eliminates serious-event risk.

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

The posted results establish what was recorded in this study’s safety groups: participant counts for those with serious adverse events, other adverse events, and deaths. No serious adverse events or deaths are reported in the listed groups. Other adverse-event counts are reported by dose and route for CD388, and by route for pooled placebo. These observations can be used to describe the experience of the participants enrolled in this Phase 1 study.

They do not, by themselves, establish that CD388 is safer or less safe than placebo, that one route is preferable, or that adverse-event frequency changes with dose. The groups differ in route, dose, cohort structure, and in some cases dosing sequence. Follow-up windows also vary. The record does not provide a formal statistical comparison or an analysis that accounts for those features. The posted counts should not be converted into an unadjusted treatment claim.

The results also do not establish safety in populations beyond the healthy subjects studied. The registry identifies the participants as healthy and describes the study as first-in-human. This page cannot extend those observations to other populations, clinical conditions, or patterns of use. Nor does the primary safety endpoint measure clinical effectiveness: it counts participants with at least one TEAE.

Precision is important. The group counts describe a limited set of observed participants, and no confidence intervals for a comparative estimate are reported in the registry record. A lack of reported serious events in these groups does not prove that the underlying probability is zero. Likewise, differences between the displayed counts can arise from chance, unequal group sizes, follow-up differences, or other factors; the record does not quantify their relative contribution.

The most defensible conclusion is therefore a descriptive one. The registry posts the safety counts and study structure, but does not report the statistical analysis needed to support a definitive comparison. Readers should distinguish these observations from conclusions about causation, comparative risk, or broader clinical use.

13. Why This Trial Matters Statistically

This trial is statistically informative because it shows why early safety data need to be read in the context of their design. A randomized, masked study can help organize comparisons, but randomization does not remove uncertainty when each dose-and-route group contains a limited number of participants. The posted results are divided across several treatment groups rather than summarized as one direct contrast.

The design also illustrates how the question being asked influences what can be concluded. The primary endpoint counts participants with at least one TEAE. That is an understandable summary for safety monitoring, but it compresses distinct event types and clinical findings into a single participant-level count. It cannot show event severity, recurrence, timing, or attribution without additional information.

Route and dose are intertwined with cohort membership, and the placebo groups are pooled by route. Some cohorts receive a further single administration after a washout. These features make a simple comparison of counts potentially misleading if considered without the design details. Differences in follow-up windows add another reason to avoid treating each count as if it arose under identical observation conditions.

The registry record is also a useful example of the limits of public summaries. It identifies the study population, endpoint, and posted group counts, but lists 0 analyses and does not report a statistical analysis plan, multiplicity handling, or missing-data methods. Statistical transparency matters because it allows readers to distinguish descriptive summaries from prespecified inferential claims.

Finally, the planning illustrations are not evidence of observed power and are separate from the trial’s actual design. Keeping that distinction clear helps prevent a hypothetical sample-size calculation from being mistaken for proof that the study could detect a particular difference. The trial’s statistical value lies in the structured safety observations it reports and in recognizing the uncertainty and limits around those observations.

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 registry record supplies group-level participant counts but not detailed event-level listings in the information. It does not show the types, severity, duration, relatedness, or timing of each other adverse event. As a result, the broad TEAE count cannot identify which clinical findings drove the group totals.

The groups are organized by route and dose, and placebo is pooled separately by route. These are not identical to a single two-arm randomized comparison across the whole study. The cohort descriptions also include sentinel and main groups, and some mid- and high-dose cohorts received another single dose after a washout. The record does not provide enough detail to assess whether the posted event counts distinguish events around the first and further administrations.

Observation windows differ across cohorts: Day 1 through Day 120 (±14 days), Day 1 through Day 374 (±14 days), or Day 1 through Day 206 (±10 days), depending on cohort. Counts from different windows may reflect different opportunities to record events. The record does not report time-adjusted event rates or a common follow-up analysis.

Although the safety population is defined, the registry does not report missing-data handling, endpoint completeness, or the number of participants with incomplete follow-up. It also does not report confidence intervals, a formal primary-endpoint comparison, a statistical analysis plan, or a multiplicity approach. Details of randomization implementation, the roles covered by quadruple masking, dose-escalation decision rules, and interim analyses are not reported in the registry record.

These limitations restrict interpretation to the observed summaries. They do not establish that the trial lacked procedures not described in the registry; they identify what cannot be assessed from the posted record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Study of CD388 Intramuscular or Subcutaneous Administration in Healthy Subjects — NCT05285137.
• Registry record last updated 2025-02-27; status last verified 2025-02.
• Results first posted 2025-01-24.
• 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

This completed Phase 1 study evaluated CD388 by intramuscular or subcutaneous injection in healthy subjects, with saline placebo as comparator. The registry describes randomized, quadruple-masked, sequential dose escalation and a safety population of 77 participants: 33 by the intramuscular route and 44 by the subcutaneous route.

The primary endpoint counts participants with at least one TEAE during cohort-specific follow-up. Posted adverse-event groups report 0 serious adverse events and 0 deaths in each listed group, alongside other-adverse-event counts by CD388 dose and route and pooled placebo by route. The record lists 32 outcome measures and 0 analyses. It does not report a formal comparative analysis, confidence intervals, a statistical analysis plan, or detailed missing-data and multiplicity methods.

Accordingly, the posted data support descriptive reading of the recorded safety counts, not a definitive claim about comparative risk, dose response, or safety beyond the study population.