Study to Evaluate Pharmacokinetic Comparability Between AZD7442 Co-formulation (AZD8895 + AZD1061) vs AZD8895 and AZD1061 Individually in Adult Healthy Participants: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study to Evaluate Pharmacokinetic Comparability Between AZD7442 Co-formulation (AZD8895 + AZD1061) vs AZD8895 and AZD1061 Individually in Adult Healthy Participants (NCT05166421), a randomized phase 1 study. The primary outcome is Area Under the Concentration-time Curve From Time Zero Extrapolated to Infinity (AUCinf).

2. Clinical Question

The question is about pharmacokinetic comparability: whether the measured exposure profiles are similar across formulations and manufacturing materials. It is not a direct test of clinical benefit or prevention of disease. The registry lists Corona Virus Disease as the condition and describes a study in healthy adults, but the primary endpoint is a serum concentration-derived measure rather than a clinical outcome.

3. Trial Design

This was a randomized, open-label, parallel-group Phase 1 study with three arms and a single dose. The registry records an enrollment of 224 participants. Participants were assigned to one of three treatment groups: AZD7442 as a co-formulation, separate AZD8895 and AZD1061 using clonal cell line material, or separate AZD8895 and AZD1061 using cell pool material. In the separate-dose groups, AZD8895 was administered before AZD1061 on Day 1. The co-formulation was also administered on Day 1.

Open-label means the study was not masked according to the registry. Random allocation can reduce systematic differences between groups at assignment, while a parallel-group structure means participants remained in their assigned treatment group rather than crossing over between formulations. These are general features of trial design; they do not establish that groups were balanced on every characteristic or that all potential sources of bias were eliminated.

Serum pharmacokinetic sampling was scheduled predose on Study Day 1, at 2 hours, 4 hours, and 8 hours post dose, on Study Day 2 at 24 hours post dose, and on Study Days 5, 8, 15, 22, 31, 61, 91, 181, 271, and 361. The primary endpoint was AUCinf. Secondary measures listed in the registry include Tmax, AUC over several specified follow-up intervals, Tlast, terminal half-life, and apparent clearance after extravascular administration.

The study status is completed. Its start date is 2021-11-30, and its primary completion date is 2023-07-19. The registry record does not report further details of the randomization procedure, allocation concealment, or the rationale for the planned 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.

Before assignment: A total 224 participants were randomized in this study. The screening period was up to 28 days. ICF was signed prior to screening procedures. Subjects received study drug in a randomized order. All study assessments were performed as per the schedule of assessments.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The PK analysis set consisted of all participants in the safety analysis set who received IMP and had evaluable serum PK data, with no important protocol deviations thought to impact on the analysis of the PK data. Here, 'number of participants analyzed' specifies all participants who were evaluated for this outcome measure and 'number analyzed in each row' signifies the participants with available data that were analyzed for each drug for this outcome measure.

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 analysis set included all participants who were randomized and received any amount of investigational medicinal product (IMP).

6. Primary Endpoint

The registry lists the primary outcome as Area Under the Concentration-time Curve From Time Zero Extrapolated to Infinity (AUCinf), measured over Predose on Study Day 1 (2 hours, 4 hours, 8 hours post dose), Study Day 2 (24 hours post dose) and on Study Days 5, 8, 15, 22, 31, 61, 91, 181, 271 and 361.

The primary endpoint is the area under the serum concentration-time curve extrapolated from time zero to infinity, abbreviated AUCinf. It is expressed in day*μg/mL. AUC summarizes drug concentration over time; the extrapolated endpoint uses the measured concentration-time profile together with an estimate of the remaining exposure beyond the last measured concentration.

In general, AUC is used in pharmacokinetic studies because it captures overall systemic exposure, rather than relying on a single concentration measurement. Comparing AUCinf across formulations can help characterize whether the amount of exposure is similar after administration by different formulation approaches. AUCinf does not, by itself, describe every aspect of the concentration-time curve. Measures such as peak concentration, time to peak, and terminal half-life address other features, and the registry lists several such secondary measures.

The registry specifies a geometric mean as the primary summary measure and geometric coefficient of variation as its dispersion measure. In general, geometric summaries are useful for positive pharmacokinetic measurements that may have a right-skewed distribution; the geometric mean summarizes values on a multiplicative scale, while the geometric coefficient of variation describes relative variability. The registry record does not report the observed AUCinf geometric means, geometric coefficients of variation, treatment contrasts, or confidence intervals. Consequently, the magnitude and precision of the primary comparison cannot be described from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a geometric-mean analysis of AUCinf, with geometric coefficient of variation as the dispersion measure. The interpretation of those summaries depends on the shape of the pharmacokinetic data, the comparison being made, and the analysis plan. Numerical estimates and inferential results are not reported in the registry record.

What does AUCinf represent?

In general, the area under a concentration-time curve combines concentration measurements across the observation period to summarize overall exposure. AUCinf extends the measured area beyond the last quantifiable sample by extrapolation. The resulting estimate therefore reflects both observed concentrations and an estimate of the unobserved tail of the curve. The registry lists serum sampling through Study Day 361; the endpoint is still defined as an extrapolated area to infinity, rather than as the area only through the last scheduled sample.

Extrapolation is a standard pharmacokinetic concept, but its reliability depends on the concentration profile and the terminal portion of that profile. The registry record does not report the proportion of AUCinf that was extrapolated, the rules for estimating the terminal phase, or any sensitivity analyses of the extrapolation.

Why use geometric summaries?

General statistical explanation: pharmacokinetic measurements are positive and can have a skewed distribution. A geometric mean summarizes the central level on a multiplicative scale. This can be useful when relative rather than absolute differences are meaningful. The geometric coefficient of variation expresses variability relative to the geometric mean. It is not the same as a standard deviation expressed in the original measurement units. The registry names these summaries but does not give their observed values.

For comparisons of positive exposure measures, analysts commonly work with logarithmically transformed values and then express results on the original scale. This general approach can make multiplicative differences easier to assess and may better match the distribution of exposure measurements. The registry record does not specify the transformation, model, covariates, or exact method used for the treatment comparisons; these details are not reported in the registry record.

What is the role of randomization and the parallel design?

General statistical explanation: randomization is intended to make treatment assignment independent of measured and unmeasured participant characteristics on average. It supports a fair comparison, but it does not guarantee identical groups, particularly in a finite sample. A parallel-group design compares participants assigned to different groups over the same study rather than comparing each participant under multiple formulations. The registry identifies randomized allocation and a parallel model, but the randomization sequence and allocation procedures are not reported in the registry record.

The open-label design means treatment assignment was not masked. For an objectively measured serum concentration endpoint, the measurement itself is less dependent on subjective judgment than a self-reported outcome. Nevertheless, open-label status can matter for study conduct, handling, or decisions about data inclusion. The registry record does not describe any specific effect of masking or lack of masking on pharmacokinetic measurements.

How should uncertainty and comparability be evaluated?

General statistical explanation: an estimate describes the observed contrast, while a confidence interval communicates its uncertainty. For a comparability objective, the interpretation also requires a prespecified acceptable range or margin. The analysis should show whether the confidence interval lies within that range, rather than relying only on whether a conventional test rejects a null hypothesis. The margin, confidence level, treatment contrast estimates, and confidence intervals are not reported in the registry record, so that assessment cannot be reproduced from the registry entry.

The record lists a planning illustration based on a stated fraction of an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Such a planning illustration is not the original trial design calculation and is not observed power. The actual trial's sample-size justification and the details needed to interpret any illustration are not reported in the registry record. No numerical planning results are available in the registry record.

Why can over-dispersion matter?

General statistical explanation: over-dispersion occurs when the variability in data exceeds what a chosen model assumes. If variability is underestimated, standard errors may be too small and confidence intervals too narrow; if the model does not fit, inferential results can be unreliable. Pharmacokinetic data can vary substantially between participants, which makes appropriate characterization of variability important. The registry reports geometric coefficients of variation as a dispersion measure but does not report model diagnostics, checks for over-dispersion, or a sensitivity analysis.

The registry identifies 14 outcome measures and 27 analyses. In general, making many comparisons can increase the chance of at least one apparently notable result if the analyses are treated as independent confirmatory tests. Methods such as a prespecified hierarchy or multiplicity adjustment can control this issue, but the applicable testing structure and any adjustment are not reported in the registry record. The analysis plan, interim analyses, and any changes to the planned methods are also not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 14 outcome measures and 27 analyses, while the primary endpoint is AUCinf. Multiple endpoints and comparisons can create multiplicity: when many hypotheses are tested, the chance of at least one false-positive finding can increase if no strategy accounts for the number or structure of tests. General approaches include defining a primary comparison in advance, ordering tests in a hierarchy, or adjusting inference across a family of comparisons. The registry record does not report which approach, if any, was used, nor does it identify the testing hierarchy or provide a multiplicity-adjusted analysis.

Missing-data handling is also not reported in the registry record. The pharmacokinetic analysis set is described as participants in the safety analysis set who received investigational medicinal product, had evaluable serum pharmacokinetic data, and had no important protocol deviations thought to affect the analysis. This definition explains the stated analysis population, but not how missing samples, below-quantification concentrations, incomplete profiles, or unevaluable AUCinf values were handled. The number excluded and reasons for exclusion are not reported in the registry record.

The registry refers to a safety analysis set and a pharmacokinetic analysis set, but does not give their complete definitions or arm-specific analysis counts. It also does not report whether additional analysis populations or sensitivity analyses were used. These omissions limit assessment of how participant inclusion, missing measurements, and multiple comparisons may affect the interpretation of the pharmacokinetic findings.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: major depression (1.3%), angina pectoris (1.3%), coronary artery occlusion (1.3%).

The registry reports serious adverse events and other adverse events by treatment group. For the co-formulation group, 76 participants were at risk for serious adverse events and 2 were affected; 76 were at risk for other adverse events and 2 were affected. For separate vials using clonal cell line material, the corresponding figures were 72 at risk and 0 affected for serious adverse events, and 72 at risk and 8 affected for other adverse events. For separate vials using cell pool material, 76 were at risk and 1 was affected for serious adverse events, while 76 were at risk and 10 were affected for other adverse events. Deaths were 0 in each group.

The registry lists Major depression, Angina pectoris, and Coronary artery occlusion among the top serious adverse event terms, each at 1.3%. The record does not report enough detail to attribute those terms to a particular treatment group. Event counts describe what was recorded in this study; they do not by themselves establish a causal relationship or support a reliable comparison of safety between groups. The registry record does not report additional details such as event timing, duration, resolution, or adjudication.

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

The study was designed to compare serum pharmacokinetic exposure across formulations of AZD7442 and across two sources of material used for the separately administered antibodies. Its primary endpoint, AUCinf, is a measure of overall exposure derived from the serum concentration-time profile. The randomized, parallel-group design provides a framework for comparing groups, and the registry identifies the population and scheduled sampling times.

What the registry record does not report is the numerical AUCinf result: there are no group-level geometric means, measures of dispersion, treatment contrasts, confidence intervals, or p-values in the record. It also does not report a comparability margin or the statistical decision rule. Therefore, the available information does not establish whether the formulations were statistically comparable, how large any exposure difference was, or how precisely that difference was estimated.

This is a pharmacokinetic study in adult healthy participants, not a clinical-outcome comparison. AUCinf can characterize exposure, but it is not itself a measure of prevention, symptom improvement, or other patient benefit. The registry lists Corona Virus Disease as a condition, but the primary question described is about pharmacokinetic comparability following a single intramuscular dose.

The adverse-event counts provide a descriptive account of recorded events in the treatment groups. They do not demonstrate that a treatment caused or prevented an event, and the limited registry information does not allow a detailed safety comparison. The record's completion status and enrollment number do not substitute for results or for an assessment of the precision of the primary comparison.

In short, the design and endpoint define what the trial set out to evaluate. Without the numerical endpoint results and statistical analysis details, the degree of comparability remains not reported in the registry record.

13. Why This Trial Matters Statistically

Pharmacokinetic comparability is a statistical question about whether exposure profiles are sufficiently similar across formulation approaches, not simply whether two groups have identical observed values. This study's three-arm structure distinguishes the co-formulation from separate administration using clonal cell line material, and distinguishes the two material sources among the separate-dose groups. Keeping those contrasts separate is important: each addresses a different formulation question.

The primary endpoint, AUCinf, summarizes total exposure across time and uses an extrapolated tail beyond the observed concentration profile. That makes it useful for comparing overall exposure, while also making transparent reporting of the estimation method and uncertainty important. Geometric summaries are specified, which is consistent with expressing positive pharmacokinetic measures on a multiplicative scale, but the registry does not provide the resulting estimates.

For biostatisticians and clinical researchers, the record illustrates why a trial's design description is not enough to assess its statistical conclusion. Interpretation requires the numerical contrast, an uncertainty interval, a defined comparability criterion, and a clear account of the analysis population and missing data. The registry record identifies the main endpoint and analysis-set principle but does not report these inferential details.

The listed outcome and analysis counts also make multiplicity relevant to interpretation. When several outcomes and comparisons are examined, readers need to know which analyses were primary and how the others were handled. The registry does not report that strategy. Thus, the record makes the scientific question and structure of the comparison identifiable, while leaving the strength and precision of the evidence for comparability unresolved.

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 central limitation for interpreting this trial from the registry record is the absence of numerical primary endpoint results. AUCinf geometric means, geometric coefficients of variation, treatment contrasts, confidence intervals, and p-values are not reported in the registry record. Without these values, the direction, magnitude, and precision of the exposure comparisons cannot be evaluated.

The registry also does not report a prespecified comparability margin or the decision rule used to assess comparability. It does not provide the detailed statistical model, transformation, covariate strategy, or sensitivity analyses. Although the primary endpoint is identified, the analysis plan for the 27 listed analyses is not reported in the registry record. The approach to multiplicity and any interim analyses are likewise not reported.

The analysis-set description specifies that participants needed evaluable serum pharmacokinetic data and no important protocol deviations thought to impact the analysis. However, arm-specific numbers analyzed, exclusions, missing-sample procedures, and handling of incomplete or unevaluable profiles are not reported in the registry record. The listed enrollment of 224 therefore should not be read as the number contributing to every endpoint.

The study was open-label, and the registry does not describe allocation concealment or the randomization procedure. These details limit assessment of conduct, although the primary endpoint is based on serum measurements. The registry also does not provide detailed adverse-event context, such as timing or duration. Finally, the study population was adult healthy participants, so its pharmacokinetic findings, even if fully reported, would not directly describe every population or clinical outcome.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Study to Evaluate Pharmacokinetic Comparability Between AZD7442 Co-formulation (AZD8895 + AZD1061) vs AZD8895 and AZD1061 Individually in Adult Healthy Participants — NCT05166421.
• Registry record last updated 2024-11-25; status last verified 2024-10.
• Results first posted 2024-11-25.
• 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

NCT05166421 is a completed randomized, open-label, parallel-group Phase 1 study with three arms and a single dose in adult healthy participants. Enrollment was 224. The study compared AZD7442 as a co-formulation with separate sequential administration of AZD8895 and AZD1061, and also evaluated separate-vial material types.

The primary endpoint was AUCinf, summarized using a geometric mean and geometric coefficient of variation. The registry lists 14 outcome measures and 27 analyses, along with pharmacokinetic sampling through Study Day 361. It reports adverse-event counts by treatment group and 0 deaths in each group.

Numerical results for the primary pharmacokinetic comparisons, confidence intervals, comparability criteria, and detailed statistical analysis methods are not reported in the registry record. The available record describes the trial question and design but does not establish the degree of pharmacokinetic comparability.