Pharmacokinetic Study of Oral ALXN1840 in Japanese and Non-Japanese Adult Healthy Participants: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Pharmacokinetic Study of Oral ALXN1840 in Japanese and Non-Japanese Adult Healthy Participants (NCT05641311), a non-randomized phase 1 study. The primary outcome is Area Under The Plasma Concentration Versus Time Curve From Time 0 (Dosing) To The Last Quantifiable Concentration (AUCt) Of Plasma Total Molybdenum After Each Dose.

2. Clinical Question

The registry describes the study’s purpose as confirming how long ALXN1840 stays in the body of Japanese and non-Japanese healthy participants. The primary endpoint is an exposure measure derived from plasma concentrations over time, rather than a clinical outcome or a measure of treatment benefit. The record does not provide the cohort-specific endpoint results, so the magnitude and precision of any difference between cohorts cannot be assessed from the recorded results.

The population is important to the question: the study examines pharmacokinetics by participant group, not treatment versus no treatment. Because allocation was non-randomized, observed cohort differences would be descriptive and could not be interpreted as a randomized causal comparison. The registry record does not report further eligibility criteria or other details that would clarify how participants were selected.

3. Trial Design

This is a completed Phase 1, open-label, non-randomized, parallel-group study. Its official title describes a two-single-dose, two-period design assessing pharmacokinetics and safety in healthy adult Japanese and non-Japanese subjects. The listed intervention is ALXN1840. The registry identifies Wilson Disease as a condition, while the described study population is healthy adults; it does not describe this as a therapeutic efficacy trial in people with Wilson Disease.

The Japanese cohort received a single 15 mg dose in Dosing Period 1 and a single 60 mg dose in Dosing Period 2. The non-Japanese cohort is described as receiving the same doses in the same periods. The parallel-group feature means the cohorts are organized by participant group, rather than described as randomized treatment arms. The record does not report a placebo group or a separate untreated group. It also does not report the sequence or timing of sample collection beyond the primary endpoint timeframe, or whether any washout period was used.

The registry lists enrollment as 24. Each cohort lists 12 participants at risk for serious adverse events and 12 at risk for other adverse events. These safety counts should not be treated as confirmation that every enrolled participant contributed usable pharmacokinetic data: the pharmacokinetic population has its own sample-availability criterion, and participant counts by endpoint analysis are not reported in the registry record.

The study started on 2019-02-20, reached primary completion on 2019-05-02, and is recorded as completed. The record describes open-label conduct and does not report masking. It does not report a detailed protocol, a sample-size justification, or the rationale for the cohort sizes. Since cohort assignment was non-randomized, differences between cohorts may reflect factors other than the participant group itself. The design is therefore best read as a pharmacokinetic assessment across cohorts, not as a randomized comparison of interventions.

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 of 24 participants were screened, all of whom were enrolled and received ALXN1840 in the study at 1 study site. Of the 24 enrolled, 12 were Japanese, therefore, they were allocated to Cohort 1, and 12 were non-Japanese, therefore, they were allocated to Cohort 2. All participants were included in all analysis sets.

Dosing Period 1

Reasons for not completing this period:

Dosing Period 2

Analysis population for the primary outcome, as defined in the registry: The PK population consisted of all participants who had sufficient plasma samples to enable the calculation of PK parameters of at least area under the curve (AUC) for at least one period.

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 consisted of all participants who received at least 1 dose of the study drug.

6. Primary Endpoint

The registry lists the primary outcome as Area Under The Plasma Concentration Versus Time Curve From Time 0 (Dosing) To The Last Quantifiable Concentration (AUCt) Of Plasma Total Molybdenum After Each Dose, measured over Day 1 through Day 11 of Dosing Periods 1 and 2.

The primary endpoint is the area under the plasma concentration-versus-time curve from time 0, the time of dosing, to the last quantifiable concentration, for plasma total molybdenum after each dose. Its unit is hours* nanograms/milliliters. The stated timeframe is Day 1 through Day 11 of Dosing Periods 1 and 2.

AUC is a measure of exposure over time: it combines information about the measured concentrations across the sampling interval, rather than describing concentration at a single sampling time. Ending the interval at the last quantifiable concentration makes the endpoint depend on the period during which concentrations can be measured above the assay’s quantification threshold. This is a general explanation of the measure; the registry record does not describe the assay or its threshold.

In pharmacokinetic studies, an AUC measure can help characterize how much of a measured substance is present in the body over time after dosing. Here, the registered analyte is plasma total molybdenum. The endpoint title specifies that it is assessed after each dose, allowing the pharmacokinetic profile to be described for the two dosing periods. It is not itself a direct measure of clinical benefit, disease control, or long-term safety.

The record identifies the summary parameter as the mean and the dispersion measure as the standard deviation. However, it does not report the endpoint means, standard deviations, participant counts in the endpoint analyses, or a comparison estimate. Without these results, the endpoint’s observed values and their variability cannot be evaluated from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous: it is a measured AUC value, and the registry identifies the mean as its summary parameter. A mean describes the central level of the measured values in a group. The standard deviation describes how spread out individual measurements are around that mean. These statistics answer different questions: the mean characterizes the group’s average exposure, while the standard deviation characterizes participant-to-participant variability. The registry record names both summaries but does not report their values.

As a general statistical explanation, a confidence interval expresses uncertainty around an estimated quantity. Its width depends on the amount of information and the variability in the data, among other factors. A narrow interval indicates greater precision than a wide interval, but neither width nor the estimate itself can be evaluated without the results. No confidence interval or other uncertainty interval is reported in the registry record for the primary endpoint.

Likewise, a hypothesis test would require a specified contrast, an estimate, and an inferential procedure. The registry lists zero analyses and does not report a p-value or a statistical comparison for the primary endpoint. It would therefore be inappropriate to describe the cohorts as statistically different or similar on the basis of the registry information. A missing test result is not evidence that a test found no difference.

The study’s non-randomized parallel-group design also shapes interpretation. Random allocation can, in expectation, balance measured and unmeasured characteristics between comparison groups. This study does not describe random allocation, so a cohort contrast may be influenced by factors other than cohort membership. In general, adjustment can address measured differences under appropriate assumptions, but the registry record does not report adjusted analyses or a covariate set. Even an adjusted result would not automatically remove uncertainty from unmeasured differences.

The record describes a pharmacokinetic population based on sample availability: participants must have sufficient plasma samples to calculate pharmacokinetic parameters, including at least AUC, for at least one period. This definition allows a participant with usable data for one period to qualify, without requiring usable data for every period. The record does not report how many participants qualified, whether all available data were used, or how incomplete concentration profiles were handled. These details affect how the endpoint summaries should be understood.

For continuous concentration-derived outcomes, variability may arise from genuine differences among participants, sampling, measurement, and the shape of the concentration profile. As a general explanation, over-dispersion means that observed variability is greater than a statistical model assumes. A model that fails to account for such extra variability can give uncertainty estimates that are too small. The registry record does not describe a model for the AUC endpoint or report whether over-dispersion was assessed; no claim about its presence or absence can be made.

The registry includes sample-size assumptions for planning illustrations: a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation, with the effect to detect expressed as a stated fraction of an observed effect. These assumptions describe illustrations computed from an observed effect, not the trial’s own design. The values of the illustrations are not reported in the registry record. They should not be read as evidence that the study had a particular probability of detecting an effect. In general, statistical power is a design concept tied to an assumed effect and analysis; it is not a measure of what the completed study actually found.

The listed design is parallel group, while each cohort’s description includes the same dose in each of two dosing periods. The registry does not report a within-person model, period effect assessment, sequence effect assessment, or details that would establish how the two periods were handled analytically. Those methods should not be inferred from the period descriptions alone.

For safety, the record gives counts of participants at risk and affected for serious and other adverse events. Such counts are descriptive summaries. A more detailed safety interpretation would require event definitions and, for example, information about timing, severity, and exposure duration; these details are not reported in the registry record. No rate calculations or comparative safety tests are reported, and none should be inferred from the counts alone.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists one outcome measure and no analyses. It does not report a statistical analysis plan, a hierarchy of hypotheses, or a procedure for controlling multiplicity. The primary endpoint is assessed after each dose, but the registry record does not explain whether dose-specific estimates were intended as separate inferential tests, how any cohort comparisons were organized, or whether adjustment for multiple comparisons was planned. Multiplicity handling is not reported in the registry record.

The pharmacokinetic population is defined by availability of enough plasma samples to calculate pharmacokinetic parameters, including at least AUC, for at least one period. That criterion indicates that participants with insufficient samples may not contribute to the pharmacokinetic analysis. The record does not report the number excluded by this criterion, the number with data for each period, or whether exclusions differed by cohort. It also does not describe imputation, handling of values below quantification limits, or other missing-data procedures.

These omissions limit interpretation because the amount and pattern of missing data can affect both the estimate and its precision. As a general statistical principle, missingness that differs across groups or periods can make comparisons less representative of the enrolled participants. Whether that occurred cannot be determined from the registry record.

The enrollment figure is not a substitute for endpoint-specific analysis counts. The registry lists 24 enrolled, but the number contributing to each AUC summary and any cohort contrast is not reported. The record also does not report a prespecified analysis population beyond the pharmacokinetic population definition, nor does it explain how participants with data from only one period were represented in analyses.

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 safety record reports serious adverse event counts separately for each cohort. In the Japanese cohort, 0 participants were affected among 12 at risk; in the non-Japanese cohort, 0 participants were affected among 12 at risk. Deaths are recorded as 0 in each cohort. These are counts from the recorded study period, not estimates proving that serious adverse events cannot occur.

For other adverse events, the record lists 5 participants affected among 12 at risk in the Japanese cohort and 5 among 12 at risk in the non-Japanese cohort. These figures describe the number affected, not necessarily the total number of event occurrences. The record does not report event names in the listed summary, or provide details about severity, timing, duration, or relationship to ALXN1840. No event-rate calculation or statistical comparison is reported.

Safety counts are descriptive and should be interpreted in the context of the study population and observation. The participants were healthy adults in a Phase 1 pharmacokinetic study, and the registry does not supply a separate untreated comparison. The counts therefore do not establish comparative risk or predict safety in other populations.

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

The record establishes that this completed Phase 1 study assessed ALXN1840 pharmacokinetics in healthy Japanese and non-Japanese adults using two single-dose periods. Its primary measure was plasma total molybdenum AUC from dosing to the last quantifiable concentration. The registered question is pharmacokinetic: it concerns exposure over time and differences between participant cohorts, not whether ALXN1840 improves a clinical outcome.

The registry does not report the primary endpoint means, standard deviations, cohort contrasts, confidence intervals, or p-values. As a result, it is not possible from the recorded results to state how large exposure was, how variable it was, whether the cohorts differed, or how precise a comparison might be. The absence of those numerical findings should not be interpreted as evidence of no difference.

The non-randomized design also means that even a reported difference between cohorts would not, on its own, show that cohort membership caused the difference. The study has no listed placebo or untreated group, and both cohorts receive the same dose sequence. The record therefore does not provide a randomized treatment-effect comparison.

The safety figures show 0 serious adverse event participants and 0 deaths in each cohort, alongside 5 participants with other adverse events in each cohort. Those counts are observations from the study record. They do not rule out uncommon or later events, and the record lacks the event-level detail needed to characterize the other adverse events.

Accordingly, the record supports a description of the study question, its design, the endpoint definition, and the listed safety counts. It does not support a quantitative conclusion about pharmacokinetic similarity, a clinical benefit claim, or a broad safety conclusion. Such conclusions would require results and analysis details that are not reported in the registry record.

13. Why This Trial Matters Statistically

Pharmacokinetic studies help characterize exposure after dosing, and this study focuses on whether that profile is described in Japanese and non-Japanese healthy adults. Its AUC endpoint uses concentrations over a stated sampling interval rather than a single measurement. That makes the endpoint relevant to exposure characterization, while keeping the question distinct from clinical effectiveness.

The design is statistically important because it is non-randomized and organized into parallel cohorts. A cohort contrast is not equivalent to a randomized treatment comparison. Statistical descriptions must keep the design and the target question aligned: the study can describe pharmacokinetic observations in the enrolled groups, but causal interpretation of group differences requires caution.

The endpoint also illustrates why summary statistics matter. A mean alone would not describe how much individual exposure varies; the standard deviation helps convey that dispersion. Uncertainty intervals and analysis counts would further help readers judge precision. Although the record identifies mean and standard deviation summaries, it does not report their values or the endpoint-specific counts, leaving the central statistical findings unavailable.

The pharmacokinetic population definition makes sample availability part of the interpretation. Participants need sufficient plasma samples for at least one period, but the number meeting that requirement is not reported. That distinction between enrollment and evaluable endpoint data is important in studies with repeated sampling and multiple periods.

Finally, the safety summaries are useful as descriptive counts but do not replace detailed event information or a comparator. Taken together, the record is informative about the question and methods at a high level, while its missing numerical outcome results prevent readers from judging the size and precision of the pharmacokinetic findings. This is why registry completeness is itself statistically consequential.

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 primary limitation for interpreting results is that the registry record does not include the AUC means or standard deviations, despite identifying those as the endpoint summaries. It also lists no analyses, and does not report cohort contrasts, uncertainty intervals, or hypothesis tests. The pharmacokinetic findings therefore cannot be quantified from the recorded results.

The record reports enrollment as 24 but does not provide the number of participants included in each endpoint analysis. The pharmacokinetic population requires sufficient samples for at least one period, so enrollment does not establish how many participants contributed data after each dose or in each cohort. Missing concentration data and their handling are not reported.

The cohort comparison is non-randomized. The registry does not report participant characteristics, methods to address between-cohort differences, or adjusted analyses. As a result, potential differences in the groups cannot be separated from a cohort-associated pharmacokinetic contrast using the information recorded.

Important design and analysis details are also absent. The record does not describe the sampling schedule beyond the stated timeframe, assay characteristics, handling of measurements below quantification limits, period-related analyses, or the statistical plan. It does not report multiplicity procedures or a sample-size justification. The planning assumptions describe illustrations rather than the trial’s own design, and the illustration values are not reported.

Safety interpretation is limited to aggregate counts. Although serious adverse event and death counts are listed, the registry does not provide event details, duration of observation, or a comparator group. The counts are informative as descriptive observations but cannot establish the absence of risk or characterize events comprehensively.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Pharmacokinetic Study of Oral ALXN1840 in Japanese and Non-Japanese Adult Healthy Participants — NCT05641311.
• Registry record last updated 2023-11-07; status last verified 2023-11.
• Results first posted 2023-11-07.
• 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 registry describes a completed, open-label, non-randomized Phase 1 parallel-group study of oral ALXN1840 in healthy Japanese and non-Japanese adults. It lists enrollment as 24 and describes a single 15 mg dose in Dosing Period 1 followed by a single 60 mg dose in Dosing Period 2 for each cohort.

The primary endpoint is plasma total molybdenum AUC from dosing to the last quantifiable concentration, with mean and standard deviation identified as the planned summaries. The record does not report endpoint values or analyses, so the pharmacokinetic comparison cannot be quantified.

Each cohort records 0 serious adverse event participants and 0 deaths, with 5 participants affected by other adverse events. These are descriptive counts; further event details are not reported in the registry record.