Anemia Studies in CKD: Erythropoiesis Via a Novel PHI Daprodustat - Pediatric (ASCEND-P): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Anemia Studies in CKD: Erythropoiesis Via a Novel PHI Daprodustat - Pediatric (ASCEND-P) (NCT05682326), a na phase 3 study. The primary outcome is Number of Participants With Any Adverse Events (AEs) and Serious Adverse Events (SAEs).

2. Clinical Question

The clinical question is framed around pharmacokinetics and safety in pediatric CKD-associated anemia, alongside hemoglobin response. The record states that outcomes were to be assessed separately in the two sub-trials and overall, including age subgroups. It identifies four age ranges: 12 to under 18 years, 6 to under 12 years, 2 to under 6 years, and 3 months to under 2 years. Pharmacokinetics and dose change were to be assessed within age groups only.

The primary endpoint recorded is a count of participants with any adverse event and serious adverse events. That is a descriptive safety question: it records whether participants experienced events during follow-up. It is not a direct test of whether daprodustat changes risk compared with another treatment or with no treatment. Such a comparative question cannot be answered from this single-group record.

3. Trial Design

ASCEND-P is listed as a Phase 3, completed, open-label, single-group study. The registry record gives an enrollment of 4 participants. The study is described as an international, multicenter trial of daprodustat for anemia associated with chronic kidney disease in male and female children and adolescents aged 3 months to under 18 years. The record gives a start date of 2023-09-06 and a primary completion date of 2024-10-18.

The study includes two independent sub-trials: participants not yet receiving dialysis, described as having CKD stage 3 to 5, and participants with CKD stage 5d receiving peritoneal dialysis or hemodialysis. Outcomes were intended to be assessed separately in these groups. They are clinically distinct populations, not randomized arms intended as like-for-like controls. The record lists daprodustat as the intervention and states that all participants would receive it for up to 52 weeks. Masking is listed as none.

The planned maximum study duration is approximately 60 weeks: a screening period of up to 4 weeks, a 52-week treatment period, and a 4-week follow-up period. The brief description identifies pharmacokinetics over 4 weeks, and safety and hemoglobin response over 52 weeks. The primary adverse-event endpoint has a timeframe of up to 56 weeks, so its specified observation period is not identical to the stated 52-week safety assessment.

The record does not report the reason for the enrollment of 4, a sample-size justification, or whether recruitment ended early. It also does not report the allocation process beyond listing allocation as not applicable. The study is not described as a randomized trial, and there is no separate comparator group listed. These features constrain interpretation: event counts can describe the participants recorded in each subgroup, but do not establish a comparative treatment effect.

The record lists 31 outcome measures, including the primary safety outcome and secondary laboratory outcomes. It states that measures were intended to be assessed in each sub-trial and across age subgroups, with the stated exceptions for pharmacokinetics and dose change. No statistical analysis results are listed 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.

Before assignment: A total of 4 participants were enrolled. As pre-specified in protocol design, data for the 2 sub-trials (ND and D) have been presented in two arms for this study.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The analysis was performed on the Safety Set that included all participants who were enrolled and took at least one dose of study medication.

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 Number of Participants With Any Adverse Events (AEs) and Serious Adverse Events (SAEs), measured over Up to 56 weeks.

The primary endpoint is the number of participants with any adverse events and serious adverse events, with a timeframe of up to 56 weeks. It is a count-based endpoint: it describes how many participants experienced an event, rather than the total number of events or the time until an event. The record defines an adverse event as an untoward medical occurrence temporally associated with use of a study intervention, whether or not the event is considered related to the intervention.

Serious adverse events are defined by specified consequences or circumstances. These include death, a life-threatening event, inpatient hospitalization or prolongation of existing hospitalization, persistent or significant disability or incapacity, a congenital anomaly or birth defect, and other situations judged serious by the investigator using medical and scientific judgment. Seriousness is therefore a defined classification, not a statement that the intervention caused the event.

Collecting participant counts for adverse events is useful for describing safety experience during treatment and follow-up. It can identify whether events were recorded and whether they met the serious-event definition. In a single-group study, however, such counts do not by themselves estimate how event frequency would differ under another treatment or without the study intervention. The registry record does not provide a comparative estimate or an analysis adjusting for other factors.

The analysis population is described as the Safety Set, including all participants who were enrolled and took at least one dose of study medication. The reported subgroup counts are small, so each participant’s experience has substantial influence on the count. The record does not provide a confidence interval for the primary endpoint or a statistical model for estimating event risk.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record identifies a count of participants with adverse events as the primary endpoint. A count endpoint answers how many people experienced an event during the stated observation period. It differs from an event count, which could include multiple events in one person, and from a time-to-event endpoint, which considers when an event occurred. The record names participants as the unit and gives a timeframe of up to 56 weeks.

What does a descriptive count show?

A descriptive count records observed experience in the study participants. It does not automatically estimate what would happen in a different population or under a different treatment. In this study, the reported groups contain 2 participants each. The counts are therefore highly sensitive to individual outcomes: one additional participant with an event would materially change the group description. This is a general property of small samples, not a statistical result specific to this intervention.

A proportion can be useful for describing the fraction of participants with an event, but its precision depends on the amount of information in the data. A confidence interval, when reported, communicates uncertainty around an estimate: it gives a range of values compatible with the data under the assumptions of the method. The registry record does not report confidence intervals for the adverse-event results. No interval should be inferred from the counts alone in this explanation.

Why does the design matter?

The trial is single-group and open-label, with two sub-trials defined by dialysis status. Both groups received daprodustat. A randomized comparator would support a direct estimate of a treatment contrast by comparing groups assigned to different strategies. That design is not listed. Dialysis status is part of the population definition, not a randomized intervention. Accordingly, subgroup counts can describe the participants in each sub-trial but cannot be interpreted as a controlled comparison of treatment effects.

Open-label means masking is listed as none. Knowledge of treatment assignment can matter for outcomes that depend on reporting, assessment, or judgment. Serious adverse events have defined criteria in the record, but the investigator’s judgment is included for other serious situations. The registry record does not report procedures to reduce assessment bias, independent adjudication, or blinding of outcome assessors.

What do the safety definitions mean?

An adverse event is defined broadly as an untoward medical occurrence temporally associated with study intervention, regardless of whether it is considered related. This captures events occurring during the study without requiring a causal judgment. A serious adverse event is distinguished by its consequence or circumstance, such as death, life-threatening status, hospitalization, significant disability, or a congenital anomaly or birth defect. The classification of an event as serious is not the same as a conclusion that the treatment caused it.

The endpoint counts participants, so a person with more than one event still contributes as a participant who experienced an event. The record also lists specific serious-event terms. Without further detail, the listed terms should not be added together or treated as mutually exclusive. The record does not report event-level timing, duration, recurrence, or a detailed relationship assessment for each event.

What analysis is reported?

The record identifies the Safety Set as participants who were enrolled and took at least one dose. That definition sets the intended analysis population for the primary safety outcome. The registry record lists zero analyses, and does not report a statistical model, adjustment strategy, hypothesis test, confidence interval, or missing-data method. It is therefore not possible to assess how an inferential analysis was conducted, or whether any such analysis was performed beyond the posted record.

General statistical interpretation distinguishes estimation from testing. Estimation describes the size of an outcome and its uncertainty; hypothesis testing evaluates data relative to a specified null hypothesis and analysis plan. A p-value, when available, does not measure the probability that a treatment is effective or the probability that the observed result occurred by chance. No p-value or comparative estimate is reported for these results.

How should planning calculations be understood?

The record describes sample-size planning illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. The illustrations are planning scenarios, not evidence about the trial’s original design, and they are not observed power. Their assumptions do not change the actual design: this study enrolled 4 participants, had a single treatment group, and was not a randomized comparison. A planning calculation cannot make a small observed dataset more precise or supply a missing control group. The registry record does not report the trial’s sample-size justification, and the planning assumptions should not be taken as proof that the trial was designed to detect a particular effect.

For binary outcomes, general planning methods depend on the event probability and the effect one wishes to detect. When an observed effect is used as an input, the resulting calculation is conditional on that estimate and may be unstable when the underlying study is very small. The record’s planning description does not establish that the observed effect is a reliable estimate of a population effect. Any numerical planning illustration should be understood as hypothetical rather than as a description of what was observed.

Why can over-dispersion matter in general?

Over-dispersion occurs when observed variability is greater than a statistical model expects. If a model assumes less variability than the data contain, uncertainty can be understated and tests can be too optimistic. This is a general consideration for count outcomes, especially when event rates vary across participants. The registry record does not report an over-dispersion assessment or a count model, and the primary endpoint is a participant count rather than a reported repeated-event rate. No claim about over-dispersion can be made for this trial.

10. Multiplicity, Missing Data and Analysis Populations

The record lists 31 outcome measures. It describes safety and hemoglobin response over 52 weeks and pharmacokinetics over 4 weeks, as well as multiple laboratory outcomes. Outcomes were intended to be assessed separately in the dialysis and non-dialysis sub-trials and across age subgroups. Considering many outcomes, subgroups, or time points can raise a multiplicity issue: the more analyses considered, the greater the chance that some findings may appear notable by chance. This is a general statistical concern, not a statement that a particular result is false.

The registry record does not report a multiplicity adjustment, a hierarchy of outcomes, a prespecified testing sequence, or a statistical analysis plan. It also lists zero analyses. Therefore, it is not possible to determine which outcomes were formally tested, how any tests were prioritized, or whether adjustment was used. The presence of many listed outcomes alone does not establish that all were analyzed.

Missing-data handling is not reported in the registry record. The record defines the Safety Set as participants enrolled and taking at least one dose, but does not state how incomplete follow-up, unavailable measurements, or discontinuation were handled for individual outcomes. It also does not report the number of participants with observed data at each assessment or reasons for missing measurements. The Safety Set definition should not be mistaken for a complete-case rule or an imputation method.

The stated subgroup assessments and the overall assessments may have different amounts of information, but subgroup-specific sample sizes for each outcome are not separately described beyond the adverse-event counts. No precision estimates are reported. With 4 participants enrolled, any subdivision by dialysis status or age group necessarily describes a limited set of participants; the registry record does not support broad subgroup comparisons.

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 serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: congenital uterine anomaly (50.0%), retroperitoneal haematoma (50.0%), hypertension (50.0%).

For participants requiring dialysis, the registry record lists 2 at risk for serious adverse events and 1 affected. For participants not yet requiring dialysis, it lists 2 at risk and 0 affected. The record reports 2 at risk and 2 affected for other adverse events in each subgroup. Deaths are listed as 0 in both groups. These figures describe participant counts during the stated safety follow-up; they are not comparative treatment-effect estimates.

The serious-event terms listed are Congenital uterine anomaly, Retroperitoneal haematoma, and Hypertension, each reported at 50.0%. The record does not explain whether terms overlap within participants, so the percentages should not be summed or used to infer a total number of distinct participants. The term-level listing is descriptive and does not establish that daprodustat caused an event.

Adverse events are defined as medical occurrences temporally associated with study intervention, whether or not considered related. Seriousness refers to specified outcomes or circumstances, including hospitalization, life-threatening status, or other investigator judgment. These definitions separate event recording from causal attribution. The small subgroup counts also mean that the observed pattern is imprecise and should not be generalized as a stable rate for a wider population.

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

The posted results describe safety experience among the four participants enrolled in ASCEND-P, separated by whether dialysis was required. They show that the registry recorded serious adverse events in 1 participant in the dialysis subgroup and none in the subgroup not yet requiring dialysis. Other adverse events were recorded in both participants in each subgroup, and no deaths were listed. The record also names three serious-event terms, each reported at 50.0%.

These observations are limited to the participants and follow-up recorded. They do not show how event frequency would compare with a different treatment or with no treatment, because there is no comparator group. They do not demonstrate that dialysis status explains any difference in the counts, because the groups were not randomized and are distinct clinical populations. They do not establish that daprodustat caused the events, since the adverse-event definition includes events regardless of their assessed relation to study intervention.

The counts do not give a precise estimate of risk in all children and adolescents with CKD-associated anemia. The registry record does not report confidence intervals or an inferential analysis, and only 4 participants were enrolled. A zero count in a small group cannot establish that an event is impossible or absent from the broader population. A nonzero count likewise does not establish a typical rate.

The trial description includes hemoglobin response and pharmacokinetics among its aims, but the registry record does not report corresponding results. The record lists 31 outcome measures and zero analyses. It therefore does not support a conclusion about the magnitude, precision, or statistical significance of hemoglobin response, nor does it provide a comparative estimate for safety or efficacy.

In short, the posted data are a small, descriptive safety record. They identify which events were recorded in the enrolled participants, but do not establish treatment benefit, lack of benefit, causality, or comparative safety. Interpretation beyond those participants would require evidence and analysis not reported in the registry record.

13. Why This Trial Matters Statistically

This trial is statistically important to read in the context of its design and scale. Pediatric studies in a specific clinical population can have limited enrollment, and ASCEND-P records 4 participants across two sub-trials. That makes clear why simple counts and careful description matter: each participant contributes substantially to the observed pattern, while estimates for a wider population remain uncertain.

The study also illustrates the difference between separate clinical cohorts and comparator arms. Dialysis status divides participants into populations with different CKD and treatment characteristics. Because all participants received daprodustat and allocation is listed as not applicable, the two groups do not provide a randomized comparison. Treating them as control and treatment groups would attach a causal interpretation that the design does not support.

The registry record distinguishes safety observation from causal attribution. Adverse events are captured whether or not they are considered related to the intervention, while serious adverse events are defined by clinical consequences and circumstances. This distinction is important when interpreting event lists: recording an event is not proof that the intervention caused it.

The record lists many outcomes and intended subgroup assessments, but reports no analyses. That underscores the value of transparent analysis plans, explicit missing-data methods, and clear explanations of how multiple outcomes are handled. Without those details, readers cannot evaluate inferential results or the precision of estimates. The posted record remains useful for describing the design, population, follow-up, and observed safety counts, while its limits should guide how far those observations are interpreted.

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 is the small enrollment: 4 participants in total, with adverse-event counts reported in subgroups of 2 participants each. Such counts provide limited information about event frequency beyond the participants observed. No confidence intervals or other uncertainty estimates are reported, so the precision of the safety findings cannot be assessed from the registry record.

The single-group, open-label design has no randomized comparator. Dialysis status defines two distinct sub-trials and should not be treated as a control assignment. The record therefore cannot estimate a treatment contrast or separate treatment effects from differences in the underlying populations. Open-label status may also matter for the reporting or assessment of events, and the record does not describe independent event adjudication or blinded assessment.

The primary safety timeframe is up to 56 weeks, while the study description specifies a 52-week treatment period and 4-week follow-up. The registry record does not explain the relationship between these periods for each participant or provide individual follow-up durations. It also does not report event timing, recurrence, or detailed relatedness assessments for the listed events.

Although hemoglobin response and pharmacokinetics are stated study aims, results for those outcomes are not reported in the registry record. The record lists 31 outcome measures but zero analyses, and does not report a statistical analysis plan, multiplicity approach, sample-size justification, or handling of missing data. These omissions limit assessment of outcome selection, precision, and the interpretation of any subgroup or laboratory findings.

The record’s enrollment and completion status do not explain why enrollment was 4 or whether the planned recruitment target changed. That information is not reported in the registry record. The findings should therefore be read as descriptive information about this small enrolled cohort, not as a definitive estimate for the wider population.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Anemia Studies in CKD: Erythropoiesis Via a Novel PHI Daprodustat - Pediatric (ASCEND-P) — NCT05682326.
• Registry record last updated 2025-11-10; status last verified 2025-10.
• Results first posted 2025-11-10.
• 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

ASCEND-P, NCT05682326, is listed as a completed Phase 3, open-label, single-group trial of daprodustat for anemia associated with chronic kidney disease in children and adolescents aged 3 months to under 18 years. The record reports 4 enrolled participants, a start date of 2023-09-06, and a primary completion date of 2024-10-18.

The study had two independent sub-trials: participants requiring dialysis and participants not yet requiring dialysis. Daprodustat was given for up to 52 weeks. The primary endpoint was the number of participants with any adverse events and serious adverse events, assessed up to 56 weeks. The posted counts include serious adverse events in 1 of 2 participants requiring dialysis and 0 of 2 participants not yet requiring dialysis; other adverse events were reported in 2 of 2 participants in each subgroup, with no deaths listed.

The registry record lists 31 outcome measures and zero analyses. It does not report comparative results, confidence intervals, missing-data handling, or a statistical analysis plan. The available counts are descriptive and do not establish causality or a treatment comparison.