This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Study of ASN51 in Adults With Early Alzheimer's Disease (NCT06677203), a randomized phase 2 study. The primary outcome is Number of Participants With Adverse Events (AEs).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT06677203 |
| Phase | Phase 2 |
| Condition | Alzheimer Disease |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 123 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Asceneuron S.A. |
| Results posted | Yes |
2. Clinical Question
Population
Adults with early Alzheimer’s disease were the intended study population. The registry record lists Alzheimer Disease as the condition and enrollment as 123. However, it also states that the study was terminated before any participants received treatment and that no data were collected or evaluated. The enrollment entry therefore does not provide a treated population or an analysis denominator.
Intervention
The planned intervention was oral ASN51 once daily. The registry describes low-dose and high-dose groups, identified in the adverse-event entries as ASN51 10 mg and ASN51 20 mg. Treatment was planned for up to 24 weeks during the double-blind, placebo-controlled period. The record also describes a long-term extension for the ASN51 groups, planned for up to 36 weeks.
Comparator
The comparator was matching placebo, taken orally once daily during the double-blind intervention period planned for up to 24 weeks. The registry describes a parallel-group design, meaning the intended groups would receive their assigned study intervention rather than switching between interventions. No participants received ASN51 or placebo, so there are no observed group outcomes to compare.
Primary question
The primary endpoint was the number of participants with adverse events from first dose through the end of the study, up to Week 28. This endpoint was intended to characterize safety and tolerability. Because treatment never began and the registry states that no data were collected, the record cannot answer whether adverse events differed between ASN51 and placebo. It also cannot provide an estimate of the frequency of adverse events among treated participants.
3. Trial Design
The registry identifies this as a Phase 2, randomized, double-blind, placebo-controlled, parallel-group study sponsored by Asceneuron S.A. It was designed to evaluate multiple doses of ASN51 in adults with early Alzheimer’s disease. The listed interventions were ASN51 and matching placebo, with intended low-dose and high-dose ASN51 groups alongside the placebo group. The planned ASN51 doses are identified in the adverse-event group entries as 10 mg and 20 mg.
Randomization describes the intended process for allocating participants to study groups. Double masking means the design was intended to keep treatment assignment concealed from participants and relevant study personnel, while a parallel-group design assigns participants to a group for the intervention period rather than having them cross over between treatments. These design features describe the planned study; they do not establish that allocation or masking occurred. The registry states that no participants received treatment.
ASN51 was planned as an oral, once-daily treatment for up to 24 weeks in the double-blind placebo-controlled period. The record also describes an extension of up to 36 weeks for participants assigned to either ASN51 dose. The placebo description covers the double-blind intervention period. The primary outcome timeframe was from first dose through the end of the study, up to Week 28. Secondary outcomes included tau-related measures in cerebrospinal fluid and plasma, tau positron emission tomography signal, and plasma pharmacokinetic measures.
The study started on 2024-10-16, and its listed primary completion date is 2024-11-08. Its status is TERMINATED. The registry says termination followed a strategic decision by the sponsor, and explicitly reports that no participants received treatment and no data were collected or evaluated. Thus, the design information describes the intended trial, not a completed comparison of randomized groups.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | ASN51 Low Dose | ASN51 High Dose | Placebo |
|---|---|---|---|
| STARTED | 0 | 0 | 0 |
| COMPLETED | 0 | 0 | 0 |
| NOT COMPLETED | 0 | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: The study was terminated due to a strategic decision by the sponsor. No participants received treatment, and no data were collected or evaluated for this study.
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
Population: The study was terminated due to a strategic decision by the sponsor. No participants received treatment, and no data were collected or evaluated for this study.
| Characteristic | Unit | ASN51 Low Dose | ASN51 High Dose | Placebo | Total |
|---|---|---|---|---|---|
| Participants analysed | 0 | 0 | 0 | 0 | |
| Sex: Female, Male: Female | — | — | — | — | |
| Sex: Female, Male: Male | — | — | — | — | |
| Ethnicity (NIH/OMB): Hispanic or Latino | — | — | — | — | |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | — | — | — | — | |
| Ethnicity (NIH/OMB): Unknown or Not Reported | — | — | — | — | |
| Race (NIH/OMB): American Indian or Alaska Native | — | — | — | — | |
| Race (NIH/OMB): Asian | — | — | — | — | |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | — | — | — | — | |
| Race (NIH/OMB): Black or African American | — | — | — | — | |
| Race (NIH/OMB): White | — | — | — | — | |
| Race (NIH/OMB): More than one race | — | — | — | — | |
| Race (NIH/OMB): Unknown or Not Reported | — | — | — | — | |
| Region of Enrollment: United States | participants | — | — | — | — |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Adverse Events (AEs), measured over From first dose up to end of the study up to Week 28.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint was the number of participants with adverse events. The registry defines an adverse event as any untoward medical occurrence associated with drug use in humans, whether or not it is considered related to the drug. The planned timeframe was from first dose through the end of the study, up to Week 28.
In general, counting participants with adverse events is a safety and tolerability measure. It can describe how many people in each treatment group experienced an event during the specified observation period. The endpoint’s definition does not require investigators to judge that the study drug caused the event; an event may be counted even when a causal relationship is not considered established. This can make the measure useful for describing the overall experience of participants during treatment, while leaving questions about event type, severity, timing, and attribution to additional summaries or analyses.
For this study, however, the endpoint was not observed in treated participants. The registry reports that no participants received treatment and that no data were collected or evaluated. The recorded adverse-event entries therefore cannot be interpreted as evidence about the frequency of events during ASN51 or placebo exposure. The endpoint’s planned definition and timeframe remain informative about what the study intended to measure, but there is no clinical result for this outcome in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes an intended comparison of low-dose ASN51, high-dose ASN51, and matching placebo in adults with early Alzheimer’s disease. It does not contain a completed comparison. The study was terminated after a strategic decision by the sponsor, before participants received treatment, and no data were collected or evaluated. Consequently, there are no observed treatment-group outcomes, effect estimates, uncertainty intervals, or hypothesis tests to interpret.
The primary endpoint was the number of participants with adverse events. Although the adverse-event entries list groups for ASN51 10 mg, ASN51 20 mg, and placebo, the registry’s accompanying population statement says there was no treatment exposure and no data collection. Those entries should not be read as estimates of adverse-event risk or as evidence that the interventions had no adverse events. Without treated participants and collected follow-up, there is no empirical basis for comparing safety outcomes.
The same constraint applies to the planned disease-related and pharmacokinetic outcomes. The record lists changes in cerebrospinal fluid and plasma tau measures, tau positron emission tomography signal, and steady-state ASN51 concentrations. But it reports no collected or evaluated data for the study. There are therefore no biomarker changes, exposure measurements, or preliminary clinical efficacy findings to interpret. A stated outcome or a planned measurement is not itself a result.
In general, an estimate from a randomized comparison is interpreted in light of both its magnitude and its uncertainty. A confidence interval describes a range of values compatible with the data under the analysis assumptions; its width conveys precision. Here, there are no outcome data from which to calculate an estimate or interval. A p-value, including an unadjusted or adjusted test, is likewise not available as a treatment comparison. The registry lists no analyses.
The enrollment field records 123, but that entry does not override the explicit statement that no participants received treatment and no data were collected or evaluated. It cannot serve as the denominator for a treatment effect or adverse-event rate. The posted record therefore documents the planned study and its termination, rather than evidence for or against an effect of ASN51.
9. Statistical Methods Explained
The registry describes a randomized, double-blind, placebo-controlled, parallel-group design, but it does not report a completed statistical analysis. The study ended before treatment exposure, and the record states that no data were collected or evaluated. The methods below explain how the planned design and endpoints would generally be understood; they are not a description of analyses actually conducted for this trial.
What does randomization contribute?
In general, randomization assigns participants to groups using a chance-based process. Its purpose is to make the groups comparable, on average, with respect to both measured and unmeasured characteristics, supporting a fair treatment comparison. Randomization does not guarantee identical groups, particularly in a study with limited enrollment, and the allocation process and resulting baseline data need to be reported to assess how the design was implemented. Here, the registry identifies randomization as planned but says no participants received treatment. There is consequently no realized allocation or baseline balance to evaluate.
What does double masking mean?
Masking is intended to limit the influence of knowledge about treatment assignment on participant experience, clinical care, outcome assessment, and reporting. The record describes the study as double-blind and placebo-controlled, with ASN51 and matching placebo. That describes the intended safeguards, not proof that masking was implemented. Since treatment never began, there is no information about whether participants or study personnel remained unaware of assignments or whether masking could have been compromised.
How would the primary endpoint be summarized?
The primary endpoint counts participants with adverse events during the stated observation period, from first dose through the end of the study, up to Week 28. In a completed study, a group-level count would usually be interpreted alongside the number of participants observed in that group and the event definitions and follow-up conditions. Comparisons could describe differences in event occurrence between treatment groups, with uncertainty reflecting the amount and variability of the data. Those requirements cannot be met from this record: no participants received treatment, and no outcomes or analysis populations are reported.
It is also important to distinguish the number of participants who experience an event from the number of events. One participant may have more than one event, while a participant-level endpoint counts that person as having an event. The primary outcome is worded as the number of participants with adverse events, but the registry does not provide collected observations that would permit either a participant-level summary or a fuller event-level account.
What do the other planned outcomes address?
The record lists changes through Week 24 in cerebrospinal fluid pTau217, cerebrospinal fluid total tau, plasma pTau217, and MK-6240 tau positron emission tomography signal. It also lists ASN51 trough plasma concentration at steady state and maximum plasma concentration at steady state. In general, biomarker outcomes can describe biological measurements, while pharmacokinetic outcomes characterize drug concentration over time or at specified points. Such measures can inform biological activity and drug exposure, but they are not substitutes for clinical outcomes. No values or analyses for these measures are reported for this study.
The registry lists eight outcome measures, while the named secondary outcomes specify the measures above. It does not provide results for those outcomes or a detailed analysis plan. The recorded analysis count is zero. There is therefore no basis for describing how outcomes were transformed, which visits were included in an analysis, or how estimates were adjusted.
What can be said about precision and statistical significance?
In general, a confidence interval communicates the precision of an estimated effect: a narrower interval indicates greater precision under the model and assumptions used, while a wider interval indicates less precision. A significance test evaluates compatibility between the observed data and a specified null hypothesis under its assumptions. Neither a confidence interval nor a test can be reconstructed without outcome data and a defined analysis. The registry reports no analyses, so it offers no treatment-effect estimate, confidence interval, or p-value.
The record includes generic assumptions for sample-size planning illustrations: a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. These are planning assumptions, not evidence that the trial achieved a particular power. Because the trial has no observed treatment effect, the illustrations cannot be interpreted as observed power or as evidence about ASN51. The registry record does not report a trial-specific sample-size justification.
Why can over-dispersion matter in general?
For count outcomes, statistical models may assume a particular relationship between the average count and its variability. Over-dispersion occurs when the observed variability is greater than that model assumption allows. If ignored, it can make uncertainty appear too small and tests too optimistic. Whether this issue would matter depends on the outcome definition, observed data, and analysis model. There are no event data or reported models for this trial, so over-dispersion cannot be assessed.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary safety endpoint and several secondary biomarker and pharmacokinetic outcomes. When a study evaluates multiple outcomes or multiple comparisons, multiplicity is a general statistical concern: the chance of at least one apparently significant finding can increase as more tests are considered. A prespecified strategy may address this through a hierarchy, adjustment, or a clearly defined distinction between confirmatory and exploratory analyses. The registry record does not report a multiplicity strategy, endpoint hierarchy, or detailed statistical analysis plan. Since no analyses were conducted or reported, there are no findings for which the effects of multiplicity adjustment can be evaluated.
The registry states that no participants received treatment and that no data were collected or evaluated. It does not report missing-data methods, rules for incomplete visits, or an approach to handling withdrawals. In general, these choices matter when outcome measurements are absent for some participants, because the assumptions used to handle missing observations can affect estimates and uncertainty. In this terminated study, the central issue is not a reported pattern of incomplete follow-up: there are no collected study outcomes to analyze. The record does not support claims about the amount or causes of missing data.
Analysis populations are also not reported. A completed trial may define populations according to randomized assignment, treatment received, or availability of particular measurements, depending on its prespecified analysis plan. Those definitions cannot be inferred from the planned randomized design. The registry’s enrollment entry does not identify a treated, randomized, or analyzed population, especially given its explicit statement that no participants received treatment. The record provides no basis for an intention-to-treat analysis, a per-protocol analysis, or a biomarker-specific analysis population.
11. What the Result Does, and Does Not, Mean
The record establishes that a Phase 2 study of ASN51 in adults with early Alzheimer’s disease was planned and then terminated. It identifies the intended randomized, double-blind, placebo-controlled, parallel-group design, the planned ASN51 dose groups and placebo comparator, the primary adverse-event endpoint, and a set of secondary biological and pharmacokinetic outcomes. It also states that termination followed a strategic decision by the sponsor.
It does not establish whether ASN51 changed a biomarker, affected a clinical measure, or produced adverse events. The registry explicitly says that no participants received treatment and no data were collected or evaluated. The absence of reported outcome data is not a finding of no effect, and the adverse-event entries are not evidence that treatment was event-free. There is no observed comparison from which to estimate benefit, harm, or uncertainty.
In general, a randomized trial can support a treatment comparison when participants are assigned, outcomes are measured, and the analysis is reported with enough detail to interpret estimates and their precision. A design description alone cannot supply those results. Likewise, a planned endpoint indicates what investigators intended to measure, not what happened to participants.
The registry’s enrollment entry of 123 should be read as a record field, not as the number of participants who completed treatment or contributed outcomes. The record separately states that no participants received treatment. It does not report a treatment-specific denominator, follow-up observations, or an analysis population.
The most defensible interpretation is therefore limited: this record documents a terminated study and its intended scientific questions, but it offers no clinical or statistical evidence about ASN51’s effects. It cannot support a conclusion for or against the intervention.
12. Why This Trial Matters Statistically
This trial matters statistically because it illustrates the distinction between a study design and evidence from a completed analysis. Randomization, masking, a placebo comparator, and specified outcomes can strengthen a planned clinical study, but those features cannot generate an effect estimate without treatment exposure and outcome data. For this record, the intended comparison remains unanswered.
The distinction is especially important for safety outcomes. A primary endpoint that counts participants with adverse events requires observation during exposure and follow-up. With no participants treated and no data collected, the record cannot establish an event rate or compare ASN51 with placebo. Recorded zero entries should not be interpreted as evidence that adverse events did not occur under treatment.
The planned biomarker and pharmacokinetic outcomes also show why a broad endpoint list is not equivalent to a results dataset. Cerebrospinal fluid and plasma tau measurements, imaging signal, and drug concentrations could have addressed different biological or exposure questions. Without measurements, none can be used to characterize biological response or connect exposure with clinical outcomes.
Statistically, the record reinforces why estimates, uncertainty intervals, and analysis choices matter. A proposed design and a registry enrollment entry do not reveal precision, treatment effects, or the population actually analyzed. The registry’s explicit termination and no-data statements should guide interpretation more than the mere presence of planned groups and outcomes. What can be learned is the study’s intended scope and why no efficacy or safety inference is available—not whether ASN51 had a particular effect.
13. 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 is that the study was terminated before treatment began. The registry reports that no participants received treatment and that no data were collected or evaluated. This prevents estimation of adverse-event frequency, biomarker changes, pharmacokinetic measures, or preliminary clinical efficacy. It also prevents assessment of randomization, masking, follow-up, and outcome completeness as implemented.
The record gives a planned enrollment of 123, but it does not describe how many people were screened, enrolled in practice, randomized, or observed. Because no participants received treatment, the enrollment field cannot be treated as an outcome-analysis denominator. No baseline characteristics or analysis populations are available to describe.
The record identifies the primary endpoint and its timeframe, but it does not provide results, effect estimates, uncertainty intervals, or hypothesis tests. It lists secondary outcomes but does not report their findings. A detailed statistical analysis plan, sample-size justification, multiplicity approach, missing-data methods, and analysis-population definitions are not reported in the registry record.
The reason given for termination is a strategic decision by the sponsor. The record does not provide additional detail about that decision, so its rationale should not be inferred. These limitations mean the record is informative about the intended design and the fact of termination, but it cannot answer the clinical or statistical questions the planned study was designed to address.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: Study of ASN51 in Adults With Early Alzheimer's Disease — NCT06677203.
- Registry record last updated 2025-06-29; status last verified 2025-06.
- Results first posted 2025-06-29.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
17. Record Summary
The registry record for NCT06677203 describes a Phase 2 randomized, double-blind, placebo-controlled, parallel-group study of ASN51 in adults with early Alzheimer’s disease. It planned oral, once-daily low-dose and high-dose ASN51 groups and a matching placebo group. The primary endpoint was the number of participants with adverse events from first dose through the end of the study, up to Week 28. Secondary outcomes included tau-related biomarker measures, tau positron emission tomography signal, and ASN51 pharmacokinetic measures.
The study started on 2024-10-16, with a listed primary completion date of 2024-11-08, and is recorded as TERMINATED. The stated reason was a strategic decision by the sponsor. The registry says no participants received treatment and no data were collected or evaluated. Although the enrollment field lists 123, the record contains no analyzed treatment outcomes. It therefore describes a planned trial and its termination, not evidence about ASN51’s safety, biological effects, or clinical efficacy.