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 Efficacy and Safety Study to Evaluate MT-6548 in Hemodialysis Subjects Not Receiving ESAs With Anemia Associated With Chronic Kidney Disease in Japan (NCT03461146), a na phase 3 study. The primary outcome is Mean Hb Level of Week 20 and Week 24.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03461146 |
| Phase | Phase 3 |
| Condition | Anemia; Hemodialysis Dependent Chronic Kidney Disease |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 24 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Tanabe Pharma Corporation |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned hemodialysis subjects in Japan with anemia associated with chronic kidney disease who were not receiving ESAs. The registry lists 24 participants enrolled. The primary endpoint analysis population was described as subjects who had a hemoglobin measurement at least once after baseline; the number in that analysis population is not reported in the registry record.
Intervention
The intervention was MT-6548, listed as a drug. The study description says it was intended to evaluate hemoglobin correction and maintenance effects, as well as safety, in this population. The registry does not provide an arm description beyond identifying MT-6548 as the intervention.
Comparator
There was no concurrent comparator group in the registered design. The study is listed as single-group, with allocation recorded as not applicable and masking as none. As a result, the study does not provide a randomized comparison between MT-6548 and another treatment or a control condition.
Primary question
The primary outcome was the least-squares mean hemoglobin level at Week 20 and Week 24, with the timeframe listed as up to Week 24 and the unit as g/dL. This endpoint focuses on measured hemoglobin levels at those visits. The registry record does not report the estimated mean levels or their confidence interval, so the size and precision of the primary outcome cannot be assessed from the registered results.
3. Trial Design
The registry describes a Phase III, open-label study of MT-6548 in hemodialysis subjects with anemia associated with chronic kidney disease in Japan. It is listed as a single-group study, with allocation recorded as not applicable and masking as none. The registered enrollment was 24, and the study status is completed. The registry lists the study start as 2018-03-05 and primary completion as 2018-12-03.
All participants in the registered group received MT-6548; no separate control arm is listed. This structure is important when interpreting the endpoint: observed hemoglobin levels during the study can describe the participants' measurements, but the design does not provide a concurrent group for estimating what their outcomes would have been without MT-6548 or under another treatment. Changes over time therefore cannot be separated from other influences through a randomized between-group comparison.
The study was open-label, meaning masking was not used. The registry does not describe further procedures intended to limit the influence of awareness of treatment on care or measurement. It also does not report the dosing schedule, treatment duration beyond the endpoint timeframe, eligibility criteria in detail, or study procedures beyond the information in the record.
The registered primary endpoint was the mean hemoglobin level at Week 20 and Week 24, characterized as a least-squares mean with a 95% confidence interval. The analysis population was described as subjects with at least one hemoglobin measurement after baseline. The registry does not provide the number of participants included in that analysis or numerical endpoint estimates. Five outcome measures are listed, but detailed results for the other measures are not available in the registry record.
The record identifies Tanabe Pharma Corporation as the sponsor. It does not report a randomized allocation process or a like-for-like control comparison, so the study design primarily supports description of measurements and safety events in the enrolled group.
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 | MT-6548 |
|---|---|
| STARTED | 24 |
| COMPLETED | 21 |
| NOT COMPLETED | 3 |
Reasons for not completing this period:
| Reason | MT-6548 |
|---|---|
| Adverse Event | 2 |
| Physician Decision | 1 |
Analysis population for the primary outcome, as defined in the registry: This analysis was performed in subjects who measured Hb at least one visit after baseline.
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.
| Characteristic | Unit | MT-6548 |
|---|---|---|
| Participants analysed | 24 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 11 |
| Age, Categorical: >=65 years | Participants | 13 |
| Sex: Female, Male: Female | Participants | 5 |
| Sex: Female, Male: Male | Participants | 19 |
| Race/Ethnicity, Customized: Asian (Japanese) | Participants | 24 |
| Race/Ethnicity, Customized: Asian (Other) | Participants | 0 |
| Race/Ethnicity, Customized: Other | Participants | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Mean Hb Level of Week 20 and Week 24, measured over Up to Week 24.
| Element | Registry entry |
|---|---|
| Result type | Least Squares Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | g/dL |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the mean hemoglobin level at Week 20 and Week 24, measured in g/dL. Hemoglobin is a continuous measure, so each participant's value can be expressed numerically and group summaries can describe the distribution or average level. The registry specifies a least-squares mean, a model-based estimate that can account for terms included in a statistical model. The model terms used for this endpoint are not reported in the registry record.
Measuring hemoglobin at scheduled visits allows the study to characterize levels at later points in follow-up. The study's stated purpose includes evaluating hemoglobin correction and maintenance effects. Repeated assessment can therefore address whether the observed levels at the specified visits are consistent with the study's stated objective. However, the registry does not give a baseline comparison, the observed values at either visit, or an estimate of change from baseline. Those details cannot be inferred from the endpoint title.
The registered precision measure is a 95% confidence interval. In general, a confidence interval communicates uncertainty around an estimated quantity: narrower intervals indicate greater precision, while wider intervals indicate less precision. The actual interval limits for this endpoint are not reported in the registry record, so its precision cannot be assessed numerically. The analysis was specified for subjects with a hemoglobin measurement at least once after baseline; how missing measurements were handled is not reported.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the primary outcome and its intended analysis measure, but it does not report a numerical least-squares mean for Week 20 or Week 24. It also does not give the limits of the stated 95% confidence interval. Consequently, the posted record does not establish the level of hemoglobin observed at either visit or how precisely that level was estimated. A numerical interpretation of the primary endpoint is not possible from the registered results alone.
The study enrolled 24 participants and used a single-group, open-label design. These details describe the scope and structure of the evidence, not an endpoint result. Since no concurrent comparator group is listed, an observed level or change during follow-up would not by itself distinguish an effect of MT-6548 from other possible influences. The study can describe outcomes among the participants assessed, but it cannot supply a randomized treatment contrast.
The primary analysis population was defined by having at least one hemoglobin measurement after baseline. The registry does not state how many participants met this condition. Thus the analysis denominator and the extent to which it differs from the enrolled group are not reported. This matters for interpreting precision and for understanding whether the endpoint reflects all enrolled participants or a subset with available follow-up measurements.
The safety record lists 7 participants affected by serious adverse events among 24 at risk, 15 affected by other adverse events among 24 at risk, and 0 deaths. These are descriptive counts for the MT-6548 group. They do not establish that the intervention caused the events, nor do they provide a comparison with background event rates or a control group. The listed serious adverse event terms and their reported percentages offer further descriptions, but the record does not provide enough information to interpret causality, timing, duration, or clinical context.
Overall, the registry supplies a design description and some safety counts but not the numerical primary endpoint findings. Any conclusion about the magnitude or precision of hemoglobin levels at Week 20 and Week 24 would require results that are not reported in the registry record. The distinction between a study objective and a study result is essential: an endpoint's stated purpose does not indicate what was observed.
9. Statistical Methods Explained
The registered primary measure is continuous: hemoglobin is expressed in g/dL, and the outcome is described as a least-squares mean at Week 20 and Week 24. In general, a mean summarizes the central level of a numeric measure across participants. A least-squares mean is a model-based mean rather than necessarily the simple arithmetic average. It can be adjusted for variables or structure specified in a statistical model. The registry record does not state which model was used, which terms it contained, or how repeated measurements were represented. The label alone therefore does not reveal the exact adjustment or estimation procedure.
What does a confidence interval communicate?
The primary endpoint specifies a 95% confidence interval. In general, a confidence interval describes statistical uncertainty around an estimate under the assumptions of the analysis. It is not a range containing every participant's measurement, nor does it guarantee that the true value lies within the particular interval. A narrower interval generally indicates more precise estimation; a wider interval indicates less precision. Because the registry does not report the interval limits or the point estimates, the precision of the primary endpoint cannot be evaluated from this record.
Confidence intervals also depend on the analysis population, model, and assumptions. Here, the primary analysis population is described as subjects who measured hemoglobin at least once after baseline. The registry does not report how many subjects were included, whether further eligibility conditions applied, or how incomplete follow-up was handled. Those details matter because estimates based on different subsets or missing-data methods can have different interpretations.
Why does the single-group design matter?
In a randomized controlled design, a concurrent comparison group can help account for influences that affect both groups, while randomization supports comparability at the start of the study. This study is listed as single-group, with no comparator arm. Its measurements can describe participants receiving MT-6548, but they do not estimate a randomized contrast against another treatment or control. General changes over time, differences in participant circumstances, and other influences cannot be separated from treatment exposure using a concurrent randomized comparison in this design.
The study is also listed as open-label, with masking recorded as none. In general, lack of masking can affect behavior, care decisions, reporting, or assessment, depending on the outcome and procedures. Hemoglobin is a laboratory measure, but the registry record does not provide details about measurement procedures, central review, or safeguards against assessment differences. These concerns do not establish that bias occurred; they identify aspects of design that affect how results would be interpreted.
What is over-dispersion, and is it relevant?
Over-dispersion is a general issue in count-data analyses when observed variability exceeds what a chosen model assumes. It can make standard errors too small if not handled appropriately. The primary endpoint in this study is a continuous hemoglobin measure, not a count outcome, so over-dispersion is not the central issue for interpreting this endpoint. The registry does not identify a count model or a method for handling over-dispersion for other outcomes.
How should planning assumptions be understood?
Any sample-size calculations described for this study are planning illustrations based on an observed effect, not a reconstruction of the trial's original design rationale. The stated illustration assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the target effect is defined as a stated fraction of the observed effect. For time-to-event outcomes, such illustrations concern the total number of events, while other illustrations concern participants per arm. The registered trial itself is single-group, so these two-arm planning assumptions do not describe its allocation or observed design. The record does not report a sample-size justification, the effect targeted when the trial was planned, or interim analyses.
Such calculations, in general, explore what sample size might be needed under specified assumptions. They are not observed power and do not substitute for the actual estimate and its uncertainty. The assumptions depend on the effect used for planning, and a planning illustration tied to an observed effect is not evidence that the original study was designed around that effect.
What can the methods description establish?
The registry establishes the named endpoint, unit, summary measure, confidence level, timeframe, and a broad description of the analysis population. It does not provide the statistical model, handling of repeated measures, missing-data method, multiplicity approach, or detailed analysis population rules. These omissions prevent a full evaluation of the estimator and its assumptions. General explanations of least-squares means and confidence intervals clarify the labels, but they cannot fill in methods that the registry does not report.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists five outcome measures and identifies mean hemoglobin level at Week 20 and Week 24 as the primary endpoint. It does not report a multiplicity strategy, such as whether statistical testing across visits or outcomes was adjusted or how any testing sequence was specified. When several outcomes or time points are evaluated, multiplicity can affect the interpretation of statistical evidence because repeated testing may increase the chance of a nominally notable result. This is a general consideration; no adjustment or unadjusted testing result is described in the registry record.
The primary analysis population is described as subjects who had a hemoglobin measurement at least once after baseline. The number of subjects meeting that definition is not reported. The registry does not state how missing hemoglobin values were handled, whether participants without post-baseline measurements were excluded, or whether any sensitivity analyses assessed the effect of missing data. It also does not describe whether the analysis used all available measurements or a particular visit-specific rule.
The record does not give detailed definitions for an intention-to-treat, per-protocol, or safety population. The 24 participants at risk in the safety listings should not be assumed to be the same denominator used for the primary endpoint analysis, because the endpoint population has its own stated post-baseline measurement condition and its size is not reported.
Without the multiplicity plan, missing-data procedures, analysis population count, and endpoint estimates, the registry record does not permit a complete assessment of statistical uncertainty or robustness. These are not reasons to infer that an inappropriate method was used; they are unreported details that limit independent interpretation.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| MT-6548 | 7 | 24 | 29.2% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| MT-6548 | 0 of 24 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| MT-6548 | 15 of 24 |
Most frequent serious adverse event terms
| Event term | Organ system | MT-6548 |
|---|---|---|
| Duodenal ulcer haemorrhage | Gastrointestinal disorders | 1 of 24 |
| Pneumonia | Infections and infestations | 1 of 24 |
| Arteriovenous fistula occlusion | Injury, poisoning and procedural complications | 1 of 24 |
| Clavicle fracture | Injury, poisoning and procedural complications | 1 of 24 |
| Pelvic fracture | Injury, poisoning and procedural complications | 1 of 24 |
| Shunt stenosis | Injury, poisoning and procedural complications | 1 of 24 |
| Vascular access malfunction | Injury, poisoning and procedural complications | 1 of 24 |
| Aneurysm | Vascular disorders | 1 of 24 |
| Peripheral arterial occlusive disease | Vascular disorders | 1 of 24 |
Most frequent non-serious adverse event terms
| Event term | Organ system | MT-6548 |
|---|---|---|
| Nasopharyngitis | Infections and infestations | 5 of 24 |
| Shunt stenosis | Injury, poisoning and procedural complications | 5 of 24 |
| Diarrhoea | Gastrointestinal disorders | 4 of 24 |
| Skin abrasion | Injury, poisoning and procedural complications | 3 of 24 |
| Vomiting | Gastrointestinal disorders | 2 of 24 |
Serious events with the highest arm-level rate: duodenal ulcer haemorrhage (4.2%), pneumonia (4.2%), arteriovenous fistula occlusion (4.2%), clavicle fracture (4.2%), pelvic fracture (4.2%).
The registry lists 24 participants at risk for serious adverse events and 7 affected. For other adverse events, it lists 24 at risk and 15 affected. The death count is 0. These figures describe the MT-6548 group in the registry record; they are not comparative estimates because no control group is listed.
The serious adverse event terms listed are duodenal ulcer haemorrhage, pneumonia, arteriovenous fistula occlusion, clavicle fracture, pelvic fracture, and shunt stenosis. Each is reported as 4.2%. These percentages should be read as the registry's reported values, not as evidence about causation or comparative risk. The record does not provide event timing, severity details beyond the serious-event classification, duration, recurrence, relatedness assessment, or treatment discontinuation information.
Adverse-event counts are descriptive safety observations. They do not, on their own, show whether an event was caused by MT-6548, whether its frequency differs from what would occur in a comparable group, or how the study's monitoring procedures affected reporting. The small enrolled group also limits how much can be learned about uncommon events, but the registry does not provide a comparative estimate of event frequency. No medical conclusion should be drawn from these counts alone.
12. What the Result Does, and Does Not, Mean
The registry record describes a completed Phase III, open-label, single-group study of MT-6548 in hemodialysis subjects in Japan with anemia associated with chronic kidney disease who were not receiving ESAs. It identifies a primary endpoint based on mean hemoglobin levels at Week 20 and Week 24 and describes the analysis population as subjects with at least one post-baseline hemoglobin measurement. It also records safety counts for the intervention group.
Those design details explain what the study set out to measure and how the registered group was structured. They do not show the numerical result for the primary endpoint. The least-squares mean values and their 95% confidence interval limits are not reported in the registry record. It is therefore not possible to describe the measured hemoglobin level, the precision of its estimate, or the pattern between the endpoint visits using the registered information.
The single-group design also limits what any outcome could establish. Without a concurrent randomized comparator, the study does not estimate a treatment difference against another group. Even if numerical pre- and post-baseline values were available, a within-group pattern alone could not separate treatment-related change from other influences. The record does not state a baseline value or a change-from-baseline estimate for the primary endpoint.
The safety counts show that serious and other adverse events were recorded in the intervention group, and that the registered death count was 0. The counts and listed terms are descriptive. They do not establish causation, comparative safety, or the likelihood of an event in a broader population.
Accordingly, the registry record supports a description of the trial design, endpoint definition, and listed adverse events. It does not support a conclusion about the magnitude or precision of the primary hemoglobin outcome, nor a controlled comparison of treatment effects. The study objective and endpoint designation should not be mistaken for numerical evidence of an outcome.
13. Why This Trial Matters Statistically
This study is statistically informative as an example of the distinction between a registered endpoint and a reported result. The record names a continuous primary outcome, identifies its unit and planned summary, and specifies a confidence interval. Those details convey the intended form of analysis, but without the estimate and interval limits they do not communicate the outcome's magnitude or precision. A clearly defined endpoint is useful, while a numerical result is necessary for interpreting what was observed.
The single-group design also makes the estimand—the quantity a study aims to estimate—important. The registered endpoint concerns hemoglobin levels in participants receiving MT-6548 at specified visits. It is not a treatment contrast against a randomized control. Statistical summaries of a group can be useful for describing that group, but they answer a different question from a comparative trial.
The analysis population definition highlights another central issue: results depend on who contributes measurements. The record specifies at least one post-baseline hemoglobin measurement, yet does not report the size of this population or the missing-data approach. Without those details, readers cannot determine how much of the enrolled group informed the primary estimate or assess the influence of incomplete follow-up.
Safety counts likewise need context. Counts and listed event terms describe what was recorded in the group, but a single-group study cannot supply a randomized safety comparison. Statistical interpretation requires attention to denominators, event definitions, follow-up, and uncertainty, not just the number of affected participants.
Finally, planning illustrations should be kept distinct from evidence about the study's outcomes. Their assumptions can clarify how hypothetical sample-size requirements depend on a target effect and design, but they are not observed power and do not replace endpoint estimates. The record's limitations make transparent reporting especially important for readers seeking to understand the study's statistical evidence.
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 most consequential limitation for interpreting the primary result is that numerical hemoglobin estimates and confidence interval limits are not reported in the registry record. Although the endpoint is identified as a least-squares mean at Week 20 and Week 24, the outcome's magnitude and precision cannot be evaluated. The record also gives no baseline hemoglobin value or change-from-baseline estimate for the primary outcome.
The study is single-group and open-label, with no concurrent comparator. This means the design does not support a randomized between-group estimate, and it cannot isolate an observed time pattern from other influences. Masking was recorded as none. The registry does not report the detailed measurement procedures or other protections against potential assessment or performance effects.
The endpoint analysis population requires at least one post-baseline hemoglobin measurement, but its size is not reported. Missing-data handling, exclusions, adherence information, and sensitivity analyses are also not reported in the registry record. The model used for the least-squares mean, including any adjustment terms or repeated-measure structure, is not described.
The record lists five outcome measures but does not report a multiplicity strategy or detailed statistical testing plan. It does not describe a sample-size justification or interim analyses. These absences do not show that such methods were not used; they mean their use and implications cannot be assessed from the registry entry.
The safety information is also limited to group-level counts and listed serious adverse event terms. The record does not give timing, duration, relatedness, recurrence, or a comparator rate. With enrollment of 24, the available safety description is limited to the participants recorded in the study and cannot characterize uncommon events reliably. These constraints should be kept in view when interpreting the registry's descriptive findings.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Efficacy and Safety Study to Evaluate MT-6548 in Hemodialysis Subjects Not Receiving ESAs With Anemia Associated With Chronic Kidney Disease in Japan — NCT03461146.
- Registry record last updated 2026-04-06; status last verified 2026-03.
- Results first posted 2021-05-07.
- 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.
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18. Record Summary
NCT03461146 is a completed Phase III, open-label, single-group study sponsored by Tanabe Pharma Corporation. It enrolled 24 participants and evaluated MT-6548 in hemodialysis subjects in Japan with anemia associated with chronic kidney disease who were not receiving ESAs. The registered primary endpoint was the least-squares mean hemoglobin level at Week 20 and Week 24, in g/dL, with a 95% confidence interval. The analysis population was described as subjects with at least one hemoglobin measurement after baseline.
The registry lists 7 participants with serious adverse events and 15 with other adverse events, each among 24 at risk; deaths were 0. Numerical primary-endpoint estimates, confidence interval limits, detailed statistical methods, and missing-data procedures are not reported in the registry record. The single-group design does not include a concurrent randomized comparator.