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 A Phase 1 Study of MP-424, Peginterferon Alfa 2b, and Ribavirin in Hepatitis C (NCT00630058), a randomized phase 1 study. The primary outcome is Cmax (Maximum Observed Concentration in Plasma) of MP-424.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00630058 |
| Phase | Phase 1 |
| Condition | Hepatitis C |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 20 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Tanabe Pharma Corporation |
| Results posted | Yes |
2. Clinical Question
Population
Patients with genotype 1b hepatitis C are identified in the official title. The brief summary describes patients with chronic hepatitis C. Further eligibility criteria and participant characteristics are not reported in the registry record.
Intervention
One arm received MP-424 at the high dose with peginterferon alfa 2b and ribavirin. The other received MP-424 at the low dose with the same named background medicines. The specific doses and treatment details are not reported in the registry record.
Comparator
The comparison is between the high- and low-dose MP-424 regimens. Both arms are described as combinations with peginterferon alfa 2b and ribavirin; the record does not describe a placebo or a no-treatment group.
Primary question
The named primary endpoint is Cmax, the maximum observed concentration of MP-424 in plasma. The registry record does not report numerical Cmax results, so the size or precision of the difference between the arms cannot be assessed from the recorded primary endpoint information.
In statistical terms, the comparison asks whether the observed peak plasma concentrations differed between the two randomized regimens. Cmax is a pharmacokinetic measure: it describes the highest observed concentration over the measurement schedule, rather than a clinical outcome or a measure of the total amount of drug exposure. The registry record also describes safety, pharmacokinetics, HCV RNA kinetics, and other viral characteristics as study interests. It lists an antiviral-effects outcome using the term TVR, while the intervention names identify MP-424; the relationship between those terms is not explained in the record.
3. Trial Design
This was a Phase I, randomized, open-label, parallel, two-arm study. The registry lists an enrollment of 20. Group A is named MP-424 High and Group B MP-424 Low. Each group has 10 participants listed at risk in the adverse-event information. The registry does not describe the randomization procedure, the specific MP-424 doses, or the basis for selecting those doses.
The two groups received MP-424 with peginterferon alfa 2b and ribavirin. No placebo or untreated comparison group is listed. Because the study was open-label, masking was not used. The registry does not report whether laboratory measurement or outcome assessment was blinded. In general, random allocation can make treatment groups more comparable on average, but the record does not provide enough information to assess how the allocation was generated or concealed.
The study start is recorded as 2008-04, and primary completion as 2009-03. Its status is completed. The sponsor is Tanabe Pharma Corporation. The study summary describes assessments of safety, pharmacokinetics, HCV RNA kinetics, and other viral characteristics after administration of the two MP-424 arms with the background medicines.
The primary endpoint is Cmax, with data collection described from Day1 to Day85. Concentration measurements were scheduled before the first dose in the morning and at 1, 2.5, 4, 6, 8, 12, 16 and 24 h after the first dose on days 1, 14 and 85. Predose data were also collected at Day3, Day8, Day29, Day43 and Day57. The registry record does not state the analysis population, the treatment duration, or the handling of participants who did not complete all scheduled measurements.
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 | Group A (MP-424 High) | Group B (MP-424 Low) |
|---|---|---|
| STARTED | 10 | 10 |
| COMPLETED | 6 | 6 |
| NOT COMPLETED | 4 | 4 |
Reasons for not completing this period:
| Reason | Group A (MP-424 High) | Group B (MP-424 Low) |
|---|---|---|
| Adverse Event | 1 | 1 |
| Withdrawal by Subject | 0 | 1 |
| stopping criteria | 3 | 2 |
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 | Group A (MP-424 High) | Group B (MP-424 Low) | Total |
|---|---|---|---|---|
| Participants analysed | 10 | 10 | 20 | |
| Age, Continuous | years | 50.1 (SD 6.8) | 54.3 (SD 8.5) | 52.2 (SD 7.8) |
| Sex: Female, Male: Female | Participants | 4 | 6 | 10 |
| Sex: Female, Male: Male | Participants | 6 | 4 | 10 |
6. Primary Endpoint
The registry lists the primary outcome as Cmax (Maximum Observed Concentration in Plasma) of MP-424, measured over Data were collected at Day1 to Day85.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | μg/mL |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is Cmax, defined in the registry record as the maximum observed concentration of MP-424 in plasma. It is measured in μg/mL and described as a mean with standard deviation. The measurement schedule includes samples around dosing on days 1, 14 and 85, as well as predose collections on other listed days. The record does not specify whether the reported Cmax was to be selected separately for each measurement day or summarized across the schedule.
As a general pharmacokinetic concept, Cmax describes peak concentration: the highest concentration observed under the specified sampling schedule. It can be used to characterize peak drug exposure and to compare concentration patterns between regimens. The result depends on when samples are collected, because a peak between scheduled measurements may not be observed. The registry gives a detailed sampling schedule, but it does not report the numerical Cmax estimates or their variability.
Cmax does not, by itself, describe the full concentration-time profile, total exposure, viral response, or clinical outcome. Other measures may address different aspects of pharmacokinetics, but their definitions and numerical results are not reported in the registry record. The record also does not state a target concentration or a threshold for interpreting Cmax. Therefore, the endpoint identifies the type of measurement planned, but the posted primary endpoint information does not establish the observed concentration pattern or the precision of an arm-to-arm comparison.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a randomized comparison of high- and low-dose MP-424, each combined with peginterferon alfa 2b and ribavirin. It names Cmax as the primary endpoint, but numerical Cmax results are not reported in the registry record. Without arm-level estimates and measures of uncertainty, the magnitude, direction, and precision of the primary comparison cannot be assessed from that endpoint information.
The record lists six outcome measures and no analyses. It does not report a primary endpoint estimate, a confidence interval, a p-value, or an adjusted comparison. The endpoint description supplies the measurement unit and the mean-and-standard-deviation summary format, but not the resulting means or standard deviations. Consequently, no conclusion about whether the observed Cmax values were similar or different can be drawn from the available primary endpoint details.
The adverse-event information does contain arm-level counts. For serious adverse events, each group has 2 affected participants among 10 at risk. The registry lists Anaemia, Appetite disorders, Dizziness, Vertigo, and Drug eruption among the top serious terms, each at 10.0%. The record does not specify which group or groups contributed each listed term, nor does it provide event-level detail in the registry record recorded. Deaths are not reported in the registry record.
These safety counts are descriptive. They do not establish a comparative treatment effect, particularly without further information about event definitions, timing, severity, exposure, and participant-level overlap. The other-adverse-event fields list 10 affected participants among 10 at risk in each group. Those fields do not provide a basis for interpreting the number, type, or severity of individual events.
The registry’s study summary states that safety, pharmacokinetics, HCV RNA kinetics, and other viral characteristics were assessed. A secondary outcome refers to assessment of antiviral effects by measuring plasma HCV RNA levels, but numerical viral-response results are not reported in the registry record. The record also does not provide enough information to connect the secondary outcome’s use of “TVR” with the named MP-424 interventions.
Overall, the record identifies the design, treatment arms, endpoint, sampling schedule, and some adverse-event counts. It does not report the numerical primary outcome results or enough analysis detail to judge the uncertainty of an efficacy or pharmacokinetic comparison. The study description therefore supports a description of what was assessed, not a quantitative conclusion about the primary comparison.
9. Statistical Methods Explained
The registry describes a randomized, open-label, parallel comparison. It names the primary endpoint and its summary format, but does not report numerical endpoint estimates or an analysis plan. The explanations below describe general statistical ideas that are relevant to this design; they should not be read as methods confirmed to have been used in this study.
What does randomization contribute?
In general, randomization assigns participants to treatment groups by chance. Its purpose is to reduce systematic differences between groups at the start of a study, including differences that may not have been measured. In a small study, randomization does not guarantee that every characteristic will be balanced. The registry record does not describe the sequence-generation method, allocation concealment, or any stratification factors, so those details cannot be assessed.
A parallel design keeps participants in their assigned group rather than having each participant receive both regimens in sequence. This allows a between-group comparison. The record identifies two groups but does not report the analysis population or whether the primary analysis followed randomized assignment. The exact analysis population is therefore not reported in the registry record.
What does open-label mean for interpretation?
Open-label means the study was not masked. In general, knowledge of assigned treatment can influence participant expectations, treatment decisions, reporting, and some assessments. The extent of such influence depends on the outcome and the study procedures. Plasma concentration is a laboratory measurement, but the record does not state whether laboratory personnel were blinded to assignment or describe quality-control procedures. The practical effect of the open-label design on the primary measurement cannot be determined from the record.
How should a mean and standard deviation be read?
The registry identifies the primary endpoint as a continuous measure summarized by a mean and standard deviation. In general, a mean describes the average value in a group, while the standard deviation describes the spread of individual values around that group’s mean. The standard deviation is not the same as the uncertainty in the estimated mean or the uncertainty in the difference between group means. A confidence interval for a mean or for a between-group contrast would address estimation precision, but such intervals are not reported in the registry record.
Pharmacokinetic measurements can be distributed unevenly, and a small number of high values may influence a mean. General statistical practice may consider the distribution of the data and whether a transformation or alternative summary is appropriate. The registry record does not report distributional checks, transformations, covariate adjustment, or the exact comparison procedure. It is therefore not possible to determine how these issues were handled.
Why does the sampling schedule matter?
Cmax is the maximum observed concentration, so it depends on the timing of measurements. In general, more frequent sampling around a concentration peak makes it more likely that the observed maximum will be close to the underlying peak. The record specifies measurements before dosing and at several post-dose times on days 1, 14 and 85, with additional predose measurements on other days. It does not state whether Cmax was calculated from measured concentrations alone, whether any interpolation was used, or how missing samples were handled.
Sampling on multiple days may allow evaluation of concentration patterns over time, but the primary endpoint description does not clarify whether the analysis treated each day separately or selected a particular day for the arm comparison. That detail is not reported in the registry record. The endpoint information also does not describe additional pharmacokinetic parameters or their analysis.
What does a confidence interval add?
In general, a confidence interval communicates the uncertainty around an estimate under the assumptions of the statistical method. A narrow interval indicates greater precision than a wide interval, although interpretation also depends on the scale and the question being asked. A confidence interval for a difference between arms would help distinguish a relatively precise estimate from one compatible with a broad range of values. No such interval is reported for the primary endpoint in the registry record, so its precision cannot be assessed.
A p-value, in general, summarizes how incompatible the observed data are with a specified null model, under the assumptions of the test. It is not a measure of the size or importance of an effect. The registry record does not report a p-value or a test for the primary endpoint. No significance claim can be evaluated from the primary endpoint information.
How should planning calculations be understood?
The registry’s planning assumptions describe an illustration based on an observed effect, a two-sided significance level of 0.05, equal allocation, and a normal approximation. Such calculations are planning illustrations, not observed power. In general, a planning calculation asks how many participants per arm might be needed under stated assumptions about the effect to detect and the variability. It does not show that a trial had a particular probability of detecting an effect after the data were collected.
The record does not report the trial’s original sample-size justification, target effect, or protocol-level planning assumptions. It also does not provide numerical primary endpoint results in the information recorded. A planning illustration based on an observed effect should therefore be kept distinct from the trial’s design rationale and from evidence about the precision of its actual estimates.
What is not described?
The registry record does not report a detailed statistical analysis plan, the method used to compare groups, adjustment for covariates, treatment of repeated measurements, missing-data methods, or a defined analysis population. It lists six outcome measures and no analyses. Those omissions limit evaluation of how the collected measurements were converted into reported estimates. General statistical concepts can clarify what an analysis might address, but they cannot establish which methods this study used.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists six outcome measures and describes several domains of interest, including safety, pharmacokinetics, HCV RNA kinetics, and other viral characteristics. The primary endpoint description includes measurements on multiple days and at multiple times around dosing. When a study evaluates several outcomes, time points, or comparisons, the chance of at least one apparently unusual result can increase if each is tested separately. In general, a prespecified hierarchy or multiplicity adjustment can help control that issue. The registry record does not report a multiplicity strategy, endpoint hierarchy beyond naming Cmax as primary, or a statistical plan for selecting among time points.
The record says there are no analyses listed. It does not report an analysis population, an intention-to-treat or per-protocol definition, or rules for excluding observations. It also does not describe missing-data methods, the extent of missing measurements, or whether any participant failed to complete scheduled sampling. These details are not reported in the registry record.
For a pharmacokinetic endpoint, missing samples can affect whether the maximum observed concentration is captured. As a general point, a missed measurement near the peak could have a different consequence from a missed measurement at another time. The registry provides a collection schedule but does not explain how incomplete profiles were handled or whether the primary measure required a complete profile.
Without details on multiplicity, missingness, and analysis populations, it is difficult to assess whether reported estimates would represent all randomized participants or a selected subset, or how multiple endpoint assessments were interpreted. Since numerical primary endpoint results and analyses are not reported in the registry record, those questions cannot be resolved from the recorded information.
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 |
|---|---|---|---|
| Group A (MP-424 High) | 2 | 10 | 20.0% |
| Group B (MP-424 Low) | 2 | 10 | 20.0% |
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 |
|---|---|
| Group A (MP-424 High) | 10 of 10 |
| Group B (MP-424 Low) | 10 of 10 |
Most frequent serious adverse event terms
| Event term | Organ system | Group A (MP-424 High) | Group B (MP-424 Low) |
|---|---|---|---|
| Anaemia | Blood and lymphatic system disorders | 1 of 10 | 1 of 10 |
| Appetite disorders | Metabolism and nutrition disorders | 0 of 10 | 1 of 10 |
| Dizziness | Nervous system disorders | 0 of 10 | 1 of 10 |
| Vertigo | Ear and labyrinth disorders | 1 of 10 | 0 of 10 |
| Drug eruption | Skin and subcutaneous tissue disorders | 0 of 10 | 1 of 10 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Group A (MP-424 High) | Group B (MP-424 Low) |
|---|---|---|---|
| Platelet count decreased | Investigations | 10 of 10 | 10 of 10 |
| White blood cell count decreased | Investigations | 9 of 10 | 10 of 10 |
| Anaemia | Blood and lymphatic system disorders | 9 of 10 | 8 of 10 |
| Rash | Skin and subcutaneous tissue disorders | 7 of 10 | 7 of 10 |
| Pyrexia | General disorders | 6 of 10 | 8 of 10 |
| Malaise | General disorders | 6 of 10 | 5 of 10 |
| Blood triglycerides increased | Investigations | 6 of 10 | 5 of 10 |
| Headache | Nervous system disorders | 3 of 10 | 7 of 10 |
| Blood lactate dehydrogenase increased | Investigations | 3 of 10 | 7 of 10 |
| Nausea | Gastrointestinal disorders | 3 of 10 | 5 of 10 |
Serious events with the highest arm-level rate: anaemia (10.0%), appetite disorders (10.0%), dizziness (10.0%), vertigo (10.0%), drug eruption (10.0%).
The registry lists 2 participants with serious adverse events among 10 at risk in Group A (MP-424 High) and 2 among 10 at risk in Group B (MP-424 Low). These are counts of affected participants as recorded, not a complete account of event frequency or severity. The record does not report deaths.
The listed top serious terms are Anaemia, Appetite disorders, Dizziness, Vertigo, and Drug eruption, each at 10.0%. The registry record does not specify the group attribution for each term or provide enough detail to determine whether a participant had more than one listed term. The percentages should therefore be read as recorded term-level summaries, not as evidence that the same proportion occurred in each arm.
The other-adverse-event fields list 10 affected among 10 at risk in each group. These fields do not identify the event types or severity in the information recorded. Serious-event counts and other-adverse-event counts describe different categories in the registry; they should not be combined or treated as interchangeable. Without additional detail on definitions, timing, duration, exposure, and participant overlap, these figures support only a limited descriptive reading and do not establish a comparative safety effect.
12. What the Result Does, and Does Not, Mean
The record establishes that a randomized, open-label, two-arm Phase I study compared high- and low-dose MP-424 in combination with peginterferon alfa 2b and ribavirin. It identifies Cmax as the primary endpoint and describes the concentration sampling schedule. These details explain the comparison the study set out to make, but they do not provide the numerical primary endpoint findings.
Without arm-level Cmax estimates and measures of uncertainty, the record cannot show how large or precise the observed difference was. It also does not support a conclusion about viral response from the secondary outcome description, which gives no numerical HCV RNA results. The listed adverse-event counts are descriptive and do not, on their own, establish whether one regimen had a different safety profile.
In general, a Phase I pharmacokinetic comparison can characterize concentrations under specified dosing and sampling conditions. Cmax is only one aspect of exposure, and the record does not state a threshold for interpreting it or provide other pharmacokinetic results. It is not a direct measure of clinical benefit. The registry’s broad study aims include safety and viral characteristics, but those aims should not be confused with results.
The registry record also does not report the detailed statistical plan, analysis population, handling of missing observations, or the rationale for the sample size. These omissions prevent a full assessment of the methods and the certainty of any treatment comparison. The appropriate interpretation is therefore bounded: the study design and intended endpoint are identifiable, some safety counts are recorded, and the primary numerical result and its precision are not reported in the registry record.
13. Why This Trial Matters Statistically
Statistically, this trial illustrates the difference between knowing a study’s design and knowing its results. The record identifies randomized assignment, an open-label parallel structure, two MP-424 dose groups, and a continuous pharmacokinetic endpoint. It also gives a detailed collection schedule. Those features allow a reader to understand what was intended to be compared and how concentrations were to be observed.
The missing numerical Cmax estimates are consequential for interpretation. Naming a primary endpoint does not establish the direction, size, or precision of a group difference. A mean and standard deviation are identified as the summary format, but the actual summaries are not reported in the registry record. Without them, the primary comparison cannot be reconstructed or evaluated quantitatively.
The study also highlights why endpoint timing and analysis choices matter for pharmacokinetic measures. Cmax depends on observed concentration values and their sampling times. The record makes the schedule visible, while leaving the calculation details and handling of incomplete profiles unspecified. This is a reminder that an endpoint definition and a measurement schedule do not fully describe an analysis.
Finally, the safety information demonstrates the limits of isolated counts. Affected-participant counts and term-level percentages can describe what was recorded, but group attribution and event detail are incomplete. The design and record are useful for framing the questions, while the available statistical information does not resolve them. Recognizing that distinction is central to responsible interpretation of registry data.
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 principal limitation for interpreting the primary endpoint is that numerical Cmax results are not reported in the registry record. The record identifies the endpoint, unit, summary type, and sampling schedule, but does not provide group means, standard deviations, or an estimated between-group contrast. Precision cannot be assessed without uncertainty estimates.
Several analysis details are also absent. The registry does not report the randomization method, allocation concealment, a detailed statistical plan, the analysis population, or the method used to compare groups. It does not explain how repeated measurements were handled, how Cmax was derived from the observed profile, or how missing samples were treated. Although the study is described as open-label, blinding of laboratory or endpoint assessment is not reported.
The record lists six outcome measures and no analyses. It does not describe a multiplicity approach, a primary analysis time point, or a hierarchy for the other outcomes. Numerical results for HCV RNA or other viral characteristics are not reported in the registry information. The secondary outcome uses the term TVR, while the intervention names identify MP-424; the record does not explain this terminology.
For safety, the registry gives affected-participant counts and a short list of serious terms, but does not report group attribution for each term, event-level detail, or deaths. The other-adverse-event fields do not identify event types in the information recorded. The registry also does not report detailed participant characteristics, eligibility criteria, or treatment doses. These limitations constrain both the descriptive interpretation and the assessment of how broadly the findings might apply.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Phase 1 Study of MP-424, Peginterferon Alfa 2b, and Ribavirin in Hepatitis C — NCT00630058.
- Registry record last updated 2026-01-06; status last verified 2025-12.
- Results first posted 2013-01-18.
- 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.
18. Record Summary
NCT00630058 is recorded as a completed Phase I, randomized, open-label, parallel, two-arm study sponsored by Tanabe Pharma Corporation. Its enrollment is listed as 20. The study compared high- and low-dose MP-424, each in combination with peginterferon alfa 2b and ribavirin, in patients described as having genotype 1b hepatitis C.
The primary endpoint is Cmax of MP-424 in plasma, summarized as a mean with standard deviation and measured in μg/mL. The registry describes collection from Day1 to Day85, with scheduled post-dose and predose sampling. Numerical primary endpoint results and analyses are not reported in the registry record.
The adverse-event information lists 2 serious-event-affected participants among 10 at risk in each group. It also lists five serious terms at 10.0% each. The record does not provide enough detail to interpret those terms by group. Its stated study interests include safety, pharmacokinetics, HCV RNA kinetics, and other viral characteristics.