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 Study of Respiratory Muscle Strength in Patients With Late-onset Pompe Disease (LOPD) (NCT02191917), a registered phase not stated study. The primary outcome is Maximal Inspiratory Pressure (MIP).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02191917 |
| Phase | Phase not stated |
| Condition | Late-onset Pompe Disease |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 8 |
| Arms in the primary outcome | n/a |
| Lead sponsor | BioMarin Pharmaceutical |
| Results posted | Yes |
2. Clinical Question
Population
People with late-onset Pompe disease (LOPD). The registry lists enrollment of 8 participants. The primary-outcome population is defined as the Full Analysis Set (FAS), including enrolled subjects with at least one study assessment; the number meeting that definition is not reported in the registry record.
Intervention
The listed intervention is measurement of respiratory muscle strength using different techniques. The study summary also describes participants as treated or not treated with BMN 701, but the record does not provide detailed arm descriptions or explain how treatment status was determined.
Comparator
The summary refers to treated and untreated participants, but allocation is not stated. The registry record cautions that the arms are not a like-for-like control comparison. The comparator therefore cannot be interpreted as a randomized control group from the information recorded.
Primary question
The primary outcome is maximal inspiratory pressure (MIP), measured in cm H2O. The listed timeframe is Baseline, Week 28, and the outcome description concerns change in MIP. Numerical outcome estimates for these time points are not reported in the registry record.
3. Trial Design
The registry identifies this as Study 701-201, a study of respiratory muscle strength in patients with late-onset Pompe disease. Its listed intervention is a procedure: respiratory muscle strength measurements by different techniques. Maximal inspiratory pressure (MIP) is the primary outcome, and maximal expiratory pressure (MEP) is listed as a secondary outcome. The record also states that there are 2 outcome measures.
The brief summary describes assessment initially and again after 24 weeks in subjects treated or not treated with BMN 701. Separately, the primary outcome timeframe is recorded as Baseline, Week 28. These are the time descriptions in the registry record; further detail reconciling them is not reported. The arm description field does not supply additional information about the groups.
Enrollment is listed as 8. The study started on 2014-10-21, primary completion is listed as 2016-06-22, and the status is TERMINATED. The registry record does not state the reason for termination. Allocation is not stated, and the record cautions that the arms are not a like-for-like control comparison. Details about assignment procedures, masking, or other design features are not reported in the registry record.
The record includes a sample-size planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It is explicitly a planning illustration rather than the trial’s own design justification. The registry record does not report the original sample-size rationale. No numerical outcome analysis estimates are recorded, so the illustration should not be read as evidence about the precision or results observed in this study.
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 | Overall |
|---|---|
| STARTED | 8 |
| COMPLETED | 7 |
| NOT COMPLETED | 1 |
Analysis population for the primary outcome, as defined in the registry: Full Analysis Set (FAS) population includes all enrolled subjects who have at least one study assessment.
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 | Overall |
|---|---|---|
| Participants analysed | 8 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 8 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 2 |
| Sex: Female, Male: Male | Participants | 6 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 8 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race/Ethnicity, Customized: American Indian or Alaska Native | Participants | 0 |
| Race/Ethnicity, Customized: Asian | Participants | 0 |
| Race/Ethnicity, Customized: Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race/Ethnicity, Customized: Black or African American | Participants | 0 |
| Race/Ethnicity, Customized: White | Participants | 8 |
| Race/Ethnicity, Customized: Other | Participants | 0 |
| Region of Enrollment: United Kingdom | Participants | 7 |
| Region of Enrollment: United States | Participants | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Maximal Inspiratory Pressure (MIP), measured over Baseline, Week 28.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | cm H2O |
| Endpoint classification | Continuous Endpoint |
Maximal inspiratory pressure (MIP) is a measure of the pressure generated during an inspiratory effort. The registry records the unit as cm H2O and describes the endpoint as a pulmonary measure of change in MIP. The specified timeframe is Baseline, Week 28. These details identify what was intended to be assessed, but the registry record does not report numerical MIP values or a change estimate.
As a general statistical explanation, a continuous measurement such as pressure can be summarized by its mean to describe the average in a defined group. The standard deviation describes how much individual measurements vary around that mean. A change endpoint compares measurements across specified time points; interpreting such a change depends on knowing the actual values, the analysis population, and the method used to handle participants without measurements at every time point.
MIP is relevant to a study focused on respiratory muscle strength because it quantifies an aspect of inspiratory pressure. That general rationale does not establish what happened to MIP in this study. Without posted estimates, variability, or uncertainty intervals, the direction and precision of any change cannot be assessed from the registry record. The secondary outcome, MEP, concerns maximal expiratory pressure, but its numerical results are also not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies MIP as the primary outcome and gives its unit, summary parameter, dispersion measure, and assessment timeframe. It specifies a mean, with standard deviation, for the Full Analysis Set population. This is an outcome definition, not a result. Numerical group means, changes from baseline, standard deviations, confidence intervals, and significance tests are not reported in the registry record. The record lists no analysis records.
Consequently, the posted information does not establish whether MIP increased, decreased, or remained similar over time. It also does not show how much individual measurements varied or how precisely a group-level change was estimated. Without those quantities, there is no basis for describing the magnitude or statistical uncertainty of an outcome effect. The same limitation applies to MEP, which is listed as a secondary outcome but has no numerical result in the record.
The study summary refers to participants treated or not treated with BMN 701. However, allocation is not stated, and the registry record cautions that the arms are not a like-for-like control comparison. Any apparent difference between such groups, if reported elsewhere, could not be treated as a randomized treatment contrast on the basis of this record. The posted registry information does not give arm-specific outcome estimates in any case.
The enrollment of 8 describes the number recorded as enrolled, not necessarily the number included in the primary-outcome analysis. The FAS definition requires at least one study assessment, but the number meeting that criterion is not reported in the registry record. The extent of missing outcome data and its handling are also not reported. Thus, the stated analysis population cannot be used to infer how many MIP observations contributed to an estimate.
The study status is TERMINATED, but the reason is not reported in the registry record. Termination alone does not explain whether outcome collection was incomplete, whether an analysis was conducted outside the registry, or why results are absent from the record. The registry does not support a conclusion about treatment benefit, lack of benefit, or clinical importance. It supports only a description of the planned measurement and of the information recorded about the study.
9. Statistical Methods Explained
The registry record identifies the primary measure as MIP, a continuous outcome summarized by a mean and standard deviation. It describes change in MIP and specifies Baseline, Week 28 as the timeframe. No numerical results or analysis estimates are reported. The following concepts explain how such an analysis is generally read; they do not describe an analysis method confirmed for this study unless explicitly stated in the registry record.
What does a mean describe?
As a general explanation, a mean is the arithmetic average of the measurements in the analysis group. For a pressure measure, it gives a group-level description rather than the value for every participant. A mean change can describe the average difference between measurements at specified time points, but its meaning depends on which participants contributed data and how missing measurements were handled. The registry record gives no MIP means or change estimates, so no direction or magnitude can be interpreted.
What does the standard deviation describe?
The standard deviation describes the spread of individual measurements around their mean. It is not the same as a confidence interval and does not, by itself, quantify the precision of a mean estimate. A confidence interval is generally used to express uncertainty around an estimated quantity, such as a mean or difference. The registry record names standard deviation as the dispersion measure, but does not report its value or a confidence interval for MIP.
What can a comparison show?
In general, a comparison between groups is most interpretable when the groups are formed in a way that supports a fair contrast and when their outcome definitions and follow-up are comparable. Here, the summary mentions participants treated or not treated with BMN 701, but allocation is not stated. The registry record explicitly cautions that the arms are not a like-for-like control comparison. This limits causal interpretation: a difference between groups would not, on this information alone, isolate the effect of treatment from other differences between participants or groups.
The record does not report an adjusted or unadjusted comparison, a model specification, or a test statistic. It lists no analysis records. Therefore, methods such as covariate adjustment, repeated-measures modeling, or a particular approach to testing change should not be attributed to the study. Their use is not reported in the registry record.
How should the planning illustration be read?
The registry describes a sample-size planning illustration computed from the observed effect, not from the trial’s own documented design. Its stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. These are planning assumptions, not evidence that the study had a particular design or achieved a particular level of power. The numerical planning outputs are not, and the record does not report an original sample-size justification. A planning calculation cannot replace the observed estimate and its uncertainty.
As a general point, power is a property of a design under specified assumptions about the effect, variability, allocation, and analysis. It is not a retrospective measure of whether a result is trustworthy. A sample-size illustration based on an observed effect should not be described as observed power. The assumptions listed in the registry serve only to frame that planning illustration.
Why does variability matter?
Continuous outcomes can vary among participants, and the amount of variation affects how precisely group averages or changes can be estimated. In general, greater dispersion can make a mean less precise when other design features are held constant. The standard deviation is therefore informative alongside the mean. Because neither the MIP mean nor its standard deviation is reported, readers cannot judge the observed spread or estimate precision from this record.
Some statistical methods also account for over-dispersion, which occurs when variation is greater than a model assumes. That concept is most relevant to outcomes modeled as counts or rates, rather than being an analysis method established for this continuous pressure endpoint. No model details are reported, so there is no basis to say that an over-dispersion adjustment was needed or used in this study.
Overall, the record gives enough information to identify the primary endpoint’s type, unit, summary measure, and intended timeframe. It does not give enough information to reconstruct an outcome analysis. The distinction between a defined endpoint, a planning illustration, and an observed result is essential: only the first two are described in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The record lists 2 outcome measures: MIP as the primary outcome and MEP as a secondary outcome. Considering multiple outcomes can raise a multiplicity question because testing several outcomes may increase the chance of at least one apparently unusual result. As a general statistical principle, researchers may specify which outcome is primary and whether any adjustment or hierarchy will guide interpretation. The registry record identifies the primary outcome, but a multiplicity strategy or adjustment is not reported in the registry record.
No numerical analysis results or analysis records are listed. It is therefore not possible to determine which outcomes were analyzed, what tests were applied, or whether any multiplicity procedure was used. The registry record does not report interim analyses or a statistical analysis plan; their presence or absence beyond the information in the record cannot be inferred.
The primary-outcome population is the Full Analysis Set (FAS), defined as enrolled subjects with at least one study assessment. The number meeting this definition is not reported in the registry record. The enrollment of 8 should not be treated as the analysis denominator because the record does not state how many participants had an eligible assessment.
Missing-data handling is not reported in the registry record. The record does not explain whether participants lacking a later measurement were excluded from a change analysis, whether any values were imputed, or how incomplete follow-up was addressed. These choices can affect both the population represented by an estimate and its uncertainty. Without those details and the outcome data, the risk of bias related to missingness cannot be evaluated from the registry record.
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 |
|---|---|---|---|
| Overall | 0 | 8 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Overall | 0 of 8 |
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 |
|---|---|
| Overall | 1 of 8 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Overall |
|---|---|---|
| Post procedural haemorrhage | Injury, poisoning and procedural complications | 1 of 8 |
The overall safety figures list 8 at risk for serious adverse events, with 0 affected, and 8 at risk for other adverse events, with 1 affected. Deaths are listed as 0. The registry also lists no top serious adverse-event terms. These are the counts recorded; they are not measures of treatment effect and should not be interpreted as a comparison between randomized groups.
The record labels the group Overall. It does not provide further detail about the event definitions, observation periods, event severity beyond the serious-adverse-event category, or the relationship of events to treatment. The entries for those at risk do not establish the number with complete safety follow-up at every point, and the record does not describe how safety information was collected.
As a general statistical explanation, a count of affected participants describes recorded events in the specified group and observation context. A small observed count does not establish that an event cannot occur, and a zero count does not establish the absence of risk. The registry record’s safety figures should therefore be read as descriptive reporting, with the study’s limited enrollment and the missing contextual detail in mind.
12. What the Result Does, and Does Not, Mean
The registry record establishes that this study assessed respiratory muscle strength in people with late-onset Pompe disease and identified MIP as its primary outcome. It specifies the unit, summary parameter, dispersion measure, analysis-population definition, and a Baseline, Week 28 timeframe. The study summary also refers to measurements initially and after 24 weeks. These details describe the intended assessment, not its observed result.
The record does not report numerical MIP or MEP findings, estimates of change, confidence intervals, or statistical tests. It therefore cannot show the direction, size, or precision of any change. The absence of numerical outcome analyses in this record should not be turned into a claim that there was no change or that a treatment did or did not work.
The summary refers to participants treated or not treated with BMN 701, but allocation is not stated and the registry cautions that the arms are not a like-for-like control comparison. The record consequently does not support interpreting a group contrast as a randomized treatment effect. It also does not report the reason for termination, the completeness of outcome follow-up, or the handling of missing measurements.
As a general statistical distinction, a study’s planned question, its observed estimate, and the certainty around that estimate are separate pieces of information. The registry supplies the endpoint definition and some design context, but does not report the estimates or uncertainty needed to assess the observed MIP result. The safety counts are descriptive and do not resolve that gap. Conclusions should remain limited to what is recorded: a study of respiratory muscle measurements was conducted, while numerical outcome results and important analysis details are not reported in the registry record.
13. Why This Trial Matters Statistically
This study is statistically notable because it focuses on defining and measuring respiratory muscle strength, including an effort-dependent pressure outcome, in people with late-onset Pompe disease. MIP is named as the primary measure and MEP as a secondary measure. The record gives the unit and specifies a mean with standard deviation, helping readers understand what kind of outcome was intended to be summarized.
The record also illustrates why endpoint definitions alone are not enough for interpretation. A timeframe is listed, but numerical results, measures of uncertainty, and analysis records are absent. Without those, readers cannot determine whether the measurements changed, how variable they were, or how precisely any average change was estimated. The reported enrollment is small, but no further inference about precision should be made without actual estimates and their uncertainty.
Design context matters as well. The summary mentions treated and untreated participants, while allocation is not stated and the record warns that the arms are not a like-for-like control comparison. This is important when distinguishing descriptive changes from causal comparisons. A group contrast does not automatically establish a treatment effect, particularly when assignment procedures and analysis methods are not reported.
The study’s TERMINATED status and absence of numerical outcome analyses also emphasize the value of complete registry reporting. The reason for termination is not reported in the registry record, so the status does not explain why results are missing. In statistical terms, the record documents the question and some measurement plans, but leaves the results and key interpretive details unresolved. That distinction helps prevent readers from mistaking an endpoint description or planning illustration for evidence about an observed outcome.
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.
Several trial-specific limitations affect interpretation of the registry record. Enrollment is listed as 8, and the status is TERMINATED. The reason for termination is not reported in the registry record. The available information does not establish whether outcome collection was complete or why numerical analyses are absent.
The primary outcome is defined as change in MIP, with Baseline, Week 28 as the timeframe, while the brief summary describes an initial measurement and a repeat measurement after 24 weeks. The record does not explain how these time descriptions relate. It also does not provide the actual values at either time point, a change estimate, or a measure of uncertainty.
The FAS definition includes enrolled subjects with at least one study assessment, but the number meeting that definition is not reported in the registry record. The number contributing to each outcome or time point is also not reported. Missing-data handling, analysis methods, and any adjustment for multiplicity are not reported, limiting assessment of how the endpoint was analyzed.
The summary describes treated and untreated participants, but allocation is not stated, and the registry cautions that the arms are not a like-for-like control comparison. The arm description contains no additional detail. This prevents a treatment-group contrast from being interpreted as a randomized comparison using the registry information alone.
Finally, the record lists MEP as a secondary outcome but provides no numerical results for it, and no analysis records are listed. The safety counts are descriptive, with limited contextual information about observation and event collection. Together, these gaps mean that the record supports a description of the study’s stated measurements and design caveats, but not an assessment of outcome magnitude, precision, or treatment effect.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Study of Respiratory Muscle Strength in Patients With Late-onset Pompe Disease (LOPD) — NCT02191917.
- Registry record last updated 2023-01-09; status last verified 2022-04.
- Results first posted 2023-01-09.
- 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
This is Study 701-201, sponsored by BioMarin Pharmaceutical, with the title A Study of Respiratory Muscle Strength in Patients With Late-onset Pompe Disease (LOPD). The listed condition is late-onset Pompe disease. Enrollment is 8; the study started on 2014-10-21, primary completion is listed as 2016-06-22, and status is TERMINATED.
The intervention is respiratory muscle strength measurement by different techniques. MIP is the primary outcome, measured in cm H2O, with a mean and standard deviation specified and Baseline, Week 28 listed as the timeframe. MEP is a secondary outcome. Numerical outcome estimates and analysis records are not reported in the registry record.
The summary refers to participants treated or not treated with BMN 701. Allocation is not stated, and the registry cautions that the arms are not a like-for-like control comparison. The record defines the FAS as enrolled subjects with at least one study assessment, but does not report the number meeting that definition. It also does not report the reason for termination.