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 to Assess the Efficacy and Safety of PT003, PT005, and PT001 in Subjects With Moderate to Very Severe COPD (NCT02343458), a randomized phase 3 study. The primary outcome is Change From Baseline in Morning Pre-dose Trough FEV1 at Week 24 of Treatment (US/China Approach).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02343458 |
| Phase | Phase 3 |
| Condition | Chronic Obstructive Pulmonary Disease |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 1756 |
| Arms in the primary outcome | 4 |
| Lead sponsor | Pearl Therapeutics, Inc. |
| Results posted | Yes |
2. Clinical Question
Population
People with moderate to very severe chronic obstructive pulmonary disease (COPD). The primary outcome population was the intention-to-treat (ITT) population: participants randomized to treatment who received at least 1 dose, analyzed according to their randomized assignment. The number analyzed depended on having available data.
Intervention
GFF MDI (PT003), containing glycopyrronium and formoterol fumarate, administered as 2 inhalations twice-daily. The registry also describes FF MDI (PT005), containing formoterol fumarate, and GP MDI (PT001), containing glycopyrronium, each administered as 2 inhalations twice-daily.
Comparator
Matching placebo MDI, administered as 2 inhalations twice-daily. The study included the three active inhalers and placebo in parallel groups.
Primary question
For the US/China approach, what was the change from baseline in morning pre-dose trough FEV1 at Week 24 of treatment in each group? The posted results give least-squares mean estimates and 95% confidence intervals for the arms. A direct numerical estimate of the difference between an active-treatment arm and placebo is not posted in the registry record.
FEV1 is forced expiratory volume in one second, a measure of how much air a person can forcefully exhale during the first second of the breathing test. The endpoint focuses on the morning measurement before dosing, rather than a measurement taken shortly after an inhalation. The primary comparison was intended to assess changes from each participant's baseline, with results reported for Week 24.
The clinical question is therefore specific to this measure, time point, and US/China approach. The registry record also lists secondary outcomes involving symptom scores, peak FEV1 change, and health status, with different regional approaches and time periods. Those additional endpoints do not change the definition of the primary endpoint.
3. Trial Design
This was a Phase 3, randomized, quadruple-masked, parallel-group study comparing GFF MDI (PT003), FF MDI (PT005), and GP MDI (PT001) with placebo MDI in people with moderate to very severe COPD. The official title describes chronic dosing for 24 weeks, placebo control, and a multicenter design. The registry lists enrollment as 1756 and status as completed.
The registry dates the study start to 2015-03-30 and primary completion to 2017-08-31. Each active treatment was delivered by metered dose inhaler as 2 inhalations twice-daily. The placebo inhaler was described as matching the active inhalers and was administered on the same schedule. The reported primary endpoint was assessed at Week 24.
Randomization assigns participants to study groups by chance, helping limit systematic differences between groups at the point of assignment. Masking is intended to reduce the influence of knowledge about treatment assignment on care, participant experience, and assessment. The record labels masking as quadruple, but which specific roles were masked is not reported in the registry record. The allocation ratio and details of the randomization procedure are not reported in the registry record.
The primary endpoint results use the ITT population defined in the registry as randomized participants who received at least 1 dose. Participants were analyzed according to their assigned treatment, and the analyzed number reflects those with available data. For the primary endpoint, the posted arm counts are 488 for GFF MDI, 413 for FF MDI, 412 for GP MDI, and 196 for placebo. These are the numbers analyzed for that endpoint, not a statement that every randomized participant contributed data at that time point.
The record does not report the planned sample-size justification, the intended allocation ratio, the detailed statistical analysis plan, or interim analyses. Study completion and the enrollment figure alone do not establish how the trial was powered or whether any planned analyses were changed.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Before assignment: Subjects were randomized in a 7:6:6:3 scheme (GFF MDI, FF MDI, GP MDI, and Placebo MDI). Randomization was stratified by reversibility to Ventolin HFA and COPD disease severity (moderate vs severe or very severe) to ensure a similar distribution of treatment arms across stratum.
Overall Study
| Stage | GFF MDI 14.4/9.6 ug | FF MDI 9.6 ug | GP MDI 14.4 ug | Placebo MDI |
|---|---|---|---|---|
| STARTED | 555 | 483 | 480 | 238 |
| COMPLETED | 494 | 417 | 417 | 200 |
| NOT COMPLETED | 61 | 66 | 63 | 38 |
Reasons for not completing this period:
| Reason | GFF MDI 14.4/9.6 ug | FF MDI 9.6 ug | GP MDI 14.4 ug | Placebo MDI |
|---|---|---|---|---|
| Adverse Event | 15 | 14 | 15 | 3 |
| Lack of Efficacy | 3 | 8 | 4 | 8 |
| Withdrawal by Subject | 18 | 17 | 23 | 14 |
| Physician Decision | 1 | 4 | 2 | 2 |
| Lost to Follow-up | 5 | 5 | 3 | 1 |
| Protocol Violation | 2 | 5 | 2 | 2 |
| Protocol Specified Criteria | 17 | 13 | 14 | 8 |
Analysis population for the primary outcome, as defined in the registry: ITT Population - defined as all subjects who were randomized to treatment and received at least 1 dose of the study treatment. Subjects were analyzed according to the treatment they were assigned to at randomization. Number of participants analyzed reflects the ITT population with available data
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 data reported from one site was not included in the final analysis.
| Characteristic | Unit | GFF MDI 14.4/9.6 ug | FF MDI 9.6 ug | GP MDI 14.4 ug | Placebo MDI | Total |
|---|---|---|---|---|---|---|
| Participants analysed | 551 | 480 | 474 | 235 | 1740 | |
| Age, Continuous | Years | 64.7 (SD 7.4) | 64.1 (SD 7.6) | 64.0 (SD 8.1) | 63.9 (SD 7.5) | 64.2 (SD 7.7) |
| Sex: Female, Male: Female | Participants | 143 | 115 | 128 | 64 | 450 |
| Sex: Female, Male: Male | Participants | 408 | 365 | 346 | 171 | 1290 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 1 | 0 | 0 | 0 | 1 |
| Race (NIH/OMB): Asian | Participants | 223 | 204 | 181 | 92 | 700 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 12 | 16 | 18 | 6 | 52 |
| Race (NIH/OMB): White | Participants | 315 | 260 | 275 | 137 | 987 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 | 0 | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Change From Baseline in Morning Pre-dose Trough FEV1 at Week 24 of Treatment (US/China Approach), measured over at week 24.
| Element | Registry entry |
|---|---|
| Result type | Least Squares Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | mL |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is change from baseline in morning pre-dose trough FEV1 at Week 24 of treatment, reported for the US/China approach. FEV1 measures the volume of air a person can forcefully exhale in the first second of a breathing test. A trough measurement is taken before the next scheduled dose; in this study the measurement is specified as morning and pre-dose. Change from baseline expresses the Week 24 measurement relative to the participant's starting measurement.
The registry reports the endpoint in mL as a least-squares mean with a 95% confidence interval for each treatment arm. A least-squares mean is a model-based estimate of a group mean. The model and any covariates used to produce these estimates are not reported in the registry record. The posted estimates are 120 mL (95% CI 102 to 138) for GFF MDI, 47 mL (95% CI 28 to 67) for FF MDI, 60 mL (95% CI 41 to 80) for GP MDI, and -45 mL (95% CI -73 to -17) for placebo.
FEV1 is used as a measure of lung function, and change from baseline allows the result to be expressed relative to the starting measurement. A pre-dose endpoint addresses lung function at a scheduled point before dosing rather than peak change shortly after dosing. These estimates describe each arm's mean change; they are not estimates of the between-group treatment effects. The registry record does not post a confidence interval or p-value for a direct comparison of an active arm with placebo.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The primary endpoint estimates describe change from baseline in morning pre-dose trough FEV1 at Week 24. The posted least-squares mean was 120 mL for GFF MDI, with a 95% confidence interval from 102 to 138. For FF MDI, the estimate was 47 mL, with a 95% confidence interval from 28 to 67. For GP MDI, it was 60 mL, with a 95% confidence interval from 41 to 80. The placebo estimate was -45 mL, with a 95% confidence interval from -73 to -17. These values should be read as arm-level changes, not as treatment-versus-placebo contrasts.
A 95% confidence interval describes the uncertainty around an estimated mean under the statistical method used. It is not a range containing 95% of individual participants' measurements, and it does not show the distribution of responses. The widths of the posted intervals convey uncertainty around each arm's estimate, but they do not by themselves quantify the uncertainty in a difference between arms. A direct contrast requires its own estimate and uncertainty calculation.
The numerical estimates differ across the treatment arms and placebo, but the registry record does not provide the primary between-group estimates, their confidence intervals, or their p-values. It is therefore not possible to characterize from these posted arm estimates alone the size or precision of an active-treatment effect relative to placebo. Nor should arm-level confidence intervals be treated as a substitute for a confidence interval on a treatment contrast. The reported numbers support description of each arm's mean change, not a conclusion about the statistical evidence for a difference between arms.
The primary endpoint results are based on the ITT population with available data, according to the registry definition. The analyzed counts are 488 for GFF MDI, 413 for FF MDI, 412 for GP MDI, and 196 for placebo. The registry does not explain in the results record why the endpoint counts differ from one another or how missing Week 24 measurements were handled in the model. A reader should not interpret the estimates as measurements from every randomized participant.
There are also secondary endpoints covering symptom scores, peak FEV1 change, and health status. Their regional approaches and time periods are not identical to the primary endpoint. The record lists 17 outcome measures and 14 posted secondary outcomes, but does not provide an analysis count beyond 0 analyses. The primary arm estimates do not resolve questions about multiplicity or the interpretation of the secondary results.
Overall, the registry results provide descriptive estimates of change in the specified lung-function measure at Week 24. They do not provide enough information to reconstruct the sponsor's primary comparison or its statistical uncertainty. Interpretation should remain limited to the endpoint, population, and regional approach that are explicitly described.
9. Statistical Methods Explained
The primary endpoint is continuous: change from baseline in FEV1, measured in mL. For a continuous outcome, a group summary such as a mean describes the central value of measurements, while a measure of uncertainty indicates how precisely that group summary has been estimated. The registry reports least-squares means and 95% confidence intervals for each arm. It does not report a standard deviation or standard error alongside these results.
What does a least-squares mean represent?
In general, a least-squares mean is a model-based estimate of a group mean. It can account for specified features of the analysis model, whereas a simple arithmetic mean is calculated directly from observed values. The registry record does not state which model terms, covariates, or missing-data assumptions were used to obtain the least-squares means in this study. It is therefore not appropriate to infer those details from the estimates alone.
The reported primary estimates are 120 mL for GFF MDI, 47 mL for FF MDI, 60 mL for GP MDI, and -45 mL for placebo. Each estimate has its own 95% confidence interval. The interval for GFF MDI is 102 to 138; for FF MDI, 28 to 67; for GP MDI, 41 to 80; and for placebo, -73 to -17. These are uncertainty intervals around the arm-specific estimates. They are not intervals for the difference between an active treatment and placebo.
How should confidence intervals be read?
In general, a confidence interval represents the precision of an estimate under the assumptions of the statistical method used. A narrower interval indicates more precision than a wider interval for the same kind of estimate, while neither interval guarantees that the underlying value lies within its endpoints. A 95% confidence interval is not a description of where 95% of individual measurements fall. Here, the intervals quantify uncertainty around mean change by arm, not the spread of participants' FEV1 changes.
To estimate a treatment contrast, an analysis compares the arm estimates directly using an appropriate model and accounts for uncertainty in that contrast. The uncertainty in a difference cannot be read off from the arm estimates alone. No numerical active-treatment-versus-placebo contrast, confidence interval, or p-value for the primary endpoint is reported in the registry record. The record therefore does not support a recalculated comparison from these posted summary statistics. The reported arm estimates should not be converted into a contrast by subtracting one displayed value from another.
What does the ITT definition tell us?
The primary outcome population is described as participants randomized to treatment who received at least 1 dose. They were analyzed according to the treatment assigned at randomization. The registry also states that the analyzed number reflects the ITT population with available data. This describes the intended assignment basis and the data availability condition for the posted analysis. It does not establish that all randomized participants had an observed Week 24 measurement, nor does it reveal how unavailable measurements were addressed statistically.
In general, analyzing participants according to randomized assignment helps preserve the comparison created by randomization. However, the presence of missing measurements can affect the interpretation of an analysis, depending on why data are missing and how the analysis handles them. The missing-data method and assumptions are not reported in the registry record. The model cannot be fully assessed without those details.
Why is a direct comparison important?
In a randomized trial, the principal efficacy question is commonly about a contrast between assigned groups, rather than whether each group's mean change differs from zero. A group-level interval that excludes zero does not, by itself, establish a difference from another group. Likewise, overlapping or non-overlapping arm intervals are not a substitute for the model-based contrast and its uncertainty. These are general statistical principles; the registry record does not post a primary contrast with which to assess them for this trial.
The registry records 0 analyses and does not report a statistical analysis plan, the choice of model, adjustment variables, or an interim analysis plan. The exact role of these registry analysis fields is not further described, so they should not be used to infer what was or was not done outside the posted record. The posted primary arm-level estimates remain interpretable as estimates, but the inferential comparison is not documented in the record.
What do planning illustrations mean?
In general, a sample-size planning illustration asks how many participants per arm might be needed under stated assumptions to detect an effect with a chosen power and significance level. Such calculations depend on the effect size, outcome variability, allocation, and analysis assumptions. The planning assumptions associated with this study describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect set as a fraction of the observed effect. These are planning assumptions, not evidence about the trial's original design.
Any such planning estimates are hypothetical illustrations and are not observed power. They do not show the probability that the completed study detected a true effect, and they do not replace a reported treatment contrast. The trial's own sample-size justification and statistical plan are not reported in the registry record. No planning count should be interpreted as an observed result or as proof of the precision of the posted comparisons.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 17 outcome measures and 14 posted secondary outcomes, in addition to the primary endpoint. The secondary outcomes include TDI Focal Score results, peak change from baseline in FEV1, and change in SGRQ Total Score. Some are defined for particular regional approaches or symptom subgroups, and their assessment periods vary. This creates multiple outcome and analysis questions, but the registry record does not report how multiplicity was handled.
In general, testing many outcomes or contrasts can increase the chance that at least one result appears noteworthy by chance. Methods such as prespecified testing sequences or adjustment procedures can address that issue, but no such method is reported in the registry record. The number of listed outcome measures alone does not reveal how many tests were conducted or which results were considered confirmatory. The record lists 0 analyses, so the multiplicity strategy and the full set of inferential tests cannot be established from the posted record.
Missing outcome data also affect interpretation. The primary endpoint population is defined as randomized participants who received at least 1 dose, analyzed according to assigned treatment; the number analyzed reflects those with available data. The numbers analyzed for the primary endpoint are 488 for GFF MDI, 413 for FF MDI, 412 for GP MDI, and 196 for placebo. The registry does not report the number with missing measurements by arm, reasons for missingness, or the method used to handle missing data. It also does not report sensitivity analyses assessing alternative assumptions about missing outcomes.
In general, randomization supports comparability of assigned groups, but missing measurements can weaken that protection if availability is related to treatment or outcome. The extent and direction of any effect cannot be inferred without information about missingness and the analysis method. The registry record does not report whether additional analysis populations were used or how they were defined beyond the ITT description for the primary endpoint. These gaps limit assessment of multiplicity, missing-data robustness, and the relationship between the planned and posted analyses.
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 |
|---|---|---|---|
| GFF MDI 14.4/9.6 ug | 53 | 551 | 9.6% |
| FF MDI 9.6 ug | 40 | 480 | 8.3% |
| GP MDI 14.4 ug | 34 | 474 | 7.2% |
| Placebo MDI | 19 | 235 | 8.1% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| GFF MDI 14.4/9.6 ug | 1 of 551 |
| FF MDI 9.6 ug | 1 of 480 |
| GP MDI 14.4 ug | 1 of 474 |
| Placebo MDI | 1 of 235 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 2% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| GFF MDI 14.4/9.6 ug | 166 of 551 |
| FF MDI 9.6 ug | 123 of 480 |
| GP MDI 14.4 ug | 128 of 474 |
| Placebo MDI | 61 of 235 |
Most frequent serious adverse event terms
| Event term | Organ system | GFF MDI 14.4/9.6 ug | FF MDI 9.6 ug | GP MDI 14.4 ug | Placebo MDI |
|---|---|---|---|---|---|
| Chronic Obstructive Pulmonary Disease | Respiratory, thoracic and mediastinal disorders | 16 of 551 | 13 of 480 | 12 of 474 | 7 of 235 |
| Pneumonia | Infections and infestations | 7 of 551 | 2 of 480 | 3 of 474 | 3 of 235 |
| Cellulitis | Infections and infestations | 3 of 551 | 0 of 480 | 0 of 474 | 0 of 235 |
| Lung Infection | Infections and infestations | 0 of 551 | 2 of 480 | 1 of 474 | 0 of 235 |
| Acute myocardial infarction | Cardiac disorders | 0 of 551 | 1 of 480 | 2 of 474 | 0 of 235 |
| Coronary artery disease | Cardiac disorders | 0 of 551 | 2 of 480 | 1 of 474 | 0 of 235 |
| Inguinal hernia | Gastrointestinal disorders | 1 of 551 | 0 of 480 | 2 of 474 | 0 of 235 |
| Non-cardiac chest pain | General disorders | 2 of 551 | 0 of 480 | 1 of 474 | 0 of 235 |
| Pneumothorax | Respiratory, thoracic and mediastinal disorders | 0 of 551 | 0 of 480 | 1 of 474 | 1 of 235 |
| Angina unstable | Cardiac disorders | 1 of 551 | 1 of 480 | 0 of 474 | 0 of 235 |
Most frequent non-serious adverse event terms
| Event term | Organ system | GFF MDI 14.4/9.6 ug | FF MDI 9.6 ug | GP MDI 14.4 ug | Placebo MDI |
|---|---|---|---|---|---|
| Viral upper respiratory tract infection | Infections and infestations | 50 of 551 | 46 of 480 | 44 of 474 | 16 of 235 |
| Upper respiratory tract infection | Infections and infestations | 37 of 551 | 29 of 480 | 33 of 474 | 20 of 235 |
| Chronic obstructive pulmonary disease | Respiratory, thoracic and mediastinal disorders | 16 of 551 | 13 of 480 | 12 of 474 | 7 of 235 |
| Cough | Respiratory, thoracic and mediastinal disorders | 13 of 551 | 8 of 480 | 10 of 474 | 2 of 235 |
| Dyspnoea | Respiratory, thoracic and mediastinal disorders | 11 of 551 | 7 of 480 | 6 of 474 | 7 of 235 |
| Back Pain | Musculoskeletal and connective tissue disorders | 15 of 551 | 5 of 480 | 7 of 474 | 1 of 235 |
| Pneumonia | Infections and infestations | 9 of 551 | 5 of 480 | 5 of 474 | 6 of 235 |
| Bronchitis | Infections and infestations | 4 of 551 | 6 of 480 | 8 of 474 | 5 of 235 |
| Pharyngitis | Infections and infestations | 11 of 551 | 4 of 480 | 3 of 474 | 0 of 235 |
Serious events with the highest arm-level rate: chronic obstructive pulmonary disease (3.0%), pneumonia (1.3%), cellulitis (0.5%), pneumothorax (0.4%), gastrointestinal infection (0.4%).
The registry reports serious adverse event counts and other adverse event counts separately by group. For GFF MDI, 53 participants were listed as affected by serious adverse events among 551 at risk, and 166 were listed as affected by other adverse events among 551 at risk. For FF MDI, the corresponding counts were 40 among 480 for serious adverse events and 123 among 480 for other adverse events. For GP MDI, they were 34 among 474 and 128 among 474. For placebo, they were 19 among 235 and 61 among 235.
These figures are counts of participants affected relative to the listed at-risk group, not treatment-effect estimates. The safety denominators differ from the analyzed counts for the primary endpoint. The registry record does not explain the differences between those populations or provide a method to adjust the safety counts for exposure time. Comparisons of raw counts should therefore be read with the group sizes and record definitions in mind.
The registry lists 1 death in each group. It does not provide a treatment comparison for deaths in the registry record described, and these counts alone do not establish a difference between groups. The most frequently listed serious adverse event terms include Chronic Obstructive Pulmonary Disease (3.0%), Pneumonia (1.3%), Cellulitis (0.5%), Pneumothorax (0.4%), Gastrointestinal Infection (0.4%), and Gastrointestinal haemorrhage (0.4%). These percentages are quoted as recorded; the basis for each percentage is not reported in the registry record.
Safety counts describe events recorded during the trial, not causal effects attributable to treatment. The registry record does not report a formal statistical comparison or detailed adjudication rules for these events.
12. What the Result Does, and Does Not, Mean
The posted primary results show mean changes from baseline in morning pre-dose trough FEV1 at Week 24 for each study arm. The estimates are reported as least-squares means with 95% confidence intervals in the ITT population with available data. They provide information about the direction and precision of each arm's estimated mean change under the analysis represented in the registry.
They do not provide a numerical treatment effect comparing any active arm with placebo. A direct comparison needs an estimate for the between-group difference and its uncertainty. Those results are not reported in the registry record. For this reason, the arm-specific estimates should not be presented as the size of the active treatment effect, and the arm confidence intervals should not be treated as confidence intervals for an active-versus-placebo difference.
The record also does not report the model specification, missing-data method, multiplicity procedure, or full statistical analysis plan. Without these details, the exact assumptions underlying the least-squares means cannot be evaluated. The primary outcome population is described, but the record does not explain the availability of measurements or how missing Week 24 data were addressed.
The study design provides important context: it was randomized, quadruple-masked, parallel-group, and placebo-controlled, with chronic dosing for 24 weeks. Randomization and masking can reduce some sources of bias in general, but they do not make unreported comparisons or analysis assumptions available. The record's designation of quadruple masking also does not identify which roles were masked.
The results do not establish how participants' individual experiences varied, since the posted primary outcome summaries are means and confidence intervals. They do not address all possible time points or every outcome of interest. The registry lists secondary measures related to symptoms, peak lung-function change, and health status, but multiplicity handling is not reported. Safety event counts are descriptive and do not, on their own, establish causation or a comparative safety effect.
The appropriate statistical reading is therefore bounded: the registry reports arm-level estimates for a specified lung-function endpoint and time point, but not the primary comparative inference. The posted figures alone do not support a claim that one assigned treatment differed from placebo by a particular amount, or a conclusion about the statistical significance of that difference.
13. Why This Trial Matters Statistically
This trial illustrates why a randomized design and an interpretable treatment comparison are distinct pieces of evidence. Randomization assigns participants to groups in a way intended to reduce systematic baseline differences. For a treatment question, however, the key statistical result is usually a between-group contrast with an uncertainty estimate. The registry reports arm-level primary endpoint estimates, but the primary contrast is not reported in the registry record.
The study also has multiple active-treatment arms and a placebo group, while the primary outcome is defined for a specific regional approach and Week 24. Secondary outcomes use other measures, time periods, and regional approaches. This structure makes clear why readers need to know which outcomes and comparisons were prespecified and how multiplicity was handled. Those methods are not reported in the registry record, so a complete account of the confirmatory analysis cannot be reconstructed.
Another important statistical distinction is between an endpoint estimate and an analysis population. The primary results use an ITT definition requiring randomization and at least 1 dose, with available data for the endpoint. The listed numbers analyzed differ across arms, and the record does not detail missing measurements or their handling. Naming an analysis population is helpful, but it does not by itself answer how missingness may affect the estimate.
Finally, the study's size and completed status should not be mistaken for proof of a particular level of statistical power or precision. The sample-size justification is not reported in the registry record. Planning calculations based on observed effects are illustrative rather than observed power and cannot substitute for the prespecified design rationale or the reported treatment contrast. These distinctions are useful when evaluating registry results across clinical trials: design, outcome summaries, comparative estimates, and analysis assumptions each answer different questions.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The main limitation for interpreting efficacy is that the posted primary results are arm-level estimates rather than direct comparisons with placebo. No between-group estimate, confidence interval for the contrast, or p-value is reported in the registry record. The arm estimates therefore describe mean change within groups but do not establish the magnitude or precision of a treatment-versus-placebo difference.
The statistical model used to calculate the least-squares means is not reported in the registry record. Covariate adjustment, model assumptions, and the method for handling repeated or unavailable measurements are also not described. The primary population definition refers to participants with available data, but the record does not give missing-measurement counts or reasons by group. It is not possible to assess from the posted results how sensitive the estimates are to missing-data assumptions.
The registry does not report the sample-size justification or the planned statistical analysis, including an interim analysis plan or multiplicity procedure. The presence of several secondary outcomes and regional approaches makes those details relevant to interpreting the full outcome set. The record lists 17 outcome measures and 14 posted secondary outcomes, but does not explain the relationship between those counts or the analyses conducted for them.
For safety, the listed at-risk counts differ from the primary endpoint analysis counts. The record does not explain the denominator definitions, provide exposure-adjusted rates, or report comparative statistical analyses for the adverse event counts. The listed serious adverse event terms and percentages are descriptive; their percentage denominators are not reported in the registry record.
These limitations do not invalidate the posted arm estimates, but they narrow what can be concluded from them. They leave important aspects of comparative efficacy, robustness to missing data, multiplicity, and safety comparisons unresolved in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study to Assess the Efficacy and Safety of PT003, PT005, and PT001 in Subjects With Moderate to Very Severe COPD — NCT02343458.
- Registry record last updated 2019-02-20; status last verified 2019-01.
- Results first posted 2019-02-20.
- 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
The registry record describes a completed Phase 3 randomized, quadruple-masked, parallel-group, placebo-controlled study of GFF MDI (PT003), FF MDI (PT005), and GP MDI (PT001) in people with moderate to very severe COPD. Enrollment was 1756, and the study used chronic dosing for 24 weeks.
The primary endpoint was change from baseline in morning pre-dose trough FEV1 at Week 24 for the US/China approach. Arm-level least-squares mean estimates and 95% confidence intervals are posted for the ITT population with available data. A direct active-treatment-versus-placebo estimate is not reported in the registry record.
The record lists secondary outcomes involving symptoms, FEV1, and health status, as well as serious and other adverse event counts. It does not report the detailed statistical analysis plan, multiplicity method, sample-size justification, or missing-data method. These omissions limit assessment of the comparative and confirmatory interpretation of the posted results.