Stage 1 Study of ARALAST NP and GLASSIA in A1PI Deficiency: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Stage 1 Study of ARALAST NP and GLASSIA in A1PI Deficiency (NCT02722304), a randomized phase 3 study. The primary outcome is Rate of Change in Lung Density Based on Group 1 (ARALAST NP) Versus Placebo, Group 3 and Group 4 (GLASSIA) Versus Placebo.

2. Clinical Question

The central statistical question was whether lung-density trajectories differed between the specified active-treatment groups and placebo. The primary outcome description names ARALAST NP Group 1 versus placebo, and GLASSIA Groups 3 and 4 versus placebo. It does not include the ARALAST NP 120 mg/kg group in those stated primary comparisons. The record does not explain why that group is absent from the primary comparison description.

This was a pilot study intended to evaluate safety and efficacy of weekly A1PI augmentation therapy in people with A1PI deficiency and emphysema/COPD. Its record identifies a randomized, placebo-controlled, double-blind design. However, the efficacy question cannot be answered from the primary endpoint because the registry states that no data were collected for it after early termination. The record therefore describes the clinical question and planned measurement, but does not provide a comparative lung-density result.

3. Trial Design

The study is registered as a randomized, double-blind, parallel-group, placebo-controlled Phase 3 trial. Its title also describes it as a Stage 1 study and its brief summary calls it a pilot study. These labels are all present in the registry record; the record does not explain their relationship.

The treatment groups were ARALAST NP 60 mg/kg, ARALAST NP 120 mg/kg, GLASSIA 60 mg/kg, GLASSIA 120 mg/kg, and placebo. The active-treatment descriptions specify weekly dosing by body weight. Placebo was Human Albumin 2%. The planned primary comparisons named ARALAST NP Group 1 versus placebo and GLASSIA Groups 3 and 4 versus placebo. Group 2 was an ARALAST NP 120 mg/kg arm, but it is not named in that primary comparison statement.

The registry reports enrollment of 7. That figure is the reported study enrollment, not an arm-by-arm allocation. The safety figures list separate risk counts for the treatment groups, but the record does not provide a complete account of randomization or group assignment. Allocation is identified as randomized, masking as double, and the model as parallel; additional operational details are not reported in the registry record.

The study started on 2016-11-02, and the listed primary completion date is 2018-09-14. Its status is terminated. The primary outcome description says the study was terminated early due to a low and slow rate of enrollment. The record does not report a detailed account of the termination decision or the timing of each participant's treatment and follow-up.

Secondary outcomes covered lung-density change by treatment group, steady-state trough concentrations of antigenic and functional A1PI for ARALAST NP and GLASSIA at each dose level, and adverse-event measures. The adverse-event measures included event counts and participant percentages for related, unrelated, and temporally related treatment-emergent events, as well as suspected adverse reactions. The registry lists 11 outcome measures, but it does not provide analysis results for these outcomes in the registry record described by the record.

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: A total of 22 participants were screened for entry of study, of these, 15 participants were considered screen failures. Remaining 7 participants were enrolled and randomized in the study.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Study was early terminated due to low and slow rate of enrollment, hence, data was not collected for this efficacy endpoint.

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: Safety Analysis Set (SAS) included all participants who had received any amount of investigational product (IP) or placebo, regardless of protocol deviations or non-adherence to the study procedures. Analysis was performed according to the treatment regimen received regardless of the randomized treatment regimen.

6. Primary Endpoint

The registry lists the primary outcome as Rate of Change in Lung Density Based on Group 1 (ARALAST NP) Versus Placebo, Group 3 and Group 4 (GLASSIA) Versus Placebo, measured over Baseline, Early termination of the study (approximately 22 months).

The primary endpoint was the rate of change in lung density measured by computed tomography (CT) densitometry. CT scans were used to measure lung density at study visits. The specified measure was CT lung density at the 15th percentile, or PD15: the threshold below which 15% of the measured voxels have lower densities. The registry describes PD15 as the parameter used to estimate the rate of lung-density decline.

The endpoint was intended as a quantitative assessment of emphysema progression and treatment efficacy. In general, repeated measurements of a continuous marker can be used to estimate a trajectory over time. Comparing trajectories between treatment groups and placebo can describe whether the observed rates of change differ, provided measurements and follow-up are available and the analysis is appropriately specified.

The listed timeframe runs from baseline to early termination of the study, described as approximately 22 months. This is the endpoint's stated timeframe; it should not be read as a completed follow-up period for every participant. The registry explicitly states that the study was terminated early because enrollment was low and slow, and that data were not collected for this efficacy endpoint. Consequently, the record gives the measurement definition and rationale but no observed lung-density change, group estimate, uncertainty interval, or treatment comparison.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a randomized, double-blind, parallel-group, placebo-controlled study. These design features indicate an intention to allocate participants among treatment groups by chance, conceal treatment assignment from participants and relevant study personnel, and compare groups followed within the same study. In general, random allocation can reduce systematic differences between groups at entry, while masking can reduce some influences of expectations on care or measurement. Neither feature guarantees comparable groups when the available data are very sparse, and neither can substitute for outcomes that were not collected.

What does the primary endpoint measure?

The primary outcome was a rate of change in CT lung density, based on PD15. The record defines PD15 as the threshold below which 15% of voxels have lower densities. It says this measure was used to estimate the rate of lung-density decline and was treated as a quantitative assessment of emphysema progression and treatment efficacy. A rate describes change over time rather than a value at just one visit. In general, estimating such a rate requires observations over time and a defined approach to relating those observations to time and treatment group.

The listed period for the endpoint was baseline to early termination, approximately 22 months. The record says no data were collected for this efficacy endpoint because the study was terminated early due to low and slow enrollment. Thus, the endpoint definition does not come with the measurements needed for a reported rate or a between-group estimate.

What comparisons were specified?

The primary outcome title describes ARALAST NP Group 1 versus placebo and GLASSIA Groups 3 and 4 versus placebo. The treatment groups are identified as ARALAST NP 60 mg/kg, ARALAST NP 120 mg/kg, GLASSIA 60 mg/kg, GLASSIA 120 mg/kg, and placebo. Group 2, the ARALAST NP 120 mg/kg group, is not included in the stated primary comparisons. The registry record does not explain the analysis rationale or clarify whether other comparisons were planned.

In general, a treatment comparison should be interpreted in the context of its prespecified estimand: the outcome, comparison groups, analysis population, and time period being addressed. The registry provides a brief outcome description and comparison labels, but not a complete estimand specification. It does not report the planned statistical model, covariate adjustment, missing-data strategy, or rules for handling measurements collected at different visits. These details are not reported in the registry record.

What can a confidence interval or p-value tell a reader?

In general, a confidence interval describes the range of estimates reasonably compatible with the data under the assumptions of the analysis. A p-value evaluates how incompatible the observed data are with a specified null model, under the method's assumptions. Neither measure establishes clinical importance on its own, and both depend on having analyzed data and a defined comparison. The registry record does not report a primary endpoint estimate, confidence interval, or p-value, so these concepts cannot be applied to a treatment effect for lung density in this trial.

The record lists 0 analyses. That does not supply a statistical result; it reinforces that there is no analysis result to interpret in the information described. The registry's statement that the endpoint data were not collected is especially important: a statistical method cannot recover a treatment comparison from an endpoint that was not measured.

How should sparse safety counts be read?

The safety information lists the number at risk and affected counts for serious and other adverse events, along with deaths, by group. In general, a count is a descriptive summary and is not automatically a treatment-effect estimate. Comparisons of event risks require attention to the number of participants observed, the period at risk, event definitions, and whether multiple events per participant are possible. Those details and an inferential safety analysis are not reported in the registry record.

Over-dispersion is a general statistical issue that can arise when event counts vary more than a chosen model expects. In such settings, a model that assumes less variability can produce uncertainty estimates that are too narrow. The record does not report an event-count model or enough detail to determine whether over-dispersion was assessed. Given the sparse risk counts, elaborate conclusions from these safety figures would not be warranted.

What do planning calculations mean?

In general, a sample-size calculation depends on assumptions about the effect to detect, variability, significance level, allocation, and analysis method. Planning calculations are prospective illustrations, not observed power and not evidence that an effect occurred. The record's planning assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with effects expressed as a stated fraction of an observed effect. However, no primary endpoint data were collected, so there is no observed lung-density effect from this trial on which to base an observed-effect illustration. Any planning figure should not be read as a result from the study or as a justification reported by its investigators; the registry does not report the protocol's sample-size rationale.

10. Multiplicity, Missing Data and Analysis Populations

The record lists multiple secondary outcome areas, including lung-density change, antigenic and functional A1PI trough concentrations, and several adverse-event summaries. The primary outcome description also names more than one treatment comparison. When a study makes multiple statistical comparisons, the chance of at least one apparently unusual result can increase. In general, a prespecified multiplicity strategy can address that issue by defining which comparisons are confirmatory and how error rates are controlled. Such a strategy is not reported in the registry record.

The primary endpoint data were not collected because the study was terminated early due to low and slow enrollment. The record does not describe partial collection, reasons for any missing measurements beyond early termination, or a method for handling missing endpoint data. It therefore does not support assumptions about whether missingness was related to treatment, participant characteristics, or outcome values.

The primary outcome description says the safety analysis set was used for efficacy parameter assessment. The registry does not define that population, explain how participants entered it, or describe how it differed from an intention-to-treat or per-protocol population. With no primary endpoint data collected, the stated analysis population cannot produce a reported efficacy estimate in this record.

The registry also does not report an interim-analysis plan, stopping boundary, or statistical analysis plan. The stated reason for termination is low and slow enrollment; no additional statistical stopping rationale is reported. These absent details limit assessment of how the planned multiplicity, missing data, and analysis populations were intended to be handled.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry's safety figures list the number at risk and the number affected for serious and other adverse events, plus deaths, for each group. For ARALAST NP 60 mg/kg, the serious-event figures are 1 at risk and 0 affected; the other-event figures are 1 at risk and 1 affected; deaths are 0. For ARALAST NP 120 mg/kg, the listed risk counts and affected counts are 0 for serious events and 0 for other events; deaths are 0.

For GLASSIA 60 mg/kg and GLASSIA 120 mg/kg, each group has 1 at risk and 0 affected for serious events, 1 at risk and 0 affected for other events, and 0 deaths. For placebo, the figures are 2 at risk and 0 affected for serious events, 2 at risk and 2 affected for other events, and 0 deaths.

These are descriptive registry figures, not a formal comparison of treatment safety. The risk counts are sparse, and the record does not provide event narratives, follow-up time by participant, or an inferential analysis. It also does not identify the listed other events as related or unrelated. Zero serious events or deaths in these groups should not be interpreted as proof of no risk, and the counts alone do not establish whether any event was caused by treatment.

12. What the Result Does, and Does Not, Mean

The registry record documents a planned randomized, double-blind comparison of weekly ARALAST NP and GLASSIA regimens with placebo in people with A1PI deficiency and COPD. It identifies CT lung-density change based on PD15 as the primary efficacy outcome and describes why that measure was selected. It also records the study's termination and gives sparse descriptive safety figures.

Most importantly, the record says the study was terminated early because enrollment was low and slow, and that no data were collected for the primary efficacy endpoint. That means there is no reported rate of lung-density change and no estimate of how the active-treatment groups compared with placebo. The record cannot establish that the treatments had equal or different effects on lung density. It also cannot establish that a treatment benefit was present or absent.

The registry lists enrollment of 7, but this total should not be mistaken for the number assigned to any one group. The separate safety risk counts show that the amount of information available for safety descriptions was limited. The observed counts do not provide a precise estimate of the likelihood of adverse events, nor do they support a dependable comparison among groups. The record does not report whether the non-serious events were treatment-related.

In general, a study's design and its results answer different questions. A randomized design describes how a comparison was intended to be conducted; it does not itself demonstrate a treatment effect. Likewise, a defined endpoint explains what investigators planned to measure, but an endpoint without collected data cannot yield an efficacy conclusion. The outcomes described in the registry should therefore be understood as plans and limited safety descriptions, not as evidence of a measured lung-density effect.

The result does not answer the original primary clinical question. It does document a trial that was initiated, randomized, and ultimately terminated, with the registry attributing termination to low and slow enrollment. Further details about the decision, the analysis plan, and any unreported results are not reported in the registry record.

13. Why This Trial Matters Statistically

This trial illustrates a basic distinction in clinical-trial interpretation: a clear outcome definition is not the same as an observed outcome. The registry specifies CT lung density at PD15 and identifies the intended treatment comparisons. But early termination meant that data were not collected for the primary efficacy endpoint. As a result, the central question remains unanswered by the posted primary outcome information.

The record also shows why arm labels and comparison definitions matter. There are four active-treatment regimens and a placebo group, while the primary outcome description names only particular comparisons. The ARALAST NP 120 mg/kg group is present in the intervention list but absent from the stated primary comparison description. Without a reported explanation, readers should not infer how that group was intended to contribute to the primary analysis.

Statistically, the safety record is a reminder that sparse counts are not equivalent to robust comparative evidence. Counts of affected participants can be useful for describing what was recorded, but small risk sets leave considerable uncertainty. A zero count is not proof that an event cannot occur, and differences in sparse observed counts do not by themselves establish a treatment difference.

The trial's termination reason also matters when interpreting planning assumptions. A study may have proposed an endpoint and a design, but the ability to estimate an effect depends on collecting the necessary measurements. The registry does not report a sample-size justification or a completed efficacy analysis. Therefore, the trial's statistical contribution is chiefly its documented design, endpoint plan, termination, and limited safety summary—not an estimate of comparative efficacy.

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 primary limitation is that no data were collected for the primary lung-density efficacy endpoint. This prevents estimation of the planned rate of change and means there is no primary comparison to interpret. The record attributes early termination to low and slow enrollment, but does not describe how that decision affected follow-up or the availability of other outcomes.

Enrollment was 7, and the safety risk counts are sparse and uneven across groups, including a listed risk count of 0 for ARALAST NP 120 mg/kg. These figures limit descriptive interpretation and do not support precise comparisons. The registry does not provide uncertainty intervals or an inferential analysis for the safety figures.

The primary comparison statement does not name every intervention group: ARALAST NP Group 2 is not listed among the stated comparisons. The record does not explain this omission or provide a complete analysis plan. It also does not report the intended sample-size justification, multiplicity procedure, interim-analysis plan, or approach to missing data.

Further details about the safety population, event definitions, follow-up time, event relatedness, and outcome ascertainment are not reported in the registry record. These omissions constrain interpretation of both the sparse safety counts and the planned secondary outcomes. The registry lists secondary measures, but the registry entries available do not include their results. Accordingly, the record supports description of what was planned and why the study ended, but not a broad evaluation of efficacy or comparative safety.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Stage 1 Study of ARALAST NP and GLASSIA in A1PI Deficiency — NCT02722304.
• Registry record last updated 2021-05-13; status last verified 2021-04.
• Results first posted 2019-10-08.
• 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.

18. Record Summary

NCT02722304 is a randomized, double-blind, placebo-controlled, parallel-group Phase 3 study of ARALAST NP and GLASSIA augmentation therapy in people with A1PI deficiency and COPD. The record also calls it a Stage 1 study and describes it as a pilot study. The interventions included weekly ARALAST NP and GLASSIA at 60 mg/kg and 120 mg/kg, with Human Albumin 2% as placebo.

The primary endpoint was the rate of change in CT lung density based on PD15. The registry states that the study was terminated early because enrollment was low and slow, and no data were collected for that efficacy endpoint. Enrollment was 7. The posted safety figures list sparse group-level counts, with no serious adverse events or deaths recorded. The record does not provide a primary efficacy result or a complete statistical analysis plan.