A Study to Assess the Efficacy, Safety and Tolerability of ABT-SLV187 Monotherapy in Subjects With Advanced Parkinson's Disease (PD) and Persistent Motor Complications, Despite Optimized Treatment With Available Anti-Parkinsonian Medications: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study to Assess the Efficacy, Safety and Tolerability of ABT-SLV187 Monotherapy in Subjects With Advanced Parkinson's Disease (PD) and Persistent Motor Complications, Despite Optimized Treatment With Available Anti-Parkinsonian Medications (NCT01960842), a na phase 3 study. The primary outcome is Average Daily Normalized "Off" Time: Change From Baseline To The Final PEG-J Visit.

2. Clinical Question

The clinical question is about change during LCIG treatment in a population with advanced disease and persistent motor complications. It is not a direct test of whether LCIG performs better than another treatment, because the design has no concurrent control arm. Comparing participants with their own baseline can describe change over time, but by itself cannot separate treatment-associated change from other influences, such as the natural course of symptoms, expectations, changes in care, or differences in measurement conditions.

The primary outcome is focused on time when Parkinson’s disease symptoms are not adequately controlled, rather than on a broad measure of health or functioning. Other registered outcomes address “On” time, troublesome dyskinesia, quality of life, global impressions and parts of the Unified Parkinson’s Disease Rating Scale. Those additional measures widen the clinical description, but their presence does not supply a numerical result for the primary question.

3. Trial Design

The registry describes a Phase 3, open-label, single-arm, baseline-controlled, multicenter study. It was completed, with 31 participants enrolled. The record gives a start date of 2013-10 and a primary completion date of 2015-03. It does not describe random allocation or masking; allocation is listed as not applicable and masking as none.

All participants in the listed treatment group received LCIG. The treatment description distinguishes an N-J test period from a post-PEG-J long-term treatment period. LCIG was delivered through the N-J tube during the test period and through a PEG-J tube during the long-term treatment period. The record also lists a CADD-Legacy® 1400 ambulatory infusion pump, PEG tube and J-tube as interventions or devices. Further details about the individualized starting dose are not reported in the registry record.

Baseline is described as the end of the screening period. The primary outcome is assessed at the final PEG-J visit, with the timeframe extending up to week 12. This is a within-group change design: the outcome after treatment is compared with the earlier baseline measurement, rather than with an outcome from a separate control group. Because participants and study personnel were not masked, expectations and awareness of treatment could potentially influence subjective reporting or assessment. The registry record does not report procedures intended to address those possibilities.

The primary analysis population is defined as the Full Analysis Set. It includes enrolled participants who received at least 1 dose of LCIG infusion during the PEG-J Period and had available baseline and at least 1 post-PEG-J efficacy assessment. The number meeting that definition is not reported in the registry record. Enrollment is not necessarily the same as the number contributing to a particular endpoint, so the enrolled count should not be treated as the primary-outcome denominator.

The design can describe the observed trajectory among participants with qualifying data, but it does not provide a randomized, like-for-like comparison with another treatment or with continued usual care. The statistical plan, including the planned handling of potential confounding in this baseline-controlled design, is not reported in the registry 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 31 participants were enrolled and had undergone the N-J placement procedure and were included in the Safety Analysis Set; 1 participant did not have at least 1 post-PEG efficacy assessment and was excluded from the Full Analysis Set (FAS), which consisted of 30 participants.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All participants in the Full Analysis Set (FAS; all enrolled participants who received at least 1 dose of LCIG infusion during the PEG-J Period and had data for baseline and at least 1 post-PEG-J efficacy assessment) 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: Safety Analysis Set: All subjects who had undergone the N-J placement procedure.

6. Primary Endpoint

The registry lists the primary outcome as Average Daily Normalized "Off" Time: Change From Baseline To The Final PEG-J Visit, measured over Baseline (end of screening period) and Final PEG-J Visit (up to week 12).

The primary endpoint is the change from baseline in average daily normalized “Off” time at the final PEG-J visit. The outcome is a mean measured in hours. In the registry’s description, “Off” time is when Parkinson’s disease symptoms are not adequately controlled by the drug; “On” time is when symptoms are well controlled. Negative change from baseline for “Off” time is defined as improvement.

The measure is based on the Parkinson’s Disease Symptom Diary. Participants complete the diary every 30 minutes for the full 24 hours of each of 3 days before selected clinic visits. It includes both waking and sleeping time. The daily totals are normalized to a 16-hour scale, described as 16 hours of awake time, and the normalized totals for the 3 days before a visit are averaged for analysis. Normalization is intended to express diary time on a common scale rather than allowing different amounts of recorded time to determine the daily total.

This endpoint is used to quantify a symptom-related feature that matters to the study question: time spent with inadequate symptom control. Repeated diary entries across several days can capture more than a single momentary assessment, while averaging the daily normalized totals gives a participant-level summary for analysis. As a general statistical point, a summary measure can make a repeated diary easier to compare across visits, but it can also conceal variation across days or across individuals.

The registry record does not report the numerical baseline mean, final-visit mean, mean change, standard deviation, confidence interval or significance test for this endpoint. Consequently, the direction and magnitude of the observed group change, and its precision, cannot be evaluated from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean change represent?

The primary outcome is continuous: each participant’s diary-based “Off” time is expressed in hours, and the group result is described using a mean. A mean change summarizes the average difference between baseline and the final PEG-J visit among participants contributing to the analysis. It is a group-level summary, not a statement that every participant changed by that amount. Individual responses can vary around the mean, and the mean alone does not describe the full distribution.

The registry identifies standard deviation as the dispersion measure for the primary outcome. In general, a standard deviation describes how spread out individual observations are around their mean. It is not the same as the uncertainty in the estimated mean: uncertainty also depends on how many observations contribute and on the analysis method. The numerical standard deviation and mean change are not reported in the registry record, so the degree of participant-to-participant variation cannot be assessed.

Why compare measurements within participants?

A baseline-controlled analysis uses each participant’s earlier measurement as a reference for a later measurement. In general, comparing within the same person can account for stable differences between people, because those characteristics are present at both measurement times. However, a before-and-after comparison remains vulnerable to changes over time that are unrelated to the intervention. Without a concurrent comparison group, the observed change cannot distinguish treatment effects from time trends, changes in other care, fluctuating symptoms, or other influences.

The endpoint is based on diaries completed at repeated intervals and summarized over days before clinic visits. Averaging repeated entries can reduce the influence of a single unusual diary entry, while normalization places totals on a common time scale. These choices define what is being estimated: average normalized diary time rather than an isolated symptom rating or a direct measure of all aspects of disease. General statistical interpretation should keep that measurement definition in view.

How should uncertainty be understood?

A confidence interval is a statistical range designed to express uncertainty around an estimate under a specified model and sampling framework. A relatively narrow interval indicates greater precision than a wide interval, while an interval spanning values in different directions may leave the direction of the underlying effect uncertain. The interval does not show the range of outcomes for individual participants, and it does not account automatically for biases that the design or measurement process may introduce.

No confidence interval for the primary mean change is reported in the registry record. Nor are the underlying group means and dispersion values available to support a simple unadjusted recalculation from the record. Accordingly, an effect estimate or its precision should not be reconstructed by assumption. The record’s stated direction convention can be used to interpret a result if one is reported elsewhere, but it cannot substitute for the missing numerical result.

What does the design imply for statistical inference?

The study is single-group and open-label, with change from baseline as the central comparison. A statistical test in such a design, if conducted, would assess evidence of change under its own assumptions; it would not establish comparative effectiveness against an untreated group or another therapy. Statistical significance, if reported, would also not on its own establish that the size of a change is important to participants. The test, model and inferential procedure used for the primary outcome are not reported in the registry record.

As a general concept, over-dispersion occurs when observed variation is greater than a model assumes. When that happens, standard errors based on an overly restrictive model can be too small, making intervals too narrow and tests too optimistic. The primary endpoint is a continuous mean, and the registry does not report a model that would permit assessment of whether over-dispersion was relevant or how it was handled. For diary measures, variability across participants and across days can be distinct features; a single group summary may not reveal either in detail.

How do the planning illustrations relate to the trial?

Any sample-size figures associated with planning illustrations should be understood as hypothetical calculations based on an observed effect and stated assumptions, not as the original design justification or as observed power. The registry’s description of those illustrations assumes a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a fraction of the observed effect. Those are planning assumptions for a hypothetical two-arm calculation, not a description of this single-group trial’s allocation or analysis.

Sample-size planning asks how many participants might be needed under assumed conditions to detect a specified effect with a chosen probability. It does not tell the reader the probability that the completed study’s result is true, and it is not a substitute for an estimate with an uncertainty interval. Since the primary numerical effect is not reported in the registry record, the planning illustrations cannot be used to assess the observed change. The original sample-size justification and statistical plan are not reported in the registry record.

The registry’s safety entries use counts and percentages for reported events. These have a different interpretation from a mean change in a continuous endpoint. The number at risk defines the group in which events were recorded, while the count affected describes people with at least one event in the relevant category as represented in the record. The record does not give enough detail to infer event timing, duration, recurrence, or comparative risk. Statistical interpretation should therefore remain tied to the reported category and denominator, without turning the entries into a causal comparison.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 22 outcome measures and 20 analyses. The named secondary outcomes cover normalized “On” time without troublesome dyskinesia, the PDQ-39 summary index and domains, global impressions, and UPDRS parts. These outcomes address different aspects of symptoms, function and reported experience. When a study assesses multiple outcomes, the chance of obtaining at least one apparently notable result can increase if each is interpreted independently. General statistical approaches can address multiplicity through prespecified hierarchies, adjusted significance thresholds or other procedures, but the multiplicity strategy is not reported in the registry record.

The record does not report which secondary outcomes were prioritized, whether any analyses were exploratory, or how multiplicity was handled. The count of outcomes and analyses does not establish that every analysis was prespecified or that the results were interpreted under a particular correction. Numerical results for the listed secondary outcomes are not reported in the registry record, so their estimates and precision cannot be assessed.

The primary analysis population is the Full Analysis Set: enrolled participants who received at least 1 dose of LCIG infusion during the PEG-J Period and had baseline and at least 1 post-PEG-J efficacy assessment, with available data. The number meeting this definition is not reported in the registry record. This population definition makes outcome availability part of inclusion in the analysis; it should not be assumed to be identical to all enrolled participants.

Missing-data handling is not reported in the registry record. It is not stated whether incomplete diaries, missed visits or discontinuations were addressed by imputation, a model using available observations, or another method. As a general point, analyses restricted to observed data can be biased if the availability of measurements is related to participants’ outcomes. The direction and extent of any such bias cannot be determined without information about missingness and the analytic approach.

The registry record also does not report interim analyses, a statistical analysis plan, or a sample-size justification for the trial. These absences limit assessment of prespecification and analytic choices; they do not establish that such plans did or did not exist outside the registry record.

11. Safety Results

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

Other (non-serious) adverse events

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

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: pneumonia aspiration (6.5%), disseminated intravascular coagulation (3.2%), abdominal pain (3.2%), constipation (3.2%), gastrointestinal perforation (3.2%).

The registry lists 31 participants at risk for the LCIG group’s serious adverse event information, with 4 affected by serious adverse events. It separately lists 31 at risk and 31 affected for other adverse events. The record does not report a death count. A missing death value should be read as not reported in the registry record, rather than interpreted as a confirmed absence of deaths.

The selected serious event terms are aspiration pneumonia, listed as 6.5%; disseminated intravascular coagulation, abdominal pain, constipation, gastrointestinal perforation and melaena, each listed as 3.2%. These are event-specific percentages as recorded. The registry entry does not provide enough detail to establish when events occurred, how long they lasted, whether they recurred, or how they were judged to be related to treatment.

These figures describe events recorded in a treated group, not a comparison of risk between treatments. Without a concurrent control group, they cannot quantify whether the frequency was higher or lower than it would have been under another treatment or without LCIG. The record does not state whether participants could contribute to more than one event term, so the listed terms should not be added or treated as a total number of affected people. A serious event count and an event-term percentage also answer different questions: one concerns people affected by serious events overall, while the other describes selected reported categories.

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

The registry record establishes that a completed Phase 3, open-label, single-group study evaluated LCIG in people with advanced Parkinson’s disease and persistent motor complications despite optimized treatment with available anti-Parkinsonian medication. It specifies a primary diary-based measure of normalized “Off” time and defines negative change from baseline as improvement. It also describes the treatment periods, the final PEG-J visit and the Full Analysis Set criteria.

What the record does not establish is the size of the primary outcome change. Numerical results for the primary endpoint are not reported in the registry record, so readers cannot assess the direction, magnitude or precision of the group’s change. The endpoint definition indicates how a result would be interpreted, but does not reveal what result was observed. No conclusion about the size or certainty of the primary change can be drawn from an outcome definition alone.

Even if a within-group change were reported, this design would not by itself show that the treatment caused that change. The absence of a concurrent control means that change over time cannot be separated from other possible influences. Open-label treatment and diary-based assessment are additional features to consider when evaluating subjective outcomes. These limitations do not invalidate descriptive observations, but they restrict causal and comparative interpretations.

The record’s safety information identifies serious adverse events in the treated group and gives selected event terms with percentages. It does not provide a comparative safety estimate. The number of participants in the primary analysis population, missing-data methods, multiplicity strategy and original statistical plan are not reported in the registry record. Each omission limits a different aspect of interpretation: the analysis denominator, potential sensitivity to unavailable observations, interpretation across outcomes, and evaluation of prespecified methods.

Thus, the registry record is informative about the study question, design and outcome definitions, but incomplete for judging the primary efficacy estimate. A planning illustration is not a replacement for an observed result, and it is not observed power. The stated planning assumptions concern a hypothetical two-arm calculation, whereas the trial itself is single-group. Keeping those distinctions clear prevents a design description, a planning calculation and an outcome result from being mistaken for one another.

13. Why This Trial Matters Statistically

This study is statistically notable because its primary question is framed as a change from baseline in a continuous, diary-derived outcome, while the design has no concurrent control group. That combination can describe change within the treated group, but it cannot provide the direct randomized comparison that would help distinguish treatment-associated change from other changes over time. Readers need to match the strength of the conclusion to the strength of the design.

The outcome construction also matters. Diary entries are collected repeatedly, normalized to a 16-hour scale and averaged across the 3 days before selected visits. Those steps define the estimand—the quantity the analysis is intended to describe. They offer a structured summary of daily “Off” time, but the resulting mean does not show every participant’s experience or the day-to-day pattern. The registry record gives the measurement definition but not the numerical mean change or its uncertainty.

The analysis population is defined using treatment exposure and availability of baseline and post-PEG-J efficacy data. This makes missing-data practices and the number contributing to analysis important for interpretation, yet neither is reported. The registry also lists numerous outcome measures. Without a reported multiplicity strategy or numerical results, the reader cannot assess how secondary findings should be weighed relative to the primary endpoint.

Finally, the safety record offers counts and selected event percentages in the LCIG group, but no concurrent comparator. Those data support a description of reported events, not a comparative risk estimate. Taken together, the record illustrates why statistical interpretation requires more than an endpoint label: design, analysis population, uncertainty, missingness, multiplicity and comparison structure all shape what a result can mean. In this case, the registered methods and safety entries can be described, but the primary numerical result needed to quantify change is not reported in the registry record.

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 trial-specific limitation for interpreting efficacy is that the registry describes a single-arm, open-label, baseline-controlled design. A within-group comparison does not control for time-related changes or other influences in the way a concurrent comparison group could. Awareness of treatment may also affect diary reporting and other subjective assessments. The registry record does not report methods for addressing these design limitations.

Numerical results for the primary “Off” time endpoint are not reported in the registry record. Without the baseline and final means, the mean change, its standard deviation and an uncertainty interval, the observed effect and its precision cannot be evaluated. The number meeting the Full Analysis Set definition is also not reported, so the primary analysis denominator cannot be determined from the record.

The record does not report how missing diaries or visits were handled, whether analyses were prespecified in a statistical analysis plan, or how multiplicity across outcome measures was addressed. The listed secondary outcome names therefore do not establish the strength of evidence for those measures. The original sample-size justification and any interim analyses are not reported in the registry record.

Safety interpretation is limited by the absence of a concurrent control group and by the level of detail in the registry entries. The selected serious adverse event terms and percentages do not provide timing, recurrence, duration or a comparative estimate. The record does not report a death count. These limitations mean the entries can be described as registry-reported events, but should not be treated as a complete account of clinical context or comparative safety.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Study to Assess the Efficacy, Safety and Tolerability of ABT-SLV187 Monotherapy in Subjects With Advanced Parkinson's Disease (PD) and Persistent Motor Complications, Despite Optimized Treatment With Available Anti-Parkinsonian Medications — NCT01960842.
• Registry record last updated 2018-05-30; status last verified 2016-04.
• Results first posted 2016-04-20.
• 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.

18. Record Summary

The registry record describes a completed Phase 3, multicenter, open-label, single-arm study of LCIG in advanced Parkinson’s disease with persistent motor complications despite optimized treatment with available anti-Parkinsonian medication. It lists 31 participants enrolled and identifies the primary endpoint as change from baseline in average daily normalized “Off” time at the final PEG-J visit, up to week 12. Negative change is defined as improvement.

The primary endpoint is based on the Parkinson’s Disease Symptom Diary, with normalized daily totals averaged across the 3 days before selected visits. The Full Analysis Set requires treatment exposure and available baseline and post-PEG-J efficacy data. Its size is not reported in the registry record.

Numerical results for the primary endpoint, its precision and the secondary outcomes are not reported in the registry record. Serious adverse event information lists 4 affected participants among 31 at risk; selected event terms are also listed with percentages. A death count is not reported. The design supports description of within-group change and reported events, but does not provide a randomized treatment comparison.