A Study To Evaluate The Safety And Efficacy Of IPX066 In Subjects With Parkinson's Disease: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study To Evaluate The Safety And Efficacy Of IPX066 In Subjects With Parkinson's Disease (NCT00880620), a randomized phase 3 study. The primary outcome is Change From Baseline in the Sum of UPDRS Part II + UPDRS Part III at Week 30.

2. Clinical Question

3. Trial Design

This was a Phase 3 randomized, quadruple-masked, parallel-group study of IPX066 in people with Parkinson’s disease. The registry identifies placebo and several IPX066 interventions. The primary results report placebo and three IPX066 dose groups: 145 mg LD, 245 mg LD, and 390 mg LD. The registry reports enrollment of 381 and marks the study completed. The recorded start is 2009-04, and primary completion is listed as 2010-10.

The arm descriptions indicate staged dosing. For the 145 mg LD group, the description starts with IPX066 95 mg LD and then changes to 145 mg LD; for the 245 mg LD group, it describes progression through several dose levels before the study’s week 30 end. The 390 mg LD description also specifies staged dosing and describes two IPX066 195 mg LD capsules during the later period. Placebo dosing is described as changing during the study. These descriptions help distinguish the treatment courses, but they do not establish the rationale for the dosing schedule.

The registry’s intervention listing and arm descriptions are not fully aligned with the primary outcome arms: the intervention listing includes doses that do not appear as primary-result arms, while the results include a 390 mg LD arm. The record does not explain this difference. The registry identifies the design as randomized, masked, and parallel group, but details about the allocation procedure, masking roles, sequence generation, and concealment are not reported in the registry record.

The primary outcome was assessed at week 30, described as the end of study. Enrollment is not a substitute for the number contributing to an outcome: the primary results give separate arm-specific analysis counts. The registry does not report the original sample-size justification or its design assumptions.

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: Following enrollment, subjects were randomized into one of the four treatment groups.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Analysis included all treated subjects with at least one efficacy measurement after dosing. Subjects who had no post-baseline efficacy assessments (N4) and those who had early termination assessments\>3 days after last dose and no other post-baseline measurements (N16) were not included in the efficacy analysis set. Randomized (381)-(4+16) = 361.

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: Baseline Analysis Population is all treated

6. Primary Endpoint

The registry lists the primary outcome as Change From Baseline in the Sum of UPDRS Part II + UPDRS Part III at Week 30, measured over Week 30.

The primary endpoint was change from baseline to week 30 in the sum of UPDRS Part II and UPDRS Part III. Part II assesses activities of daily living, and Part III assesses motor examination. Combining the two parts gives a single continuous score covering both domains. The registry states that higher UPDRS scores represent worse outcomes; accordingly, a negative change indicates a lower score at follow-up than at baseline.

A continuous score preserves information about the amount of change rather than reducing each participant’s result to a category such as improved or not improved. Comparing mean changes between groups can therefore describe the average difference in score change. In this study, the reported mean differences contrast each IPX066 dose group with placebo. Those differences are group-level summaries and do not describe the response of every participant.

The registry describes an analysis population including treated subjects with at least one efficacy measurement after dosing. It also states that some subjects were excluded for having no post-baseline efficacy assessment or for having only an early-termination assessment more than three days after the last dose. The description is truncated, so its complete wording and any further population details are not reported in the registry record. A threshold for a clinically important change in the combined score is also not reported in the registry record. Thus, the endpoint supports interpretation of measured score differences, but the record alone does not establish their clinical importance.

7. Results Posted in the Registry

• IPX066 145mg LD: mean -11.70 versus -0.60 on control; difference -11.10 (95% CI -14.30 to -7.90), standardized effect d = -1.04; z-test p = <0.001.
• IPX066 245 mg LD: mean -12.90 versus -0.60 on control; difference -12.30 (95% CI -15.41 to -9.19), standardized effect d = -1.13; z-test p = <0.001.
• IPX066 390 mg LD: mean -14.90 versus -0.60 on control; difference -14.30 (95% CI -17.55 to -11.05), standardized effect d = -1.28; z-test p = <0.001.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Summary of Change From Baseline to End of Study in Mean Parkinson's Disease Questionnaire-39 (PDQ-39) Score

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • IPX066 145 mg LD: mean -4.40 versus 0.60 on control; difference -5.00 (95% CI -8.51 to -1.49), standardized effect d = -0.43; z-test p = 0.005.
  • IPX066 245 mg LD: mean -3.80 versus 0.60 on control; difference -4.40 (95% CI -7.72 to -1.08), standardized effect d = -0.38; z-test p = 0.009.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for IPX066 145 mg LD than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for IPX066 245 mg LD than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The posted secondary outcome is change in the mean Parkinson’s Disease Questionnaire-39 score from baseline to week 30 or end of study. The pattern of group means is directionally consistent with lower scores in the IPX066 groups and a higher mean change in placebo. The posted comparisons against placebo also point in that direction. This offers a patient-reported quality-of-life measure alongside the primary clinician-rated UPDRS outcome, but the measures assess different aspects of the trial and should not be treated as interchangeable.

The secondary results are less definitive than a prespecified primary comparison because the registry reports them as unadjusted and does not report a multiplicity procedure. When multiple outcomes or comparisons are considered, the chance of finding at least one apparently notable result by chance can increase. A nominal p-value for a secondary comparison does not account for that wider set of questions unless an adjustment or testing strategy is specified. No reported secondary analyses are listed in the registry record.

The secondary findings can therefore be read as supportive descriptive evidence about the posted outcome, rather than as an independent confirmation of the primary result. The record does not report a hierarchy or gatekeeping strategy linking the secondary outcome to the primary endpoint, nor does it report a clinical-importance threshold for the PDQ-39 change. Statistical evidence, the consistency of outcome direction, and clinical meaning are separate considerations. The secondary pattern should be interpreted in that context and not as proof that the measures capture the same effect.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Summary of Change From Baseline to End of Study in Mean Parkinson's Disease Questionnaire-39 (PDQ-39) Score

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous: it is a score, and the registry reports its mean change and standard deviation in each arm. A mean is the arithmetic average of the measured changes in an analysis group. It describes the group’s central tendency, but it does not imply that every participant had the same change. The standard deviation describes how spread out individual measurements are around that group mean. A larger standard deviation indicates greater variation among observed values, not greater uncertainty in the mean by itself.

What does the mean difference describe?

The reported mean difference compares the average change in an IPX066 group with the average change in placebo. For the primary outcome, the posted comparisons are -11.1 for IPX066 145 mg LD, -12.3 for IPX066 245 mg LD, and -14.3 for IPX066 390 mg LD. These are unadjusted contrasts, and the score’s stated direction matters: higher UPDRS scores are worse. A negative contrast means the IPX066 group’s mean change is lower than the placebo group’s mean change. It does not mean that the same amount of change occurred for each participant.

These are comparisons with a shared placebo group. They do not test whether the dose groups differ from each other. Comparing the sizes of their separate placebo contrasts can be descriptive, but a formal claim about differences among doses would require a direct comparison and its uncertainty. Such a dose-to-dose analysis is not reported in the registry record.

What does a p-value tell the reader?

A p-value describes how compatible the observed data are with a specified null hypothesis under the statistical model used. In a simple mean comparison, the null hypothesis commonly represents no difference in population means. A small p-value indicates that results at least as incompatible with that null would be unusual under the model’s assumptions. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of a difference.

The primary comparison p-values are reported as unadjusted and each is <0.001. “Unadjusted” means the values have not been corrected for the set of multiple comparisons in the posted record. This is important when several doses or outcomes are assessed, because considering more comparisons can increase the chance of at least one apparently positive result by chance. The registry does not report whether another multiplicity strategy was prespecified or used.

Why do confidence intervals matter?

A confidence interval gives a range of values compatible with the data under the method’s assumptions and conveys uncertainty around an estimate. It is more informative than a point estimate alone: the estimate is not known with perfect precision, and plausible values extend across the interval. A confidence interval’s width depends on the variation in the observations and the amount of information contributing to the estimate. It does not represent the range of individual participant outcomes.

For these results, each posted primary mean-difference interval is below zero throughout. That is consistent with the reported direction of the point estimates. The intervals are unadjusted, however, and should not be mistaken for multiplicity-adjusted intervals. Neither an interval nor a p-value determines whether a score difference matters clinically; that requires relevant clinical interpretation, and a threshold is not reported in the registry record.

How should the standard deviation and analysis counts be read?

The primary arm summaries report the mean change, standard deviation, and number analyzed in each arm. The analysis counts are not the same as the registry’s overall enrollment. The primary population description says that the analysis included treated subjects with at least one efficacy measurement after dosing and describes exclusions for certain missing or late assessments. Because the description is truncated, the full analysis-population rule is not available in the registry record.

In general, missing outcome data can affect a mean comparison if participants without measurements differ from those who contribute results. The registry record does not give a complete account of missing-data methods, imputation, or sensitivity analyses. It is therefore not possible from this record to assess how robust the reported estimates are to alternative assumptions about missing outcomes.

What can the posted analysis establish?

Randomization is intended, in general, to make treatment groups comparable on average at assignment, including on factors that are measured and unmeasured. Masking can generally reduce the influence of expectations on care, assessment, or reporting. These design features support interpretation of between-group contrasts, but they do not substitute for information about implementation, analysis, adherence, or missing data. The registry identifies randomization and quadruple masking but does not report the operational details needed to assess those processes.

The posted summaries give group means, standard deviations, mean differences, confidence intervals, and unadjusted p-values. They do not report the full statistical analysis plan, model specification, covariate adjustment, or diagnostic checks. General statistical interpretation therefore needs to stay close to what is reported: unadjusted group-level comparisons of mean change, with the stated outcome population and the record’s limitations.

11. Confidence Intervals and Precision

The confidence intervals quantify uncertainty around the reported mean differences. For the primary outcome, the interval for IPX066 145 mg LD versus placebo is -14.3 to -7.902; for IPX066 245 mg LD versus placebo it is -15.41 to -9.193; and for IPX066 390 mg LD versus placebo it is -17.55 to -11.05. Each interval lies below zero, matching the negative direction of its point estimate. These ranges describe uncertainty about the group mean contrast under the analysis method, not the spread of individual participants’ changes.

All three intervals have a finite range of values rather than identifying an exact underlying difference. Their width reflects the precision of the estimates: narrower intervals indicate greater precision, while wider intervals indicate less. The group standard deviations and analysis counts contribute to the uncertainty, along with the method used for the comparison. The registry does not provide enough detail about the model to evaluate all assumptions behind the intervals.

The intervals are unadjusted, as are the posted p-values. They should not be read as confidence intervals simultaneously covering all primary dose comparisons with a controlled familywise error rate. The registry record does not report a multiplicity procedure. In addition, a confidence interval cannot determine whether a difference is clinically meaningful. A threshold for clinical importance on the combined UPDRS score is not reported in the registry record.

The intervals are consistent with a mean contrast below zero for each dose comparison under the reported calculation. They do not establish the range of individual responses, and they do not show whether all participants’ results were in the same direction. They also do not quantify uncertainty about comparisons between active doses, which are not the contrasts reported for the primary outcome.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size estimates are planning illustrations based on the observed mean differences, not the original trial design. For these continuous outcomes, the figures are participants per arm, not a total across arms or a total number of events. The stated assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. Each planning row uses the stated fraction of the observed effect as the effect to detect.

The 80% power column gives the illustrative number of participants per arm for a design with an 80% chance of detecting the specified effect under those assumptions, if that effect were the true effect and the model assumptions held. The 90% power column gives the corresponding per-arm figure for a 90% chance. These are design probabilities, not probabilities that a finding is true and not estimates of how likely the completed trial was to detect its result.

Rows using a smaller fraction of the observed effect represent planning for a smaller difference. Smaller effects are harder to distinguish from random variation, so they require more participants per arm to reach the same target power under otherwise unchanged assumptions. The displayed figures are conditional on the observed trial effect and the stated simplified assumptions; they do not replace a prospective design calculation using a justified target effect and the trial’s planned analysis.

This is not observed power. It is a planning illustration, and it does not establish that the completed trial was adequately or inadequately powered. The registry’s own original sample-size rationale and design assumptions are not reported in the registry record.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -11.100; pooled standard deviation σ = 10.660.
2. n = 2 × (1.96 + 0.842)² × 10.660² / -11.100² = 14.5, rounded up to 15 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -11.1                      # observed difference in means
sigma <- 10.6600951877441                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(880620)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 15 (80% power), 20 (90% power)
 75% of observed effect: n per arm = 26 (80% power), 35 (90% power)
 50% of observed effect: n per arm = 58 (80% power), 78 (90% power)
power.t.test: 15.5 
Simulated power at n = 15 per arm: 0.786 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

The primary results include three comparisons of IPX066 dose groups with placebo, and the registry also reports a secondary outcome. This creates more than one statistical question. If each comparison is assessed separately without adjustment, the probability of at least one false-positive finding across a family of tests can be higher than the error rate for any single test. This is the general reason multiplicity matters; the size of that increase depends on the number and dependence of the tests and on the method used.

The primary p-values are explicitly unadjusted. The registry does not report a familywise error procedure, a hierarchical testing sequence, or another multiplicity strategy. It also does not report whether the secondary endpoint was confirmatory or exploratory in the original analysis plan. The posted p-values should therefore be read as nominal results for their individual comparisons, not as multiplicity-controlled evidence across the full set of outcomes and dose comparisons.

The record describes an efficacy analysis population based on treatment and availability of a post-dosing efficacy measurement, and it identifies types of assessments excluded from that analysis. The description is truncated before its full wording is complete. The registry does not report a complete missing-data strategy, imputation method, sensitivity analysis, or details of how participants with incomplete follow-up were handled. Those omissions limit assessment of whether the observed analysis might be affected by the way missing outcomes were treated.

The registry does not report the full statistical analysis plan, model details, covariate adjustment, interim analyses, or the original sample-size justification. These should not be inferred from the posted summary statistics. Randomization and masking are identified, but operational details of allocation and masking are not reported in the registry record. As a result, the reported contrasts can be described, while some features needed to evaluate the complete confirmatory analysis remain unknown.

15. 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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: acute myocardial infarction (1.1%), coronary artery disease (1.1%), myocardial infarction (1.1%), escherichia urinary tract infection (1.1%), urosepsis (1.1%).

The registry reports serious adverse events by treatment group as affected participants and participants at risk. For placebo, 3 of 92 participants at risk had a serious adverse event; the corresponding figures are 4 of 87 for IPX066 145 mg LD, 5 of 104 for IPX066 245 mg LD, and 2 of 98 for IPX066 390 mg LD. These are group-specific counts, not estimates adjusted for exposure duration or differences among participants.

For other adverse events, the record reports 26 of 92 for placebo, 27 of 87 for IPX066 145 mg LD, 47 of 104 for IPX066 245 mg LD, and 48 of 98 for IPX066 390 mg LD. The registry lists several serious-event terms at 1.1% each: acute myocardial infarction, coronary artery disease, myocardial infarction, Escherichia urinary tract infection, urosepsis, and cerebrovascular accident. These term-level percentages should not be added together; the record does not provide enough information to determine whether terms overlap within participants.

Death counts are not reported in the registry record. Adverse-event summaries alone do not establish causation or permit a complete comparison of safety. The record does not provide detailed event timing, exposure-adjusted rates, or a complete narrative of event assessment.

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

The primary results describe group-level changes in the combined UPDRS Part II and Part III score from baseline to week 30. The mean change was more negative in each posted IPX066 group than in placebo, and the reported mean contrasts were also negative. Since higher scores represent worse outcomes, the observed pattern is one of a greater average decrease in the score in the IPX066 groups relative to placebo. The confidence intervals and unadjusted p-values provide statistical context for those comparisons.

This does not mean that every participant changed in the same way, or that the group average describes an individual’s experience. The standard deviations indicate variation within groups, and the registry does not post participant-level outcome distributions. Nor do the separate comparisons establish that one IPX066 dose is superior to another. A direct comparison among doses is not reported.

Statistical evidence does not by itself establish clinical importance. The registry does not report a threshold for a clinically meaningful change in the combined UPDRS score. The secondary PDQ-39 outcome adds a different measure, but its unadjusted results do not remove uncertainty about multiplicity or clinical meaning. The posted summaries should therefore be interpreted as estimates of group differences on the stated measures, rather than as a complete account of benefit or overall treatment effects.

The results also have boundaries. The primary analysis population was defined by treatment and post-dosing efficacy measurement, not simply by enrollment. The full population description is truncated, and the handling of missing data is not fully reported. Multiplicity procedures and the complete statistical analysis plan are also not reported in the registry record. These limitations affect how confidently the estimates can be generalized beyond the analysis as posted.

The trial record reports adverse-event counts, but those counts do not establish that events were caused by a treatment and do not summarize every aspect of safety. The results do not support medical advice or a recommendation for an individual. They describe the posted outcomes of this randomized study, with the statistical and reporting limitations noted above.

17. Why This Trial Matters Statistically

This trial illustrates how a continuous clinical scale can be analyzed through change from baseline and between-group mean contrasts. Reporting the arm means and standard deviations alongside the mean differences allows readers to distinguish the observed group changes from the comparative estimates. The confidence intervals add information about estimate precision, while the p-values address compatibility with a null comparison under the analysis assumptions. None of these summaries alone answers every clinical question.

It also demonstrates why the analysis population matters. Enrollment and the number contributing to an endpoint are not interchangeable. The registry defines the primary efficacy population using post-dosing measurements and describes exclusions, while outcome counts are presented by arm. A clear account of who is included and how missing outcomes are handled is important for judging what a result represents.

The study reports multiple dose-versus-placebo comparisons and a secondary outcome. The p-values are unadjusted, and no multiplicity strategy is reported. This makes it important to distinguish individual nominal findings from a prespecified, multiplicity-controlled set of conclusions. Similarly, comparisons of the separate dose effects should not be mistaken for a formal test of dose differences.

Finally, this record shows the value of separating statistical evidence from clinical importance and safety interpretation. The outcome direction is interpretable because the registry states that higher UPDRS scores represent worse outcomes, but a clinical-importance threshold is not reported. Adverse events are summarized as counts, without enough information to resolve every question about causation or exposure. Careful reading therefore depends on both the numerical estimates and the boundaries of the registry’s reporting.

18. 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 limitations are specific to the posted record. The primary population description ends mid-word after describing which participants were included and excluded. It is possible to report the stated eligibility features, but the full wording and any additional population rules are not reported in the registry record. The registry also does not give a complete account of missing-data methods, imputation, or sensitivity analyses, limiting assessment of the influence of incomplete follow-up.

The primary p-values and confidence intervals are unadjusted. The record does not report how multiplicity across dose comparisons and outcomes was addressed, if at all. It does not report the full analysis plan, the model specification, covariate adjustment, or interim analyses. The original sample-size rationale and planning assumptions are not reported in the registry record; the displayed planning figures use the observed effect and are illustrations rather than the trial’s original design calculation.

There is an inconsistency between the recorded intervention listing and the primary result arms. The listing includes dose levels that are not presented as primary result arms, while the primary results include IPX066 390 mg LD. The arm descriptions also do not make every listed intervention correspond directly to a reported primary-result group. The registry does not explain this difference. The meaning of “LD” is not reported in the registry record.

The outcome summaries do not include participant-level data, and no threshold for clinical importance is reported for the primary or secondary score. Safety results are reported as event counts and selected serious-event terms; death counts are not reported in the registry record. These limits mean the posted summary should be read as a report of specific group-level outcomes, not a complete account of trial conduct or every possible clinical interpretation.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: A Study To Evaluate The Safety And Efficacy Of IPX066 In Subjects With Parkinson's Disease — NCT00880620.
• Registry record last updated 2019-10-29; status last verified 2017-08.
• Results first posted 2016-02-22.
• 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.

22. Record Summary

The registry identifies NCT00880620 as a completed Phase 3 randomized, quadruple-masked, parallel-group study of IPX066 in people with Parkinson’s disease. Enrollment is reported as 381, with a recorded start of 2009-04 and primary completion in 2010-10.

The primary outcome was change from baseline to week 30 in the sum of UPDRS Part II and Part III. The posted results compare placebo with IPX066 145 mg LD, 245 mg LD, and 390 mg LD. All three reported mean contrasts versus placebo are negative, with unadjusted p-values <0.001. A secondary PDQ-39 change outcome and adverse-event summaries are also reported.

The registry does not report a multiplicity procedure, complete missing-data methods, the full statistical analysis plan, or the original sample-size rationale. The primary analysis-population description is truncated, and the recorded intervention listing does not fully align with the primary result arms. These details constrain interpretation of the posted estimates.