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 Rasagiline Rescue in Alzheimer's Disease Clinical Trial (NCT02359552), a randomized phase 2 study. The primary outcome is Change in Regional Glucose Metabolism Between Week 24 and Baseline as Measured by 18F-2-fluoro-2-deoxy-D-glucose Positron Emission Tomography (FDG-PET)..
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02359552 |
| Phase | Phase 2 |
| Condition | Alzheimer's Disease |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 50 |
| Arms in the primary outcome | n/a |
| Lead sponsor | The Cleveland Clinic |
| Results posted | Yes |
2. Clinical Question
Population
People with mild to moderate Alzheimer’s disease were the population described for this three-site study. The registry record lists Alzheimer’s disease as the condition. Further eligibility details, such as specific diagnostic criteria or participant characteristics, are not reported in the registry record. The record lists an enrollment of 50.
Intervention
The intervention was rasagiline, a drug. The arm description says participants were randomized to rasagiline or matching placebo and describes a 24-week treatment period. It also begins to describe a once-daily dose starting at 0.5 mg and titration to 1 mg, but the full regimen is not reported in the registry record.
Comparator
The comparator was matching placebo. The study is described as placebo controlled, randomized, and parallel group. The arm descriptions state that assignment was in a 1:1 ratio. The registry record does not report the outcome values needed to assess how the groups compared on the primary measure.
Primary question
The primary question was whether change in regional brain glucose metabolism from baseline to week 24, measured using FDG-PET and expressed as SUVR, differed with rasagiline compared with placebo. The planned measure covered several specified brain regions. The record explains how the change score was calculated and how its direction is interpreted, but does not report group results or a statistical comparison.
3. Trial Design
The registry describes a completed Phase II, randomized, placebo-controlled, parallel-group study conducted at three sites. Its official title calls it a proof-of-concept study and describes double blinding; the registry’s masking classification is triple. These descriptions identify the study as masked, but the record does not explain which groups of people were included in the masking classification or how masking was maintained.
The study compared rasagiline with matching placebo over a 24-week treatment period. The arm descriptions state that participants were randomized in a 1:1 ratio. The registry lists enrollment as 50, but arm-specific enrollment and the numbers contributing to each outcome are not reported in the registry record. The arm descriptions include a fragment about once-daily dosing, starting with 0.5 mg and titrating to 1 mg, but the complete treatment instructions are not available in the record.
The primary outcome was change in regional glucose metabolism measured by FDG-PET at week 24 relative to baseline. Secondary outcomes listed in the registry include changes in cognitive, daily-living, neuropsychiatric, and quality-of-life measures, as well as Digit Span and COWAT scores. The record lists 8 outcome measures, but does not provide results for these measures.
The record marks the trial completed and lists a primary completion date of 2018-08-29. A full protocol, the detailed statistical analysis plan, participant flow, and an explanation of the enrollment target are not reported in the registry record. The fact that the trial is marked completed does not, by itself, establish what its results were or whether all planned analyses were performed.
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: Of 96 screened participants, 50 met inclusion criteria and were enrolled and randomized to treatment.
Overall Study
| Stage | Placebo | Rasagiline |
|---|---|---|
| STARTED | 25 | 25 |
| COMPLETED | 22 | 21 |
| NOT COMPLETED | 3 | 4 |
Reasons for not completing this period:
| Reason | Placebo | Rasagiline |
|---|---|---|
| Lost to Follow-up | 3 | 4 |
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | Placebo | Rasagiline | Total |
|---|---|---|---|---|
| Participants analysed | 25 | 25 | 50 | |
| Age, Continuous | years | 73.44 (SD 7.12) | 74.72 (SD 7.35) | 74.08 (SD 7.19) |
| Sex: Female, Male: Female | Participants | 11 | 14 | 25 |
| Sex: Female, Male: Male | Participants | 14 | 11 | 25 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 25 | 25 | 50 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 1 | 1 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 1 | 0 | 1 |
| Race (NIH/OMB): White | Participants | 24 | 24 | 48 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | participants | 25 | 25 | 50 |
| Alzheimer's Disease Assessment Scale - Cognitive 11 score | units on a scale | 27.96 (SD 10.53) | 23.2 (SD 6) | 25.58 (SD 8.81) |
| Mini Mental Status Examination (MMSE) | units on a scale | 19.04 (SD 4.61) | 21.24 (SD 3.54) | 20.14 (SD 4.21) |
| Alzheimer's Disease Cooperative Study - Activities of Daily Living (ADCS-ADL) score | units on a scale | 58.2 (SD 11.1) | 61.88 (SD 8.44) | 60 (SD 9.96) |
| Neuropsychiatric Inventory (NPI) score | units on a scale | 8.28 (SD 8.97) | 7.62 (SD 7.61) | 7.96 (SD 8.25) |
| digit span | units on a scale | 11.76 (SD 3.23) | 13.08 (SD 2.75) | 12.42 (SD 3.04) |
| Controlled Oral Word Association Test (cowat) score | units on a scale | 21.16 (SD 13.16) | 26.72 (SD 12.6) | 23.94 (SD 13.06) |
| Quality of Life - Alzheimer's Disease (QoL-AD) | units on a scale | 39.58 (SD 5.24) | 36.73 (SD 5.35) | 38.22 (SD 5.43) |
6. Primary Endpoint
The registry lists the primary outcome as Change in Regional Glucose Metabolism Between Week 24 and Baseline as Measured by 18F-2-fluoro-2-deoxy-D-glucose Positron Emission Tomography (FDG-PET)., measured over 24 weeks.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | SUVR |
| Endpoint classification | Continuous Endpoint |
The primary endpoint was change in regional glucose metabolism between baseline and week 24, measured with FDG-PET and expressed as SUVR. The registry names several prespecified regions: medial temporal, lateral temporal, posterior cingulate-precuneus, inferior parietal, middle frontal, anterior cingulate, and striatum. The record describes the measure as a mean with standard deviation and gives a 24-week timeframe.
FDG-PET is used to assess glucose metabolism in the brain. As a general explanation, a regional imaging measure can provide information about brain function that is not captured by a symptom or cognitive score alone. This endpoint therefore focuses on a biological measure rather than directly measuring memory, everyday function, or quality of life. The registry also lists changes in several such clinical measures as secondary outcomes.
The registry states that the change score was calculated by subtracting the value at 24 weeks from baseline. It says negative values indicate increased hypometabolism, described in the record as worsening of cell function. That stated direction matters when interpreting any reported score: a negative change should not be casually described as an increase in metabolism. However, no regional values, group summaries, uncertainty estimates, or between-group comparison are reported in the registry record. The endpoint definition alone does not establish the direction or magnitude of any observed difference.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The record identifies a randomized comparison of rasagiline and placebo, but it does not report the primary outcome results. In particular, there are no group-level SUVR change values, estimates of the difference between groups, confidence intervals, or test results in the registry record. The primary outcome is also specified across several brain regions, and the record does not provide a result for any of those regions. A treatment effect, its direction, and its precision therefore cannot be interpreted from the registry information available.
The registry lists 8 outcome measures and 0 analyses. This means that the posted record does not include outcome-analysis entries from which to assess the primary comparison or the secondary outcomes. It does not establish whether analyses were conducted elsewhere, whether results were omitted, or what results such analyses might have produced. Those details are not reported in the registry record.
For a continuous outcome, a group mean describes the average measurement in that group, while a between-group estimate describes the contrast between groups. A confidence interval, as a general statistical concept, gives a range of values compatible with the estimate under the method used. The width of such an interval helps convey precision. Neither group means nor an interval for the primary endpoint is reported, so the precision of any contrast cannot be assessed.
The registry’s safety information lists serious adverse events affecting 4 participants in the placebo group and 1 in the rasagiline group, with 25 at risk in each group. It lists other adverse events affecting 15 participants in the placebo group and 16 in the rasagiline group, again with 25 at risk in each group. Deaths are listed as 0 in each group. These are descriptive counts; the record does not provide an inferential comparison or the information needed to determine whether the groups differed beyond chance. They should not be read as proof of a treatment effect or as evidence about causation.
Overall, the record establishes the trial’s design, intended primary measure, and some adverse-event counts, but not its efficacy results. Without outcome estimates and their uncertainty, no conclusion about the comparative primary endpoint can be drawn from this registry record.
9. Statistical Methods Explained
The registry describes a randomized, parallel-group comparison of rasagiline with placebo. Randomization is intended, in general, to make treatment groups comparable with respect to measured and unmeasured characteristics on average. It does not guarantee that groups will be identical in a particular trial, especially when enrollment is limited. The record states a 1:1 allocation ratio but does not report the method used to generate the random sequence, whether allocation was concealed, or whether any randomization procedures were stratified.
What does a continuous endpoint mean?
The primary endpoint is a continuous measurement: SUVR change in regional brain glucose metabolism. A continuous measure can take a range of numerical values rather than placing each participant into a small set of categories. The registry describes the outcome as a mean with standard deviation. A mean represents the average, while a standard deviation describes the spread of individual measurements around that average. These are different summaries: the standard deviation describes variation among observations, not the uncertainty of the group mean.
The record defines change by subtracting the week 24 value from baseline and states that negative scores indicate increased hypometabolism. This direction is important because change scores can be defined in either order. In general, interpreting a change score requires following the specific definition used, rather than assuming that positive values always indicate improvement or that negative values always indicate worsening. The record does not report the observed scores, so this definition cannot be used to infer what happened in either group.
Why does the regional structure matter?
The primary outcome description names several brain regions. In general, measurements from different regions may show different patterns, so an average across regions can answer a different question from a region-by-region analysis. The registry record does not report whether a single combined endpoint, separate regional comparisons, or another summary was intended for the principal statistical test. It also does not report regional estimates or clarify how the multiple regions were handled in the analysis.
When a study considers multiple outcomes or regions, the chance of at least one apparently unusual result can increase if each is tested separately without an appropriate plan. Methods for addressing multiplicity may include prespecifying a primary comparison, adjusting inference, or treating secondary analyses as exploratory. Which approach was used in this trial is not reported in the registry record. No correction or unadjusted test result can be inferred from the endpoint list alone.
What would an uncertainty estimate add?
As a general explanation, a confidence interval around a treatment contrast communicates both the estimated difference and its statistical precision. A narrow interval indicates greater precision than a wide interval, under the assumptions of the method. A p-value, if reported, would address compatibility between the observed data and a specified null hypothesis under a particular testing procedure; it would not measure the probability that a treatment works. The registry does not report a confidence interval, p-value, or primary group contrast, so neither statistical significance nor precision can be evaluated.
For continuous outcomes, analyses can compare group means or adjust for baseline measurements and other prespecified factors. Adjusting for baseline can sometimes improve precision, but the analysis choice and covariates must be specified and justified. The statistical model, any baseline adjustment, handling of repeated or regional measures, and assumptions used for the primary analysis are not reported in the registry record. It is therefore not possible to reproduce or judge the planned analysis from the registry entries.
How should planning illustrations be read?
The registry describes sample-size planning illustrations based on an observed effect, using a two-sided significance level of 0.05, equal allocation, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. Such illustrations are hypothetical planning calculations: they describe participant counts under stated assumptions, not outcomes observed in this trial. They are not observed power. The registry record does not give numerical planning estimates in the information available for this analysis, so no planning count can be interpreted or repeated.
In general, planning calculations depend on the target effect, variability, significance level, allocation, and analysis method. A calculation based on an observed effect is particularly dependent on the stability of that effect estimate. It should not be mistaken for evidence that the trial had a particular probability of detecting a real effect. No sample-size justification, target effect, or protocol-based power calculation is reported in the registry record.
Finally, statistical interpretation depends on who was analyzed, how missing outcome measurements were handled, and whether the analysis followed the planned approach. The registry record does not report analysis populations, missing-data methods, exclusions, or a detailed analysis plan. Those omissions limit assessment of both the validity and reproducibility of any hypothetical interpretation; they do not permit assumptions about what methods were actually used.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary imaging endpoint involving several specified brain regions and also lists secondary cognitive, functional, neuropsychiatric, and quality-of-life outcomes. Considering multiple regions and outcomes raises a general multiplicity issue: when many statistical tests are performed, the overall chance of at least one false-positive finding can be greater than for a single prespecified test. Researchers can address this through a prespecified hierarchy, statistical adjustment, or by treating some analyses as exploratory. The approach used in this trial is not reported in the registry record.
The record does not include outcome analysis entries, despite listing 8 outcome measures. It therefore does not show which outcomes were analyzed, whether all prespecified analyses were reported, or how multiple comparisons were handled. There are no posted primary or secondary outcome estimates to compare or interpret.
Missing outcome data can affect both the estimated treatment contrast and its precision. As a general explanation, the consequences depend on how much data are missing, why they are missing, and the assumptions and methods used to address them. Participant flow, outcome-specific denominators, reasons for missing measurements, and imputation or other missing-data methods are not reported in the registry record.
The record also does not identify whether the primary analysis used all randomized participants, only participants with available endpoint measurements, or another analysis population. It does not report protocol deviations or exclusions. These omissions prevent assessment of whether the analysis preserved the randomized comparison and how sensitive results might be to missingness or analysis choices. They should be treated as unreported information, not evidence that a particular method was or was not used.
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 |
|---|---|---|---|
| Placebo | 4 | 25 | 16.0% |
| Rasagiline | 1 | 25 | 4.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Placebo | 0 of 25 |
| Rasagiline | 0 of 25 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Placebo | 15 of 25 |
| Rasagiline | 16 of 25 |
Most frequent serious adverse event terms
| Event term | Organ system | Placebo | Rasagiline |
|---|---|---|---|
| confusion | Psychiatric disorders | 1 of 25 | 0 of 25 |
| delusions | Psychiatric disorders | 1 of 25 | 0 of 25 |
| atrial fibrillation | Cardiac disorders | 0 of 25 | 1 of 25 |
| fall | Injury, poisoning and procedural complications | 1 of 25 | 0 of 25 |
| stroke | Nervous system disorders | 1 of 25 | 0 of 25 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Placebo | Rasagiline |
|---|---|---|---|
| Delusions | Psychiatric disorders | 3 of 25 | 3 of 25 |
| Elevated blood pressure | Vascular disorders | 2 of 25 | 3 of 25 |
| Confusion | Psychiatric disorders | 2 of 25 | 2 of 25 |
| Abnormal UA | Renal and urinary disorders | 1 of 25 | 2 of 25 |
| Elevated Thyroid Stimulating Hormone | Endocrine disorders | 1 of 25 | 2 of 25 |
| Fall | Injury, poisoning and procedural complications | 1 of 25 | 2 of 25 |
| Rash/skin lesion | Skin and subcutaneous tissue disorders | 1 of 25 | 2 of 25 |
| Agitation | Psychiatric disorders | 2 of 25 | 0 of 25 |
| Insomnia | Psychiatric disorders | 2 of 25 | 0 of 25 |
Serious events with the highest arm-level rate: confusion (4.0%), delusions (4.0%), atrial fibrillation (4.0%), fall (4.0%), stroke (4.0%).
The registry lists serious adverse events for 4 participants in the placebo group and 1 participant in the rasagiline group; each group has 25 participants listed as at risk. It lists other adverse events for 15 participants in the placebo group and 16 in the rasagiline group, with 25 at risk in each group. Deaths are listed as 0 in both groups. These entries are counts, not adjusted estimates of a treatment contrast.
The registry lists confusion, delusions, atrial fibrillation, fall, and stroke among the top serious event terms, each shown as 4.0%. The record does not provide enough detail to interpret these terms as unique participants or to establish the circumstances, timing, or relationship to treatment. It also does not report an inferential analysis of the safety counts.
As a general statistical point, adverse-event counts are descriptive and can be affected by follow-up duration, event definitions, reporting practices, and the number of participants observed. A comparison of counts alone does not establish causation, nor does a zero death count establish that no other safety concern occurred. The registry’s safety entries should be read as reported observations, not as proof that either treatment caused or prevented an event.
12. What the Result Does, and Does Not, Mean
This record documents a completed randomized Phase II study comparing rasagiline with placebo in people with mild to moderate Alzheimer’s disease. Its primary question concerned change in regional brain glucose metabolism measured by FDG-PET at week 24. The registry specifies the outcome’s measurement and direction, and it lists secondary clinical measures and adverse-event counts.
What the record does not establish is the result of the primary comparison. It contains no reported SUVR group means, between-group estimate, confidence interval, or test result. It also does not report analyses for the secondary outcomes. Consequently, the record cannot show whether the primary measure differed between groups, how large or precise any difference was, or whether any secondary outcome changed in a particular direction.
That absence of results is not evidence that the groups were the same, and it is not evidence that one group did better. A conclusion of no difference would require suitable estimates and uncertainty, not merely a missing result. Likewise, trial completion and a listed enrollment do not demonstrate that a treatment had a particular effect.
The serious and other adverse-event counts provide descriptive safety information, but they do not establish that treatment caused an event or that one group’s safety profile was better. The record does not report a statistical safety comparison or provide enough context to interpret event timing and attribution.
In general, a sound interpretation of a randomized trial combines the estimated effect, its precision, the analysis population, missing-data handling, and the prespecified analysis plan. Several of these details are not reported in the registry record. The appropriate conclusion is therefore limited: the record describes the study and some safety observations, while its posted information does not support a conclusion about comparative efficacy or the precision of the primary endpoint result.
13. Why This Trial Matters Statistically
This trial is statistically notable because its primary endpoint is an imaging measure rather than a direct clinical outcome. FDG-PET SUVR change is intended to quantify regional brain glucose metabolism, while the listed secondary outcomes include cognitive performance, daily activities, neuropsychiatric symptoms, and quality of life. These measures address different aspects of disease and should not be treated as interchangeable.
The endpoint is also regional. The registry names several brain regions, which makes clarity about the primary comparison and multiplicity especially important. A study that measures multiple regions can yield a set of estimates with different patterns and degrees of uncertainty. Without the planned analysis approach and region-specific results, it is not possible to judge whether any apparent pattern was prespecified or how it should be interpreted.
The randomized placebo-controlled design provides a framework for comparing treatment groups, but the design alone does not supply evidence about the outcome. Results and uncertainty estimates are needed to evaluate the contrast. This distinction is central to statistical reading: a carefully designed study can still be uninterpretable from a registry entry if outcome analyses are not reported there.
The record also illustrates why endpoint definitions matter. Its change score is defined as baseline minus week 24, and negative values are explicitly linked to increased hypometabolism. Correctly following that convention is necessary to avoid reversing the meaning of a reported value. In this case, however, there are no reported primary values to interpret.
Finally, the listed adverse-event counts are useful descriptive context but do not replace a comparative safety analysis. Taken together, the record offers information about the intended scientific question and trial structure, while leaving the principal statistical evidence unavailable 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 limitation for interpretation is that the registry record does not report the primary outcome values or analyses. There are no regional SUVR summaries, estimates of a group contrast, confidence intervals, or test results. The listed secondary outcomes likewise have no reported results, so neither efficacy nor precision can be evaluated.
The primary outcome encompasses several prespecified brain regions, but the record does not explain which regional analysis was primary, whether a combined measure was used, or how multiplicity was addressed. These details matter for interpreting a family of regional results. The detailed statistical analysis plan is not reported in the registry record.
The registry reports enrollment of 50 and a 1:1 allocation description, but does not report the numbers analyzed for the primary endpoint or participant flow by group. Missing measurements, reasons for withdrawal, analysis populations, and missing-data procedures are not reported. These omissions prevent evaluation of how complete the endpoint data were and whether the randomized comparison was retained in analysis.
The arm descriptions include only a partial account of dosing, and the complete regimen is not reported in the registry record. The record also does not provide the detailed eligibility criteria, baseline characteristics, protocol deviations, or an explanation of the enrollment target. These details would help assess applicability and the context of the analysis.
Safety information is limited to counts and listed event terms. The registry does not report a statistical comparison, event timing, attribution, or enough detail to assess how events were collected. These limitations do not show that methods or results were absent from all sources; they describe what is not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Rasagiline Rescue in Alzheimer's Disease Clinical Trial — NCT02359552.
- Registry record last updated 2020-11-10; status last verified 2020-10.
- Results first posted 2020-10-20.
- 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 NCT02359552, a completed Phase II randomized, parallel-group, placebo-controlled study of rasagiline in people with mild to moderate Alzheimer’s disease. It lists enrollment of 50 and a 24-week treatment period. The primary endpoint was change in regional FDG-PET SUVR from baseline to week 24, with the score defined as baseline minus week 24.
The listed secondary outcomes cover cognitive, functional, neuropsychiatric, and quality-of-life measures. The record lists 8 outcome measures but includes 0 analyses. It therefore does not report primary or secondary outcome results, group contrasts, or uncertainty estimates.
Safety entries list serious adverse events, other adverse events, and deaths by group. These are descriptive counts and do not establish causation or a comparative safety effect. Important details about the analysis plan, missing data, and analysis populations are not reported in the registry record.