A Study to Assess Efficacy, Safety, Tolerability, and Pharmacokinetics of ABBV-8E12 in Subjects With Progressive Supranuclear Palsy (PSP): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study to Assess Efficacy, Safety, Tolerability, and Pharmacokinetics of ABBV-8E12 in Subjects With Progressive Supranuclear Palsy (PSP) (NCT02985879), a randomized phase 2 study. The primary outcome is Change From Baseline to Week 52 in Progressive Supranuclear Palsy Rating Scale (PSPRS) Total Score.

2. Clinical Question

This is a question about average change over the recorded follow-up, not about whether every participant improved or worsened. The endpoint captures several aspects of PSP, including daily activities, behavior, bulbar function, ocular motor function, limb motor function, and gait or midline function. The reported group estimates therefore summarize a broad disability measure rather than a single symptom. The comparison is also specific to the treatment schedules and participants represented in this trial; the registry record does not report a treatment effect beyond the measured follow-up.

3. Trial Design

This was a randomized, double-blind, placebo-controlled, parallel-group Phase 2 study sponsored by AbbVie. The registry record describes quadruple masking. It lists 378 participants as the enrollment and reports a start date of 2016-12-12 and a primary completion date of 2019-11-20. The overall status is terminated. Why the study was terminated is not reported in the registry record.

Participants were assigned to placebo, ABBV-8E12 2000 mg, or ABBV-8E12 4000 mg. Each group followed an intravenous infusion schedule beginning on Day 1, Day 15, and Day 29, followed by infusions every 28 days for 52 weeks. The placebo was 0.9% Sodium Chloride Injection/Solution for Infusion. The drug formulation description differs by country: the registry lists 300 mg/15 mL for participants in countries other than Japan or Spain, and 1000 mg/10 mL for participants in Japan or Spain. The record does not explain the reason for these formulation descriptions.

The primary endpoint was change from baseline to Week 52 in PSPRS total score. The record also lists secondary outcomes covering activities of daily living, clinical global impression, midbrain volume measured by MRI, and serum pharmacokinetics. The study included 19 outcome measures and 26 analyses. The registry record does not report the protocol’s sample-size justification, the planned allocation proportions, or a detailed statistical analysis plan. The posted enrollment figure should not be treated as the number contributing to every endpoint: the primary endpoint and secondary outcomes have their own analysis populations and available-data requirements. The registry record gives endpoint-specific analysis counts, but does not explain every difference in those counts.

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: All randomized participants; one participant in the ABBV-8E12 2000 mg dose group never received study drug

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: ITT dataset: all randomized participants who received at least one dose of study drug and those with available data at baseline and at Week 52

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 dataset: all randomized participants who received at least one dose of study drug

6. Primary Endpoint

The registry lists the primary outcome as Change From Baseline to Week 52 in Progressive Supranuclear Palsy Rating Scale (PSPRS) Total Score, measured over Baseline, Week 52.

The primary endpoint is the change in PSPRS total score from baseline to Week 52. PSPRS is a clinical rating scale with 28 items organized across six domains: daily activities by history, behavior, bulbar function, ocular motor function, limb motor function, and gait or midline function. Each item is scored on a scale, with most items scored from 0 to 4 and six items scored from 0 to 2. The total score ranges from 0 to 100. Higher totals indicate more severe disability or movement abnormality; positive changes indicate worsening from baseline.

A change score focuses the comparison on how the measured level shifted during follow-up rather than on the Week 52 score alone. Comparing average changes between randomized groups can help describe whether the groups followed different measured courses over that period. PSPRS is relevant to this question because it combines several functional and motor domains affected in PSP. Its breadth is also a limitation: a total score can conceal different patterns across individual domains or participants.

The registry reports least-squares means and standard errors for the primary endpoint, and the sponsor’s stated method is a mixed-effects model with repeated measures. The record identifies the primary analysis population as randomized participants who received at least one dose and had available baseline and Week 52 data. The scale’s direction matters when reading estimates: a positive change is worsening, so a positive difference in change relative to placebo would indicate a larger average increase in PSPRS for that treatment group. That direction alone does not establish a clinically important difference. A threshold for clinical importance is not reported in the registry record.

7. Results Posted in the Registry

• ABBV-8E12 2000mg: mean 10.50 versus 10.50 on control; difference 0.00 (95% CI -2.63 to 2.63), standardized effect d = 0.00; z-test p = 1.000.
• ABBV-8E12 4000mg: mean 11.40 versus 10.50 on control; difference 0.90 (95% CI -1.71 to 3.51), standardized effect d = 0.12; z-test p = 0.498.

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.

Mean Change From Baseline to Week 52 in Unified Parkinson's Disease Rating Scale (UPDRS) Part II (Activities of Daily Living)

• 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 errors.
• Result:
  • ABBV-8E12 2000mg: mean 5.80 versus 5.60 on control; difference 0.20 (95% CI -1.53 to 1.93), standardized effect d = 0.04; z-test p = 0.821.
  • ABBV-8E12 4000mg: mean 7.00 versus 5.60 on control; difference 1.40 (95% CI -0.33 to 3.13), standardized effect d = 0.29; z-test p = 0.113.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between ABBV-8E12 2000mg and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between ABBV-8E12 4000mg and the control. The interval gives the range of effects that remain compatible with the data.

Clinical Global Impression of Change (CGI-C) Score at Week 52

• 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 errors.
• Result:
  • ABBV-8E12 2000mg: mean 5.10 versus 5.10 on control; difference 0.00 (95% CI -0.30 to 0.30), standardized effect d = 0.00; z-test p = 1.000.
  • ABBV-8E12 4000mg: mean 5.00 versus 5.10 on control; difference -0.10 (95% CI -0.40 to 0.20), standardized effect d = -0.13; z-test p = 0.520.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between ABBV-8E12 2000mg and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between ABBV-8E12 4000mg and the control. The interval gives the range of effects that remain compatible with the data.

Mean Change From Baseline to Week 52 in Midbrain Atrophy As Measured by Volumetric Magnetic Resonance Imaging (MRI)

• 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 errors.
• Result:
  • ABBV-8E12 2000mg: mean -129.10 versus -122.00 on control; difference -7.10 (95% CI -33.89 to 19.69), standardized effect d = -0.10; z-test p = 0.603.
  • ABBV-8E12 4000mg: mean -128.30 versus -122.00 on control; difference -6.30 (95% CI -33.09 to 20.49), standardized effect d = -0.09; z-test p = 0.645.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between ABBV-8E12 2000mg and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between ABBV-8E12 4000mg and the control. The interval gives the range of effects that remain compatible with the data.

The registry record includes secondary outcomes spanning daily functioning, clinician-rated change, midbrain volume measured by MRI, and pharmacokinetic measures. The available clinical comparisons generally do not present a clear, consistent separation from placebo. Across the reported clinical contrasts, the confidence intervals include zero, and the model-based p-values do not provide strong evidence of group differences. This broad pattern is compatible with the primary result: neither the primary comparison nor the reported secondary comparisons establish a clear difference from placebo in the measures described.

This overall reading should not be mistaken for a claim that every secondary outcome had the same result or that the measures are interchangeable. They assess different aspects of function, clinical impression, imaging, and drug concentration. An outcome’s direction and meaning depend on its own scale and definition. The record lists 17 posted secondary outcomes, but not all outcomes address the same clinical question. Pharmacokinetic outcomes, in particular, describe drug exposure rather than clinical benefit.

Secondary findings generally carry less weight than the primary comparison for a confirmatory conclusion. The primary endpoint is the designated principal outcome, while secondary outcomes expand the scope of testing. When many outcomes and comparisons are examined, the chance of obtaining an apparently notable result by chance can increase. Whether and how the study controlled this multiplicity is not reported in the registry record. The secondary p-values described as unadjusted should therefore be interpreted cautiously; they are exploratory evidence, not a collection of independent confirmatory tests.

The consistency of a broad pattern can help contextualize the primary endpoint, but it does not erase uncertainty in any individual estimate. Nor can the secondary outcomes resolve limitations in the primary analysis population or missing-data handling. The posted summaries do not establish that treatment effects are absent across every domain, and no claim about unreported secondary values should be inferred from the general pattern.

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

• Mean Change From Baseline to Week 52 in Unified Parkinson's Disease Rating Scale (UPDRS) Part II (Activities of Daily Living)
• Clinical Global Impression of Change (CGI-C) Score at Week 52
• Mean Change From Baseline to Week 52 in Midbrain Atrophy As Measured by Volumetric Magnetic Resonance Imaging (MRI)
• Mean Change From Baseline to Week 52 in Schwab and England Activities of Daily Living Scale (SEADL)
• Maximum Observed Serum Concentration (Cmax) for ABBV-8E12
• Time to Maximum Observed Serum Concentration (Tmax) for ABBV-8E12
• Area Under the Concentration Time Curve (AUC) for ABBV-8E12
• Serum Concentration of ABBV-8E12 Prior to Infusion of a Day of Dosing (Ctrough)

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous: it is a score change measured on a numerical scale. The posted arm summaries are least-squares means with standard errors. A least-squares mean is a model-based group estimate, rather than necessarily the raw arithmetic average of all observed scores. The registry record identifies a mixed-effects model with repeated measures for the sponsor’s primary comparisons. It does not report enough detail to reconstruct every feature of that model, such as its covariance structure, the precise handling of missing observations, or all included model terms. Those details are not reported in the registry record.

What does a mean difference describe?

A mean difference expresses the estimated separation between two group averages in the outcome’s original units. For this endpoint, a positive difference in change means a greater average increase in PSPRS relative to placebo, and a negative difference means a smaller average increase. The unit is PSPRS score units. The sponsor’s model-based differences are reported as least-squares mean differences. The recalculated differences are simple, unadjusted comparisons based on the posted group summaries; they are not adjusted estimates from the repeated-measures model.

Why use a repeated-measures model?

Repeated-measures methods are designed for outcomes observed at multiple time points. In general, such methods can use the pattern of measurements over time to estimate group trajectories and contrasts while accounting for the fact that observations from the same participant are related. They can also be useful when not every participant has a measurement at every scheduled time. These are general properties of the method, not a claim about the exact model implementation in this study. The registry names the method but does not report its full specification or assumptions, and the method label alone does not establish how missing measurements were handled.

What does a standard error convey?

A standard error describes the statistical uncertainty around an estimated mean. A smaller standard error indicates a more precisely estimated mean, whereas a larger one indicates greater uncertainty. It is not the same as the spread of individual participant outcomes. The primary endpoint summaries report standard errors for the group estimates, but the registry does not provide a standard deviation for those primary summaries. The recalculation therefore uses an approximate standard deviation derived from the posted standard errors and group sizes. This is why the recalculated comparison is explicitly an approximation and should not be confused with the sponsor’s model.

How should the p-value be read?

A p-value describes how incompatible the observed data are with a specified null hypothesis, under the assumptions of the analysis. It is not the probability that the null hypothesis is true, and it does not measure the clinical importance of an estimate. The sponsor reports p = 0.998 for the 2000mg comparison and p = 0.464 for the 4000mg comparison. The unadjusted recalculated p-values are 1.0 and 0.498, respectively. These p-values do not, by themselves, establish equivalence or prove that a treatment has no effect. The registry record does not report an equivalence or non-inferiority margin.

What is the role of a confidence interval?

A confidence interval gives a range of estimates compatible with the data and method at its stated confidence level. In repeated use, intervals constructed by the same procedure would cover the target quantity at the stated rate if the model assumptions hold. For an individual trial, the interval shows the range of uncertainty around the estimated difference. Here, both sponsor-reported primary confidence intervals include zero. They also span values on either side of zero, so they do not isolate one direction of difference. The interval should be read alongside the point estimate and the clinical scale, not as a boundary on every participant’s possible outcome.

How should the planning illustrations be interpreted?

The posted planning illustrations are based on observed effects and are not the trial’s original sample-size justification. They assume a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is expressed as a stated fraction of the observed effect. For the primary 4000mg comparison, the illustration gives 1,011 participants per arm for 80% power when planning for 100% of the observed effect, 1,797 when planning for 75% of the observed effect, and 4,042 when planning for 50% of the observed effect. These are hypothetical planning quantities, not observed power and not evidence that the trial was designed around those assumptions. They are sensitive to the observed effect, which is uncertain. The registry record does not report the original sample-size justification.

Because the primary outcome is continuous, the recalculation treats the posted group summaries as sufficient for a simple two-group comparison. That simplification does not reproduce the repeated-measures model. Nor does it adjust for multiple comparisons. The recalculated values are useful as a transparent check on the summary statistics, while the sponsor’s analysis remains the primary reported analysis.

11. Confidence Intervals and Precision

The precision of a treatment comparison is conveyed by its confidence interval, not by the point estimate alone. For the sponsor’s primary comparison of ABBV-8E12 2000mg with placebo, the estimated difference is 0.0 PSPRS units and the 95% confidence interval extends from -2.63 to 2.63. For 4000mg versus placebo, the estimate is 1.0 and the interval extends from -1.63 to 3.58. Both intervals include zero, the value corresponding to no difference in average change. They also include values in both directions, so the data do not rule out either a smaller or a larger average increase in the treatment group within those ranges.

These intervals describe uncertainty in the group contrast under the sponsor’s analysis; they are not ranges containing a stated proportion of individual participants’ changes. They do not establish equivalence. To make an equivalence claim, a prespecified margin and an appropriate analysis would be needed; such a margin is not reported in the registry record. Nor does a confidence interval directly state whether a difference would be clinically important. A clinical-importance threshold is not reported in the registry record.

The recalculated intervals are close in broad interpretation but arise from an unadjusted calculation using posted summary statistics. For the 2000mg comparison, the recalculated interval is -2.633 to 2.633; for 4000mg, it is -1.705 to 3.505. Both include zero. Since the sponsor’s repeated-measures analysis is the reported analysis, it takes precedence over these simple recalculations. Differences between the endpoints of the intervals should not be read as evidence that one method is more valid without the full model specification and participant-level data.

The intervals are wide enough to leave uncertainty about the magnitude and direction of the group differences. A non-significant p-value does not imply precision, and the point estimates alone do not settle the question. Interpretation should therefore keep the estimated direction, the interval width, the endpoint’s scale, and the analysis method together. The record does not report a prespecified threshold that would define a clinically meaningful difference.

12. Analyses Reported by the Sponsor

The sponsor’s primary analysis used a mixed-effects model with repeated measures and reported least-squares mean differences. For ABBV-8E12 2000mg versus placebo, it reported 0.0, a 95% confidence interval from -2.63 to 2.63, and p = 0.998. For ABBV-8E12 4000mg versus placebo, it reported 1.0, a 95% confidence interval from -1.63 to 3.58, and p = 0.464.

The simple recalculation from the posted group summaries gives 0.0, with a 95% confidence interval from -2.633 to 2.633 and p = 1.0, for the 2000mg comparison. For the 4000mg comparison it gives 0.9, with a 95% confidence interval from -1.705 to 3.505 and p = 0.498. The results are similar in broad direction and both methods produce intervals that include zero, but the numerical estimates and p-values are not identical.

This is expected when a basic unadjusted calculation is compared with a repeated-measures model: they need not use the same estimation procedure or make the same use of the recorded data. The recalculation is a check based on the posted summary statistics, not a substitute for the sponsor’s model. The registry record indicates no discrepancy flag. The sponsor’s own analysis takes precedence, and its model details beyond the method label are not reported in the registry record.

13. Multiplicity, Missing Data and Analysis Populations

The study reports a primary endpoint and multiple secondary outcomes and analyses. Testing more than one contrast or outcome raises a multiplicity concern: without an adjustment strategy, repeated testing can increase the chance that one or more results appear notable by chance. The registry record identifies the sponsor’s comparisons as superiority analyses, but does not report a prespecified multiplicity procedure, a hierarchy of hypotheses, or whether any reported p-values were adjusted. This absence matters particularly when interpreting secondary results, which should be treated as less definitive than a prespecified primary comparison.

The primary analysis population is described as the ITT dataset consisting of all randomized participants who received at least one dose of study drug and those with available baseline and Week 52 data. The wording combines randomization, treatment receipt, and outcome availability; the registry does not explain how this operational definition relates to a conventional intention-to-treat analysis. The endpoint-specific group counts differ from the enrollment figure, and counts also vary across secondary outcomes. Such variation can reflect endpoint availability or analysis requirements, but the exact reasons are not reported in the registry record.

Missing measurements can affect estimates when availability is related to participants’ condition, treatment, or other factors. Repeated-measures models can sometimes use incomplete longitudinal data, but their validity depends on assumptions and implementation. The registry identifies a mixed-effects model with repeated measures for the sponsor’s analyses, but does not report the missing-data assumptions, imputation procedures, sensitivity analyses, or reasons for missing observations. It is therefore not possible to assess from the registry record whether the findings are robust to alternative approaches to missing data.

The record also does not report whether interim analyses were planned or conducted, the detailed statistical analysis plan, or the original sample-size justification. These omissions do not demonstrate that a procedure was absent; they mean it is not reported in the registry record. The observed-effect planning illustrations are not a substitute for those design details. Interpretation should remain focused on the posted analysis and acknowledge the uncertainty around multiplicity and missing-data handling.

14. 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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: fall (4.8%), pneumonia (3.2%), progressive supranuclear palsy (3.2%), rib fracture (2.4%), loss of consciousness (2.4%).

The registry reports serious adverse events affecting 33 of 126 participants at risk in the placebo group, 29 of 126 in the ABBV-8E12 2000mg group, and 34 of 125 in the ABBV-8E12 4000mg group. Deaths are listed for 8 participants in the placebo group, 9 in the 2000mg group, and 9 in the 4000mg group. These are group-level counts; they do not by themselves establish that an event or death was caused by study treatment.

The record also lists serious adverse event terms and their reported percentages: FALL, 4.8%; PNEUMONIA, 3.2%; PROGRESSIVE SUPRANUCLEAR PALSY, 3.2%; RIB FRACTURE, 2.4%; LOSS OF CONSCIOUSNESS, 2.4%; and URINARY TRACT INFECTION, 2.4%. These terms are not separated by treatment group in the information, so they should not be attributed to a particular arm. The registry record does not provide event-level narratives or a causal assessment for these terms.

Serious adverse event counts are not a complete account of safety, tolerability, or the timing and duration of events. Comparisons of counts alone also do not establish a treatment-related difference. The trial’s objective included safety and tolerability, but conclusions about those outcomes require fuller context than the group counts and listed terms. The reason for termination is not reported in the registry record and should not be inferred from the safety figures.

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

The primary result is an estimate of average PSPRS change through Week 52 in the randomized study groups. The sponsor’s model-based comparisons do not show a statistically clear separation between either ABBV-8E12 dose and placebo on that endpoint. Both confidence intervals include zero and allow differences in either direction. The point estimates are close to zero for the 2000mg comparison and positive for the 4000mg comparison; on this scale, positive change indicates worsening from baseline.

This does not prove that the treatments and placebo have identical effects. A non-significant result can reflect a small difference, uncertainty in the estimate, or both. The confidence intervals describe the range of values compatible with the data and model at the stated level; they do not establish equivalence, and the registry does not report an equivalence margin. They also do not show how individual participants fared. Group averages can conceal variation in responses and differences across PSPRS domains.

The results also do not establish what would occur beyond Week 52 or in populations not represented by the trial. The record describes a randomized, double-blind, placebo-controlled parallel-group study, but the registry status is terminated and the reason is not reported. The posted results should not be used to infer why the study ended. No conclusion about outcomes not reported in the registry record follows from these primary estimates.

Secondary outcomes and safety counts add context, but they do not transform the primary comparison into a definitive statement about efficacy or safety. Secondary testing raises multiplicity concerns, and the statistical adjustment strategy is not reported. Safety event counts do not alone establish causality. In short, the posted data describe measured group outcomes and their uncertainty; they do not justify a claim that ABBV-8E12 works, does not work, or has a particular causal safety profile.

16. Why This Trial Matters Statistically

This trial is statistically informative because it illustrates why the point estimate, confidence interval, and analysis method need to be read together. On the primary endpoint, the reported group averages and model-based estimates are close, but closeness alone is not proof of equivalence. The confidence intervals express uncertainty that a point estimate cannot show, and their inclusion of zero means the comparisons do not establish a difference from placebo under the reported analysis.

The study also makes the distinction between a sponsor’s model and an unadjusted recalculation visible. A calculation from group summaries can be a useful check, but it does not reproduce a repeated-measures analysis. Differences between the estimates are not necessarily errors; they can reflect different methods and information use. The sponsor’s reported analysis takes precedence for interpretation of the trial’s primary result.

Finally, the registry record highlights the importance of design and reporting details. Multiplicity procedures, missing-data assumptions, the full model specification, and the sample-size justification are not reported. Without them, readers cannot fully evaluate how the analyses were planned or how sensitive the conclusions may be to assumptions. The planning illustrations based on observed effects are not evidence of the study’s original design or its observed power. These considerations are relevant when interpreting a trial with several outcomes and analyses, especially when the primary estimates remain uncertain.

17. 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 analysis population is described as randomized participants who received at least one dose and had data available at baseline and Week 52. Because the endpoint requires measurements at both time points, the analysis may not represent every randomized participant. The registry record does not explain the reasons for unavailable observations or provide sensitivity analyses for missing data. It also does not give enough detail to assess the assumptions used by the repeated-measures model.

The full statistical analysis plan, multiplicity procedure, interim-analysis information, and original sample-size justification are not reported in the registry record. Consequently, it is not possible to determine from the posted information how the primary and secondary hypotheses were ordered or whether secondary testing was adjusted. The recalculated comparisons are approximate, unadjusted calculations based on summary statistics and should not be treated as a reproduction of the sponsor’s model.

The record reports that the study was terminated, but not why. No explanation should be inferred from the efficacy or safety summaries. The primary outcome is a broad total score, so it may not reveal whether specific PSPRS domains behaved differently. A threshold for a clinically meaningful difference is not reported, limiting interpretation of the practical importance of the estimated differences.

Finally, the results concern the reported treatment schedules, endpoint, analysis population, and follow-up through Week 52. The registry information does not establish outcomes beyond that period. Safety counts are group summaries without the event-level context needed to assess causality, timing, or duration. These limits mean the posted results should be read as an account of measured outcomes with uncertainty, rather than as a complete evaluation of every potential benefit or harm.

18. Related Tutorials

19. Related Statistical Calculators

20. Sources

• ClinicalTrials.gov: A Study to Assess Efficacy, Safety, Tolerability, and Pharmacokinetics of ABBV-8E12 in Subjects With Progressive Supranuclear Palsy (PSP) — NCT02985879.
• Registry record last updated 2021-02-03; status last verified 2021-02.
• Results first posted 2021-02-03.
• 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.

21. Record Summary

NCT02985879 is a randomized, double-blind, placebo-controlled, parallel-group Phase 2 study of ABBV-8E12 in participants with progressive supranuclear palsy. The registry lists 378 enrolled participants and reports the study as terminated. The primary endpoint was change from baseline to Week 52 in PSPRS total score, where a positive change indicates worsening. The sponsor’s mixed-effects repeated-measures analyses reported no statistically clear difference from placebo for either dose; both primary confidence intervals include zero.

Simple unadjusted recalculations from posted summary statistics are broadly consistent with that interpretation but are not substitutes for the sponsor’s model. The registry record does not report the reason for termination, full model specification, missing-data assumptions, multiplicity procedure, or original sample-size justification. The findings should therefore be understood as uncertain group-level estimates over the reported follow-up, not as proof of equivalence or a definitive statement about treatment efficacy or safety.