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

A Randomized, Double-Blind, Placebo-Controlled Multiple Dose Study to Assess Efficacy, Safety, Tolerability, and Pharmacokinetics of ABBV-8E12 in Progressive Supranuclear Palsy

The purpose of this study was to assess efficacy, safety, tolerability, and pharmacokinetics of ABBV-8E12 in participants with progressive supranuclear palsy (PSP).

This was a Phase 2, randomized, double-blind, placebo-controlled, multiple dose, multicenter study consisting of a screening period of up to 8 weeks (56 days), a 52-week double-blind treatment period, and a post-treatment follow-up period of approximately 20 weeks following last study drug administration (for those participants who prematurely discontinued from treatment, declined to participate in or did not qualify for participation in a long term extension [LTE] study). At the end of the treatment period, extended treatment was available for eligible participants who completed the 52-week treatment period and entered the separate long-term extension study (NCT03391765; Study M15-563). There were 3 cohorts in the study (Cohort 1, Cohort J1, and Cohort 2). Cohort 1 had augmented safety and pharmacokinetic (PK) assessments in the first 30 participants enrolled into the global study from countries other than Japan. Cohort J1 had augmented safety and PK assessments in the first 9 participants enrolled into the study from Japan. Cohort 2 consisted of all other participants enrolled in the global study not participating in Cohort 1 or Cohort J1.

This study was prematurely discontinued because the program for progressive supranuclear palsy was discontinued due to lack of efficacy of study drug.

Key Inclusion Criteria:

• Male or female participant with age 40 years or greater at the time of signed consent
• Meets the criteria for possible or probable progressive supranuclear palsy (PSP; Steele-Richardson-Olszewski Syndrome)
• Presence of PSP symptoms for less than 5 years
• Participant is able to walk 5 steps with minimal assistance (stabilization of one arm or use of cane/walker)
• Participant has an identified, reliable, study partner (e.g., caregiver, family member, social worker, or friend)

Key Exclusion Criteria:

• Participants who weigh less than 44 kg (97 lbs) at screening
• Mini-Mental State Examination (MMSE) score less than 15 at screening
• Any contraindication or inability to tolerate brain magnetic resonance imaging (MRI)
• Participant resides at a skilled nursing or dementia care facility, or admission to such a facility is planned during the study period
• Evidence of any clinically significant neurological disorder other than PSP
• The participant has a history of or currently has schizophrenia, schizoaffective disorder or bipolar disorder according to Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-V) or International Classification of Diseases (ICD-10) criteria
• Participant has had a significant illness or infection requiring medical intervention in the past 30 days