A Study to Assess Efficacy, Safety, Tolerability, and Pharmacokinetics of ABBV-8E12 in Subjects 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.