Phase 2B Study to Evaluate the Efficacy of Bentracimab (PB2452) in Reversal of Ticagrelor in Subjects Aged 50-80 Years Old

The study will consist of a Screening period, a Check-in day, an on-site Randomization/Treatment day, a 2-day on-site Follow-up period (Days 2 through 3), a Follow-up visit (Day 7), and a Final Follow-up visit (Day 35±3). If needed and at the discretion of the Investigator, a subject may remain in the study facility beyond the scheduled Day 3 discharge to accommodate Day 7 and Day 35±3 follow-up visits. Seven days prior to enrollment, subjects will be administered ASA 81 mg orally once daily (QD) until the final dose on Day 1. Beginning in the morning on Day -2, a single dose of oral ticagrelor 180 mg will be given, followed by oral ticagrelor 90 mg every 12 hours for 4 additional doses through to Day 1 (2 hours before study drug is initiated; this will be 5 total doses of ticagrelor). On Day 1, subjects who meet all the inclusion criteria and none of the exclusion criteria will be randomized with 3:1 allocation ratio (active:placebo), to receive an IV dose of bentracimab (PB2452) or placebo 2 hours following the 5th ticagrelor dose. Subjects may be discharged from the clinical site on Day 3 and will return for a Follow-up visit on Day 7, if already discharged, and on Day 35 (±3 days). A subject may remain in the study facility beyond the scheduled Day 3 discharge to accommodate Day 7 and Day 35±3 follow-up visits. If a subject is taking a moderate or strong cytochrome P450 3A isozyme (CYP3A) inhibitor, a 36 g alternative regimen of bentracimab (PB2452) will be administered consisting of 12 g infused over 10 minutes followed by a 12 g loading dose infused over 6 hours, then a maintenance dose of 12 g infused over the next 18 hours immediately following completion of the loading period for a total infusion time of approximately 24 hours.