PhaseBio Pharmaceuticals, Inc. announced the complete results from its Phase 2b clinical trial of bentracimab that were presented on April 2nd during a Late Breaking Featured Clinical Research Presentation at the American College of Cardiology's 71st Annual Scientific Session. The Phase 2b trial was a multi-center, randomized, double-blind, placebo-controlled study, which enrolled a total of 205 older volunteers (50-80 years old), with 154 subjects receiving bentracimab and 51 subjects receiving placebo, after all were pretreated with dual antiplatelet therapy composed of ticagrelor and low-dose aspirin. The Phase 2b pivotal trial was conducted concurrently with the company's ongoing REVERSE-IT Phase 3 pivotal trial of bentracimab, as agreed upon with the U.S. Food and Drug Administration following an End-of-Phase 1 meeting in July 2019.

Bentracimab is a novel, recombinant, human monoclonal antibody antigen-binding fragment designed to reverse the antiplatelet activity of ticagrelor in patients presenting with uncontrolled bleeding or in need of surgery. The primary efficacy endpoint for the Phase 2b trial was reversal of ticagrelor's inhibition of platelet function in actively treated subjects versus placebo as measured using the point-of-care VerifyNow PRUTest platelet function assay (VerifyNow). In the Phase 2b trial, bentracimab significantly restored platelet function within five minutes of administration (p<0.001), as measured by multiple assays including VerifyNow.

The reversal results were tightly correlated across all assays used in the study to measure platelet function. VerifyNow is also the primary measurement used to evaluate efficacy in the ongoing REVERSE-IT Phase 3 trial. There were no drug-related serious adverse events or thrombotic events reported in the Phase 2b trial.

Overall, bentracimab appeared well tolerated, with subjects reporting only non-serious adverse events. The most-commonly reported adverse events were injection site bruising and headache, with similar rates seen in both the placebo and active-treatment arms. There was no significant difference between bentracimab and placebo for any of the adverse events reported. These complete safety and efficacy data from the Phase 2b trial are consistent with results from PhaseBio's previously completed Phase 1 trial, conducted in healthy younger volunteers treated with ticagrelor alone and not aspirin, and its Phase 2a trial, conducted in healthy, older (ages 50-80) subjects on dual antiplatelet therapy of ticagrelor and low-dose aspirin and with topline results previously announced for the Phase 2b trial on November 3, 2021.

More than 300 subjects have been treated with bentracimab across the Phase 1, 2, and 3 clinical trials that comprise the bentracimab development program. Additional information on the Phase 2b trial can be found on www.ClinicalTrials.gov using the identifier NCT04122170. Bentracimab has been studied in Phase 1 and Phase 2 clinical trials and has demonstrated the potential to bring life-saving therapeutic benefit through immediate and sustained reversal of the antiplatelet activity of ticagrelor, potentially mitigating concerns regarding bleeding risks associated with the use of this antiplatelet drug.

Bentracimab is currently being evaluated in the REVERSE-IT study, a global Phase 3, multi-center, open-label, prospective single-arm trial designed to study reversal of the antiplatelet effects of ticagrelor with bentracimab in patients who present with uncontrolled major or life-threatening bleeding or who require urgent surgery or invasive procedure. Approximately 200 patients are being targeted for enrollment in the REVERSE-IT study at major health centers worldwide. Patients with reported use of ticagrelor within the prior three days who require urgent ticagrelor reversal are eligible for enrollment.

A prespecified interim analysis from the REVERSE-IT trial was presented on November 15, 2021, during a late-breaking science session at the American Heart Association's Scientific Sessions 2021. The Company is commencing preparation of a BLA and targeting submission to the FDA in mid-2022.