Milvexian, FXIa Inhibitor, Wins US FDA Fast Track Designation for 3 Indications in Phase 3 Trial Program

The FDA has granted fast track designation for 3 prospective indications for milvexian, an investigational oral factor Xla inhibitor, in joint development by Janssen Pharmaceutical and Bristol Myers Squibb.

The indications are stroke prevention after an acute ischemic stroke or high-risk transient ischemic attack, recent acute coronary syndrome, and atrial fibrillation.

“Despite major advances in cardiovascular and stroke treatment over the past 2 decades, millions of patients currently remain untreated or undertreated due to the risk of bleeding, but for whom thrombotic events could be prevented,” Robert Harrington, MD, Arthur L Bloomfield professor of medicine and chair of the Department of Medicine at Stanford University, said in a statement. “If successful, milvexian could open the door to treat an entirely new set of patients who are currently overlooked due to bleeding risk.”


If successful, milvexian could open the door to treat an entirely new set of patients who are currently overlooked due to bleeding risk.


The designation is supported by 3 studies within the phase 3 Librexia development program, which include Librexia STROKE (NCT05702034), Librexia ACS (NCT05754957), and Librexia AF (NCT05757869). The Librexia program has enrolled nearly 50 000 participants across the 3 studies.

The Librexia program is currently considered the most comprehensive FXla clinical development program to date and was implemented after positive phase 2 efficacy and safety data. The program is intended to investigate whether the drug can enhance the risk-benefit profile in the intention-to-treat population.

Librexia STROKE is a phase 3 randomized, double-blind, placebo-controlled study to determine the efficacy and safety of milvexian, in addition to single or dual antiplatelet therapy, for stroke prevention after an acute ischemic stroke or high-risk transient ischemic attack.

In Librexia ACS investigators will determine the safety and efficacy of milvexian after a recent acute coronary syndrome and in Librezia AF in those with atrial fibrillation when compared to apixaban.

“For milvexian to receive fast track designation from the FDA for all 3 indications demonstrates the enormous unmet need that still exists for the treatment of thrombotic events, like heart attack and stroke,” James F List, MD, PhD, global therapeutic area head at Janssen Research & Development, LLC, said in the statement. “We are now focused on enrolling patients to these trials with urgency, bringing us one step closer to potentially improving outcomes in a wide range of patients with thrombotic diseases.”

Proof of concept data from the phase 2 AXIOMATIC-TRK (NCT03891524) and AXIOMATIC-SSP (NCT03766581) trials demonstrated a differentiated antithrombotic profile for the drug as both monotherapy and in combination with antiplatelet therapy, according to the statement. The data also indicted a positive efficacy and bleeding profile in stroke patients for whom FXa inhibitors are not indicated.