The new oral anticoagulants have many advantages over vitamin K antagonists, but 
they are still associated with a troublesome incidence of major bleeding. 
Additionally, the absence of a reversal agent for the new oral anticoagulants is 
a barrier to their more widespread use. Currently, there are 3 potential 
reversal agents in development: idarucizumab is a humanized murine monoclonal 
antibody fragment directed specifically at dabigatran; andexanet alfa is a 
recombinant modified decoy factor Xa that binds to factor Xa inhibitors; and 
PER977 is a small molecule that binds to factor Xa and IIa inhibitors and to 
heparin-based anticoagulants through charge interaction. These agents have 
undergone phase I clinical testing, appear to be well tolerated in healthy 
volunteers, and are effective in neutralizing their respective targets. All 3 
are currently undergoing or entering into a phase II or III clinical study. This 
article reviews the available data for idarucizumab, andexanet alfa, and PER977.