CERC-301 (formerly known as MK-0657) is an orally-active, selective NMDA receptor subunit 2B (NR2B) antagonist which is under development by Cerecor in the United States as an adjunctive therapy for treatment-resistant depression (TRD). In November 2013, phase II clinical trials were initiated, and in the same month, CERC-301 received Fast Track Designation from the Food and Drug Administration for TRD.
A pilot study was published in 2012, and a phase 2 trial was completed in 2014.