Relmada Therapeutics Inc. said the U.S. FDA cleared the company's investigational new drug application for d-Methadone, its novel, N-methyl-D-aspartate receptor antagonist.

D-Methadone is a rapid acting, oral agent for the treatment of depression, neuropathic pain and other potential central nervous system pathological conditions.

The company can now advance the development program for d-Methadone to a phase 2a proof-of-concept clinical study in patients with treatment-resistant depression.