The Food and Drug Administration (FDA) has granted Fast Track Designation to REL-1017 (esmethadone) as a monotherapy for the treatment of major depressive disorder (MDD).

REL-1017 is a novel N-methyl-D-aspartate receptor (NMDAR) channel blocker. The investigational treatment is administered orally once daily and is designed to target overactive NMDAR GluN1-GluN2D channels while maintaining physiological glutamatergic neurotransmission.

The designation is supported by data from a Phase 2 study ( Identifier: NCT03051256), which demonstrated that treatment with REL-1017 produced rapid, robust, and sustained antidepressant effects in patients with MDD compared to to the placebo. The safety profile of REL-1017 was found to be comparable to placebo, with no opioid, dissociative, or psychotomimetic symptoms or withdrawal effects observed upon discontinuation of treatment.

REL-1017 is currently being evaluated for the treatment of MDD as monotherapy in the Phase 3 RELIANCE-III trial ( Identifier: NCT05081167) and as adjuvant therapy in the Phase 3 RELIANCE-I ( Identifier: NCT04688164) and RELIANCE-II trials ( Identifier: NCT04855747). RELIANCE-OLS, an open-label safety study ( Identifier: NCT04855760), will include participants from the 3 pivotal studies and will assess long-term effects.

“Achieving Fast Track designation represents an important milestone for our promising late-stage REL-1017 development program,” said Paolo Manfredi, our CSO. “This designation further supports the potential of REL-1017 as a breakthrough new stand-alone treatment for MDD and highlights the significant unmet medical need in a therapeutic area where little has changed in recent decades: treatments available remains inadequate for the majority of patients with MDD.


  1. Relmada Therapeutics Receives Fast Track Designation from the FDA for REL-1017 as a Monotherapy for the Treatment of Major Depressive Disorder. Press release. Relmada Therapeutics, Inc. Accessed August 9, 2022. -for-the-treatment-of-major-depressive-disorder-301602264.html
  2. Relmada Therapeutics announces the publication of results from the REL-1017 Phase 2 study in The American Journal of Psychiatry. Press release. Relmada Therapeutics, Inc. December 22, 2021. Accessed August 9, 2022.