Rapastinel (INNTooltip International Nonproprietary Name) (former developmental code name GLYX-13) is a novel antidepressant that was under development by Allergan (previously Naurex) as an adjunctive therapy for the treatment of treatment-resistant depression.

[4] As of 2015, the drug had completed phase II clinical development for this indication and achieved proof of concept as a rapid-acting antidepressant by demonstrating reduced depressive symptoms at days 1 through 7, as assessed by the HAM-D, without eliciting psychotomimetic or other significant side effects.

[5] On January 29, 2016, Allergan (who acquired Naurex in July 2015) announced that rapastinel had received Breakthrough Therapy designation from the U.S. FDA for adjunctive treatment of major depressive disorder.

[8] Rapastinel was originally invented by Joseph Moskal, the co-founder of Naurex, via structural modification of B6B21, a monoclonal antibody that similarly binds to and modulates the NMDA receptor.

[14][15] In addition to its rapid and sustained antidepressant effects, rapastinel has been shown to enhance memory and learning in both young adult and learning-impaired, aging rat models.