The second study – an open-label, international study – involved 802 patients with major depressive disorder who had all failed to respond to at least two oral antidepressants. They were treated with an esketamine nasal spray (28 mg, 56 mg, or 84 mg) in combination with a new oral antidepressant.
The study involved a screening phase, induction phase, and optimization/maintenance phase, but only 24.9% of patients completed the optimization/maintenance phase. However, this was enough to meet a predefined total patient exposure, and the study was terminated by the sponsor.
More than three-quarters of patients responded during the induction phase, and by the end of the induction phase, 47.2% of patients had achieved remission. By the end of the optimization/maintenance phase, 58.2% of patients who entered that phase achieved remission.
More than 90% of patients experienced at least one adverse event, although most were mild to moderate. There were two deaths during the optimization/maintenance phase – one from acute respiratory and cardiac failure and one from suicide – but neither was considered as being related to the esketamine.