Janssen's esketamine has picked up a breakthrough therapy designation in the US as a treatment for major depressive disorder with imminent risk for suicide, potentially speeding up development and review timelines.

The nasally-administered drug is a non-competitive and subtype non-selective activity-dependent N-methyl-D-aspartate (NMDA) receptor antagonist, offering a new mechanism of action from currently available therapies for depression.

If approved by the FDA, esketamine would be one of the first new approaches to treat major depressive disorder - which affects around 16 million people in the US alone - available to patients in the last 50 years.

"In the US alone, there are more than 41,000 suicides each year, many of which result from untreated or poorly treated major depression," said Husseini Manji, global head, Neuroscience Therapeutic Area, Janssen.

"This designation reinforces the potential of esketamine as a novel treatment for patients with major depressive disorder who are at imminent risk for suicide, a condition for which there currently is no approved treatment and which represents a major public health challenge".

The investigational antidepressant already carries breakthrough status for treatment resistant depression, which is currently being investigated in Phase III clinical trials, and Janssen expects it to ultimately pull in sales of more than $1 billion.