Clinical researchers are testing new agents they hope will be safer and more effective. There are more than 130 antidepressants in today's research pipeline. These include newer SNRI drugs, kinase blocking agents and NMDA receptor agonists.
The SNRI drug
Viibryd (vilazodone) was introduced in 2011, and another SNRI, called levomilnacipran, was submitted for regulatory review in the fall of 2012.
Kinase blocking drugs
. Kinase acts to produce cytokines-pro-inflammatory molecules that are part of the immune response. People suffering from depression have increased blood levels of cytokines. Kinase blocking drugs are in clinical trials to learn how they might relieve depression symptoms. One of these, called Losmapimod, is in Phase II trials.
NMDA receptor agonists
act through the body's glutamate system. Recent studies show that the glutamate system stimulates connections of existing neurons in the brain and provides a quicker, more direct way to build signaling pathways than the slower process based on neurotransmitters. NMDA receptor agonists (promoters) have potential to relieve symptoms sooner. Current studies of potential NMDAs include trials of GLYX-13, now in Phase II trials.
Also on the horizon is an experimental drug called ALKS 5461. It combines an agent used to treat opioid addiction with an opioid modulator. The hope is to create a therapy that could enhance mood and reduce anxiety without the potential for addition. Early Phase I-II studies have shown promise to treat patients with "treatment-resistant" depression who have not benefited from existing therapies.
Cowen and Company, Therapeutic Category Outlook 2010.
CenterWatch, 2012. New Medical Therapies