AMO-04 (tianeptine)

AMO-04 (tianeptine), marketed by AMO Pharma, is an antidepressant that is being investigated as a potential treatment for Rett syndrome and breathing disorders.

The U.S. Food and Drug Administration (FDA) granted AMO-04 orphan drug status for treating Rett syndrome in June 2018.

How AMO-04 works

The active compound in AMO-04, is tianeptine, an antidepressive agent. It acts by binding to glutamate receptors found on nerve cells. Glutamate is a neurotransmitter (a cell-signaling molecule) in the brain. It plays an essential role in the function and maintenance of nerve cells. By binding to glutamate receptors, AMO-04 modulates glutamate signaling. AMO-04 also is known to increase the levels of brain-derived neurotrophic factor (BDNF), which also is crucial for nerve cell development and function.

Rett syndrome is caused by mutations in the MECP2 gene. Because the protein that this gene encodes for plays an essential role in brain development, a loss of function caused by mutations leads to the neurobehavioral deficits that are seen in Rett syndrome patients. Tianeptine’s action on glutamate signaling and BDNF is thought to compensate for the deficits in nerve cell function.

Studies with AMO-04

AMO-04 has been investigated in preclinical studies that were conducted under the Scout Program, a screening program that is testing compounds that potentially could treat Rett syndrome.

A study in mice investigated AMO-04 in a mouse model for Rett syndrome. These mice, like Rett syndrome patients, have a mutation in their MECP2 gene and develop signs similar to the symptoms of the disease seen in patients, such as impaired motor skills and abnormal eye movements. In the study, AMO-04 was well-tolerated and treatment could reverse abnormal eye movements. Another study had shown that AMO-04 treatment improves gait features and motor coordination.

Additional information

When used as an antidepressant, AMO-04 is known to cause side effects such as constipation, nausea, dizziness, headache, and abdominal pain.


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