The US Food and Drug Administration (FDA) has approved Rexulti (brexpiprazole) tablets, by Otsuka Pharmaceutical Co., Ltd. and H. Lundbeck A/S to treat adults with schizophrenia and as an add-on treatment to an antidepressant medication to treat adults with major depressive disorder (MDD). Rexulti was discovered by Otsuka and co-developed with Lundbeck. It will be co-marketed by the two companies and is expected to become available to patients in the United States in early August 2015.

The drug is slated by some analysts for blockbuster potential. A recent Thomson Reuters analysis offered 2019 sales estimates of the drug at $1.35 billion.

The mechanism of action of in the treatment of MDD or schizophrenia is unknown. However, the efficacy of Rexulti may be mediated through a combination of partial agonist activity at serotonRexult in 5-HT1A and dopamine D2 receptors, and antagonist activity at serotonin 5-HT2A receptors. In addition, Rexult exhibits high affinity (subnanomolar) for these receptors, as well as for noradrenaline alpha1B/2C receptors, according to information from Otsuka.

Source: FDA, Otsuka Pharmaceutical, and Lundeck