Vanda Pharmaceuticals has received approval from the U.S. Food and Drug Administration (FDA) for its atypical antipsychotic drug milsaperidone, which will be marketed as Bysanti. The medication is intended for frontline use in treating schizophrenia and manic or mixed episodes in patients with bipolar I disorder.
According to Vanda, Bysanti will become available by the third quarter of this year. Following the announcement, shares of Vanda rose significantly before Monday’s market opening.
Bysanti contains milsaperidone, an active metabolite of iloperidone—the same compound used in Vanda’s existing psychiatric drug Fanapt. Both drugs are indicated for schizophrenia and manic or mixed episodes in bipolar disorder. After oral administration, Bysanti “rapidly interconverts to iloperidone,” according to the company, blocking dopamine D2, serotonin 5-HT2A, and alpha1-adrenergic receptors.
The company stated that Bysanti is bioequivalent to Fanapt based on pharmacokinetic data presented last May, which showed similar drug level trajectories over time for both medications.
In addition to bioequivalence studies, Vanda supported its application with data from Fanapt’s clinical history, covering more than 100,000 patient-years of use. “Bysanti offers patients and providers a reliable new treatment grounded in extensive clinical heritage,” said CEO Mihael Polymeropoulos.
This regulatory success follows a setback for Vanda earlier this year when the FDA rejected its sedative Hetlioz as a treatment for jet lag. The agency concluded that Vanda had not provided sufficient evidence of Hetlioz’s efficacy for this indication—a position disputed by the company at the time.
Vanda maintained that its research models “are widely accepted in circadian rhythm research as valid and reliable surrogates for simulating the core circadian misalignment underlying eastward jet lag.”
Hetlioz has been involved in ongoing legal disputes between Vanda and the FDA since an initial rejection in 2019. After appealing and requesting a hearing in mid-2022 without response from the agency, Vanda filed a lawsuit later that year. In March 2024, a judge ordered the FDA to either hold a hearing or resolve the application; the agency chose resolution instead. This decision was challenged by Vanda and ultimately overturned on appeal in August 2025.
Apart from developments with Hetlioz, Vanda also secured FDA approval late last year for Nereus as a treatment for motion sickness—the first such approval granted by regulators in over forty years.
