The U.S. Food and Drug Administration approved Otsuka Pharmaceutical's brexpiprazole to treat agitation in patients with Alzheimer's on Thursday, making it the first approved drug for the indication, the company said in a statement.

The decision comes after an advisory panel in April voted 9-1 that the company had enough data to identify the population in whom benefits from the treatment outweigh its risks.

Patients with Alzheimer's sometimes show signs of extreme aggression or become restless and anxious as their brain loses its ability to negotiate with new stimulus as a result of the disease.

Presently in the U.S., such patients are calmed down using non-pharmacological strategies first, only to be followed by off-label treatment with antipsychotics and anti-depressants in worse scenarios.

The approval of brexpiprazole is based on two late-stage studies, which showed significant improvement in calming agitated patients with Alzheimer's, when compared with a placebo.

Brexpiprazole, co-developed with Danish drugmaker Lundbeck , was previously approved in the U.S. to treat adults with major depressive disorder and schizophrenia.