U.S. biotechnology company Biogen Inc said it would buy Pfizer Inc’s experimental treatment for a symptom associated with schizophrenia in a deal that could near $600 million and mark its foray into the emerging market for neuropsychiatry.

Biogen said it plans to start mid-stage tests on the drug, which is being developed to treat cognitive impairment associated with schizophrenia, in the latter half of the year once the deal closes as expected in the second quarter.

Pfizer’s drug is designed to bridge signals in the central nervous system that have been disrupted by the disease.

Biogen said it would pay Pfizer $75 million upfront, up to $515 million in development and commercialization milestone payments, as well as royalties.