Biogen said it would buy Pfizer's experimental treatment for a symptom associated with schizophrenia in a deal that could near $600m.
The deal would also mark Biogen's 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.
A majority of the 20 million people living with schizophrenia worldwide experience some degree of cognitive impairment, Biogen said.
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 $75m upfront, up to $515m in development and commercialisation milestone payments, as well as royalties.
