Novo Nordisk is exploring beyond its well-paved diabetes track, acquiring its first investigational neurological compound, PRX004, from Prothena in a deal potentially worth up to $1.2 billion.

For an upfront payment of $100 million, Novo Nordisk purchased both the phase 2-ready antibody, intended to treat transthyretin amyloidosis (ATTR), and Prothena’s entire ATTR developmental program. Prothena will also be eligible for $1.2 billion in development and sales milestone payments.

ATTR is a rare, progressive, fatal disease characterized by extracellular amyloid deposits in the heart and peripheral nerve tissue. PRX004 targets abnormally folded transthyretin (TTR) proteins. Produced in the liver, TTR transports vitamin A and the thyroid hormone thyroxine. About 400,000 patients have wild-type ATTR and 50,000, the inherited form.