Royalty Pharma (RPRX) said Wednesday that it will pay up to $425 million, including a $125 million upfront payment, to biopharmaceutical company Neurimmune for a 3% to 4% royalty on worldwide net sales of its interest in AstraZeneca's (AZN) cliramitug.

Cliramitug, which is currently in the Phase 3 DepleTTR-CM trial, is intended to treat patients with transthyretin amyloid cardiomyopathy.

"Cliramitug combines a differentiated scientific approach with promising clinical data and addresses a rapidly growing market with significant unmet need," Chief Executive Pablo Legorreta said in a statement.