The British drugmaker will pay $21 per share for Fusion, including $2 billion in cash upfront and another $400 million in milestone payments. That represents a 126% premium to Fusion's closing price before the announcement.

Canadian biotech company Fusion specializes in radioconjugates, a type of drug that delivers a radioactive isotope directly to cancer cells with precise targeting, minimizing damage to healthy cells. The company is in Phase 2 clinical trials and offers a potential new treatment for advanced prostate cancer that competes with Novartis' Pluvicto.

AstraZeneca's acquisition of Fusion joins a string of billion-dollar takeovers that reflect the ongoing consolidation in the pharmaceutical industry. AstraZeneca's other recent acquisitions include Amolyt Pharma for up to $1.05 billion, Gracell Biotechnologies for $1.2 billion and Icosavax for $1.1 billion. In addition, AstraZeneca acquired a gene therapy portfolio from Pfizer for up to $1 billion last year.