Eli Lilly to acquire Ajax Therapeutics for up to $2.3 billion to develop improved JAK inhibitor

Eli Lilly announced Monday it will purchase Ajax Therapeutics, a biotech based in New York and Cambridge, Massachusetts, in a deal valued at up to $2.3 billion.

The transaction includes cash up front and milestone payments linked to clinical and regulatory milestones. The acquisition centers on an experimental drug that Lilly believes could improve on existing JAK inhibitors.

Current JAK inhibitors are used for myelofibrosis, polycythemia vera and rheumatoid arthritis, but they do not alter disease progression and have raised safety concerns, leading many patients to stop therapy.

Ajax’s candidate is designed to work through a different mechanism, aiming to provide more durable responses for myelofibrosis patients.