Eli Lilly and Company has agreed to acquire Ajax Therapeutics, a bio/pharmaceutical company developing JAK inhibitors for treating myeloproliferative neoplasms, a group of rare, chronic blood cancers, for $2.3 billion. 

JAK inhibitors are a class of targeted immunomodulatory medications that block specific enzymes (JAK1, JAK2, JAK3, TYK2) to reduce inflammation and manage autoimmune disorders. Ajax’s lead asset, AJ1-11095, is an investigational, once-daily oral Type II JAK2 inhibitor currently being evaluated in a Phase I clinical trial with first proof-of-concept clinical data to be presented later in 2026. It is being evaluated for treating myelofibrosis in patients who have previously been treated with a Type I JAK2 inhibitor. AJ1-11095 was designed as a selective Type II JAK2 inhibitor to provide deeper and more durable efficacy than existing JAK2 inhibitors and a option for those patients who become resistant to Type I JAK2 inhibitors, according to information from Lilly.

Under the agreement, Lilly will acquire Ajax and Ajax shareholders could receive up to $2.3 billion in cash, inclusive of an upfront payment and subsequent payments upon the achievement of certain clinical and regulatory milestones. 

The transaction is subject to customary closing conditions, including approval under the Hart-Scott-Rodino Antitrust Improvements Act of 1976. 

Source: Eli Lilly and Company