Eli Lilly and Company and Ajax Therapeutics have announced a definitive agreement for Lilly to acquire Ajax. Ajax's lead asset, AJ1-11095, is an investigational, once-daily oral, first-in-class type2 JAK2 inhibitor currently being evaluated in a phase 1 clinical trial, AJX-101, in patients with myelofibrosis who have previously been treated with a type 1 JAK2 inhibitor.

All approved JAK2 inhibitors for patients with MPNs, including myelofibrosis and polycythemia vera, bind the type 1 confirmation of JAK2. While these JAK2 inhibitors provide clinical and symptomatic relief, many patients often discontinue type 1 JAK2 treatment due to a lack of durable benefit or loss of response. AJ1-11095 was designed as a selective type 2 JAK2 inhibitor to not only deliver deeper and more durable efficacy than existing JAK2 inhibitors but also to provide a novel treatment option for those patients who become resistant to type 1 JAK2 inhibitors. The phase 1 clinical trial of AJ1-11095 began in late 2024 and dose selection for future clinical development is expected in 2026.

Jacob Van Naarden, Executive Vice President and President, Lilly Oncology and Head of Corporate Business Development, said, "As a founding strategic investor in Ajax, Lilly has long believed in the approach and is excited about the potential for AJ1-11095 to deliver deeper and more durable efficacy than available treatments with a tolerability profile that would allow for patients to remain on therapy longer and be used across both the first- and second-line settings. We look forward to the presentation of clinical proof-of-concept data later in 2026, rapidly advancing AJ1-11095 into registrational clinical trials, and using our expertise in blood cancer to hopefully deliver another important new medicine to patients and hematologists."

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

Martin Vogelbaum, Co-Founder and Chief Executive Officer, Ajax Therapeutics, said, “We started Ajax to build on the work of its five scientific founders, including Ross Levine, MD, Chief Scientific Officer, Memorial Sloan Kettering Cancer Center and Chair, Ajax's scientific advisory board, who sought to develop a novel class of selective and more potent JAK2 inhibitors to address the significant unmet need of patients with MPNs. With a small but highly motivated team, we have successfully applied this work to the design and development of our highly selective, first-in-class type 2 JAK2 inhibitor, AJ1-11095.  We now look forward to Lilly advancing AJ1-11095 through the clinic and providing a much-needed new therapy for patients with MPNs. It has been an honor working with our employees and scientific advisors and we're grateful to our clinical investigators, and most importantly, the patients who have participated in our ongoing phase 1 study, AJX-101."