Eli Lilly commits up to US$2.3 billion to test a new option for resistant myelofibrosis patients
Eli Lilly is putting up to US$2.3bn behind a single experimental JAK2 drug as it pushes deeper into blood cancers and looks past its obesity franchise.
According to Reuters, Lilly agreed to buy privately held Ajax Therapeutics for up to US$2.3bn in cash.
The total includes an upfront payment and subsequent payments tied to clinical and regulatory milestones.
The companies said in their press release that the deal remains subject to customary closing conditions, including approval under the Hart‑Scott‑Rodino Antitrust Improvements Act of 1976, and that Lilly will determine the accounting treatment under Generally Accepted Accounting Principles after closing.
The transaction centres on AJ1‑11095, Ajax’s lead asset.
The companies described it as an investigational, once‑daily oral, first‑in‑class Type II JAK2 inhibitor.
It is currently being evaluated in a Phase 1 clinical trial, AJX‑101 (NCT06343805), in patients with myelofibrosis who have previously been treated with a Type I JAK2 inhibitor.
The Phase 1 trial began in late 2024 and dose selection for future clinical development is expected in 2026.
Ajax focuses on myeloproliferative neoplasms (MPNs), a group of rare blood cancers where the bone marrow produces too many red blood cells, said PharmaceuticalTechnology.
Reuters added that Ajax is testing AJ1‑11095 as an experimental once‑daily oral treatment in early‑stage studies for previously treated patients with myelofibrosis, “a rare, chronic blood cancer where scar tissue builds up in the bone marrow, disrupting normal blood cell production.”
The company is also developing the drug for related diseases, including polycythemia vera, “a disorder in which the body makes too many red blood cells.”
All approved JAK2 inhibitors for patients with MPNs, including myelofibrosis and polycythemia vera, bind the Type I conformation of JAK2.
The press release noted that while these JAK2 inhibitors provide clinical and symptomatic relief, “many patients often discontinue Type I JAK2 treatment due to a lack of durable benefit or loss of response.”
According to Ajax, AJ1‑11095 works by blocking JAK2, “a signaling protein that helps drive several blood cancers.”
The company said the drug is designed to attach to JAK2 in a different way from currently available medicines, which could help it work better or for longer in patients who stop responding to older treatments.
Lilly and Ajax said AJ1‑11095 “was designed as a selective Type II 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 I JAK2 inhibitors.”
Scotiabank analyst Louise Chen said the transaction “builds on Lilly’s established capabilities in blood cancers and helps expand its future commercial products beyond obesity,” according to Reuters.
PharmaceuticalTechnology noted that Lilly already markets a JAK inhibitor under the brand name Olumiant (baricitinib), a once‑daily therapy whose US label includes indications in rheumatoid arthritis, alopecia areata and Covid‑19.
Lilly has been “doubling down on its search for next‑generation cancer treatments” with a recent dealmaking spree that includes companies such as Scorpion Therapeutics, Orna Therapeutics and Kelonia Therapeutics, Reuters reported.
PharmaceuticalTechnology said Lilly has “inked six M&A deals so far in 2026,” with half oncology‑focused, and highlighted agreements to acquire in vivo CAR‑T developers Orna Therapeutics and Kelonia in February and April.
Lilly was already an investor in Ajax.
PharmaceuticalTechnology reported that in 2024 Lilly participated in Ajax’s US$95m Series C financing round and described Lilly as a “founding strategic investor.”
“As a founding strategic investor in Ajax, Lilly has long believed in the approach,” said Jacob Van Naarden, executive vice‑president and president of Lilly Oncology and head of corporate business development.
He said Lilly expects to present proof‑of‑concept data in 2026, push AJ1‑11095 into registrational trials and use its blood cancer expertise to deliver another important medicine to patients and hematologists.
“We started Ajax to build on the work of its five scientific founders,” said Ajax co‑founder and chief executive officer Martin Vogelbaum, citing Ross Levine, MD, of Memorial Sloan Kettering Cancer Center.
He said the team turned that research into the JAK2 inhibitor AJ1‑11095 and now expects Lilly to advance the drug and bring a much‑needed new option to patients with MPNs.
