Lilly to present initial clinical data for first-in-class type II JAK2 inhibitor in patients with previously treated myelofibrosis at the 2026 EHA Annual Meeting
Key claim: The first-in-class type II JAK2 inhibitor AJ1-11095 demonstrated an encouraging safety profile and promising spleen volume reduction activity in myelofibrosis patients who had previously failed type I JAK2 inhibitor therapy, including those with JAK2, MPL, and CALR type 1 and 2 mutations.
Abstract
Eli Lilly announced new data from the Phase 1 AJX-101 study showing that its investigational type II JAK2 inhibitor (AJ1-11095) demonstrated an encouraging safety profile and promising clinical activity in patients with myelofibrosis who have been failed by a type I JAK2 inhibitor. Among 17 patients who reached week 24 of treatment, 59% saw a reduction of 20% or greater and 35% saw a reduction of 50% or greater, including JAK2, MPL, and CALR type 1 and type 2 mutations. Data will be highlighted in an oral presentation at the 2026 European Hematology Association (EHA) Annual Meeting taking place in Stockholm, Sweden.
Why this matters
Splenomegaly remains the dominant driver of symptom burden in myelofibrosis, and patients who fail type I JAK inhibitors (ruxolitinib, fedratinib, momelotinib, pacritinib) have few effective spleen-directed options. A type II JAK2 inhibitor binding the inactive kinase conformation offers a mechanistically distinct way to reduce spleen volume in this refractory population, potentially expanding the symptom-management toolkit when standard JAK inhibition fails.