A Phase 1 Study of AJ1-11095 in Patients With Primary Myelofibrosis (PMF), Post-Polycythemia Vera Myelofibrosis (PPV-MF), or Post-Essential Thrombocythemia Myelofibrosis (PET-MF) Who Have Been Failed by a Type I JAK2 Inhibitor (JAK2i)
Key claim: AJX-101 is a first-in-human phase 1 trial evaluating the safety, tolerability, pharmacokinetics, and clinical activity of AJ1-11095, an oral type II JAK2 inhibitor, in myelofibrosis patients who have failed at least one type I JAK2 inhibitor.
Abstract
AJX-101 is a first-in-human (FIH), phase 1, non-randomized, multi-center, open-label clinical trial designed to investigate the safety, tolerability, pharmacokinetics (PK), clinical activity and changes in biomarkers of an orally administered type II JAK2 inhibitor, AJ1-11095, in subjects with primary or secondary myelofibrosis previously treated with at least one type I JAK2 inhibitor.
Why this matters
Type I JAK2 inhibitor failure defines a high-unmet-need subpopulation across PMF and post-MPN MF, where natural history converges on cytopenias, progressive splenomegaly, and short survival regardless of starting subtype. AJ1-11095 is the first type II JAK2 inhibitor to enter human testing and is being deployed precisely in this resistance setting, making it a subtype-relevant probe of whether mechanistically distinct JAK2 inhibition can alter the post-ruxolitinib trajectory shared by PMF, PPV-MF, and PET-MF.