Comparative phenotypic profiling of the JAK2 inhibitors ruxolitinib, fedratinib, momelotinib, and pacritinib reveals distinct mechanistic signatures

• Published in: PloS one Vol. 14; no. 9; p. e0222944
• Main Authors: Singer, Jack W, Al-Fayoumi, Suliman, Taylor, Jason, Velichko, Sharlene, O'Mahony, Alison
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 27.09.2019; Public Library of Science (PLoS)
• Subjects: Analysis; B cells; Benchmarking; Benzamides - pharmacology; Biology and Life Sciences; Biomarkers; Bridged-Ring Compounds - pharmacology; Cancer; Cell activation; Cell culture; Cell Proliferation - drug effects; Cell survival; Cells, Cultured; Cellular signal transduction; Criminal investigation; Cytokines - immunology; Cytokines - metabolism; Disease; DNA sequencing; Fibroblasts; Healthy Volunteers; Humans; Immune response; Inflammation; Inflammation Mediators - immunology; Inflammation Mediators - metabolism; Inflammatory diseases; Inhibitor drugs; Inhibitors; Janus kinase; Janus kinase 2; Janus Kinase 2 - antagonists & inhibitors; Janus Kinase 2 - immunology; Janus Kinase 2 - metabolism; Kinases; Leukemia; Lymphocytes; Lymphocytes B; Lymphocytes T; Lymphoma; Medicine and Health Sciences; Myelofibrosis; Nitriles; Pharmacology; Physical Sciences; Polycythemia; Polycythemia vera; Primary Cell Culture; Primary Myelofibrosis - drug therapy; Protein Kinase Inhibitors - pharmacology; Pyrazoles - pharmacology; Pyrimidines - pharmacology; Pyrrolidines - pharmacology; Ruxolitinib; Signal Transduction - drug effects; Signaling; Signatures; Smooth muscle; Sulfonamides - pharmacology; T cells; Toxicity Tests; Transcription factors; Transducers; Translation; Treatment outcome; United States > US; California
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0222944

Janus kinase-signal transducers and activators of transcription (JAK-STAT) signaling is critical to multiple cellular processes, including survival, differentiation, and proliferation. JAK-STAT signaling dysregulation has been noted in inflammatory disorders, and aberrant JAK2 pathway activation has been implicated in myelofibrosis and polycythemia vera. Moreover, 4 therapeutic JAK2 inhibitors (ruxolitinib, fedratinib, momelotinib, and pacritinib) have either been approved or are in advanced clinical development for myelofibrosis. Although all inhibit JAK2, reports indicate that they also inhibit other kinases. Profiling based solely on in vitro potencies is insufficient to predict the observed clinical effects. To provide further translational insights into clinical outcomes, we compared phenotypic biomarker profiles of ruxolitinib, fedratinib, momelotinib, and pacritinib in the BioMAP® Diversity PLUS panel of 12 human primary cell systems designed to recapitulate key aspects of tissue and disease states. Biomarker activity profiles that represent mechanistic signatures for each agent were compared with each other and a database of reference benchmark profiles. At clinically relevant concentrations, these agents had distinct biomarker impacts indicating diverse mechanistic signatures, suggesting divergent clinical effects for each agent. They disparately modulated inflammatory cytokine production and immune function. At clinically relevant concentrations, ruxolitinib had the broadest scope of activities across all 12 cellular systems, whereas pacritinib was more specific for the BT system (modelling T cell-dependent B cell activation) and exhibited the strongest inhibition of sIL-17A, sIL-2, and sIL-6. All 4 agents were antiproliferative to B cells, but ruxolitinib and momelotinib were also antiproliferative to T cells. These differential activities likely reflect distinct secondary pharmacology for these agents known primarily as JAK2 inhibitors. The phenotypic analysis reported herein represents key data on distinct modes-of-action that may provide insights on clinical outcomes reported for these agents. Such translational findings may also inform the development of next-generation molecules with improved efficacy and safety.