Janus kinase inhibitor

Janus kinase inhibitor is a class of medicines that function by inhibiting the effect of one or more of the Janus kinase family of enzymes (JAK1, JAK2, JAK3, TYK2), interfering with the JAK-STAT signaling pathway.

Some JAK2 inhibitors are under development for the treatment of polycythemia vera, essential thrombocythemia, and myeloid metaplasia with myelofibrosis. Some inhibitors of JAK2 are in clinical trials, e.g. for psoriasis.

JAK3 is also being targeted for a variety of inflammatory diseases, and one has had good results in a phase II trial for rheumatoid arthritis.

Examples

 * Lestaurtinib against JAK2, for acute myelogenous leukemia (AML)
 * Tofacitinib (previously called tasocitinib) (CP-690550) against JAK3 for psoriasis, and rheumatoid arthritis. Early Phase III results in November 2010 were encouraging.
 * Ruxolitinib against JAK1/JAK2 for psoriasis, myelofibrosis, and rheumatoid arthritis
 * Pacritinib (SB1518) against JAK2 for relapsed lymphoma, advanced myeloid malignancies, myelofibrosis and CIMF Phase II results for polycythemia vera and thrombocythemia myelofibrosis
 * CYT387 against JAK2 for myeloproliferative disorders
 * LY3009104 (INCB28050) against JAK1/JAK2 starting phase IIb for rheumatoid arthritis
 * TG101348 against JAK2; phase I results for myelofibrosis are published