INCB16562 is a novel, selective, and orally bioavailable small-molecule inhibitor of JAK1 and JAK2 markedly selective over JAK3. Treatment of myeloma cells with INCB16562 potently inhibited interleukin-6 (IL-6)-induced phosphorylation of STAT3. INCB16562 abrogated the protective effects of recombinant cytokines or bone marrow stromal cells and sensitized myeloma cells to cell death by exposure to dexamethasone, melphalan, or bortezomib. Oral administration of INCB16562 antagonized the growth of myeloma xenografts in mice and enhanced the antitumor activity of relevant agents in combination studies. INCB16562 is a potent JAK1/2 inhibitor and that mitigation of JAK/STAT signaling by targeting JAK1 and JAK2 will be beneficial in the treatment of myeloma patients, particularly in combination with other agents. ( source: Neoplasia. 2010 Jan;12(1):28-38. ).