Pexmetinib: a novel dual inhibitor of Tie-2 and p38 MAPK with efficacy in preclinical models of myelodysplastic syndromes and acute myeloid leukemia | Aplastic Anemia and MDS International Foundation

Pexmetinib: a novel dual inhibitor of Tie-2 and p38 MAPK with efficacy in preclinical models of myelodysplastic syndromes and acute myeloid leukemia

Journal Title: 
Cancer Res.
Primary Author: 
Bachegowda L
Author(s): 
Bachegowda L, Morrone K, Winski SL, Mantzaris I, Bartenstein M, Ramachandra N, Giricz O, Sukrithan V, Nwankwo G, Shahnaz S, Bhagat T, Bhattacharyya S, Assal A, Shastri A, Gordon-Mitchell S, Pellagatti A, Boultwood J, Schinke C, Yu Y, Guha C, Rizzi J, Garr
Original Publication Date: 
Friday, June 10, 2016

Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) suppress normal hematopoietic activity in part by enabling a pathogenic inflammatory milieu in the bone marrow. In this report, we show that elevation of angiopoietin-1 in myelodysplastic CD34+ stem-like cells is associated with higher risk disease and reduced overall survival in MDS and AML patients. Increased angiopoietin-1 expression was associated with a transcriptomic signature similar to known MDS/AML stem-like cell profiles. In seeking a small molecule inhibitor of this pathway, we discovered and validated pexmetinib (ARRY-614), an inhibitor of the angiopoietin-1 receptor Tie-2, which was also found to inhibit the pro-inflammatory kinase p38 MAPK (which is overactivated in MDS). Pexmetinib inhibited leukemic proliferation, prevented activation of downstream effector kinases and abrogated the effects of TNF-alpha on healthy hematopoietic stem cells. Notably, treatment of primary MDS specimens with this compound stimulated hematopoiesis. Our results provide preclinical proof of concept for pexmetinib as a Tie-2/p38 MAPK dual inhibitor applicable to the treatment of MDS/AML.

Bone Marrow Diseases: