Uterine Leiomyosarcomas harboring MAP2K4 gene amplification are markedly sensitive in vivo to PLX8725, a Novel MAP2K4 Inhibitor

Uterine leiomyosarcoma (uLMS) is a rare, highly aggressive tumor with an estimated 5-year overall survival of 50% for even early-stage disease. Up to 30% of uLMS may harbor a gain of function in the MAP2K4 gene, a member of the MAPK family which plays an important role in tumor cell proliferation, differentiation, and metastasization. We sought to investigate the in vivo activity of a novel MAP2K4 inhibitor, PLX8725, against uLMS harboring MAP2K4 gene amplification.