GSK1904529A is a potent, selective, orally active, and ATP-competitive inhibitor of insulin-like growth factor-1 receptor (IGF-1R) and insulin receptor (IR), with IC50s of 27 and 25 nM, respectively. GSK1904529A shows poor activity (IC50>1 μM) in 45 other serine/threonine and tyrosine kinases. GSK1904529A exhibits anti-tumor activity