Using fragment-based screening techniques, 5-methyl-4-phenyl-1 H-pyrazole (IC50 80 μM) was identified as a novel, low molecular weight inhibitor of protein kinase B (PKB). Herein we describe the rapid elaboration of highly potent and ligand efficient analogues using a fragment growing approach. Iterative structure-based design was supported by protein- ligand structure determinations using a PKA-PKB “chimera” and a final protein-ligand ...