Described herein are polymeric nanoparticles that comprise 8-[4-(1-aminocyclobutyl)phenyl]-9-phenyl-2H-[1,2,4]-triazolo-[3,4-fJ[1,6]-naphthyridin-3-one (Compound A), or a pharmaceutically acceptable salt thereof, and methods of making and using such nanoparticles. The nanoparticle comprises about 50 to about 99.8 weight percent of a diblock poly(lactic) acid-poly(ethylene)glycol copolymer or a diblock poly(lactic acid-co-glycolic acid)-poly(ethylene)glycol copolymer, wherein the total amount of poly(ethylene)glycol in the nanoparticle is about 10 to about 30 weight percent poly(ethylene)glycol and about 0.2 to about 30 weight percent of Compound A.
