Mice with LNCaP-AR s.c. tumors were treated with a single activity of 300nCi (11.1kBq) [225Ac]hu5A10, 18.5MBq (500µCi) [90Y]hu5A10, or left untreated. (A) Tumor volumes. Data represent mean + SD of n=22 tumors (control), n=9 tumors ([90Y]hu5A10), and n=18 tumors ([225Ac]hu5A10). (B) TTN. Treatment with [90Y]hu5A10 (n=9 tumors) demonstrated overall more rapid effects on tumor volume than [225Ac]hu5A10 (n=18 tumors), with median TTN of 7 days and 38 days, respectively (p<0.0001). (C) TTP was 24 days following treatment with [90Y]hu5A10 (n=9 tumors) and 72.5 days following [225Ac]hu5A10 (n=18 tumors; p<0.0001). (D) Survival following [90Y]hu5A10 (blue line; n=6 mice), [225Ac]hu5A10 (orange line; n=14 mice), or no treatment (dashed lines; n=6–9 mice). Alpha-RIT increased survival from 32 days (control) to 188 days (p<0.0001), while beta-RIT increased survival to 64 days (p=0.0054 vs control; p=0.0009 vs. [225Ac]hu5A10).