Combined PS-341 and 153-Sm-EDTMP therapy prolongs survival in C57BL/KaLwRij mice. 5TGM1 cells (5 × 10⁶) were inoculated via the tail vein on day 0. Therapy was initiated intraperitoneally on day 14, and mice were followed for disease progression. Kaplan-Meier survival plot of mice (n = 5 per group) in the pilot study is shown.