GPT and glioblastoma: 19–21 ALT-803 also exerted a significant antitumor activity in murine models of multiple myeloma, glioblastoma, ovarian cancer, and in murine breast, colon, and melanoma tumor-bearing mice.22–26 Moreover, intravesical ALT-803 and Bacillus Calmette-Guerin (BCG) administration showed a reduction of tumor burden in a bladder cancer rat model.27 Promising preclinical data on the use of ALT-803 as an anticancer drug have spurred interest in using it in the clinic.