Multiple dosing of SGN-CD70A eradicated established tumors, leading to long-term survival of tumor-bearing PDXs. The survival rate (A), serial measurements of cfDNA concentration (B), and tumor size in individual mice (C) throughout the drug therapy in 4 treatment groups, PBS control, IgG isotype control of SGN-CD70A, and 1 dose vs 3 weekly doses of SGN-CD70A. NSG mice were implanted with PRS-1 primary tumor cells subcutaneously at the right flank on day 0. On day 7, mice were divided into 4 groups and administrated intraperitoneally a single dose of PBS (n = 4), IgG control (n = 3), 300 μg/kg of SGN-CD70A (CD70A300, n = 4), or 3 weekly doses of SGN-CD70A (SGN70A300x3) as indicated. The tumor volume and cfDNA were represented as mean ± SEM and statistically analyzed by an unpaired t test with 2-tailed P value. P < .05 represents as a significant difference. The survival curves were generated by the Kaplan-Meier method and analyzed by the Mantel-Cox test.