Anti-huCD20 mAb therapy leads to long-lasting survival after tumor challenge in vivo. (A) Mice were intravenously injected on day 0 with 5 × 105 EL4-huCD20 cells (n = 25) and were divided into 2 groups. The first group (□, n = 8) was left untreated. Mice from the second group (■, n = 17) received CAT-13 mAb therapy (5 × 200 μg intraperitoneal injections on days 1, 4, 7, 10, and 13). *P < .001. Black arrows indicate CAT-13 mAb injections. (B) Surviving CAT-13–treated mice were challenged intravenously with either 5 × 105 EL4-wt cells (●, n = 7) or EL4-huCD20 cells (■, n = 7). Naive mice injected with either 5 × 105 EL4-wt (○, n = 7) or EL4-huCD20 cells (□, n = 7) were used as controls. **P < .001. Statistical comparisons were performed with the log-rank test.
