Anti-CD137 agonistic mAb enhances antilymphoma activity of murine anti-CD20 mAb in vivo. C57BL/6 mice were inoculated with 5 × 106 BL3750 lymphoma tumor cells subcutaneously on the abdomen. (A-B) After tumor inoculation, mice received rat IgG control on day 3 (●), anti-CD20 antibody on day 3 (■), anti-CD137 antibody on day 4 (♦), or anti-CD20 antibody on day 3 and anti-CD137 antibody on day 4 (▴). Mice (10 per group) were then monitored for tumor growth (A; *P < .001) and overall survival (B; *P = .048). (C-D) Tumor growth and survival with identical treatment sequence but with treatment delayed until day 8 after tumor inoculation. Mice received rat IgG control on day 8 (●), anti-CD20 antibody on day 8 (■), anti-CD137 antibody on day 9 (♦), or anti-CD20 antibody on day 8 and anti-CD137 antibody on day 9 (▴). Mice (10 per group) were then monitored for tumor growth (C; *P < .001) and overall survival (D; *P < .001).
