Results with rituximab followed by CTX.

NOD/SCID mice that received transplants of 10 × 10⁶Namalwa cells intraperitoneally were given 3 courses of rituximab (25 mg/kg) on days 3, 5, and 7 after transplantation and randomly assigned to receive 75 of mg/kg CTX (⧫) or PBS (▪) on days 15, 17, and 19 (first course) and on days 25, 27, and 29 (second course). CTX delayed tumor growth in comparison with results in PBS-treated controls but did not prevent tumor growth or induce significant tumor regression after tumor regrowth. The dotted line indicates tumor growth in untreated controls (▴). Results are mean ± SD values for tumor volume (n = 4 per group). *P = .003; †P = .02.