Evaluation of combined bevacizumab and intraperitoneal carboplatin or paclitaxel therapy in a mouse model of ovarian cancer

Purpose: To evaluate the pharmacokinetics of bevacizumab following IP and IV administration, and to investigate combined bevacizumab therapy (IP or IV) with IP paclitaxel or carboplatin in a mouse model of ovarian cancer. Methods: Bevacizumab pharmacokinetics were investigated following IV or IP dosing, and mice bearing peritoneal A2780 xenografts were treated with vehicle, IV or IP bevacizumab, IP paclitaxel, IP paclitaxel with co-administration of IV or IP bevacizumab, IP carboplatin, and IP carboplatin with co-administration of IV or IP bevacizumab. Survival time was defined as the time to death or the time to reach 120% of baseline body weight. Results: Following IP administration, bevacizumab was rapidly absorbed and bioavailability was 92.8%. Median survival time, which was 33 days for control mice, was increased by 24% with IP paclitaxel. IP carboplatin failed to increase survival time when administered alone. IV and IP bevacizumab increased survival time by 42 and 33%. Combined bevacizumab and IP paclitaxel was superior to paclitaxel alone (P = 0.01 for IV and P = 0.04 for IP bevacizumab), and combined bevacizumab and IP carboplatin was superior to carboplatin alone (P = 0.002 for IV and P = 0.02 for IP bevacizumab). There were no significant differences in survival between groups receiving bevacizumab IV or IP, either alone (P = 0.586), in combination with paclitaxel (P = 0.467), or in combination with carboplatin (P = 0.149). Conclusions: Following IP administration to mice, bevacizumab demonstrates rapid and near complete absorption. Bevacizumab therapy, initiated prior to IP carboplatin or paclitaxel administration, increased survival time significantly in mice, and results were not dependent on the route of bevacizumab administration (IV vs. IP).