Bevacizumab in patients with advanced platinum-resistant ovarian cancer

Abstract

5006 Background: Bevacizumab (BV), a recombinant, humanized monoclonal antibody directed against vascular endothelial growth factor, has demonstrated clinical benefit in multiple tumor types. Activity in ovarian cancer (OC) has been reported in phase II studies in patients (pts) with recurrent disease. We now describe the activity/safety of BV in pts with platinum-resistant OC (PROC) that progressed after topotecan or liposomal doxorubicin (LD). Methods: Eligibility criteria for this multicenter, Phase II study included primary or secondary PROC that progressed within 3 months of topotecan or LD, 3 or fewer prior chemotherapy regimens, and a performance status (PS) 0 or 1. BV was dosed at 15 mg/kg q 3 weeks until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) as defined by RECIST. A two-stage design was utilized with H1 set at 15%. Secondary endpoints included progression-free survival (PFS), duration of response, overall survival (OS), and safety. Results: The study enrolled 44 of the intended 53 pts, closing early due to a higher than expected rate of gastrointestinal perforations (GIP). Baseline characteristics included median age 60 yrs (range 31–87); PS 0 in 26 pts, 1 in 18 pts; 2 prior chemotherapy regimens in 20 pts, 3 in 24 pts. Preliminary efficacy: ORR (CR+PR), 7/44 (16%). Median duration of response was 12 weeks, with 2 pts continuing on study >5 months. Serious adverse events (SAEs) were reported in 18/44 pts (41%). Selected SAEs included GIP 5 (11%; one occurred more than 30 days after coming off study while on paclitaxel and commercial Avastin®), bowel obstruction 5 (11%), arterial thromboembolic events 4 (9%), delayed wound healing 2 (5%), and one case each of pulmonary hypertension, hypertensive encephalopathy, and hypoxia. Conclusions: BV has single agent activity in women with PROC, but is associated with substantial toxicity in this population. Trials are ongoing in less heavily treated, newly diagnosed pts with OC to evaluate the efficacy and safety of BV in these disease settings. Identification of risk factors for BV-associated adverse events requires further study. [Table: see text]