A phase II evaluation of bevacizumab in the treatment of recurrent or persistent endometrial cancer: A Gynecologic Oncology Group (GOG) Study

Abstract

5531 Background: Bevacizumab (BV) is a recombinant, humanized monoclonal antibody directed against vascular endothelial growth factor, has demonstrated clinical benefit in multiple tumor types. This is the first report of the activity of bevacizumab in patients with recurrent or persistent endometrial cancer (EMC). Methods: Eligible patients had persistent or recurrent EMC after receiving 1–2 prior cytotoxic regimens, measurable disease, and GOG performance status < 2. Treatment consisted of BV 15 mg/kg IV q 3 weeks until disease progression or prohibitive toxicity. Primary endpoints were progression-free survival (PFS) at 6 months, objective response rate, and toxicity by NCI CTCAE v3.0. The clinical trial was carried out in a flexible 2-stage group sequential design intended to detect either cytostatic or cytotoxic activity. Sample sizes were targeted to limit the probability of designating ineffective regimens as being active 10% with at least 90% statistical power. Clinically significant improvements were 20% increases in the proportion responding or surviving progression-free at 6 months over historical controls. Results: From March 2006 to January 2008, 56 patients were enrolled. Two were excluded due to a second primary and one due to inadequate pathology; thus, the sample included 53 patients. Median age was 62 (range 44–84) years, and prior treatment consisted of 1 or 2 regimens in 33 and 20 patients, respectively. Twenty-eight patients (52.8%) had prior radiation. Early results showed 8/53 (15.1%) response rate, with 1 complete response and 7 partial responses; and 19/53 (35.8%) of patients progression free at 6 months with 2 patients pending at the time of data analysis. Median PFS was 4.2 months. Median Overall survival (OS) was 10.5 months. The following grade 3 or 4 toxicities were observed: anemia (1 grade 3), cardiovascular (4 grade 3), constitutional (2 grade 3), hemorrhage (1 grade 3), hepatic (1 grade 3), musculoskeletal (2 grade 3), metabolic (1 grade 3, 1 grade 4), neurologic (1 grade 3), pain (4 grade 3), and vascular (1 grade 3, 1 grade 4). Conclusions: BV appears to have single agent activity in women with recurrent or persistent EMC and warrants further investigation. No significant financial relationships to disclose.