Abstract A45: Treatment patterns and outcomes among platinum-refractory/resistant ovarian cancer patients

Abstract

Background: Real-world evidence on current treatment patterns and outcomes is limited for patients with platinum-refractory/resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer (PRROC). This study aimed to describe the treatment patterns and outcomes of patients with PRROC in the United States (US), the United Kingdom (UK), and Canada (CA). Methods: Physicians retrospectively reviewed medical records of females aged ≥18 years diagnosed with PRROC from January 2010 to June 2014. Follow-up data available through October 2016 were extracted. Patient characteristics, initial PRROC treatment regimens, and associated health care utilization were assessed descriptively; clinical outcomes were estimated using the Kaplan-Meier and Cox proportional-hazards methods. Results: Data were obtained on 392 US, 296 UK, and 82 CA patients. At initial diagnosis of epithelial ovarian, fallopian tube, or peritoneal cancer, 65.8% (US), 93.3% (UK), and 82.9% (CA) of patients had stage III/IV disease and 43.6% (US), 73.7% (UK), and 56.1% (CA) had high-grade tumors. Most patients were diagnosed with PRROC in 2013 or 2014 (US: 64.8%, UK: 72.3%, CA: 64.6%) and mean age at PRROC diagnosis was 57 years in the US and CA and 59 years in the UK. The proportion of patients with ECOG performance status (PS) ≤1 at PRROC diagnosis was 57.7% in the US, 80.1% in the UK, and 36.6% in CA. Most patients received systemic treatment after PRROC diagnosis (US 71.4%; UK 83.1%; CA 81.7%). Most of the patients received only one treatment line at the time of extraction (US: 64.3%, UK: 75.6%, CA: 70.2%). Bevacizumab ± chemotherapy (US 41.4%; UK 12.6%; CA 35.8%) and pegylated liposomal doxorubicin (PLD) monotherapy (US 18.6%; UK 50.0%; CA 34.3%) were the most common initial therapies. Common subsequent treatments varied between the countries, including topotecan, gemcitabine, PLD, paclitaxel. During initial treatment for PRROC, 80.7%, 59.8%, and 44.8% of patients had at least one office visit and 18.9%, 7.3%, and 19.4% of patients had at least one emergency department visit in the US, UK, and CA, respectively. Hospitalizations during initial treatment for PRROC were observed among 17.5% of patients in the US, 10.2% in the UK, and 14.9% in CA. Treatment toxicity was the most common reason for hospitalization (US 75.5%; UK 64.0%; CA 80.0%). Median progression-free survival (PFS; 95% confidence interval) was 6.4 (5.4-9.3), 8.0 (6.8-9.2), and 5.6 (4.9-6.2) months in the US, UK, and CA, respectively. The Cox proportional-hazards model showed that stage III/IV, high-grade tumors, and poorer PS were associated with shorter survival. Conclusions: Even though bevacizumab ± chemotherapy and PLD were the most common initial PRROC treatments in the three countries, relatively higher utilization of bevacizumab ± chemotherapy was observed in the US and CA than the UK, plausibly due to lack of bevacizumab reimbursement in the UK for the treatment of PRROC. Limited PFS and a high prevalence of hospitalization due to treatment toxicity observed with initial treatments suggest a continued need for more effective and tolerable treatment strategies for PRROC. Citation Format: Rohan Parikh, Samantha Kurosky, Margarita Udall, Jane Chang, Joseph C. Cappelleri, Jim P. Doherty, James A. Kaye. Treatment patterns and outcomes among platinum-refractory/resistant ovarian cancer patients. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr A45.