Real-world eligibility of advanced pancreatic (APC) patients for maintenance olaparib.

Abstract

653 Background: The POLO trial demonstrated an improvement in progression free survival (PFS, 7.4 months vs. 3.8 months; hazard ratio, HR, 0.53; 95% confidence interval, 95% CI, 0.35 to 0.82; P=0.004) with olaparib compared to placebo, as maintenance therapy in APC patients with germline BRCA 1/2 mutations with disease control after 16 weeks (DC16) of platinum-based first-line therapy. This study aims to identify the proportion of real-world APC patients eligible for olaparib, and to determine the PFS and overall survival (OS) after DC16. Methods: APC patients treated with first-line FFX in Alberta were identified (2011-2018). We conducted an analysis of baseline characteristics to identify factors associated with DC16. Results: We identified 165 APC patients treated with FFX with unknown BRCA 1/2 status, of which 56% were males and median age at diagnosis was 59 years (interquartile range 38-75 years). Of these, 72 (44%) had DC16. Normal LDH and ALP, and albumin more than 35 g/L were associated with a higher likelihood of having DC16 (table). The PFS of patients with DC16 was significantly higher than those with DC<16 weeks (9.3 vs 2.5 months, HR=0.22, 95% CI 0.15-0.32, P<0.001). In patients who had DC16, median PFS and OS from that point were 5.6 months and 17.9 months, respectively. Conclusions: Less than half of real-world patients treated with first-line FFX would be eligible for olaparib by the criteria of DC16 with FFX. Median PFS after DC16 is 5.6 months with FFX in patients with unknown BRCA 1/2 status. This provides a baseline for future trials evaluating maintenance strategies. Patients with APC and higher disease burden (higher ALP and LDH) and low albumin are less likely to have DC16. [Table: see text]