Real-world impact of olaparib use in patients (pts) with advanced pancreatic cancer (PC) harboring germline BRCA1/2 (gBRCA) mutations.

Abstract

e16278 Background: g BRCA mutations are found in approximately 8% of Italian PC pts screened within 3 months from diagnosis. g BRCA PC pts display enhanced sensitivity to platinum-based chemotherapy (CHT) and PARP inhibitors, such as olaparib. In metastatic g BRCA PC pts, maintenance olaparib after platinum-based CHT doubled PFS and resulted in twice as many long-term (3-yr) survivors (34% versus 18%) in the randomized POLO trial. However, despite guideline recommendations, olaparib is currently not reimbursed in Italy in metastatic g BRCA PC pts, based on the absence of significant differences in median OS. Methods: We analyzed the impact of exposure to olaparib on OS from the start of I-line treatment in a cohort of 114 Italian g BRCA PC pts, whose clinical characteristics and outcomes in response to first () and subsequent chemotherapy lines have been previously reported ( 10.1016/j.esmoop.2021.100238 ; 10.1038/s41416-022-02086-w ). Results: Clinical characteristics of patients who did or did not receive olaparib were well balanced, except for baseline CA19.9 levels (significantly lower in patients who received olaparib, p=0.043) and exposure to platinum-containing chemotherapy (significantly less in patients who did not receive olaparib, p<0.0001). In the entire cohort of g BRCA PC pts, OS from the start of I-line treatment for metastatic disease was significantly (p=0.02) longer in pts who had been exposed to olaparib in any treatment line (n=53). Since previous surgery and response to I-line chemotherapy were strong independent predictors of OS at multivariate analysis, we analyzed pts who were diagnosed with stage IV (M+, n=87) disease and pts who did not experience PD as best response to I-line chemotherapy (no PD, n=94), separately. A statistically significant difference in OS favoring g BRCA PC pts who were exposed to olaparib in any line of treatment was observed in the M+ cohort (p=0.0025), in the no PD cohort (p=0.049), but not in the M+/no PD cohort (n=73, p=0.057) or in the POLO-like population (I-line maintenance; n=60, p=0.334). Conclusions: In g BRCA PC pts, exposure to olaparib in any line of treatment in a real-world setting significantly impacts on OS; timing and setting of administration remain to be determined in order to optimize survival advantage. [Table: see text]