The BEV1L study: Do real-world outcomes associated with the addition of bevacizumab to first-line chemotherapy in patients with ovarian cancer reinforce clinical trial findings?

5563 Background: Data from the GOG-0218 (NCT00262847) and ICON7 (NCT00483782) trials suggest that adding bevacizumab (bev) to first-line (1L) chemotherapy (CT) for treatment of stage III/IV ovarian cancer (OC) improves progression-free survival (PFS) among the overall population, but an improvement in overall survival (OS) may be limited to patients (pts) with high-risk clinical factors. Real-world (rw) evidence assessing the impact of adding bev to 1L CT may help identify subgroups of pts who may benefit from 1L CT alone vs CT + bev. Methods: This retrospective study included pts from the US nationwide Flatiron Health electronic health record–derived deidentified database who were diagnosed with stage III/IV epithelial OC on/after 1/1/2016 and initiated 1L CT ± bev on/after 1/1/2017. Pts with high-risk clinical factors were defined as those with stage IV disease or stage III disease with either visible residual disease or no evidence of surgery. Rw endpoints included time to next treatment (rwTTNT), rwPFS, and rwOS. Kaplan-Meier methods were used to estimate unadjusted median outcomes, indexed to 1L start date. Results: Among 1752 pts, median age was 68 years (IQR, 60–75 years), and median follow-up time was 18.5 months (IQR, 8.0–36.6 months). Among pts with high-risk clinical factors, median rwTTNT was significantly longer with 1L CT + bev than with CT alone; no differences were seen with median rwPFS, although a trend toward longer rwOS was observed with 1L CT + bev vs with CT alone (Table). Among pts without high-risk clinical factors, no significant differences were observed in median estimates of rwTTNT, rwPFS, or rwOS between pts receiving 1L CT + bev and pts receiving CT alone. Conclusions: This rw study provides support for findings from ICON7 and GOG-0218, suggesting that the benefit of adding bev to 1L CT may be limited to pts with high-risk clinical factors. [Table: see text]