Bevacizumab beyond progression: Impact of subsequent bevacizumab retreatment in patients with ovarian, fallopian tube, and peritoneal cancer after progression.

Abstract

5557 Background: The Food and Drug Administration approved the use of bevacizumab for treatment of recurrent epithelial ovarian, fallopian tube, and primary peritoneal carcinoma (OC) in combination with chemotherapy. This study evaluates whether patients immediately retreated with bevacizumab derive benefit after progressing on a bevacizumab-containing regimen. Methods: This multi-institutional, retrospective study compared patients with high grade non-mucinous epithelial OC who received bevacizumab followed directly by another bevacizumab-containing treatment regimen to patients who received bevacizumab followed by a regimen that did not contain bevacizumab (or received no further treatment). All patient retreated with bevacizumab had stable or progressive disease on prior bevacizumab containing regimen. Progression free survival (PFS) and overall survival (OS) were estimated using Kaplan and Meier product-limit estimator and modeled via Cox proportional hazards regression. PFS was measured from the date of first bevacizumab treatment to the date of first progression, date of death or date of last clinic visit. OS was measured from the date of first bevacizumab treatment after progression to the date of death or date of last contact/clinic visit. Statistical significance was defined at the 0.05 level. Results: 275 patients received bevacizumab, of which 226 were evaluable; 102 received sequential treatment with bevacizumab and 124 received a bevacizumab containing regimen followed by a non-bevacizumab containing regimen at the time of progression. There was no significant difference between tumor grade, stage, or BRCA mutation. Median follow-up for all subjects was 17 months (range: 1.2-138.2 months). Median PFS was 10.21 months (95%CI: 8.05 - 11.79) and median OS was 22.14 months (95%CI: 17.1 – 27.4). Median PFS for patients who received bevacizumab without retreatment was 5.1 months (95%CI: 4.3 – 6.3) and 17.6 months (95%CI: 14.3 – 21.3) for patients who received sequential bevacizumab retreatment (p < 0.001). Median OS for patients who received bevacizumab without retreatment was 12.9 months (95%CI: 9.3 – 16.7) and 30.1 months (95%CI: 26.1 – 35.4) for patients who received sequential bevacizumab retreatment (p < 0.001). Conclusions: Our study shows OC patients treated with bevacizumab-containing regimens sequentially at the time of progression have significantly prolonged survival outcomes compared to those patients who received no re-treatment with bevacizumab.