Résumé
Background: Carboplatin, gemcitabine +/-bevacizumab is a preferred regimen for recurrent, platinumsensitive ovarian cancer (PSOC). A phase III trial established that the regimen of carboplatin on Day 1 (D1) and gemcitabine on D1 and Day 8 (D8) was associated with acceptable toxicity and improved progression free survival (PFS) compared to carboplatin alone. Treatment with gemcitabine on D8 incurs more exposure to cytotoxic therapy and increased burden on patients and the healthcare system, especially during the COVID-19 pandemic. However, it is unknown whether D1/D8 gemcitabine imparts an improvement in efficacy compared to D1 alone. Our objective was to compare efficacy and toxicity of carboplatin and gemcitabine D1/D8 (CG-D1/8) with a modified D1 regimen (CG-D1). Methods: A retrospective single-institution cohort study was performed in women with recurrent PSOC treated with carboplatin, gemcitabine +/-bevacizumab from 2009-2020. Data was analyzed by intention to treat comparing women who received CG-D1/8 vs CG-D1. Data was also analyzed by 3 groups: CG-D1/8 vs CG-D1/8 but dropped D8 vs CG-D1. The primary endpoint was response rate (RR), defined as complete or partial response at 6 cycles or maximum cycles if <6. Secondary outcomes included PFS, overall survival (OS), toxicity, Neulasta use and dose reduction. Results: Of 200 patients, 26% completed CGD1/ D8, 21.5% started CG-D1/D8 but dropped D8, and 52.5% received CG-D1. There were no significant differences in age, race, or ECOG between cohorts. Among CG-D1/D8, 45.3% dropped D8 primarily due to neutropenia (51.2%) or thrombocytopenia (30.2%). The RR at 6 cycles was 68.7% for CG-D1/8 completed, 70.7% for CG-D1/8 dropped D8, and 69.3% for CG-D1 (p=0.97). The median PFS was 13.1, 12.1 and 12.4 months for CG-D1/8 completed, CG-D1/8 dropped D8, and CG-D1, respectively (p=0.29). Similarly, median OS was 28.2, 33.5 and 34.3 months for the above groups respectively (p=0.42). While there was no difference in concurrent bevacizumab use for CG-D1/8 and CG-D1 (34.7% vs 29.5%, p=0.43), among the CG-D1/8 patients, a significantly higher proportion of patients who dropped D8 received bevacizumab (51.2% vs 21.2%, p=0.006). Table 1 lists secondary outcomes. Conclusions: There was no significant difference in RR, PFS or OS among women with PSOC receiving CG-D1/8 vs CG-D1, regardless of whether D8 was dropped. CG-D1/8 was associated with significantly greater hematologic toxicity. These findings suggest a modified D1 regimen may be a suitable alternative to standard CG-D1/8 treatment and warrant prospective validation.