Efficacy and toxicity of carboplatin and gemcitabine administered on day 1 and day 8 (day1&8) versus day 1-only for platinum-sensitive recurrent epithelial ovarian cancer

Abstract

ObjectiveTo compare response rate, progression-free survival, overall survival, and toxicity of carboplatin and gemcitabine administered on day 1 and day 8 (day1&8) versus a modified day 1-only regimen in recurrent platinum-sensitive ovarian cancer.MethodsA retrospective single-institution cohort study was performed in women with recurrent platinum-sensitive ovarian cancer between January 2009 and December 2020 treated with carboplatin and gemcitabine on a 21-day cycle. The impact of dosing schedule on response rate, progression-free survival, overall survival, and toxicities was assessed with univariate and multivariate models.ResultsOf 200 patients, 26% (n=52) completed day 1&8, 21.5% (n=43) started day 1&8 but dropped day 8, and 52.5% (n=105) received day 1-only. There were no differences in demographics. Median starting carboplatin and gemcitabine doses were area under curve (AUC) 5 and 600 mg/m2for day 1-only versus AUC4 and 750 mg/m2among day 1&8, respectively (p<0.001). A total of 43 patients (45.3%) dropped day 8 primarily due to neutropenia (51.2%) or thrombocytopenia (30.2%). The response rates were 69.3% for day 1&8-completed, 67.5% for day 1&8-dropped, and 67.6% for day 1-only (p=0.92). Median progression-free survival was 13.1, 12.1, and 12.4 months for day 1&8-completed, day 1&8-dropped, and day 1-only, respectively (p=0.29). Median overall survival was 28.2, 33.5, and 34.3 months for the above groups (p=0.42). The rate of grade 3/4 hematologic toxicity (48.9% vs 31.4%, p=0.002), dose reductions (58.9% vs 33.7%, p<0.001), blood transfusions (22.1% vs 10.5%, p=0.025), and treatment with pegfilgrastim (64.2% vs 51%, p=0.059) were higher among day 1&8 versus day 1-only, respectively.ConclusionsThere was no difference in response rate, progression-free survival, or overall survival for day 1&8 versus day 1-only, regardless of whether day 8 was dropped. Day 1&8 was associated with greater hematologic toxicity. A modified day 1-only regimen may represent an alternative to day 1&8 and warrants prospective study.