Gemcitabine plus cisplatin in recurrent ovarian, fallopian tube, and primary peritoneal cancer.

5548 Background: Our objective was to explore safety and efficacy of gemcitabine plus cisplatin for treatment of patients with recurrent ovarian, fallopian tube and primary peritoneal cancer (OC). Methods: This single institution retrospective analysis conducted at MD Anderson Cancer Center, included patients with recurrent platinum sensitive (PSOC) or resistant (PROC) OC treated with gemcitabine plus cisplatin. Treatment doses were cisplatin 30-40 mg/m 2 and gemcitabine 600-800 mg/m 2 . Utilized regimens were as follows: 1) cisplatin Day 1 (D1), gemcitabine D1 on 21-day cycle; 2) cisplatin D1, gemcitabine Day 8 (D8) on 21-day cycle; or 3) cisplatin/gemcitabine every 2 weeks on 28-day cycle. Objective response rate (ORR= complete response (CR) + partial response (PR)) was calculated along with 95% confidence interval (95%CI). Adverse events were collected and graded. Results: One hundred and seventy-six patients were included; 90% had high grade serous OC and 95% were stage III/IV at diagnosis. Subjects received a median of 3 prior lines of therapy (range 1-10). ORR was 44.1% (95% CI: 36.6-51.9) with 12 CR (7%), 64 PR (37%), 42 SD (24%) and 54 PD (31%). One hundred sixteen (66.6%) patients discontinued treatment due to disease progression after median 3 cycles (range 1-19). Among responders, median number of cycles with response was 3 (range 2-13). Twenty-three percent of subjects had PSOC with ORR of 61.5% and 76.1% had PROC with ORR of 39.4% (p =0.014). Number of prior lines of cytotoxic treatment or prior use of bevacizumab wasn’t associated with response to treatment. Median platinum free interval was associated with response to therapy (5 months in responders vs 3 months in non-responders; P=0.007). Forty-four percent of patients had adverse events, with most common being thrombocytopenia (12%), neutropenia (9%), and neurotoxicity (10%). Conclusions: Cisplatin in combination with gemcitabine demonstrates activity regardless of platinum sensitivity status in patients with recurrent ovarian cancer. However, longer platinum-free interval is associated with improved response to this therapy.