Fixed-dose rate gemcitabine plus carboplatin in relapsed, platinum-sensitive ovarian cancer patients: results of a three-arm Phase I study.

OBJECTIVES: Standard infusion of gemcitabine plus carboplatin showed improved efficacy compared to carboplatin alone in patients with platinum-sensitive (Pt-S) ovarian cancer (OC). Fixed-dose rate (FDR) administration of gemcitabine produces more efficient intracellular phosphorylation of gemcitabine to its active form. This study was designed to identify the maximum tolerated dose (MTD), toxicity profile, and response rate of FDR gemcitabine plus carboplatin in Pt-S OC. METHODS: Patients with measurable OC relapsing > or =6 months after exposure to platinum (N=60) were assigned to one of three treatment cohorts, each with a different delivery schedule and escalating doses of both FDR gemcitabine (10 mg/m(2)/min) and standard infusion carboplatin (60 min). MTDs were determined using dose-limiting toxicities (DLTs). Measurable disease was assessed using modified RECIST criteria. CA-125 levels were evaluated using Rustin criteria. Toxicities were assessed using NCI Common Toxicity Criteria, version 2.0. RESULTS: The MTD of Arm 1 was FDR gemcitabine 1000 mg/m(2) on days 1 and 8 plus carboplatin AUC 5 on day 1, every 21 days. The MTD of Arm 2 was FDR gemcitabine 1000 mg/m(2) on days 1 and 8 plus carboplatin AUC 2.5+AUC 2.5 on days 1 and 8, every 21 days. Patient accrual on Arm 3 consisting of bi-weekly FDR gemcitabine plus carboplatin was terminated because dose level 1 exceeded the MTD. Overall response rates were 38.1% (Arm 1), 58.8% (Arm 2), and 44.4% (Arm 3). CONCLUSIONS: FDR gemcitabine+carboplatin on a 21-day schedule was active and produced no unusual safety signals in patients with Pt-S OC.

Development of an optimized conditionally replicative adenoviral agent for ovarian cancer.

Human ovarian cancer is a highly lethal malignant neoplasm in woman with no effective treatment if conventional chemotherapy fails. In this regard, conditionally replicative adenoviruses (CRAds) represent a promising new modality for the treatment of cancer. A key contribution to the development of CRAds was the introduction of tumor-selective viral replication to restrict amplification to the neoplastic cell population. Under ideal conditions following cellular infection, the viruses replicate selectively in the infected tumor cells, killing the cells by cytolysis, leaving normal cells unaffected. However, to date, there have been limitations to the clinical application of these CRAd agents i.e. poor viral infectivity, poor tumor specificity and high toxicity. Here, we report the in vitro and in vivo comparison of four CRAd agents developed for ovarian cancer application, specifically, Ad-Delta24.F5/3, CRAd-C.F5/3, CRAd-M.F5/3 and CRAd-S.F5/3. All CRAd agents contained fiber knob chimeras of adenovirus serotype 3, which enhanced the viral infectivity at the transductional level via a non-Coxsackie-Adenovirus Receptor alternative pathway. In addition, these CRAds embodied distinct mechanisms for the achievement of replication specificity. Tumor cell killing was assessed by using an oncolytic assay and a cell viability assay (MTS) in vitro, while tumor growth was examined in a xenograft model in vivo by using a bioluminescent imaging assay. In addition, the replication rates of the CRAd agents were determined in human liver slices. Both the Ad-Delta24.F5/3 and CRAd-S.F5/3 were demonstrated to have higher tumor killing effects in tumor cells and a lower viral replication rate in human liver. These agents are thus excellent candidates for clinical trials of CRAd agents against human ovarian cancer.