Tolerance and activity of oxaliplatin with protracted topotecan infusion in patients with previously treated ovarian cancer. A phase I study

A phase 2 study of oxaliplatin combined with continuous infusion topotecan for patients with previously treated ovarian cancer

BACKGROUND

Phase 2 trials suggest that prolonged intravenous (IV) infusion of the topoisomerase 1 inhibitor topotecan may be less toxic than when given by standard IV bolus 5-day administration. Oxaliplatin exhibits efficacy in platinum-pretreated disease and shows preclinical synergy with topoisomerase 1 inhibitors. We sought to determine the efficacy and safety of oxaliplatin plus infusion topotecan in recurrent platinum-pretreated ovarian cancer.

METHODS

Patients with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancers previously treated with 1 to 2 prior regimens including platinum and taxane received oxaliplatin (85 mg/m(2) day 1 and day 15) and topotecan (0.4 mg/m(2) per day) by continuous IV infusion over 14 days every 4 weeks. The primary objective of the trial was to estimate the objective response rate in platinum-resistant disease (stratum 1) and in platinum-sensitive disease (stratum 2). Toxicities were assessed in all patients.

RESULTS

Thirty-eight patients received 144 cycles of therapy (median, 4; range, 1-6). The most common grade 3 and grade 4 toxicities included thrombocytopenia (grade 3, 37%; and grade 4, 19%), neutropenia (grade 3, 37%; grade 4, 11%), and anemia (grade 3, 15%). Response occurred in 4 of 19 patients in stratum I (21%; 95% confidence intervals, 6%-46%) and 9 of 19 patients in stratum 2 (47%; 95% CI, 24%-71%). Three in each stratum had lengthy complete responses.

CONCLUSIONS

Biweekly oxaliplatin plus a 14-day continuous IV infusion of topotecan, given monthly, is an active regimen in platinum-pretreated ovarian cancer and merits additional evaluation.

Gemcitabine-oxaliplatin (GEMOX) as salvage treatment in pretreated epithelial ovarian cancer patients

Background

Currently, no clearly superior management strategy exists for recurrent, platinum-resistant ovarian cancer. We tested the efficacy and safety of gemcitabine combined with oxaliplatin (GEMOX) in a multicentre phase II clinical trial.

Methods

Forty one patients with recurrent, platinum-resistant ovarian cancer were enrolled. Prior to study entry, all the participants had received at least one platinum-based regimen. Gemcitabine was administered at 1000 mg/m² as protracted infusion (100 min) on day 1, and oxaliplatin at the dose of 100 mg/m² on day 2 in a 2 hour infusion. Cycles were repeated every two weeks.

Results

We observed an overall response rate of 37% [95% Confidence Interval (CI), 22.3–51.7]. Objective responses plus disease stabilization (clinical benefit) occurred in 78% of patients. Median progression-free survival was 6.8 months (95% CI, 5.8–7.8), and median overall survival was 16.5 months (95% CI, 12.2–20.8). Median time to self-reported symptom relief, which was described by 22 out of 27 symptomatic patients (81.5%), was 4 weeks (range, 2–8). Grade 4 neutropenia and febrile neutropenia were observed in 2 (5%) and 1 (2.5%) patients, while grade 3 anemia was encountered in 2 (5%) patients, respectively. The most common adverse effects of any grade were gastrointestinal symptoms, fatigue and neutropenia. Nine patients (22%) experienced mild allergic reaction to oxaliplatin, with no treatment discontinuation.

Conclusions

In our cohort of recurrent, platinum-resistant ovarian cancer patients, GEMOX showed encouraging activity and manageable toxicity. Under circumstances requiring a rapid disease control, this combination regimen may offer a particularly viable option, particularly in heavily pretreated patients.

New emerging drugs targeting the genomic integrity and replication machinery in ovarian cancer

INTRODUCTION

Ovarian cancer is a difficult to treat cancer entity with a high relapse rate. After initial surgery and chemotherapy, only a few options for therapeutic treatment remain in case of cancer recurrence. New treatment options with improved efficacies to circumvent acquired or pre-existing drug resistance are needed.

MATERIALS

This survey focuses on new prospective drugs for ovarian cancer treatment that either cause direct damage to the nuclear DNA or inhibit chromosome segregation by acting as mitotic spindle inhibitors.

RESULTS

Among a plethora of currently tested and proposed new drugs for ovarian cancer treatment, only a few appear to meet the criteria of sufficient and reliable efficacy with tolerable toxicity. These include the naturally occurring DNA-alkylating alkaloid trabectedin, the nitrogen mustard prodrug canfosfamide, and the synthetic kinase inhibitor ON-01910. The latter inhibits mitotic spindle formation without a direct tubulin interaction, avoiding adverse neurotoxic reactions common to the taxanes. Further, epothilones and oxaliplatin, already approved drugs for other cancer entities, show promising activity against ovarian cancer; they are even of interest as a first-line treatment option.

DISCUSSION

Although the current focus and interest of modern cancer drug design tends to be more specific and targeted therapies, including therapeutic antibodies and specific small molecules to inhibit growth-, apoptosis-, and angiogenesis-regulating signalling cascades, the main target for ovarian cancer treatment appears to remain its basic, though uncontrolled working proliferation machinery. This includes the current gold standard for ovarian cancer chemotherapy, carboplatin, and taxanes, as well as the few remaining alternatives, such as topotecan, doxorubicin, and gemcitabine, which all rely on their ability to bind to or to modify the DNA or the chromosome-separating spindle apparatus. Thus, the genomic integrity and replication machinery of ovarian cancer cells prove to represent an established, and obviously still effective target to be tackled for ovarian cancer treatment.

Cellular uptake and cytoplasm / DNA distribution of cisplatin and oxaliplatin and their liposomal formulation in human colorectal cancer cell HCT116

Liposomal formulations of cisplatin and oxaliplatin (Lipoplatin™ and Lipoxal™, respectively) were recently proposed to reduce systemic toxicity, while optimizing the anti-cancer effectiveness of these compounds. As the anti-neoplastic or radio-sensitizing activity of these drugs is attributed to their binding to DNA, we assessed the impact of the liposomal formulations on the time course of accumulation of these platinum compounds in the human colorectal cancer HCT116 cell lines and their distribution between cytoplasm and DNA. Their cytotoxicity was determined by colony formation assay. Intracellular platinum and platinum bound to DNA was measured by inductively coupled plasma mass spectrometry. Although, as a chemotherapeutic agent, cisplatin was as efficient as oxaliplatin after exposure for a short time, oxaliplatin and Lipoxal™ became more active than cisplatin against HCT116 cells after 24 h incubation. Lipoxal™ displayed a higher accumulation in the cytoplasm of HCT116 cells compared to free oxaliplatin, consistent with its proposed mechanism of fusion with the cell membrane. The distribution cytoplasm/DNA of free cisplatin and Lipoplatin™ were similar. Conversely, Lipoxal™ had a significantly different cytoplasm/DNA distribution from oxaliplatin: more than 95% of oxaliplatin transported by the liposome was trapped in the cytoplasm, even after 48 h incubation. Our study indicates that Lipoxal™ can largely improve the cellular uptake of oxaliplatin, but this was not followed by a similar increase in the DNA bound fraction.

A phase I study of rebeccamycin analog in combination with oxaliplatin in patients with refractory solid tumors

Rebeccamycin analog (RA) is an antitumor antibiotic with both topoisomerase I and II inhibiting activity. Topoisomerase inhibitors have demonstrated synergy with platinum agents. We performed a phase I trial of combination RA with oxaliplatin in patients with refractory solid tumors. RA was administered as a 1-hour infusion daily on days 1-5 with oxaliplatin administered on day 5. Cycles were repeated every 21 days. A total of 17 patients were enrolled. The MTD for RA was 80 mg/m(2)/d for five days along with oxaliplatin 130 mg/m(2) on day 5. Myelosuppression was a common occurrence but was mild except in one instance. Dose limiting toxicities included atrial fibrillation and hypophosphatemia. There was evidence of antitumor activity including 3 partial responses in patients with esophageal, gallbladder and hepato-cellular carcinoma; 5 additional patients had stable disease. Thus, the combination of RA and oxaliplatin is both tolerable and has evidence of clinical activity, but given the lack of significant activity for single agent RA across a variety of disease sites, it is unlikely to proceed to phase II development.

Platinum compounds 30 years after the introduction of cisplatin: implications for the treatment of ovarian cancer

Cisplatin and carboplatin have dominated the drug therapy of ovarian cancer and other gynecologic malignancies during the past three decades. This review, based on a recent international conference on metal coordination compounds, highlights advances in our understanding of their mechanisms of action and resistance. Two emerging areas are of special importance: 1) the role of transporters and exporters (first identified in the regulation of copper) in imparting the special selectivity of platinum drugs (also including oxaliplatin) for specific tumors; and 2) the relevance of inactivated DNA repair pathways, and in particular those related to BRCA genes in determining sensitivity of tumors to platinum drugs. The status of DNA repair pathways may become relevant to response to platinums and to the treatment of ovarian cancer in general: repair inhibitors are under testing alone or in combination with cytotoxic drugs for cancer.