Topotecan, an active drug in the second-line treatment of epithelial ovarian cancer: results of a large European phase II study.

PURPOSE: Topotecan is a topoisomerase I inhibitor with preclinical activity against various tumor types. We conducted a large multicenter phase II study with topotecan in ovarian cancer in patients who had failed to respond to one prior cisplatin-based chemotherapeutic regimen. PATIENTS AND METHODS: Topotecan 1.5 mg/m2/d was administered intravenously by 30-minute infusion for 5 days repeated every 3 weeks. As the cisplatin-free interval relates to response in subsequent treatment, patients were stratified in subgroups, ie, cisplatin-refractory, cisplatin-resistant, and cisplatin-sensitive. RESULTS: One-hundred eleven patients entered the study. Nineteen patients were considered to be ineligible; 92 patients were assessable for response. A total of 552 courses were given (median, four per patient; range, one to 17). The major toxicities were leukocytopenia and neutropenia, which were grade 3 to 4 in 54.2% and 69.1% of courses, respectively, but with only 4.3% of these being grade 4 neutropenia plus fever or infectious complications. Prophylactic granulocyte colony-stimulating factor (G-CSF) was given in 20.5% of courses to maintain dose-intensity. Other relatively frequent side effects were alopecia (82%), nausea (36.4%), and vomiting (17.5%). The overall response rate was 16.3%, with one complete response (CR) and 14 partial responses (PRs). In the cisplatin-refractory, cisplatin-resistant, and cisplatin-sensitive strata, the response rates were 5.9%, 17.8%, and 26.7%, respectively. The median duration of time of documented response was 21.7 weeks (range, 4.6 to 41.9). CONCLUSION: Topotecan in a daily-times-five schedule is an effective regimen as second-line treatment in ovarian cancer. Further investigations of topotecan in ovarian cancer, including first-line use and combination with other active agents, are indicated.

A phase I trial of trans-1-diaminocyclohexane oxalato-platinum (l-OHP).

Oxalato-platinum in a new platinum derivative which was found to be active in experimental tumors and devoid of nephrotoxicity. A phase I study was conducted in cancer patients according to a new design following the recommendations of our Institution's ethical committee to avoid the major drawback of classical phase I studies in which many patients receive the experimental drug at doses far under the potentially active dose extrapolated from experimental studies. The potentially active dose of l-OHP was determined from the Maximally Efficient Dose Range (MEDR) to be between 45 mg/m2 (subcurative dose) and 67 mg/m2 (subtoxic dose). The patients in this study received with increasing intervals 1/100, 1/10, 1/5, 1/3, 1/2, 2/3, 3/4, 1, of the low dose of the MEDR, this dose being reached after 90 to 120 days on study. 23 evaluable patients have entered the trial of which 19 reached the low dose of MEDR (45 mg/m2). Gastro-intestinal toxicity, nausea and vomiting, similar to those with CDDP occurred in all patients at or above the dose of 30 mg/m2. Renal toxicity was monitored with creatinine level and did not occur in any patient at any dose nor did significant hematologic toxicity occur. Thus nausea and vomiting appear to be the limiting toxicity of the drug. Responses were observed in this phase I study in lung cancer (1), breast cancer (1), melanoma (1) and perhaps hepatoma (major decrease in alpha FP levels) (1). The proposed starting dose for phase II studies is 45 mg/m2 but we plan to continue dose escalation during the phase II according to the design of Jones and Holland. This new study design allows each patient entering a phase I study to be treated with a potentially active dose of the drug studied.

Experience with independent radiological review during a topotecan trial in ovarian cancer.

BACKGROUND: The results of phase II clinical trials are usually based on response of tumours to new oncolytic agents as evidenced by radiological imaging techniques. In this trial, all claimed responders were reviewed at a specially convened meeting by the peer group of study investigators and a radiologist, independent of the study institutions. PATIENTS AND METHODS: One hundred eleven patients with advanced epithelial ovarian cancer who had previously been treated with a platinum based regimen and had subsequently relapsed and who had measurable disease were treated with topotecan at a dose of 1.5 mg/m2/day i.v. on five consecutive days repeated every 21 days to assess efficacy and tolerability. Ninety-three were considered eligible for the study per protocol and lesions were assessed by either computerised tomography (CT) or ultrasound (US). At the meeting, scans from all 24 (25.8%) claimed responders were reviewed, lesions remeasured by the radiologist and a group discussion led to a final response classification. RESULTS: Ninety-two patients were found to be eligible for the study and 14 (15.2%) were confirmed as responders. Ten were rejected as responders, mainly because the lesion did not decrease in size by < or = 50%, but one patient failed to meet the entry criteria. Remeasurement of CT scans was more objective than US scans. Difficulties were encountered during review of some CT scan sequences because of non-uniform imaging parameters. CONCLUSIONS: Independent radiological review in conjunction with the peer review group in this trial enabled rigorous and consistent application of response criteria. This decreased the response rate from 25.8% to 15.2%, but this represents a more objective assessment. CT scanning is an objective technique for assessing response rates in phase II studies whereas US is subjective and dose not necessarily allow accurate lesion assessment on subsequent examinations, nor allows independent review at a later date. For these reasons it should not be used in such studies for accurate lesion assessment. Cross-sectional imaging techniques such as CT and magnetic resonance imaging (MRI) do allow accurate lesion assessment and independent review at a later date, but standard protocols need to be instituted, to allow consistency and a comparison to be made with subsequent studies using the same agent and a broad comparison to be made with other agents.