A phase I study of sequential intravenous topotecan and etoposide in lung cancer patients

E5501: phase II study of topotecan sequenced with etoposide/cisplatin, and irinotecan/cisplatin sequenced with etoposide for extensive-stage small-cell lung cancer

PURPOSE

Sequence-dependent improved efficacy of topoisomerase I followed by topoisomerase 2 inhibitors was assessed in a randomized phase II study in extensive-stage small-cell lung cancer (SCLC).

METHODS

Patients with previously untreated extensive-stage SCLC with measurable disease, ECOG performance status of 0-3 and stable brain metastases were eligible. Arm A consisted of topotecan (0.75 mg/m(2)) on days 1, 2 and 3, etoposide (70 mg/m(2)) and cisplatin (20 mg/m(2)) (PET) on days 8, 9 and 10 in a 3-week cycle. Arm B consisted of irinotecan (50 mg/m(2)) and cisplatin (20 mg/m(2)) on days 1 and 8 followed by etoposide (85 mg/m(2) PO bid) on days 3 and 10 (PIE) in a 3-week cycle.

RESULTS

We enrolled 140 patients and randomized 66 eligible patients to each arm. Only 54.5 % of all patients completed the planned maximum 6 cycles. There were grade ≥3 treatment-related adverse events in approximately 70 % of the patients on both arms including 6 treatment-related grade 5 events. The overall response rates (CR + PR) were 69.7 % (90 % CI 59.1-78.9, 95 % CI 57.1-80.4 %) for arm A and 57.6 % (90 % CI 46.7-67.9, 95 % CI 44.8-69.7 %) for arm B. The median progression-free survival and overall survival were 6.4 months (95 % CI 5.4-7.5 months) and 11.9 months (95 % CI 9.6-13.7 months) for arm A and 6.0 months (95 % CI 5.4-7.0 months) and 11.0 months (95 % CI 8.6-13.1 months) for arm B.

CONCLUSION

Sequential administration of topoisomerase inhibitors did not improve on the historical efficacy of standard platinum-doublet chemotherapy for extensive-stage SCLC.

Topotecan, cyclophosphamide, and etoposide (TCE) in the treatment of high-risk neuroblastoma. Results of a phase-II trial

PURPOSE

Relapsed high-risk neuroblastoma patients still have a poor prognosis. This phase-II trial assessed a new topotecan containing chemotherapy approach in patients with active disease.

METHODS

Chemotherapy consisted of topotecan (1.0 mg/m(2)/day 168-h continuous infusion), cyclophosphamide (100 mg/m(2)/day 1-h-infusion days 1-7 starting 6 h prior to topotecan), and etoposide (100 mg/m(2)/day 1-h-infusion days 8-10). Patients with relapsed neuroblastoma were scheduled for six cycles, untreated patients for two cycles followed by standard high-risk treatment.

RESULTS

Main toxicity observed during 153 cycles were grade 3-4 leukopenia (97% of cycles), thrombocytopenia (92%), neutropenic fever (52%), and mucositis (10%). No treatment related fatal toxicity occurred. Complete or partial response was achieved in 19 of 31 (61%) evaluable relapsed patients and 8 of 11 (72%) untreated patients.

CONCLUSIONS

The combination of topotecan, cyclophosphamide, and etoposide is tolerable and effective in relapsed and untreated neuroblastoma. Myelotoxicity is the main side effect but seems justified in view of the encouraging response rates. A randomized phase-III trial in primary disease has been commenced.

Topotecan and etoposide in the treatment of relapsed high-risk neuroblastoma: results of a phase 2 trial

We initiated a phase 2 trial with a combination of topotecan and etoposide (TE) in patients with relapse after intensive first line chemotherapy for neuroblastoma. TE chemotherapy consisted of topotecan (schedule A: 1.0 mg/m2/d 30-minute-infusion days 1 to 5, B: 0.7 mg/m2/d continuous infusion days 1 to 7, and C: 1.0 mg/m2/d continuous infusion days 1 to 7) followed by etoposide (100 mg/m2/d 1-hour-infusion days 8 to 10). TE was repeated every 28 days. The treatment was continued until severe nonhematopoietic toxicity or progression occurred or the treating physician chose alternative consolidation treatment after response to TE. Forty patients received 153 TE cycles. Grades 3 to 4 leukopenia was frequently observed in all schedules (A 51% of cycles, B 48%, and C 74%, P=0.141). Thrombocytopenia (A 69%, B 63%, and C 93%, P=0.004) and neutropenic fever (A 12%, B 29%, and C 37%, P=0.048) occurred more frequently in schedule C. No treatment-related fatal toxicity was observed. Among 36 patients evaluable for response, 4 patients achieved complete and 13 patients achieved partial remission (47%). We conclude that the combination of TE is effective and tolerable in the treatment of relapsed high-risk neuroblastoma.

Pharmacokinetically guided phase I trial of topotecan and etoposide phosphate in recurrent ovarian cancer

A pharmacokinetically guided phase I study of topotecan and etoposide phosphate was conducted in recurrent ovarian cancer. The scheduling of the topoisomerase I and II inhibitors was determined using in vitro activity data. All patients had recurrent disease following prior platinum-containing chemotherapy. Patients had a World Health Organisation performance status of 0–2 and adequate bone marrow, renal and hepatic function. Treatment was with topotecan intravenously for 5 days followed immediately by a 5-day intravenous infusion of etoposide phosphate (EP), with pharmacokinetically guided dose adjustment. Plasma etoposide levels were measured on days 2 and 4 of the infusion. A total of 21 patients entered the study. In all, 48% were platinum resistant and 71% had received prior paclitaxel. The main toxicities were haematological, short lived and reversible. A total of 29% of patients experienced grade 4 thrombocytopenia and 66% grade 4 neutropenia after the first cycle. Neutropenia and thrombocytopenia was dose limiting. The maximum-tolerated dose was topotecan 0.85 mg m⁻² day⁻¹ days 1–5 followed immediately by a 5-day infusion of EP at a plasma concentration of 1 μg ml⁻¹. The response rate (RR) was 28% in 18 evaluable patients. There was marked interpatient variability in topoisomerase IIα levels measured from peripheral lymphocytes, with no observed increase following topotecan. This regimen of topotecan followed by EP demonstrated good activity in recurrent ovarian cancer and was noncrossresistant with paclitaxel. Both the toxicity and RR was higher than would be expected from the single agent data, in keeping with synergy of action.

Sequential topotecan and oral etoposide in recurrent ovarian carcinoma pretreated with platinum-taxane

BACKGROUND

The objectives of this study were to determine the maximum tolerable dose (MTD), toxicity, efficacy, and feasibility of a sequential regimen of fixed-dose topotecan (1.00 mg/m2 on Days 1-5) and increasing doses of oral etoposide (50 mg, 75 mg, and 100 mg on Days 6-12 or Days 6-19) in patients with recurrent ovarian carcinoma.

METHODS

This multicenter, open-label study was planned as a Phase I-II study that included patients with epithelial ovarian carcinoma who failed or who developed recurrent disease < 12 months after the end of platinum and taxane-containing chemotherapy. Dose-limiting toxicity (DLT) was defined as follows: Grade 4 neutropenia for > 1 week, or neutropenic fever 38.5 degrees C for > 24 hours/sepsis, or Grade 4 thrombocytopenia for > 1 week, or thrombocytopenia with bleeding, or Grade 3-4 nonhematologic toxicity.

RESULTS

The MTD, as defined in the protocol, could not be settled because of unpredictable toxicity, because DLT was found at all dose levels except the starting dose level. In 28 patients (Phase I), 155 cycles were evaluable for toxicity. The main DLT was neutropenia Grade 4 for > 1 week or neutropenic fever/sepsis. Overall, neutropenia Grade 4 that lasted > 1 week and sepsis were noticed in 3% and 2% of cycles, respectively. Because no MTD was reached, the planned Phase II trial was not initiated. However, the patients from Phase I were followed until they developed progressive disease and, among them, 9 patients (32%) obtained an objective response (according to Response Evaluation Criteria in Solid Tumors (RECIST) or CA125 response criteria).

CONCLUSIONS

Combined topotecan and oral etoposide was inappropriate in patients with recurrent ovarian carcinoma because of unpredictable hematologic toxicity. However, the high objective response rate highlighted the potential additive effect of topoisomerase I and II inhibitors.

Topoisomerase I interactive agents

Increased insight into the mechanism of interaction of topoisomerase I interactive agents will maximize the therapeutic index and enhance the development of additional agents. Preclinical studies designed to elucidate mechanisms by which the topoisomerase I interactive agents induce cell death will be essential. The role of ABC transporters in resistance to topoisomerase I interactive agents has been recently appreciated and future studies should be directed at circumventing this resistance. The results of preclinical studies must be translated into the design of clinical trials so that these agents can be used rationally. In this regard results of preclinical studies have clearly pointed to the enhanced antitumor activity from protracted dosing of topoisomerase I interactive agents and results of clinical trials are now supporting these preclinical findings. Finally, investigators are trying to understand better the mechanism(s) of the dose-limiting toxicities observed with the currently available topoisomerase I interactive agents in an effort to enable the optimal dosing of these agents. Even though the first priority must be to determine the therapeutic potential of the currently available agents, it is reassuring to know that other topoisomerase I interactive agents are currently under development.