Phase I evaluation of docetaxel and topotecan for patients with advanced solid tumors

Phase I study of docetaxel and topotecan in patients with advanced malignancies

Background. Docetaxel and topotecan are drugs with different mechanisms of action and significant activity against various tumour types. Topotecan may influence docetaxel metabolism by inhibiting the CYP3A4 enzyme. We designed a phase I study to evaluate the maximum tolerated dose of this combination and to assess the impact of pharmaco-kinetic interactions of the two drugs on toxicity.

Methods. Docetaxel and topotecan were administered intravenously on day 1, and days 1- 5 respectively, using a phase I dose escalation design. Plasma samples were analysed to determine docetaxel and topotecan concentration by HPLC with subsequent pharmacokinetic analysis using NONMEM.

Results. Of the 17 patients enrolled in the trial, 11 had grade 3 and 4 neutropenia and 1 had grade 4 thrombocytopenia. Nonhaematological toxicities were less frequent. The maximum tolerated dose for docetaxel and topotecan were 60 mg/m2 on day 1 and 0.75 mg/m2 days 1- 5, respectively. One patient had stable disease. Subjects with grade]3 haematologic toxicity had higher plasma docetaxel or topotecan area under the curve (AUC) (docetaxel 1.0390.11 mg-hr/L versus 0.7390.13 mghr/L; topotecan 65.8914.6 mcg-hr/L versus 41.6913.9 mcg-hr/L). There was no additive effectoftheAUCofthetwodrugsonthe likelihood of grade]3 haematologic toxicity by multiple logistic regression.

Conclusion. The dose-limiting toxicity seen with the combination of docetaxel and topotecan was myelosuppression. Future trials will require growth factor support if this combination is pursued.

A phase II study of weekly topotecan and docetaxel in heavily treated patients with recurrent uterine and ovarian cancers

OBJECTIVES

A phase II trial designed to evaluate the safety and efficacy of weekly topotecan and docetaxel in heavily treated patients with recurrent uterine or epithelial ovarian cancers.

METHODS

Eligible patients with recurrent epithelial ovarian or uterine cancers were treated with weekly topotecan 3.5 mg/m(2) and docetaxel 30 mg/m(2) for 3 consecutive weeks. Cycles were repeated every 4 weeks for 6 cycles or until evidence of disease progression, unacceptable toxicity, or death. Response was assessed as per RECIST or Rustin's criteria. Time to best response and overall survival were calculated using Kaplan-Meier statistical methods.

RESULTS

Twenty-seven patients registered, of which 24 were evaluable for response. The majority of patients had received 2 prior chemotherapy regimens. Of the total 86 cycles of chemotherapy that were administered, there were three grade 4 (all neutropenia) and ten grade 3 toxicities. Six of the grade 3 non-hematologic toxicities were unrelated to treatment. There were 8 dose delays and 4 dose reductions. The overall response rate was 25% (95% CI: 7.7%-42.3%, 8% CR, 17% PR), and 38% of the patients had clinical benefit (95% CI: 18.1%-56.9%; CR+PR+13% SD). The median duration of response was 8.5 months (range 3-19 months). The median overall survival was 18.5 months (range 1.8-50.7 months).

CONCLUSION

The combination of weekly topotecan and docetaxel has clinical benefit and is well tolerated in this heavily treated patient population. Patients with platinum-resistant tumors had clinical benefit and should be considered for further study with this regimen.

Phase I trial of weekly topotecan and gemcitabine in patients with solid tumors

OBJECTIVE

This phase I trial was designed to determine the maximal tolerated dose (MTD) of the combination of topotecan and gemcitabine given in a weekly schedule.

MATERIALS AND METHODS

In this single-arm, open label, dose-escalation study, we administered topotecan (0.75-1.5 mg/m) and gemcitabine (1000 mg/m) on days 1, 8, and 15 every 4 weeks to 25 patients with advanced solid tumors.

RESULTS

The topotecan MTD, when combined with gemcitabine, was 1.25 mg/m/wk. Dose-limiting toxicities consisted of febrile granulocytopenia in 2 patients at the highest dose level. At the MTD, no episodes of granulocytopenia were observed, whereas 2/9 patients exhibited grade 3 thrombocytopenia. Other common grades 3-4 adverse events across all cohorts included non-neutropenic infections, fatigue, skin reactions, vomiting, and fever. One partial response and 2 stable diseases were observed in patients with nasopharyngeal carcinoma. Disease stabilization was also observed in patients with squamous cell carcinoma of the head and neck (3), nonsmall cell lung cancer (1), and thymoma (1).

CONCLUSIONS

Topotecan and gemcitabine combined in a weekly schedule exhibit a favorable toxicity profile. Efficacy results support the further evaluation of this regimen in patients with head and neck cancer (particularly nasopharyngeal carcinoma).

A Phase I trial of weekly docetaxel and topotecan for solid tumors

BACKGROUND/AIMS

Topotecan and docetaxel are active agents in the treatment of various malignant diseases. Both drugs cause dose-limiting hematologic toxicity. This study defines the maximum tolerated dose (MTD) and dose-limiting toxicity of weekly topotecan when administered in combination with docetaxel 25 mg/m(2) given day 1, 8,15 every 28 days.

METHODS

Thirteen patients were enrolled. Median age was 62 years. Majority of the patients had lung cancer.

RESULTS

The maximum tolerated dose was docetaxel 25 mg/m(2) and topotecan 3 mg/m(2) administered weekly. Dose-limiting toxicity was febrile neutropenia. Eight patients developed at least grade 3 neutropenia in all cycles. Non-hematologic toxicities were mild. No objective responses were noted. Two patients with non-small cell lung cancer had stable disease as a best response.

CONCLUSION

Combination docetaxel and topotecan given weekly is tolerable. The recommended phase II dose is docetaxel 25 mg/m(2) and topotecan 3 mg/m(2) day 1, 8, 15 every 28 days.