dolastatin-10 and Breast-Neoplasms

Phase II multicenter cooperative group study investigated the efficacy and toxicity of the novel anti-microtubule agent dolastatin-10 in patients with advanced breast cancer.. Twenty-one patients with measurable metastatic breast cancer were treated with dolastatin-10 at a dose of 400 mcg/m2 by intravenous bolus once every 3 weeks. Patients must have received a total of 1 or 2 prior chemotherapy regimens and have an Eastern Cooperative Oncology Group performance status of 0-2. Patients received this treatment as either a first (n = 11) or second-line (n = 10) chemotherapy for metastatic disease. Eighteen patients (86%) had received a prior anthracycline. The National Cancer Institute provided the dolastatin-10.. One out of 21 patients (5%; 95% CI: 0-24%) achieved a partial remission for a duration of 113 days. Four patients maintained stable disease for a median of 87 days. A total of 58 courses of dolastatin-10 were administered. Patients received a median of two cycles of dolastatin-10. Hematologic toxicity was moderate, with 8 patients developing grade 4 neutropenia, and 5 with grade 3 neutropenia; one grade 3 febrile neutropenia was observed. These episodes of grade 3 and 4 neutropenia were experienced on 36% of the treatment cycles. Non-hematologic toxicity was uncommon.. While the toxicity profile of dolastatin-10 was acceptable, it had minimal activity in this advanced breast cancer study. We are not pursuing further clinical trials of this agent in the setting of advanced breast cancer.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Breast Neoplasms; Depsipeptides; Female; Humans; Middle Aged; Neoplasm Metastasis; Oligopeptides

Dolastatin 10, a pentapeptide isolated from the marine mollusk Dolabella auricularia, has antitumor activity. TZT-1027, a dolastatin 10 derivative, is a newly synthesized antitumor compound. We evaluated its antitumor activity against a variety of transplantable tumors in mice. Intermittent injections of TZT-1027 were more effective than single or repeated injections in mice with P388 leukemia and B16 melanoma. Consequently, TZT-1027 shows schedule dependency. TZT-1027 was effective against P388 leukemia not only when administered i.p., but also when given i.v. However, although TZT-1027 given i.v. was active against murine solid tumors, TZT-1027 administered i.p. was ineffective against all the tumors tested with the exception of colon 26 adenocarcinoma. The i.v. injection of TZT-1027 at a dose of 2.0 mg/kg remarkably inhibited the growth of three murine solid tumors; colon 26 adenocarcinoma, B16 melanoma and M5076 sarcoma, with T/C values of less than 6%. The antitumor activities of TZT-1027 against these tumors were superior or comparable to those of the reference agents; dolastatin 10, cisplatin, vincristine, 5-fluorouracil (5-FU) and E7010. In experiments with drug-resistant P388 leukemia, TZT-1027 showed good activity against cisplatin-resistant P388 and moderate activity against vincristine- and 5-fluorouracil-resistant P388, but no activity against adriamycin-resistant P388. TZT-1027 was also effective against human xenografts, that is, tumor regression was observed in mice bearing MX-1 breast and LX-1 lung carcinomas. TZT-1027 at 10 microM almost completely inhibited the assembly of porcine brain microtubules. Therefore, its mechanism of antitumor action seems to be, at least in part, ascribable to the inhibition of microtubule assembly. Because of its good preclinical activity, TZT-1027 has been entered into phase I clinical trials.

Topics: Animals; Antineoplastic Agents; Breast Neoplasms; Cell Division; Cisplatin; Crosses, Genetic; Depsipeptides; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Screening Assays, Antitumor; Female; Humans; Leukemia P388; Lung Neoplasms; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Inbred DBA; Mice, Nude; Mollusca; Neoplasms, Experimental; Oligopeptides; Transplantation, Heterologous