Background: TZT-1027, a novel chemotherapeutic agent, is derived from dolastatin 10, and blocks cells during G2/M-phase by interfering with microtubule assembly and stability. TZT-1027 has exhibited potential cytotoxic activity in several human cancer cell lines (in vitro) and also demonstrated antitumor activity in human xenografts (in vivo). In addition, Phase I clinical investigations suggested activity in STS (soft-tissue sarcoma).
Methods: Eligible patients were those who had histologic evidence of locally advanced or metastatic STS and who had received 1 prior treatment regimen with an anthracycline-based chemotherapy for metastatic disease. Subjects received intravenous infusions of TZT-1027 over 1 hour on Day 1 and Day 8 of each 21-day treatment course. Efficacy was evaluated per Response Evaluation Criteria in Solid Tumors (RECIST) criteria.
Results: Twenty-nine patients were enrolled and 28 patients received at least 1 course of study drug and were eligible for efficacy and safety evaluation. The median age of the patients was 48 years (range, 23-73 years) and the median baseline Eastern Cooperative Oncology Group (ECOG) performance status was 1 (range, 0-2). A total of 67 courses (range, 1-9 courses; median, 2 courses) of TZT-1027 were administered. No patient in the study demonstrated an objective response to treatment. Of 6 patients (21.4%) who experienced disease stabilization, 1 continued to have stable disease for 9.3 months. The median time to tumor progression was 44 days (95% confidence interval [95% CI], 43.0-54.0) and the median survival was 178 days (95% CI, 134.0-317.0). The most commonly reported toxicities were neutropenia, fatigue, and constipation.
Conclusions: TZT-1027 was found to be safe and well tolerated, and the hematologic toxicities observed were consistent with preclinical toxicology and Phase I study findings. No confirmed responses were seen in the current study.
Copyright 2006 American Cancer Society.