Phase II study of dacarbazine given with modern prophylactic anti-emetics and growth factor support to patients with metastatic, resistant soft tissue, and bone sarcoma

Historically, administration of dacarbazine to sarcoma patients was limited by frequent treat-ment-related nausea/vomiting and neutropenia. These toxicities are now largely preventable with contemporary antiemetics and growth factor support. In this single-arm, phase II study, dacarbazine 850 mg/m² was given on day 1 of each 3-week cycle until disease progression or intolerance with prophylactic serotonin-3 receptor, neurokinin-1 antagonists, corticosteroids, and pegfilgrastim. Coprimary endpoints included clinical benefit rate (CBR), and any grade of nausea/vomiting and/or grade 3–4 neutropenia. With a sample size of 80 patients, >24 patients with clinical benefit would indicate that the CBR exceeds the historical (<20%) [Power 0.80; alpha 0.05]. In addition, we hypothesized that the rates of nausea/vomiting would be 27% and grade 3–4 neutropenia would be 1% (historical: 90% and 36%, respectively) [power 0.95; alpha 0.05]. The CBR was 30% (24 patients: PR-2 and stable-22). The rate of nausea/vomiting was 37.5% (31 patients) and grades 3–4 neutropenia was 10% (8 patients). Median time-to-progression was 8.1 weeks (95% CI 8–9.7) and median overall survival was 35.8 weeks (95% CI 26.2–55.4). PET scans demonstrated no association with response. Modern prophylactic anti-emetics and pegfilgrastim given with dacarbazine reduced the rates of treatment related nausea/vomiting and serious neutropenia.