Phase II study of mitozolomide in advanced soft tissue sarcoma of adults: the EORTC Soft Tissue and Bone Sarcoma Group

Progression-free rate as the principal end-point for phase II trials in soft-tissue sarcomas

We have estimated progression-free rates (PFR) for various groups of soft-tissue sarcoma patients from our clinical trials database, to provide reference values for conducting phase II studies with PFR as the principal end-point. In 146 pretreated patients receiving an active agent, the PFR estimates were 39 and 14% at 3 and 6 months; with inactive regimens (234 patients), those estimates were 21 and 8% respectively. In 1154-non-pretreated patients, PFR estimates varied from 77% (synovial sarcoma) to 57% (malignant fibrous histiocytoma (MFH)) at 3 months, and from 56% (synovial sarcoma) to 38% (MFH) at 6 months. In 61 leiomyosarcomas from gastrointestinal origin, the corresponding figures were 44 and 30%, respectively. Consequently, for first-line therapy, a 6-month PFR of > or = 30-56% (depending on histology) can be considered as a reference value to suggest drug activity; for second-line therapy, a 3-month PFR of > or = 40% would suggest a drug activity, and < or = 20% would suggest inactivity.

Temozolomide in adult patients with advanced soft tissue sarcoma: a phase II study of the EORTC Soft Tissue and Bone Sarcoma Group

Temozolomide, an oral imidazotetrazine derivative, was given to 31 patients with advanced soft tissue sarcoma. The dose of 750 mg/m2 was divided over 5 consecutive days, and escalated to 1000 mg/m2 over 5 days at cycle 2 if myelosuppression no worse than common toxicity criteria grade 2 was noted in the first 28-day cycle. A total of 99 treatment cycles were given to 31 patients. The drug was well tolerated, with nausea and vomiting as the most common side-effects. Only one partial tumour response was documented, giving a response rate of 3.33%, 95% confidence interval, (CI) 0.1-17.2%. The median time to progression was 8 weeks and the median survival was 27 weeks. These results indicate that temozolomide in this schedule is not active as second-line treatment in advanced soft tissue sarcoma.