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 ≥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 ≥40% would suggest a drug activity, and ≤20% would suggest inactivity.

End-point, Phase II, Progression-free rate, Response criteria, Soft-tissue sarcoma
dx.doi.org/10.1016/S0959-8049(01)00398-7, hdl.handle.net/1765/67153
European Journal of Cancer
Department of Medical Oncology

van Glabbeke, M.M.B, Verweij, J, Judson, I.R, & Nielsen, O.S. (2002). Progression-free rate as the principal end-point for phase II trials in soft-tissue sarcomas. European Journal of Cancer, 38(4), 543–549. doi:10.1016/S0959-8049(01)00398-7