Sorafenib in patients with progressive malignant solitary fibrous tumors: a subgroup analysis from a phase II study of the French Sarcoma Group (GSF/GETO).

Malignant solitary fibrous tumors are rare soft-tissue sarcomas. They are considered as low-grade malignancies, but may display metastatic potential in 20% of the cases. In case of metastatic or locally advanced, unresectable disease, standard treatments, like anthracycline-based regimens, are poorly effective. Previous studies suggested that antiangiogenic drugs, such as sorafenib, could be efficient to treat vascular sarcomas and solitary fibrous tumors. Five patients with progressive SFT were included in this phase 2 study, and treated with sorafenib at a dose of 800 mg daily. Two patients out of the five achieved a 9 months disease control with sorafenib, while their disease had progressed within the month preceding their inclusion. Consequently, our data suggest a potential efficacy of sorafenib in SFT, Further investigation is needed to confirm these data.