SUTENT MAY BE EFFECTIVE IN LEIOMYOSARCOMAS AND LIPOSARCOMAS

Int J Cancer. 2010 Dec 10. [Epub ahead of print]
Phase II study of sunitinib malate, a multi-targeted tyrosine kinase inhibitor in patients with relapsed or refractory soft tissue sarcomas. Focus on 3 prevalent histologies: Leiomyosarcoma, liposarcoma, and malignant fibrous histiocytoma.
Mahmood ST, Agresta S, Vigil C, Zhao X, Han G, D'Amato G, Calitri CE, Dean M, Garrett C, Schell MJ, Antonia S, Chiappori A.

Sarcoma Program, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida.
Abstract

Soft tissue sarcomas (STS) represent a diverse group of histologic subtypes with targetable molecular alterations, often treated as a single disease. Sunitinib malate is a multitargeted receptor tyrosine kinase inhibitor active in other solid tumors carrying similar alterations (i.e., imatinib mesylate-refractory gastrointestinal stromal tumors). This single-institution phase II study investigated the safety and efficacy of sunitinib malate in three common STS subtypes. Patients with documented unresectable or metastatic STS (liposarcoma, leiomyosarcoma, and malignant fibrous histiocytoma [MFH]), measurable disease, and 3 or less prior lines of therapy were eligible. Treatment consisted of sunitinib malate, 50 mg daily, for 4 weeks every 6 weeks. Forty-eight patients were enrolled, and 35% were heavily pretreated (≥2 prior lines of chemotherapy). The safety profile resembled previously known sunitinib malate toxicities. Median progression-free and overall survivals for liposarcoma, leiomyosarcoma, and MFH were 3.9 and 18.6, 4.2 and 10.1, and 2.5 and 13.6 months, respectively. The 3-month progression-free rates in the untreated and pretreated (chemotherapy) patients with liposarcoma, leiomyosarcoma, and MFH were 75% and 69.2%, 60%, and 62.5%, and and 25% and 44.4%, respectively. With the caveats that a minority of patients with potentially indolent or low-grade disease could have been included and the small numbers, a 3-month progression-free rate of >40% suggests activity for sunitinib malate at least in liposarcomas and leiomyosarcomas. Thus, we believe that further investigation in these susceptible STS subtypes is warranted.