First Russian experience of pazopanib in the treatment of soft tissue sarcomas

Sarcomas include soft tissue to tumors with high vascularization where angiogenesis plays an important role in their development and metastasis. most soft tissue sarcomas have a complex genetic profile with multiple mutations or aberrations, which make it difficult for the treatment with kinase inhibitors. Pazopanib – multityrosine kinase inhibitor of angiogenesis, targeted to receptors VEGFR-1, -2 and -3, and receptor and PDGFR-A and -B, c-Kit, which can provide long-term stabilization and objective responses in sarcomas.
Objective. Aim of the study was to evaluate the efficacy and safety of pazopanib in treatment of patients with soft tissue sarcomas.
Materials and Methods. 42 patients with metastatic soft tissue sarcomas in age from 19 till 78 years old after one or more lines of chemotherapy were enrolled in the study. Pazopanib was used in a dose of 800 mg Po daily.
Results. Efficacy of pazopanib was evaluated in 40 patients: CR – none, PR – in 1 patient (2.5%), SD – in 30 patients (75%), PD – in 9 patients (22.5%). Thus, control of tumor growth (complete remission, partial remission, stabilization) was achieved in 77.5%. The median time to progression was 8.3 months. The median overall survival has not been reached. Toxicity was mild and durable and almost the same as were reported in previous worldwide studies.
Conclusions. Based on the data obtained in this study pazopanib can be used as the second or more line of therapy. In some clinical cases efficacy of pazopanib was reported in patients with rare chemoresistant subtypes of STS.