Soft tissue sarcoma is a rare type of cancer that occurs in the connective tissue that supports and surrounds other body structures, like muscles, blood vessels, and tendons. Traditional therapy is used for the treatment of soft tissue sarcoma, but outcomes in children and adults have been poor. This study aims to assess if adding pazopanib to preoperative chemoradiotherapy can improve the response rate in patients with soft tissue sarcoma.

This multicentre, open-label, randomized, phase-2 trial included a total of 81 patients (adults aged ≥18 years and children aged 2-18 years) with unresected, newly diagnosed trunk or extremity chemotherapy-sensitive soft tissue sarcoma. The patients were randomly assigned in a 1:1 ratio to receive oral pazopanib once daily (n=42) or not. The primary outcome of the study was 90% or higher pathological response at week 13.

During a median follow-up of 0.8 years in the pazopanib group and 1 year in the control group, 90% or higher pathological repose occurred 14 (58%) of 24 evaluable patients in the pazopanib group and four (22%) of 18 evaluable patients in the control group. Common grade 3 & 4 adverse events were leukopenia (43%), neutropenia (41%), and febrile neutropenia (41%) in the pazopanib group.

The research concluded that adding pazopanib to preoperative chemoradiotherapy resulted in improved pathological response rate in children and adults with soft tissue sarcoma.