Clinical Study of Concurrent Pazopanib and Radiotherapy for Non-metastatic Sarcoma Patients

Radiotherapy (RT) alone is able to induce a clinically significant effect with a variable pathologic response (a pathological complete remission, pCR, defined as ≥ 95%, or ≤ 5% remaining visible tumour cells) in only about 10% of cases. A prior phase I study (PASART-1; NCT01985295) suggested that 25 x 2 Gy preoperative RT in combination with once daily 800mg oral pazopanib is feasible, while inducing tissue replacing tumor that can consist of fibrosis and necrosis in 40% of thus treated patients. During this study, the interim analysis showed that the combination treatment of preoperative radiation with orally pazopanib is more effective than was anticipated. For this reason, the pazopanib dose of 800 mg once daily is maintained but the RT dose is reduced to 18x2Gy instead of 25x2Gy. Predominant aim of this RT dose reduction is lowering the wound complication risk after preoperative radiotherapy.