Pazopanib elicited clinically meaningful responses in adults with progressive desmoid tumors according to RECIST 1.1 criteria, based on two imaging studies within a 6-month interval in the phase 2 DESMOPAZ trial.
“Pazopanib has meaningful clinical activity in patients with progressive desmoid tumors,” Maud Toulmonde, MD, of the Institut Bergonié, Bordeaux, France, reported at the annual meeting of the American Society of Clinical Oncology.
Patients were accrued for the study at 12 centers of the French Sarcoma Group and were randomly assigned to receive either oral pazopanib 800 mg/day or methotrexate (30 mg/m²) plus vinblastine (5 mg/m²) given intravenously once a week for 6 months and then every 15 days for 6 months. Treatment was administered until disease progressed (these patients were allowed to cross over to pazopanib) or patients had unacceptable toxicity. Maximum treatment time was one year.
Based on central pathological and radiological review, tumors shrank in 38 of 46 assessable patients (82.6%) given pazopanib. A partial response was seen in 17 patients (37%) and stable disease was observed in 21 patients (45.7%).
In the patients given methotrexate plus vinblastine, tumors shrank in 11 of 20 assessable patients (55%), resulting in partial responses in 5 (25%) and stable disease in 6 (30%).
The 6-month non-progressive disease rate was 86% (95% CI = 72.1-94.7) in the pazopanib-treated patients (37/43) and 50% (95% CI = 27.2-72.8) in the methotrexate plus vinblastine-treated patients (10/20).
Dr. Toulmonde and most of her co-authors had no relevant financial disclosures. Some authors disclosed funding from a wide range of drug companies including Novartis, the maker of pazopanib (Votrient). Clinical trial information: NCT01876082
SOURCE: Toulmonde M et al. ASCO 2018 (annual meeting of the American Society of Clinical Oncology), .