Pazopanib or Methotrexate/Vinblastine in Progressive Desmoid Tumors
In the French Sarcoma Group noncomparative phase II DESMOPAZ trial reported in The Lancet Oncology, Toulmonde et al found that the oral vascular endothelial growth factor (VEGF) receptor inhibitor pazopanib was active in adult patients with progressive desmoid tumors. As noted by the investigators, VEGF overexpression is a common feature in aggressive desmoid tumors.
Study Details
In the multicenter, open-label trial, 72 patients were randomly assigned 2:1 between December 2012 and August 2017 to receive pazopanib at 800 mg/d for up to 1 year (n = 48; 46 patients assessable) or to intravenous vinblastine (5 mg/m2) and methotrexate (30 mg/m2) weekly for 6 months and then every other week for 6 months (n = 24; 20 patients assessable). The primary endpoint was the proportion of patients without disease progression by Respoinse Evaluation Criteria in Solid Tumors, version 1.1, at 6 months among the first 43 assessable patients in the pazopanib group.
Results
Median follow-up was 23.4 months. Among the first 43 patients assessable for the primary endpoint in the pazopanib group, the proportion of patients who did not have disease progression at 6 months was 83.7%. The proportion of assessable patients in the methotrexate/vinblastine group who did not have disease progression at 6 months was 45.0%.
Responses (all partial) were observed in 17 patients treated with pazopanib (37.0%), and stable disease was observed in 27 (58.7%). Responses (all partial) were observed in 5 patients treated with methotrexate/vinblastine patients (25%), and stable disease was observed in 10 (50%).
Adverse Events
Treatment-related grade 3 or 4 adverse events occurred in 27 (56%) of 48 patients in the pazopanib group and 17 (77%) of 22 patients in the methotrexate/vinblastine group, with the most common being hypertension (21%) and diarrhea (15%) in the pazopanib group and neutropenia ( 45%) and liver transaminitis (18%) in the methotrexate/vinblastine group. Treatment-related serious adverse events occurred in 11 patients treated with pazopanib (23%) and in 6 patients treated with methotrexate/vinblastine.
The investigators concluded, “Pazopanib has clinical activity in patients with progressive desmoid tumours and could be a valid treatment option in this rare and disabling disease.”
Antoine Italiano, MD, of Institut Bergonié, Department of Medicine, Bordeaux, is the corresponding author for The Lancet Oncology article.
Disclosure: The study was funded by GlaxoSmithKline and Novartis. For full disclosures of the study authors, visit thelancet.com.
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