A new study is testing the combination of Pazopanib (Votrient), Irinotecan and Temozolomide in children and young adults with refractory sarcoma:
I am not sure if this trial makes sense for synovial sarcoma. Irinotecan and Temozolomide has been effective in pediatric patients with Ewing’s sarcoma and Rhabdomyosarcoma but I couldn’t find anything about their efficacy in synovial sarcoma except for this study: