In the following article, Dr. Schwartz suggests Regorafenib may be active in synovial sarcoma:
His conclusion comes from the following European trial:
The results of the trial were presented at ASCO:
http://meetinglibrary.asco.org/content/162032-176
The study results were published in the Lancet:
http://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(16)30507-1/abstract
The study protocol is here:
Side effects of Regorafenib are reported here: