Most of the studies for the use of anti-angiogenic drugs have been taken from phase I trials of refractory solid tumors showing a lack of response in sarcomas. This may be due to an inadequate dose, wrong sequence of the treatment or lack of studies with combination treatments. Given the heterogeneity of sarcomas there may be a benefit in certain subgroups that can easily be missed. A recent clinical trial has shown improved cytotoxic cell kill and response rates by epigenetically modifying the tumor environment prior to chemotherapy. It is believed that the efficacy of angiogenesis inhibitors has been shown to be greatly improved when they are combined with other anticancer drugs.