The Dox did not overperform in the CLSN trial. It's their Thermodelivery system that did not work like they have hoped. Additionally, they targeted one of the most difficult to treat cancer ( HCC), which has eluded effective treatment for several years now. ZIOP, on the otherhand, is basically using an already proven therapy for STS but making it much more tolerable for patients.
CLSN was just hooey. ZIOP is real science. Nothing similar other than they both were used in conjunction with DOX. The smart money was on failure in CLSN. ZIOP compound is biosimiliar to existing oncology Alkylating agents. The hope is that it will have a better toxicity profile and equal or better pfs and os data. Current alkylating agents are very toxic-- liver damage dementia, really bad stuff but they work (if you don't mind losing your mind in the process)