Legal has little to do with it. I gave my word to a very highly placed source and friend as well - who might become neither if I said more than I agreed to. I will say that all ongoing FDA approved trials on oleander center around cancer. That and leukemia.
There is a fairly recent European patent by Arabian doctors for an oleander extract for use against a wide variety of cancers. leukemia ad HIV and, while I have little doubt about it's ability to treat all of those conditions, I seriously doubt that it will stand up to a strong patent challenge because it is too similar to both an age old remedy based on a common plant and an already patented medicine (Anvirzel) which is itself involved in FDA testing.
Ironically, it oleander was first reported to have been used for cancer by Arabs in the 8th century BC, though it's medicinal use has been dated back much farther to the ancient Phoenicians and Mesopotamians.