I know this is an old thread but the website www.drugs.com
says, "This medicine (eltrombopag; generic for Promacta) is not approved for use in people with a certain bone marrow problem called myelodysplastic syndrome (MDS). If you have MDS and you take this medicine (eltrombopag tablets), MDS may get worse and turn into a type of blood cancer called acute myelogenous leukemia (AML). If MDS turns into AML, you could die sooner from AML. If you have MDS, talk with your doctor." https://www.drugs.com/cdi/eltrombopag-tablets.html
This page on the website was medically reviewed on May 2, 2018, so maybe this is new-ish information. Just thought I'd post it since the topic came up.