Hi Wendy,
Your hematologist is right - Romiplostim has had "fast track designation" many years and Promacta got fast track designation in Europe August 2007. I don´t think Promacta is approved as an orphan drug yet by FDA. I have difficulties to find relevant info at the FDA site
. It is very important for a drug to get fast track designation (as a new treatment for uncommon diseases) because it makes the review time much shorter.
Kind regards
Birgitta