Nplate was apparently only approved for this purpose last year, and HHS has been talking about acquiring it since then. That might be the whole story here.
If you Google around, you'll find HHS documents from 2021 talking about this allocation.
If you Google around, you'll find HHS documents from 2021 talking about this allocation.
It looks like they may traditionally buy these types of drugs around this time of the year. Here’s one from 6 years ago.