The VPHM buyout is instructive on the value of orphan drugs. I owned Lev Pharmaceuticals when VPHM bought it out to get Cinryze.
Shire is paying 10x revenue ($405M) of Cinryze to get the company.
Cinryze is the only profit center for VPHM, and carries a significantly higher COGS% (~24%) than defibrotide (~12%) and df COGS% will drop a lot as sales and pricing ramp unlike Cinryze.
Another contrast is that df revenue is growing faster.
GENT will get bought out at some point and this is an interesting comparator.