Edit: Obviously I was both late to the party, and incorrect about the original poster. This is why I shouldn't post from my phone, while watching football, and also drinking.

Depends. If you’re doing pure DCF, then patent life would play a big part in it. But if you’re comping to existing biotech market, then the valuation multiple isn’t explicitly tied to the life of the patent. Check biotech valuations for revenue generating companies, 12x is actually pretty low in many cases. 12x is just a conservative comp number on sjacob’s part, I presume.