Perhaps they'll technobabble the blood has to be fresh or something to work.
I'm betting they'll simply ignore it altogether. Especially, if the movie takes place during the five-year mission and the Enterprise is far from Earth.
They might. But, could also simply be that it could not be replicated without the source material, and they were not willing to keep Khan around as a security risk.
Or, you can simply have the blood have nasty side effects* that Kirk is still recovering from.
Side effects may include