That would depend on why they drink blood. Personally, I don’t think the blood itself can sustain anyone, as in, a pure diet of blood isn’t gonna provide you the nutrients and whatever to enable them to survive.

If that’s the case, then it might be something inherent to living creatures that give them sustenance, like maybe a bit of your “life force” is taken away or something. If this is true, then lab grown blood wouldn’t help them, as there’s no life force being created. It’s just a bunch of protein and shit.