Bispecific vs standard mAb — how much harder is the CMC really?

Upstream is broadly similar; the burden lands downstream and in analytics. Expect mispairing/half-antibody species, extra polishing to resolve product-related impurities, and a much heavier analytical package to confirm correct chain pairing — plus more developability and stability work. Very doable on platform thinking, but ‘a mAb plus a bit’ undersells it; plan for the extra characterisation time.