When it comes to many serious and challenging diseases, healthcare has reached a point of unsustainability, due to drug costs. For example, sustained therapy for an autoimmune disease or cancer, involving large amounts of monoclonal antibodies (mAbs), might not be a viable option for simple economic reasons. As a consequence, healthcare authorities want to reduce the cost of drugs by encouraging the development of biosimilars. When biological drugs are off-patent they can be copied – which is cheaper than developing the novel drug, but still challenging because of the need to demonstrate the same efficacy and safety. Drug purification, a key to successful manufacture of biologicals, must also adapt by exploiting products and technologies that lower the overall cost of production.