Biologics, primarily therapeutic antibodies and recombinant proteins, represent a growing share of the current drug market, with projected worldwide sales of about US$278 billion by 2020, partly because of their relatively high costs. Indeed, AbbVie’s therapeutic antibody Humira (adalimumab) is currently the top-selling drug in the world by sales but not even in the top 50 by the number of monthly prescriptions. Although the process for marketing generic versions of small molecules under the Hatch–Waxman Act is well understood, the…