FDA is facing pressure to eliminate the requirement that biosimilar sponsors conduct confirmatory powered clinical studies. Two top scientists argue that these late-stage trials duplicate the analytical testing required by FDA, add unnecessary cost and violate congressional intent. The agency has approved 12 biosimilars, and all went through what FDA calls a “stepwise approach to demonstrate biosimilarity.” The process begins with analytical testing. From there sponsors use animal data to measure toxicity and then comparative human PK and PD studies...