Biosimilars developers, manufacturers of originator biologics, payers and consumer groups are battling in state capitals, at FDA headquarters, and at the World Health Organization in Geneva over the rules that will shape perceptions and prescribing practices for copycat biologics in the U.S. and around the world.

Separately, none of the conflicts will have a decisive effect on either biosimilars developers or manufacturers of the products they hope to replace. But collectively, state laws on interchangeable biosimilar substitution, national and international naming practices, and FDA's labeling policies could have powerful effects on the market penetration of biosimilars.