Sandoz in September announced the US launch for Zarxio (filgrastim-sndz), the first biosimilar to be approved by the US Food and Drug Administration (FDA) (Nat. Biotechnol. 33, 222–223, 2015). Sandoz, a Novartis company, is headquartered in Holzkirchen, Germany. The biosimilar Zarxio is a biosimilar to Thousand Oaks, California–based Amgen's Neupogen. Both originator and biosimilar products are approved for the same set of medical indications, principally several kinds of cancer involving myelosuppresive therapies. When FDA approved Zarxio in March, agency officials said that they considered 'filgrastim-sndz' a placeholder name, as the agency had yet to define a policy for naming biosimilars (Nat. Biotechnol. 31, 264, 2013). In August, not coincidentally, FDA issued its much-awaited draft guidance, proposing that biosimilars share nonproprietary names with their reference products. To set such products apart, FDA proposes designating unique four-letter suffixes for each biological product, with those suffixes otherwise carrying no particular meaning. Using suffixes would help prevent inadvertent substitutions of biological products that are not considered medically interchangeable, and they might also help with safety monitoring, FDA says. But possibly complicating matters is an approach proposed by agency officials—one evident in Zarxio's provisional name—of using suffixes that reflect the name of the company that manufactures each drug. FDA also says it may apply one or another of these approaches to renaming products that are already licensed, suggesting these extended names could help with recordkeeping and also might avoid “inaccurate perceptions” of the safety and effectiveness of biological products based on their regulatory paths to approval.