Sandoz’s version of Amgen’s Neupogen is ‘biosimilar’ but not ‘interchangeable’

The US Food and Drug Administration (FDA) has approved its first biosimilar product. Sandoz’s Zarxio is a generic version of filgrastim, which Amgen markets as Neupogen. The medication is used to prevent infection and low white blood cell counts due to chemotherapy and other causes, and several biosimilar versions are already approved in Europe.

In January, a key FDA advisory committee recommended Sandoz’s biosimilar version for licensing. While recognising their similarity, the FDA has emphasised that the two drugs are not considered interchangeable, so cannot be substituted by pharmacists without the prescriber’s permission.

Companies producing biological drugs have lobbied the FDA to distinguish biosimilars with unique generic names. The agency’s placeholder nonproprietary name for Zarxio is filgrastim-sndz. However, the FDA said this does not reflect a definitive decision on a naming policy for such products, which it is still in the process of working out.