Novartis white blood cell-stimulater Zarxio (filgrastim-sndz) has become the first biosimilar to be allowed entry to the US market, paving the way for a stream of cheaper alternatives that may increase access to traditionally expensive biologic therapies.

The US Food and Drug Administration has approved Zarxio for all indications included in the label of Amgen's Neupogen, its reference product. Clearance was issued after clinical trials confirmed drug - developed by Novartis unit Sandoz - is highly similar to Neupogen, underpinning a unanimous backing from the FDA’s Oncologic Drugs Advisory Committee in January.

Commenting on its potential, Louis Weiner, chairman of the department of oncology and director of the Lombardi Comprehensive Cancer Center at Georgetown University, said filgrastim “has proven clinical value” but is “underused in the US for a variety of reasons, including price”. He believes “have the potential to increase access and [that] the approval of Zarxio may reduce costs to the healthcare system”.

Biosimilars are coming out at about about 30% cheaper than their brand-named counterparts, and assuming this discount, Express Scripts is estimateing that Zarxio’s availability in the US could save $5.5 billion in the next decade.