Amgen is facing further biosimilar competition to its white blood cell stimulator Neupogen, after the FDA accepted a marketing application from Canada’s Apotex.
The Apotex version of Neupogen (filgrastim) – called Grastofil – will be given a 10-month review by the US regulator and could be on the market before the end of the year. Amgen’s product had US sales of around $1bn last year, according to the Canadian company.
Novartis’ Sandoz subsidiary was the first company to file for a biosimilar of Neupogen in the US and is also expected to be the first to reach the market there, after an FDA advisory committee backed the application a few weeks ago.
Sandoz’ version – with the proposed US trade name Zarxio – also has the benefit of extensive use outside the US, as it is already sold in more than 40 other countries under the brand name Zarzio.
There is also a version of filgrastim sold by Teva in the US as Granix (tbo-filgrastim), although this is not technically a biosimilar as it was approved via a full Biologics License Application (BLA). Teva’s drug is however sold as a biosimilar in Europe and Japan.
For Teva, that puts it at something of a disadvantage in the US as Granix is ineligible for indication extrapolation – in other words Teva has to carry out clinical trials to extend its uses to the full range for which Neupogen is approved. Biosimilars can automatically be used across the reference product’s indications.
Nevertheless, Teva was claiming a 15% market share in the US by the end of last year after around 15 months on the market – even with just one approved indication rather than Neupogen’s five – and says it expects to capture 20% before too long.
Moreover, there is always a chance that an ongoing lawsuit between Amgen and Sandoz seeking to block the launch of the latter’s biosimilar will go Amgen’s way, which would leave Teva with the only direct competitor to Neupogen, at least in the short-term.
Meanwhile, biosimilar competition is also looming for Amgen’s long-acting version of Neupogen, Neulasta (pegfilgrastim), which is due to lose US patent protection in October of this year.
Apotex has already filed for approval of its product under the FDA’s biosimilar pathway, which was introduced in 2010.