According to reports by Big Molecule Watch, two patent litigation suits have been dropped involving prospective filgrastim makers and the reference manufacturer Amgen. Sudden announcements like this have generally meant one of two things in the biosimilars arena.
The announcements came within days of each other: first, Accord BioPharma and Amgen announced that they jointly filed for dismissal of their ongoing suit. Then, on November 25, Big Molecule Watch reported that Kashiv Biopharma and Amgen have similarly dropped their patent litigation.
Three Scenarios Affecting Filgrastim Biosimilar Competition
The first potential scenario is that Amgen has come to an agreement with the respective manufacturers in terms of licensing or royalties associated with the sales of the biosimilar. We have seen this most recently with Pfizer bevacizumab biosimilar, where the Genentech and Pfizer’s filing to dismiss the patent suit came within days of an announcement of the new agreement. However, the new announcements involve filgrastim, a product that has been marketed since 2015, with ample competition (that is not subject to previous licensing arrangements). A new licensing agreement would be a bit less likely here, since Amgen owns less than 50% of the filgrastim share (Neupogen’s competitors Zarxio® and Granix® hold 31.7% and 20.3%, respectively, according to February 2019 IQVIA figures).
The second possibility is that Amgen has simply dropped the respective suits because of their lower marketshare; that is, the biosimilar genie is already out of the bottle, and litigating these ongoing lawsuits are simply a waste of resources.
A third possibility is that these prospective manufacturers, both of which have run into difficulties obtaining approval for their potential biosimilars in the US, have actually stopped development. This may be the most likely reason.
We reported back in May that Apobiologix (the US biosimilar subsidiary of Apotex) has likely ceased biosimilar development. They first filed for approval in early 2015, with no FDA action reported since that time. The lawsuit regarding this product was being defended by Accord (which was a subsidiary of Intas Pharmaceutical, a partner with Apotex in the development of the biosimilar); Accord’s name was substituted on the suit for Apotex’s in August 2019. Perhaps the rights for the filgrastim biosimilar reverted back to them.
Has Kashiv Biosciences Also Lost Interest in Filgrastim?
In the case of Kashiv Biosciences, this manufacturer purchased Adello Biologics in January 2019, which had been developing biosimilar versions of filgrastim and pegfilgrastim. Kashiv, which hasn’t issued a press release since the initial announcement of the purchase of Adello, still lists both agents on its pipeline. In January, the company stated to BR&R that it was proceeding with its development of the pegfilgrastim biosimilar, with a filing possible before the end of 2019. The filgrastim biosimilar filing in September 2017 is likely to have resulted in at least one complete response letter. No action from the FDA has been reported. One might also assume that the commercialization efforts for this product have been aborted.
If this is true for both cases, further litigation would be pointless. It may simply be additional evidence of a shakeout of the remaining competition in the first-generation biosimilar market.