Amgen Claims Infringement of a Patent That Didn't Exist

Tony Hagen

Tony Hagen is senior managing editor for The Center for Biosimilars®.

Trying to carve back its market share for Neupogen, its filgrastim originator product, Amgen is hoping product exclusivity can be backdated.

If a pharmaceutical company receives a patent long after competitor versions of its drug have come to market, can that company still bring a suit for lost profits and patent infringement? Amgen is trying to do just that.

Amgen has filed suit against Hospira and Pfizer over a patent involved in the manufacture of a filgrastim biosimilar to Neupogen, Amgen’s reference product.

The biosimilar in question, Nivestym, received FDA approval in July of 2018 and went on market in October of that year. The patent under dispute (No. 10,577,392) was issued on March 3, 2020.

Amgen said the patent concerns methods of purifying proteins used in the manufacture of the biological product, contending, “Before the expiration of the patent,” Hospira, acting “in concert” with Pfizer, sought regulatory approval for the biosimilar under the abbreviated Biologics License Application (BLA) pathway in the Biologics Price Competition and Innovation Act.

Nivestym was approved by the FDA for all indications of the reference product, among them lowering the incidence of infection, caused by febrile neutropenia, in patients with nonmyeloid malignancies receiving chemotherapy. Neupogen stimulates the production of a known as neutrophils, a type of white blood cell that fight the infection.

Amgen contends that by September 24, 2018, Hospira and Pfizer were importing the biosimilar into the United States and making it available for sale. The company wants to recoup profits that it claims would otherwise have been made on the sale of Neupogen had there been no infringement as alleged.

Price erosion was partly responsible for those alleged lost profits, Amgen contens, citing a 2018 statement Pfizer made to The Center for Biosimilars® that Nivestym would be offered at a wholesale price 30.3% lower than that of reference filgrastim and 20.3% lower than that of Zarxio, a filgrastim biosimilar produced by Sandoz.

Amgen said in its court filing that it has had to battle obtain a full copy of the BLA from Hospira. Initially, Hospira provided 10,000 pages worth of material, but upon checking the cross-referencing, Amgen noticed that much of the document was missing. Hospira eventually produced an additional 70,000 pages, claiming that the extra pages were “inadvertently” not included with the original paperwork, Amgen contends.

Amgen, which is seeking a jury trial, initially contended that as many as 6 patents could be subject to a claim of infringement by Hospira. In subsequent negotiations, that number was whittled down to just 1 patent, covering the purification process for reference filgrastim. This patent remains under litigation in Delaware.