Pfizer and its subsidiary Hospira were previously involved in a patent dispute over the development and marketing of its biosimilars referencing Neupogen (filgrastim) and Neulasta (pegfilgrastim), both of which were developed by Amgen and are used to treat patients undergoing chemotherapy who are at risk of developing febrile neutropenia.

According to reports from Bloomberg Law, Amgen settled with Pfizer in September 2021 for its filgrastim biosimilar and in March 2022 for its pegfilgrastim biosimilar. However, Pfizer seems to be taking a page out of Amgen’s handbook by filing a patent lawsuit against Samsung Bioepis, Merck, Sharp & Dohme, Organon, and Arrow to stop the marketing of Brenzys, which is a biosimilar referencing Enbrel (etanercept), in Australia.

In the court documents, Pfizer alleged that the respondents infringed Australian Patent No. 2005280034, a patent that covers cell culture methods. Brenzys; also known as SB4, Eticovo, and Benepali depending on the country where the drug is being marketed; was approved for use by Australia’s Therapeutic Good Administration in 2016.

Although reference product manufacturers frequently sue biosimilar manufacturers over patent infringement, often resulting in pay-for-delay agreements, in which the biosimilar manufacturer is paid by the reference biologic manufacturer to delay entry of the biosimilar to the market, Pfizer is seeking damages from the sales of the biosimilar in Australia and for the barring of future sales of the drug until Pfizer’s patent expires.

Currently, Pfizer shares marketing rights with Amgen over reference etanercept. Amgen is notorious for suing biosimilar manufacturers to delay etanercept competition in the United States, where etanercept biosimilars are barred from entering the market until 2029. There are currently 2 FDA-approved etanercept biosimilars, including Eticovo (etanercept-ykro).

In the European Union, Brenzys is marketed as Benepali and was granted marketing authorization in January 2016. There are a total of 3 etanercept biosimilars approved in the European Union.

In 2016, Brenzys was approved in Canada for the treatment of moderate-to-severe rheumatoid arthritis in adults and ankylosing spondylitis. In September 2020, it received expanded indications to include plaque psoriasis, psoriatic arthritis, and juvenile idiopathic arthritis. There are 2 etanercept biosimilars approved in Canada. Brenzys was also approved for marketing in Brazil in September 2019.