As the era of biologics and biosimilar litigations heats up in the United States, Europe’s Unified Patent Court (UPC) is also taking center stage with the first two biosimilar disputes filed in March and April.

On March 19, 2024, Alexion Pharmaceuticals (a subsidiary of AstraZeneca specializing in rare disease treatment) filed for provisional measures in the Hamburg Local Division against Amgen and Samsung Bioepis, asserting patent application EP 3167888 claiming antibodies corresponding to Alexion’s blockbuster Soliris® (eculizumab).

Initially the patent application was opted out of UPC jurisdiction, however the opt-out was withdrawn in January 2024 prior to filing these proceedings. Interestingly, these cases were brought against a patent that has not yet been granted, and it is unclear if the early application for provisional measures will be allowable.  While a preliminary injunction may have been requested, it does not appear that the defendants have filed a protective letter at the UPC.  A protective letter is a document that parties who think they may be at risk of having an ex parte preliminary injunction awarded against them file to make arguments as to why a preliminary injunction should not be granted.  A protective letter makes it more likely the UPC would have a hearing prior to deciding whether to grant a preliminary injunction.  At the writing of this article no substantive matters have occurred in these cases.

In related disputes in the U.S., Alexion settled three IPRs (IPR2019-00739, IPR2019-00740, and IPR2019-00741) brought by Amgen against Soliris® patents in June 2020, agreeing to a non-exclusive, royalty-free license for Amgen’s proposed biosimilar (an aBLA filing for which has yet to be publicly announced) starting March 1, 2025, or earlier in certain circumstances.  Alexion and Samsung Bioepis are currently involved in five instituted and pending IPRs (IPR2023-00933, IPR2023-00998, IPR2023-00999, IPR2023-01069, IPR2023-01070) as well as a litigation (1:24-cv-00005 D. Del.) related to Samsung Bioepis’s proposed biosimilar SB12 (eculizumab), an aBLA for which was accepted by FDA in July 2023.  Most recently, on May 6, 2024, the Court denied Alexion’s motion for a preliminary injunction against SB12.

AstraZeneca reported Soliris® 2023 worldwide sales of $3.145 billion USD.

On April 9, 2024, Novartis and Genentech applied to the Düsseldorf Local Division of the UPC for provisional measures against Celltrion which was granted the first EMA marketing approval for a biosimilar monoclonal antibody in 2013. Novartis and Genentech assert EP 3805248 that claims anti-IgE antibody Xolair® (omalizumab) with a specific buffer formulation. Genentech’s basic European patent for Xolair® expired in March 2024.

The patent asserted in this case was not opted out of the UPC’s jurisdiction.  It is subject to an ongoing EPO opposition proceeding filed by Celltrion in October 2023.  While there is limited public information available, a preliminary injunction may have been requested.  Celltrion had filed a protective letter in December 2023, and the UPC set a deadline of May 10, 2024 for Celltrion’s response to the application for provisional measures.

In the U.S., Celltrion disclosed its filing of an aBLA for CT-P39 (omalizumab biosimilar) with the FDA in March 2024, with a request for interchangeability.  At the writing of this article, there have not been any U.S. patent proceedings related to this or any other Xolair® biosimilar.

Xolair® generated worldwide sales of $3.85 billion USD in 2023.

For more information about these and other biosimilar patent disputes, please visit BiologicsHQ.



The authors would like to thank April Breyer Menon for her contributions to this article.



    Information contained in the Venable BiologicsHQ database relates to FDA-approved drug products listed in the CDER Purple Book or on the FDA website ( Information relating to FDA licensed products, FDA-approved indications, and aBLA and 505(b)(2) applications is obtained from public sources including the U.S. FDA website ( Information relating to litigations is given only for cases active from January 31, 2010 onward. Information relating to foreign biosimilar / biologics follow-on products approved in Australia, Canada, the E.U., Japan and South Korea is from public sources. Statistics graphics are compiled from information contained in the Venable BiologicsHQ database.


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