On April 16, 2025, EmblemHealth, Inc. (“Emblem”) filed a class action suit in the District Court for the District of Massachusetts against Alexion Pharmaceuticals, Inc. and Alexion Pharma International Operations Ltd. (collectively, “Alexion”) alleging Alexion “violated antitrust law by monopolistic acts that unlawfully delayed the introduction of biosimilar competition for eculizumab.” Enblem alleges that Alexion “defrauded a U.S. patent examiner” in order to “unlawfully procure[] a second set of five patents [following a first patent claiming eculizumab], once again claiming eculizumab, and with a expiration dates well into the future.”
SOLIRIS (eculizumab) is a humanized monoclonal antibody treatment approved to treat a range of immune disorders and blood diseases, including paroxysmal nocturnal hemoglobinuria. Emblem alleges that “[s]tarting in 2007, Alexion sold eculizumab under the brand name Soliris with protection from competition under a 2002 issued composition patent, U.S. Patent No. 6,355,245 (the “’245 patent”) [which] claims eculizumab, a biologic pharmaceutical comprising an anti-C5 antibody having a specified sequence of heavy and light chains.” Emblem further alleges that “Alexion’s 14-year grant of patent protected Soliris sales should have concluded after March of 2021 upon the expiration of its 2002 eculizumab patent,” but that “in the years before that expiration, Alexion’s senior management and scientists unlawfully procured a second set of five patents, once again claiming eculizumab.” Emblem claims that Alexion “defrauded a U.S. patent examiner” by “concealing from the patent examiner many of Alexion’s own pre-2007 publications that disclosed outright the exact sequence of eculizumab by providing a simple roadmap for its assembly” and ” falsely represent[ing] that its own ’245 patent failed to teach the eculizumab amino acid sequence.” Emblem contends that, as a result of these alleged actions, “the PTO examiner incorrectly allowed claims in a set of five related patents—three in 2017 and two in 2020—that once again covered eculizumab and known methods of using it.”
Emblem alleges that “Alexion used its fraudulently acquired patents to extract settlements from its first would-be competitor and to delay its second would-be competitor with costly and prolonged litigation” resulting in “U.S. purchasers of eculizumab—one of the most expensive drugs in the world—hav[ing] paid supra-competitive prices for eculizumab due to Alexion’s unlawful acts.”
Emblem’s complaint includes six (6) counts: (1) declaratory and injunctive relief for “monopolization in violation of Section 2 of the Sherman Act”; (2) declaratory and injunctive relief for “attempted monopolization in violation of Section of the Sherman Act”; (3) “monopolization and monopolistic scheme under state law”; (4) “attempted monopolization under state law”; (5) “violations of state consumer protection laws”; and (6) “unjust enrichment under state law.” Emblem seeks certification of a class defined as “[a]ll end payors (including any assignees of such end payors) in the United States and its territories who purchased and/or paid all or part of the purchase price of Soliris from March 2022 until the anticompetitive effects of Alexion’s conduct cease (the class period).”
Stay tuned to Big Molecule Watch as we continue to monitor this antitrust litigation.