Biosimilar Maker Leverages IPR to Avoid Patent Dance and Obtain Early Market Entry

Amgen Inc. and Alexion Pharmaceuticals Inc. settled three Inter Partes Review (IPR) proceedings concerning patents covering Alexion’s blockbuster humanized monoclonal antibody drug Soliris®, with Amgen obtaining a royalty-free license for marketing a biosimilar prior to expiration of the patents at issue.

Alexion is the maker of Soliris (eculizumab), a humanized monoclonal antibody against complement protein C5, indicated for the treatment of paroxysmal nocturnal hemoglobinuria (PNH) and other conditions. Alexion’s initial patent covering the eculizumab antibody expires in or about March 2022. See U.S. Patent No. 6,355,245.

Amgen is currently in clinical trials of its biosimilar version of eculizumab, ABP 959. In February 2019, Amgen filed separate IPR petitions against three related Alexion patents covering the eculizumab antibody, pharmaceutical compositions of eculizumab and methods of treating PNH using eculizumab. The patents at issue are U.S. Patent Nos. 9,718,880, 9,725,504 and 9,732,149, each of which expires on March 15, 2027. The Patent Trial and Appeal Board instituted all three IPRs on Aug. 30, 2019, holding that there was a reasonable likelihood that at least some claims of each of the patents were anticipated or rendered obvious in view of the prior art.

On May 28, Alexion and Amgen entered into a confidential settlement agreement to terminate the IPRs. Pursuant to the terms of the settlement agreement, effective March 1, 2025 (or earlier in certain circumstances), Alexion grants to Amgen a nonexclusive, royalty-free license under U.S. patents and patent applications related to eculizumab and various aspects of the eculizumab product, including the right for Amgen to make, have made, use, import, have imported, sell, have sold, offer for sale, have offered for sale, distribute or have distributed in or for the U.S. an eculizumab product. 

These proceedings are notable in that a biosimilar maker was able to use an IPR proceeding — several years prior to even filing a Biologics License Application or Abbreviated Biologics License Application — to leverage a settlement that included market entry prior to expiration of the patents at issue and to avoid the procedures of the Biologics Price Competition and Innovation Act, including the patent dance, entirely. It did so at a point when it would have had no standing to appeal an adverse final written decision in the IPR. Also notable is that the patents at issue were directed to the antibody itself and the primary indication of the drug.