PTAB Institutes Inter Partes Review of Three Eculizumab Patents

In February of this year, Amgen filed three petitions for inter partes review (IPR) of Alexion Pharmaceuticals’ U.S. Patent Nos. 9,725,504 (IPR2019-00739), 9,718,880 (IPR2019-00740), and 9,732,149 (IPR2019-00741). The claims of the challenged patents are directed to the monoclonal antibody eculizumab, which is the active ingredient in Alexion’s SOLIRIS, or methods of using the antibody to treat paroxysmal nocturnal hemoglobinuria (PNH).  Each of Amgen’s petitions challenges its associated patent on both anticipation and obviousness grounds.  In June, Alexion filed preliminary responses opposing institution (IPR2019-00739, IPR2019-00740, IPR2019-00741), and Amgen filed replies in support of institution in July (IPR2019-00739, IPR2019-00740, IPR2019-00741).

On August 30, 2019, the Patent Trial and Appeal Board (PTAB) granted all three petitions and instituted IPR proceedings for all three challenged patents (IPR2019-00739, IPR2019-00740, IPR2019-00741). The PTAB also scheduled oral argument, if requested, for June 1, 2020.

Amgen’s eculizumab biosimilar candidate, ABP 959, is in phase 3 clinical development in patients with PNH.

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