Alnylam Pharmaceuticals, Inc. v. Moderna, Inc., ModernaTX, Inc., Moderna US, Inc., decided June 4, 2025

Alnylam alleged that Moderna's COVID-19 vaccine, SPIKEVAX®, infringed on two of Alnylam's patents regarding cationic lipids used in mRNA delivery. The core issue on appeal is the claim construction of the term "branched alkyl" as it relates to a specific carbon atom's bonding within the lipid structure. The court analyzes the patent specification and prosecution history to determine if Alnylam acted as its own lexicographer in defining the term and if any exception to that definition was "otherwise specified" in the asserted claims. Ultimately, the court affirms the district court's construction, which required the carbon atom to be bound to at least three other carbon atoms.  Read the full case summary here: https://www.cafcnewsbriefs.com/post/alnylam-pharmaceuticals-inc-v-moderna-inc-modernatx-inc-moderna-us-inc-decided-june-4-2