Vectura sued GlaxoSmithKline (GSK) alleging that GSK infringed Vectura’s patent directed to composite active particles for dry‑powder inhalers. Vectura’s patented particles included the active ingredient and the additive material on the surface of the active ingredient. Vectura presented evidence that GSK’s accused particles met this claimed feature.
However, GSK’s particles and Vectura’s particles were produced by different processes. GSK used a multi-step mixing process to prepare the particles, whereas Vectura’s patent disclosed a milling process entailing milling solid active particles in the presence of solid additive particles with sufficient energy to break down coarse particles into fine particles, resulting in the additive particles smearing over, and fusing onto, the active particles.
During claim construction, GSK argued that “composite active particles” should be construed to include a process limitation requiring that the composite active particles be produced by the milling process disclosed in Vectura’s patent. GSK pointed to statements in the patent’s specification and statements made during the prosecution of the patent, and argued that the statements showed that the milling process was essential to the claimed composite active particles. GSK also argued that Vectura disclaimed particles made by other processes.
However, the district court rejected GSK’s proposed construction, holding that the term did not include a process limitation. The district court construed the term to mean “a single particulate entity made up of a particle of active material to which one or more particles of additive material are fixed such that the active and additive particles do not separate in the airstream.”
The district court held that GSK infringed the patent. GSK appealed the district court’s claim construction.
Did the district court err in construing “composite active particles”? (continue reading)
Summary by: Paige Soon