by Dennis Crouch
In a January 22, 2025 decision, the Federal Circuit once again maintained validity of Ravgen's fetal DNA testing patent. Its new decision also provides some important guidance on standing requirements for appealing IPR decisions. Streck, Inc. v. Ravgen, Inc., No. 2023-1989 (Fed. Cir. Jan. 22, 2025). This companion case to the recent LabCorp decision addresses similar issues regarding both patentability and procedural requirements. See, Dennis Crouch, Not Quite Teaching Away: Federal Circuit Clarifies Evidence Needed to Defeat Motivation to Combine, Patently-O (Jan 2025).
The Technology: The patent at issue (U.S. Patent No. 7,332,277) relates to methods for non-invasive fetal DNA testing. This is an incredibly important area of technology because the leading prior form of testing (amniocentesis) is relatively dangerous to the growing fetus. Cell free fetal DNA (cffDNA) floats around in the mother's blood stream. But, not very much, and what is there tends to be somewhat unstable. The claimed method involves analyzing cell-free fetal DNA from maternal blood samples while using agents that prevent cell lysis (breakdown). The key independent claim requires "determining the sequence of a locus of interest on free fetal DNA" from a maternal blood sample that includes both the fetal DNA and a cell lysis inhibitor. A dependent claim specifically identifies the inhibitor as being selected from glutaraldehyde, formaldehyde, or formalin. The patent at issue here lists Ravgen's founder Ravinder Dhallan as the inventor and claims back to a 2003 provisional application filing.
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