Federal Circuit Precedential

Holding:  A product-by-process claim is not inherently anticipated by a reference that merely discloses the claimed process.  When determining validity of a product-by-process claim, the focus is whether the prior art discloses the claimed product and not the process of making the claimed product.

Jadi Cell owns US Pat. No. 9,803,176 which is directed to stem cells with specific cell markers that are obtained from the subepithelial layer (SL) of mammalian umbilical cord tissue.  Claim 1 of the ‘176 Patent is a product-by-process claim and shown below:

Restem filed an IPR, alleging that claims 1-15 of the ‘176 Patent are inherently anticipated by a publication to Majore, or alternatively, are obvious over Majore, Phan, or Kita in view of several other references.  The PTAB found that all of the claims of the ‘176 were not shown to be unpatentable.

In its analysis, the PTAB construed the “placing” step of claim 1 to require intentional placement of the umbilical cord tissue to touch the growth substrate to allow cell culture.  This construction did not require isolating the SL from other umbilical cord tissue or placing the isolated SL interior side down on the growth substrate, even though these steps were described in the specification.  However, when determining patentability in view of the Majore reference, the PTAB considered the fact that Majore did not disclose placing the SL interior side down as evidence that Majore did not anticipate claim 1 of the ‘176 Patent.  The Federal Circuit held that the PTAB did not err by considering this feature despite it not being a requirement of the construed claim.  Instead, the Federal Circuit found that the PTAB’s analysis to be a factual finding that supported its conclusion that Majore’s process did not necessarily produce cells with the claimed cell marker expression profile.

Additionally, the PTAB construed the terms “express” and “does not express” with respect to the isolated cell to mean that “the marker is confirmed present/absent relative to a control sample.”  This construction required that the term “isolated cell” be implicitly construed to refer to a cell population since, at the time of the invention, cell marker analysis had to be performed on a population of cells rather than a single cell.  Restem argued that this construction was legal error since the specification of the ‘176 Patent specifically defined the term “isolated cell” to refer to a cell that has been isolated from the SL of a mammalian umbilical cord rather than a cell population. 

However, the Federal Circuit upheld the PTAB construction since cell marker expression could only be determined using a population of cells rather than a single cell.  Further, despite the use of the term “isolated cell” in the claim, the specification of the ‘176 Patent generally describes the invention as a cell population.  Further, the prosecution history supports the PTAB’s construction of the terms “express” and “does not express.”  The Examiner repeatedly referred to the claimed invention as a cell population and stated in the Notice of Allowance that the claims are directed to a cell population.  The failure of an applicant to address an Examiner’s clear statements regarding claim scope can indicate acquiescence to those statements and impact claim construction.  Since Jadi Cell never corrected the Examiner’s representation of the invention as a cell population, the PTAB’s construction of the claims as being drawn to a cell population is supported.

Restem also argued that for a product-by-process claim, once all the process steps are shown in a prior art reference, then the product is necessarily present, so that inherency is automatic for product-by-process claims.  However, in determining validity of a product-by-process claim, the focus is on the claimed product and not on the process of making the product.  The Federal Circuit upheld the PTAB’s finding that the process described in the Majore reference does not inherently anticipate claim 1 of the ‘176 Patent.  Restem did not provide any evidence that the process described in Majore would inevitably have led to a cell marker expression profile that fits the requirements recited in claim 1.  Since cell marker expression can depend on several factors, the process in the Majore reference could have led to different cell-to-cell interactions which would have resulted in different expressions.

Full Opinion (PDF)