Federal Circuit Finds That Fetal Diagnosis Claims Survive Written Description Attacks

Stanford University v. The Chinese University of Hong Kong. Federal Circuit Appeal No. 2015-2011. Decided June 27, 2017.

In an appeal from the Patent Trial and Appeal Board (PTAB), the Federal Circuit held that claims related to methods of testing for fetal chromosomal abnormalities were not invalid because there was not substantial evidence that the claims lacked written description support.

Stanford and the Chinese University of Hong Kong (CUHK) had each requested an interference at the Patent Office to determine who had invented certain methods of diagnosing fetal chromosomal abnormalities using cell-free fetal DNA from maternal blood samples.  The PTAB decided the interference in CUHK’s favor, finding that Stanford’s claims lacked written description support.  Stanford first appealed the Board’s decision to a District Court, but its appeal was transferred to the Federal Circuit after a recent case established that interferences declared after September 15, 2012 could only be appealed to the Federal Circuit (see Biogen MA, Inc. v. Japanese Found. For Cancer Research 785 F.3d 648 (Fed. Cir. 2015)).

Stanford’s claims required random massively parallel sequencing of nucleic acids.  The PTAB concluded that Stanford’s application only disclosed targeted massively parallel sequencing of particular nucleic acids, and therefore Stanford’s claims lacked written description support.  The PTAB repeatedly cited CUHK’s expert to support its conclusions, finding that (1) the Expert’s testimony was supported by published references (which post-dated Stanford’s priority date), and (2) Stanford’s patent application did not preclude the use of targeted sequencing. 

On appeal, the Federal Circuit looked to determine if there was substantial evidence to support the PTAB’s finding that Stanford’s claims lacked written description. Regarding item (1), the Federal Circuit noted that for written description, the relevant inquiry is possession of the claimed invention as of the patent application’s priority date.  Here, the Federal Circuit found that the Expert’s reliance on later-filed references was improper for determining what a person of skill in the art would have understood as of Stanford’s priority date.  Regarding item (2), the Federal Circuit found that because the inquiry for written description is possession, the PTAB’s finding that Stanford’s application “did not preclude” the use of targeted sequencing was insufficient to show what Stanford did or did not possess.  Accordingly, the Federal Circuit vacated the Board’s holding that Stanford’s claims were invalid for lack of written description, and sent the case back to the Board for further fact finding.

While interferences will become less common under the America Invents Act, the Federal Circuit’s reasoning in this case should remain applicable to other PTAB proceedings such as Inter Partes Reviews (IPRs) and Post Grant Reviews (PGRs) because the Federal Circuit applies the same standard of review (substantial evidence) to IPRs and PGRs as it does to interferences.  Thus, the Federal Circuit’s requirement for evidence of possession as of the priority date can be applied to expert and documentary evidence supporting or attacking written description during other PTAB proceedings.