In Yeda Research and Development Co. v. Abbott GmbH and Co., the Federal Circuit invoked the doctrine of inherent disclosure to uphold a priority claim to a German priority application that only partly described the claimed protein. Although the patent owner prevailed in this case, the fact pattern underscores the importance of including a robust disclosure in priority applications. It also highlights the tension between securing an early filing date and waiting until the claimed subject matter has been fully characterized–a dilemma faced by many applicants in biotechnology fields.

The Patent At Issue

The patent at issue was Abbott’s U.S. Patent No. 5,344,915. The court focused on claim 1:

1. A purified and isolated TNFα-binding protein which has a molecular weight of about 42,000 daltons and has at the N terminus the amino acid sequence Xaa Thr Pro Tyr Ala Pro Glu Pro Gly Set Thr Cys Arg Leu Arg Glu where Xaa is hydrogen, a phenylalanine residue (Phe), or the amino acid sequences Ala Phe, Val Ala Phe, Gln Val Ala Phe, Ala Gln Val Ala Phe, Pro Ala Gln Val Ala Phe or Leu Pro Ala Gln Val Ala Phe.

The Inherent Disclosure At Issue

As noted in the Federal Circuit decision, Yeda’s invalidity arguments “turn[ed] on whether [the ‘915 patent] benefits from the filing dates from either of two German patent applications—P39 15 072 … and P39 22 089.”

The relevant disclosures are summarized in the Federal Circuit decision as follows:

Neither the ’072 nor the ’089 application discloses the full N-terminus sequence claimed in the ’915 patent. Instead, they disclose a partial N-terminus sequence, a protocol for obtaining the protein from its biological source, and additional properties of the protein, such as molecular weight, biological activity, and degradation characteristics when exposed to trypsin. The parties agree that the only protein containing the N-terminus sequence set forth in the ’072 application is TBP-II—i.e., the same protein claimed in the ’915 patent.

The district court found that the ‘915 patent was entitled to the benefit of the filing date of the ‘072 application.

The Federal Circuit Decision

The Federal Circuit opinion was authored by Judge Reyna and joined by Judge Wallach and Judge Hughes.

The Federal Circuit opinion first states the relevant legal standard, citing 35 USC §§ 112 and 120, and its 2010 en banc decision in Ariad Pharmaceuticals, Inc. v. Eli Lilly & Co.:

In order for the claims of the ’915 patent to benefit from the ’072 application’s filing date, the claimed invention must be disclosed by the ’072 application …. in a way that clearly allows a person of ordinary skill to recognize that the inventor invented what is claimed and possessed the claimed subject matter at the date of filing.

The court then explained the doctrine of inherent disclosure:

Under the doctrine of inherent disclosure, when a specification describes an invention that has certain undisclosed yet inherent properties, that specification serves as adequate written description to support a subsequent patent application that explicitly recites the invention’s inherent properties.

Given that “it is undisputed that TBP-II is the only protein with the same partial N-terminus sequence and additional traits disclosed in the ’072 application,” the Federal Circuit concluded that “the ’072 application inherently discloses the remaining amino acids in the N-terminus sequence of TBP-II and serves as adequate written description support for the patent claiming TBP-II.”

Sufficient Inherent Disclosure

One fact that seems to have been important to the decision here was that the information provided in the priority application was sufficient to distinguish the claimed protein from other proteins, including the TBP-I protein that may represent the closet prior art. Here, it is likely that the inventors knew about the TBP-I protein, and so knew that they had to have enough characterizing information to distinguish it. In other situations inventors may not be aware of “the closest prior art” to their newly discovered proteins.

Speaking of which, do these claims satisfy 35 USC § 101?