Written Description in the U.S.: The Yin and Yang of Yeda

In UCB v. Yeda, the Federal Circuit found that Yeda’s patent claiming a monoclonal antibody (mab) did not cover UCB’s humanized/chimeric mabs.  The Federal Circuit reasoned that Yeda was estopped from covering humanized mabs in its patent because “a patent applicant cannot later obtain scope that was requested during prosecution, rejected by the Examiner, and then withdrawn by the applicant.”  But is this really what happened? 

From the Federal Circuit’s opinion, it appears that Yeda prosecuted a claim directed to a “monoclonal antibody,” and Yeda indicated during prosecution its belief that this claim covered not only murine (mouse) mabs but also other types of mabs such as chimeric mabs.  This claim issued in Yeda’s patent.  Contrary to the Federal Circuit’s opinion, it appears that Yeda did request and obtain claims covering humanized/chimeric mabs. 

 

So, what gives?

   

Yeda’s patent application was filed in 1984 (not a typo – 1984) and only discussed mouse mabs.  Looking at the patent’s narrow disclosure and what was known in the art about humanizing mabs in 1984, it might make sense that the claims should be limited to mouse mabs.  But the prosecution history of Yeda’s patent arguably tells a different story.  What happened during prosecution is this: 

 

Interestingly, the USPTO rejected the new dependent claims as containing new matter (pre-AIA 35 USC 112, 2nd par.) but not as being outside the scope of the “monoclonal antibody” claim from which they depended and, thus, not as being an improper dependent claims (pre-AIA 35 USC 112, 4th par.).  So, it appears that the USPTO considered the subject matter of the specific dependent claims to be within the scope of the “monoclonal antibody” claim, but rejected these dependent claims because the mabs identified in these claims were not specifically described in Yeda’s patent. 

 

So, why did the Federal Circuit find that Yeda’s patent does not cover humanized mabs?  Perhaps because the Federal Circuit believed it was the proper result regardless of the prosecution history.   

 

One red flag in the prosecution history for the Federal Circuit could have been the declaration submitted to overcome the enablement rejection.  The declaration apparently indicated that “it was within the level of skill” in 1984 to produce mabs from species other than mice.  However, the declaration relied on only two citations for support, one of which was the Nobel prize speech by César Milstein in 1984 “referring to chimeric antibodies.”  It appears that the declaration may have used an incorrect standard (“within the level of skill”) instead of the “one of ordinary skill in the art” standard.  And a mere “reference” during a Nobel prize speech does not seem to be very good evidence of enablement to one of ordinary skill in the art.  So, it is possible that the Federal Circuit believed that the enablement rejection of the “monoclonal antibody” claim should not have been withdrawn by the USPTO during prosecution and that such a claim is not enabled by Yeda’s patent.

In Yeda v. Abbott GmbH, Yeda challenged Abbott’s patent directed to a protein, TBP-II.  Yeda argued that Abbott did not disclose TBP-II in its German priority application, so Abbott was only entitled to the priority date of its later-filed U.S. application.  Abbott’s priority date was important because there was an anticipatory reference with an effective date earlier than the U.S. application’s date but later than the German application’s date.

The Federal Circuit ultimately found that Abbott’s German priority application inherently disclosed TBP-II, allowing Abbott to “get behind” the anticipatory reference.  The Federal Circuit then found that Abbott’s patent was valid.  Interestingly, Yeda argued that the prosecution history of Abbott’s patent supported its argument that Abbott was not entitled to the German priority date, but the Federal Circuit brushed this argument aside and relied upon the disclosure in Abbott’s patent to make its decision.

So, why did Yeda lose on both sides of disclosure issues?  It probably should be as simple as the fact that Abbott’s patent contained a sufficient disclosure/written description (of TBP-II), but Yeda’s patent did not contain a sufficient disclosure/written description (of humanized mabs).

Which makes the Federal Circuit’s reliance upon the prosecution history in the UCB case troubling. 

True, the UCB case involved interpreting the term “monoclonal antibody” in Yeda’s claims, and claim interpretation involves analyzing the prosecution history.  But is the tail wagging the dog here?   

I have seen analysis of the UCB case indicating that it stands for the general proposition that actions taken on dependent claims can affect the meaning of an otherwise-understood generic term in an independent claim.  But should cancelling a dependent claim, which is completely subsumed within an independent claim, really alter the understood meaning of the independent claim such that it changes the understood meaning to exclude the subject matter of the cancelled dependent claim? 

For example, in the UCB case, the USPTO determined that Yeda’s independent “monoclonal antibody” claim was enabled for humanized mabs and, presumably, was understood to cover humanized mabs.  Should cancelling a dependent claim change this determination or understanding? 

Yeda’s patent may be invalid because it fails to satisfy the written description requirement, but to say it doesn’t cover humanized mabs may be a stretch.

It is an old adage that “hard cases make bad law.”  UCB v. Yeda may very well be an example of this.  Time will tell whether it is limited to the facts of this case or whether it is applied more generally.  In the meantime, pay more attention to cancellation of dependent claims…