Post-Amgen Claiming Techniques in Focus

Last year’s landmark decision in Amgen V. Sanofi emphasized that “the more a party claims, the broader the monopoly it demands, the more it must enable.” That is, particularly when claiming a broad genus of antibodies, the specification cannot be a research assignment to engage in trial and error as to the recited claim scope.

Since that time and perhaps dealing with inadequate specifications filed prior to Amgen, prosecutors have considered whether fallback claiming techniques such as Jepson format claiming or mean-plus-function formatted claims can at least secure some protection in the case where broader claims fail.

The USPTO is now committed to providing clarity on these topics in In re Xencor.

In an ex parte appeal from a decision of the Patent Trial & Appeal Board (PTAB) in In re Xencor (application 16/803,690), one of the disputed issue relates to the level off 112 enablement of certain antibody claims when presented in Jepson format or MPF format. On appeal, the 112 rejection of the examiner was upheld.

On rehearing the applicant emphasized the difference between Jepson and MPF formatted claims and asserted that these differences were overlooked by the PTAB in its earlier decision.

In its Rehearing Decision the PTAB panel rejected these arguments explaining (PTAB decisions and rehearing request here):

In sum, we do not agree with Appellant that a different standard for
compliance with the written description requirement should be applied to an
antibody claim simply because the claim is written in means-plus-function
format. It is inconsistent to arrive at a different result for an antibody claim
comprising a means-plus-function element than for claim reciting the same antibody element without invoking§ 112(f).

Clearly, when you claim less, the necessary scope of enablement is less per the Amgen quote above. While a different standard of compliance is not applied, different levels of disclosure may satisfy the general antibody claim as between its MPF version. As to the second sentence when invoking MPF claim scope, unrecited structure is necessarily infused to the claim; unlike general functional claiming practices. The distinction between structure and function is critical in this context. (There is also some dispute by the panel if the single example of the specification provided adequate structure)

As to Jepson format, appellant argued that preamble was limited to administration, and not any level of efficacy. That is, if the claimed limitation of “method of treating a patient” is construed as limiting, claim 8 would still have written description support. In rejecting this argument the Board explained:

The Specification discloses the “need” met by the Specification
is to “combine variants with improved pharmacokinetic properties with
variants comprising modifications to improve efficacy.” Appellant’s statement that the claim does not require effectiveness or efficacy is incorrect because it does not consider what is described in the Specification and the stated need met by the invention.

Stated another way, the Board appears to conclude that the Jepson preamble can’t be limiting where the specification has a broader teaching. This would essentially conflate the claim language with the specification. Perhaps the Board was attempting to argue that the preamble itself is incomplete as the invention is focused only on efficacy. But, as written, the statement that the specification trumps the claim language is plainly wrong.

Today, the CAFC ordered (here) a remand of this appeal back to the USPTO at the request of the Solicitor. The Solicitor explained (here):

Xencor’s pending claims present novel questions involving the application
of the Supreme Court’s and this Court’s precedent for both Jepson-format and
means-plus-function claims in the field of biotechnology, and in particular the
antibody art. The use of Jepson format and means-plus-function claiming in the life sciences is exceedingly rare. Therefore, the USPTO seeks remand in order to issue a revised decision that clearly and thoroughly expresses the Agency’s view on application of the case law to this important area of technology. A revised decision will allow this Court to provide more effective review. . . .

The USPTO has established the Appeals Review Panel (ARP), which may be convened by the Director sua sponte to review decisions of the PTAB in ex
parte
appeals, reexamination appeals, and reissue appeals.. The ARP consists of three panel members who are, by default, the Director, the Commissioner for Patents, and the Chief Judge of the PTAB. Id

(internal link omitted to process explanation omitted)

While perhaps rare pre-Amgen, these claim drafting practices may be given new life going forward.

It is less than clear to me if the facts here would support a different outcome regardless of the claim scope. But at the very least the ARP will clarify the imprecise statements of law in this decision. Stay tuned.