In Allergan Sales, LLC, Allergan Inc. v. Sandoz, Inc., Alcon Laboratories, Inc, (Allergan v Sandoz CAFC, 2018-2207, August 29, 2019) Allergan sued Sandoz for infringement over Sandoz’s ANDA for a generic version of Allergan’s Combigan®.  Sandoz countered that the asserted claims were invalid on the basis that two wherein clauses were appropriately construed as non-limiting as being directed to an intended result.  The district court disagreed and found the wherein clauses limiting, and the Federal Circuit affirmed, with a concurrence by Chief Judge Prost.

More specifically, though the majority decision states that the inquiry begins with the language of the claims, and then continues to the language of the specification and prosecution history, Chief Judge Prost writes that the majority opinion did not give enough weight to the first prong of the analysis:

In my view, the claim language on its face confirms that these clauses give meaning and purpose to the other manipulative steps of claim 1…The majority does not address the plain language of the claim.  I take the opportunity to do so here.  Allergan, concurring opinion, page 3.

First noting that Sandoz provided no intrinsic evidence supporting the argument that the wherein clauses merely describe results that occur whenever the claimed dosages are administered,

Beginning with “the words of the claim themselves,”…Sandoz has put forth no evidence how either clause “merely states the result of the limitations in the claim.”…In my view, no part of the plain text of claim 1 shows these benchmarks are an inherent result of the dosage limitations.   Allergan, majority opinion page 3.

Chief Judge Prost then states:

On their face, these clauses state specific requirement rather than a general purpose or aspirational result for the claimed method.  The efficacy clause does not simply require some general level of therapeutic effectiveness.  Instead, it specifically requires that the claimed formulation be “as effective as the administration of 0.2% w/v brimonidine tartrate monotherapy three times per day.”  … Likewise, the safety clause does not recite that the claimed method of treatment is generally intended to improve safety.  Allergan, concurring opinion, page 5.

Chief Judge Prost summarizes:

I offer one final point about the importance of the plain language of the claim here….Sandoz attempts to label over half the claim language in claim 1 as a mere “intended result.”  By doing so, Sandoz invites us to start from a place of uncertainty about whether most of the text in the body of the claim is limiting. Accepting that invitation threatens the broader notice function of the patent claim.  Allergan, concurring opinion, page 5.

And then concludes:

As it is, claim construction can be difficult.  For instance, litigants often encounter uncertainty over whether a claim’s preamble is limiting or not.  I see no reason to inject further uncertainty into the notice provided by the body of a claim…We should not begin with the presumption that text in the body of the claim may be meaningless and can only be saved by clear statements in the specification or prosecution history.

Therefore, I would affirm the district court’s decision for the reasons stated in the majority opinion, except that I would start by explaining why the claim language of the claim compels us to reject Sandoz’s position that the “wherein” clauses here are mere statements of inherent or intended results.  Allergan, concurring opinion, pages 9-10.