In Allergan Sales, LLC v. Sandoz, Inc., (Fed. Cir. 2018-2207, Aug. 29, 2019), the Federal Circuit held that “wherein” clauses in a patent claim were limitations because the “wherein” elements were material to patentability. In doing so, the court affirmed the grant of a preliminary injunction blocking Sandoz from marketing a generic version of Allergan’s ophthalmic drug Combigan®.  

The Parties and Patents-in-Suit

Appellees Allergan Sales, LLC and Allergan, Inc. (together Allergan) sued Sandoz, Inc. and Alcon Laboratories, Inc. (together Sandoz) asserting that Sandoz’ Abbreviated New Drug Application (“ANDA”) for a generic version of Combigan® infringes Allergan’s U.S. Patent Nos. 9,77,453 (the ‘453 Patent), 9,907,801 (the ‘801 Patent), and 9,907,802 (the ‘802 Patent). 

The patents-in-suit share a common specification that relates to topical ophthalmic use of brimonidine in combination with timolol for the treatment of glaucoma or ocular hypertension. The preferred combination is from 0.01 to 0.5 percent by weight brimonidine and from 0.1 to 1.0 percent by weight timolol solution in water at a pH of 4.5 to 8.9. The court relied upon the ‘453 Patent for ease of reference in rendering its decision. Independent claim 1 of the ’453 Patent is representative and recites:

“A method of treating a patient with glaucoma or ocular hypertension comprising topically administering twice daily to an affected eye a single composition comprising 0.2% w/v brimonidine tartrate and 0.68% w/v timolol maleate, wherein the method is as effective as the administration of 0.2% w/v brimonidine tartrate monotherapy three times per day and wherein the method reduces the incidence of one o[r] more adverse events selected from the group consisting of conjunctival hyperemia, oral dryness, eye pruritus, allergic conjunctivitis, foreign body sensation, conjunctival folliculosis, and somnolence when compared to the administration of 0.2% w/v brimonidine tartrate monotherapy three times daily.”

Column 9, line 16 to column 10, line 7 (emphases added).

The specification noted that other ingredients may be desirable such as preservatives and viscosity building agents. Slip Op. at 3, citing column 2, lines 46-49 of the ‘453 Patent. It also reported on a study that compared the safety and efficacy of twice-daily (BID) dosed brimonidine 0.2% and timolol 0.5% combination with twice-daily dosed timolol 0.5% and three-times daily (TID) dosed 0.2% brimonidine ophthalmic solution in patients with glaucoma or ocular hypertension. The claimed composition concluded that the formulation with brimonidine and timolol was more effective than solo administration of either drug, and had a comparable safety profile to timolol BID and better than brimonidine TID. The superior result of the combined formulation was reflected in the two “wherein” clauses that the court construed.

An Issue of Claim Construction

In construing the claims, the district court found that the “wherein” clauses are claim limitations because “they are material to patentability and express the inventive aspect of the claimed invention.” Slip Op. at 6. The court dismissed Sandoz’ argument that the “wherein” clauses merely state the intended result of administering the formulation and therefore not material. Id. 

The Federal Circuit, in affirming the district court’s construction and ultimate grant of the preliminary injunction, noted that “[t]he specification of the Patents-in-Suit demonstrates that the claimed invention is ultimately a formulation (and methods of using that formulation) that allows for increased efficiency and safety i.e., a decreased risk of adverse events.” Slip Op. at 8, citing the ’453 Patent at column 1, lines 48-53. In addition, the court stated that:

“in distinguishing the claimed methods over the prior art, Allergan explained that the prior art does nothing to teach or suggest that the claimed fixed combination of brimonidine tartrate and timolol maleate administered twice daily would be as effective as the administration of 0.2% w/v brimonidine tartrate monotherapy three times per day, nor that administration of the claimed fixed combination would cause an unexpected reduction in adverse events.”

Slip Op. at 9. 

The court determined that prosecution history demonstrated that the formulation’s safety and efficacy captured by the “wherein” clauses “were expressly relied on to define the claimed methods and distinguish them from the prior art.” Slip Op. at 10.

Chief Judge Prost’s Concurrence

Chief Judge Prost concurred with Circuit Judge Wallach’s opinion, but wrote to make the point that the majority’s opinion did not address the plain language of the claim and the failure of Sandoz’s argument that the clauses do not merely describe the results that occur when the claimed dosage is administered. Chief Judge Prost noted that Sandoz provided no evidence how either of the wherein clauses merely state the results of the method. Chief Judge Prost also noted  that the open language of the claim indicates that other compositions (e.g., solvents, buffers, preservatives) can be present and that Sandoz provided no evidence “how the recited dosages of brimonidine … and timolol … will necessarily achieve these results if these other formulations parameters vary… Sandoz provides no basis for us to conclude with any certainty that the safety and efficacy requirements of the ‘wherein’ clauses would always result from two dosages of (1) any formulation of the combination at (2) any interval in a 24-hour period.” Concurrence at 4. 

Chief Judge Prost also wrote to “offer one final point about the importance of the plain language of the claim here.” Concurrence at 9. The judge characterized Sandoz’ effort to label the wherein clauses as intended results as an attempt

“to start from a place of uncertainty about whether most of the text in the body of the claim is limiting. Accepting that invention threatens the broader notice function of the patent claim…. 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 the claim. Given the specificity, clarity, and material limits the ‘wherein’ clauses add to the scope of claim 1 on their face, Sandoz’s position deserves rigorous scrutiny from the start.”

Concurrence at 9.