Sun Pharma Global FZE v. Lupin Ltd.

Case Name: Sun Pharma Global FZE v. Lupin Ltd., Civ No. 18-2213 (FLW), 2021 WL 4473411  (D.N.J. Sept. 30, 2021) (Wolfson, J.) 

Drug Product and Patent(s)-in-Suit: Bromsite® (bromfenac ophthalmic solution); U.S. Patent No. 8,778,999 (“the ’999 patent”)

Nature of Case and Issue(s) Presented: The ‘’999 patent discloses: (i) bromfenac; (ii) a “flowable crosslinked carboxy-containing polycarbophil mucoadhesive polymer” vehicle, referred to as “polycarbophil”; (iii) a certain pH range; (iv) a certain viscosity range; and (v) a topical ophthalmic composition. Sun sued defendants claiming that their ANDA products infringe the ’999 patent. Defendants denied infringement and alleged that the ’999 patent was invalid as obvious and indefinite, and unenforceable because Dr. Bowman, who prosecuted the patent before the PTO, failed to submit prior art he invented. After a five-day Zoom trial, the court found that defendants’ ANDA products do not literally infringe, and that the patent is invalid as obvious and indefinite. The court further found that Dr. Bowman had not engaged in inequitable conduct.

Why Defendants Prevailed: On the issue of infringement, except for viscosity, the ANDA by its terms meets every limitation in Claim 1 of the ’999 patent. Viscosity hinges on whether a solution is Newtonian or non-Newtonian. Polycarbophils such as Bromsite are non-Newtonian. The viscosity of non-Newtonian solutions varies with force and time, like ketchup or toothpaste. Water is an example of a Newtonian fluid; it does not react to any force it experiences. Thus, the equipment, conditions, and parameters for testing non-Newtonian viscosity is critical. The ’999 patent discloses two methods for measuring viscosity. The court found that “when a patent specifies a testing method, … the method in the patent is the only salient comparator for purposes of determining infringement, unless it is identifiable as part of a POSA’s general background knowledge based on a convention in the field of standard industry practice.” The ANDA specifies a viscosity between 200 and 400 cps, well below the range disclosed in the ’999 patent. But defendants’ in-house testing involved different methods and different parameters when compared to the ’999 patent. Therefore, the ANDA is not dispositive, and the only evidence in the record is Sun’s independent testing. While it applied the right method, the court found that Sun’s testing was unreliable because it did not report the time before taking measurements.

On the issue of indefiniteness, the court found that the viscosity testing method in the ’999 patent did not specify a minimum or maximum spinning time before taking a viscosity reading. All experts agreed that viscosity cannot reliably be measured or compared without comprehensive, precise information on the testing environment. Therefore, “the ’999 patent leaves a POSA who attempts to match its viscosity range to establish infringement, or to distinguish a product as non-infringing, to consult the unpredictable vagaries of any one person’s opinion without objective boundaries on spin time.” That does not satisfy the “reasonable certainty” standard under Nautilus, and the patent is indefinite.

On the issue of obviousness, the court found that the ’999 patent was obvious in view of the Bowman reference. Bowman discloses sustained-release ophthalmic polycarbophil compositions having a low viscosity and pH of greater than about 6.7. Bowman does not mention bromfenac. But claim 9 of Bowman broadly discloses any medicament “that is lipophilic and has a log partition coefficient of at least 2, preferably 3.” Additionally, when Dr. Bowman filed the ’999 patent in March 2009, the FDA had approved just five NSAIDs for use in topical ophthalmic solutions. Not only was bromfenac one, but it was “the darling” of the group because it had “highly effective anti-inflammatory activity,” “rapid onset,” and an “excellent safety profile.” “In other words, to a POSA in March 2009, there could be little doubt that bromfenac would apply in the Bowman formulation.”

Finally, on the issue of inequitable conduct, the court relied on three reasons why the patent was not unenforceable. First, defendants do not point to any falsehood that might render the declaration in question necessarily material or misleading. Second, it was unclear why the declarant would have thought to inform the Examiner that a formulation’s polycarbophil concentration also has an effect on viscosity given that the Examiner raised a pH-specific objection. And third, defendants’ expert opinion that the declarant overstated the relationship between pH and viscosity was not supported by the evidentiary record. The expert offered no data or literature to dispute the viscosity measurements the declarant submitted to show that pH changes in the bottle cause even “significant and meaningful” viscosity changes in the eye.