Amgen Inc. v. Amneal Pharm. LLC

945 F.3d 1368

AMGEN INC., Plaintiff-Appellant

v.AMNEAL PHARMACEUTICALS LLC, Amneal Pharmaceuticals of New York LLC, Piramal Healthcare Uk Limited, Defendants-Appellees

Zydus Pharmaceuticals (USA) Inc., Cadila Healthcare Ltd., dba Zydus Cadila, Defendants-Cross-Appellants

2018-2414, 2019-1086

United States Court of Appeals, Federal Circuit.

Decided: January 7, 2020

Bradford J. Badke, Sidley Austin LLP, New York, NY, argued for plaintiff-appellant. Also represented by Sona De ; Lauren Cranford Katzeff, Joshua John Fougere, Ryan C. Morris, Washington, DC; Eric Michael Agovino, Lois Kwasigroch, Wendy A. Whiteford, Amgen Inc., Thousand Oaks, CA; Alicia Alexandra Rose Russo, Fitzpatrick, Cella, Harper & Scinto, New York, NY; John Dennis Murnane, Joshua Rothman, Venable LLP, New York, NY.

Jacob M. Holdreith, Robins Kaplan LLP, Minneapolis, MN, argued for defendants-appellees Amneal Pharmaceuticals LLC, Amneal Pharmaceuticals of New York LLC. Also represented by Brenda L. Joly, Kelsey Mcelveen; Oren D. Langer, New York, NY.

Aaron Barkoff, McAndrews, Held & Malloy, Ltd., Chicago, IL, argued for defendant-appellee Piramal Healthcare UK Limited. Also represented by Alejandro Menchaca.

Steven Arthur Maddox, Maddox Edwards, PLLC, Washington, DC, argued for defendants-cross-appellants. Also represented by Jeremy J. Edwards, Matthew C. Ruedy, Kaveh Saba ; Christopher Casieri, McNeely Hare & War LLP, Princeton, NJ; William Hare, Renita Sybil Rathinam, Washington, DC.

Before Newman, Lourie, and Taranto, Circuit Judges.

Lourie, Circuit Judge.

Amgen appeals from the district court’s judgment that Amneal Pharmaceuticals LLC and Amneal Pharmaceuticals of New York LLC (collectively, "Amneal") does not infringe claims 1, 2–4, 6, 8–12, and 14–18 of U.S. Patent 9,375,405 ("the ’405 patent"), Piramal Healthcare UK Ltd. ("Piramal") does not infringe claims 1–6 and 8–20. Zydus Pharmaceuticals (USA) Inc. and Cadila Healthcare Ltd. (collectively, "Zydus") cross-appeals from the court’s judgment that they infringe claims 1–4, 6, 8–9, 15–17, and 19 of the ’405 patent. Amgen Inc. v. Amneal Pharm. LLC , 328 F. Supp. 3d 373 (D. Del. 2018) (" Decision "). We conclude that the district court construed the claims incorrectly and erred in its analysis of infringement by Amneal. However, the court properly applied prosecution history estoppel to Amgen’s arguments regarding Piramal and otherwise did not err in its fact findings for Zydus. Thus, we vacate and remand the district court’s judgment as to Amneal and affirm with respect to Piramal and Zydus.

BACKGROUND

Amgen holds approved New Drug Application No. 21688 for Sensipar ®, a formulation of cinacalcet hydrochloride used to treat secondary hyperparathyroidism in adult patients with chronic kidney disease who are on dialysis and to treat hypercalcemia in patients with parathyroid cancer and primary and secondary hyperparathyroidism. Amneal, Piramal, and Zydus each filed an Abbreviated New Drug Application (ANDA) seeking to enter the market with a generic version of Sensipar ®, and Amgen brought suit against each ANDA filer in the District of Delaware alleging that the proposed ANDA products would infringe the ’405 patent.

The ’405 patent is directed to a rapid dissolution formulation of cinacalcet. Amgen asserted different claims against each defendant, but the parties stipulated that the infringement findings for claim 1 would extend to the majority of the remaining claims.¹ Stipulation and Proposed Order Regarding Infringement, Amgen Inc. v. Aurobindo Pharma Ltd., No. 1:16-cv-00853-MSG (D. Del. Mar. 23, 2018); J.A. 2805–08. Claim 1 recites:

A pharmaceutical composition comprising:

(a) from about 10% to about 40% by weight of cinacalcet HCl in an amount of from about 20 mg to about 100 mg;

(b) from about 45% to about 85% by weight of a diluent selected from the group consisting of microcrystalline cellulose, starch, dicalcium phosphate, lactose, sorbitol, mannitol, sucrose, methyl dextrins, and mixtures thereof,

(c) from about 1% to about 5% by weight of at least one binder selected from the group consisting of povidone, hydroxypropyl methylcellulose, hydroxypropyl cellulose, sodium carboxymethylcellulose, and mixtures thereof; and

(d) from about 1% to 10% by weight of at least one disintegrant selected from the group consisting of crospovid[o]ne, sodium starch glycolate, croscarmellose sodium, and mixtures thereof,

wherein the percentage by weight is relative to the total weight of the composition, and wherein the composition is for the treatment of at least one of hyperparathyroidism, hyperphosphonia, hypercalcemia, and elevated calcium phosphorus product.

A. Prosecution History

The prosecution history is particularly relevant to the instant appeal. The ’405 patent issued from U.S. Patent Application 12/942,646 ("the ’646 application"). As originally filed, the ’646 application contained only one claim, which recited a "pharmaceutical composition comprising an effective dosage amount of a calcium receptor-active compound and at least one pharmaceutically acceptable excipient, wherein" the composition achieved a specific dissolution profile. J.A. 9171. Amgen filed a Preliminary Amendment, which cancelled claim 1 and added new claims 2–24. Newly filed claim 2, which ultimately issued as claim 1, recited a pharmaceutical composition comprising specific ranges, by weight, of cinacalcet and various excipients:

A pharmaceutical composition comprising:

(a) from about 10% to about 40% by weight of cinacalcet HCl;

(b) from about 45% to about 85% by weight of a diluent selected from the group consisting of microcrystalline cellulose, starch, dicalcium phosphate, lactose, sorbitol, mannitol, sucrose, methyl dextrins, and mixtures thereof,

(c) from about 1% to about 5% by weight of at least one binder; and

(d) from about 1% to 10% by weight of at least one disintegrant,

wherein the percentage by weight is relative to the total weight of the composition.

J.A. 9382 (emphasis added).

The Examiner rejected the claims under 35 U.S.C. § 103 over U.S. Patent 6,211,244 ("Van Wagenen") "as evidenced by" U.S. Patent 6,656,492 ("Kajiyama") in view of U.S. Patent 6,316,460 ("Creekmore") and U.S. Patent App. 2005/0147670 ("Hsu"). J.A. 9417. According to the Examiner, Van Wagenen disclosed a calcimimetic "acting on a parathyroid cell calcium receptor" that "can be used to treat diseases such a primary hyperparathyroidism and secondary hyperparathyroidism," J.A. 9417–18, and, while Van Wagenen failed to disclose the required amounts of various excipients, Creekmore and Hsu taught those limitations.

In response to this Office Action, Amgen filed an amendment narrowing the cinacalcet limitation to recite "from about 10% to 40% by weight of cinacalcet HCl in an amount of from about 20 mg to about 100 mg" ("Cinacalcet Amendment"). J.A. 9433. In support of this amendment, Amgen explained that the now narrower range of cinacalcet would not have been obvious in view of the teachings of Van Wagenen, which taught a broader range that "would translate to 0.62 mg to 3100 mg for an average human." J.A. 9438–40.

After the Cinacalcet Amendment, the Examiner conducted a telephone interview with Amgen’s counsel, and Amgen accepted an amendment proposed by the examiner ("Examiner’s Amendment"). J.A. 9464. The Examiner’s Amendment revised the binder and disintegrant limitations into their current, Markush group format. The Examiner then allowed the claims, stating that the closest prior art did not disclose or render obvious the "combination of components ... in the amounts ... set forth in claim 2." J.A. 9462.

Following the Notice of Allowance, Amgen filed a number of Requests for Continued Examination providing various additional references and updating the U.S. Patent and Trademark Office on the revocation of a related patent after opposition proceedings in the European Patent Office, J.A. 9472–509, 9643–659. The Examiner issued a Notice of Allowance after each Request. While the second of the Requests was pending, Amgen submitted a "Preliminary Amendment." J.A. 10701. This amendment recited the claims exactly as they were allowed but underlined the language that had been proposed by the Examiner in the Examiner’s Amendment. In accompanying documentation, Amgen remarked that "[t]hese amendments have not been made in response to a prior art rejection but rather to place the claims in proper format and to better define the claimed subject matter, including equivalents." J.A. 10707.

B. District Court Proceedings

In the district court litigation, the construction of the binder and disintegrant Markush groups was a key issue. Oddly, neither party sought construction of the binder and disintegrant groups during claim construction. But the proper construction of the Markush groups was placed at issue in the context of pretrial preparations. In its proposed pretrial order, Amgen argued that the Markush groups should be open to unrecited elements, but the district court disagreed. Relying on Multilayer Stretch Cling Film Holdings, Inc. v. Berry Plastics Corp. , 831 F.3d 1350 (Fed. Cir. 2016), the court held that "Amgen ha[d] not overcome the very strong presumption that the Markush groups for the binder and disintegrant elements are closed to unrecited binders and disintegrants." Amgen Inc. v. Aurobindo Pharma, Ltd. , No. 16-cv-853, 2018 WL 1061369, at *3 (D. Del. Feb. 27, 2018) (" Pretrial Order "). Amgen sought reargument on this claim construction issue, but the court again rejected its positions. Amgen Inc. v. Amneal Pharm. LLC , No. 16-cv-853, 2018 WL 1885664, at *7–8 (D. Del. Apr. 19, 2018) (" Reargument Order ").

The district court held a bench trial on the issue of infringement.² The court held that Amneal and Piramal do not infringe any claim of the ’405 patent but found that Zydus infringes claims 1–4, 6, 8–9, 15–17, and 19.

First, the district court found that Amneal does not infringe the asserted claims because its product does not meet the binder and...