The opinion of the court was delivered by: Judge Robert M. Dow, Jr.
MEMORANDUM OPINION AND ORDER
Plaintiffs Bone Care International, LLC and Genzyme Corporation (collectively "Plaintiffs") brought this patent infringement suit against Defendants Pentech Pharmaceuticals, Inc. and Cobrek Pharmaceuticals, Inc. (collectively "Defendants") for infringement of United States Patent No. 5,602,116 (the "' 116 patent"). On March 31, 2010, the Court held a tutorial and claim construction hearing, at which time it heard evidence and argument regarding the construction of various claim terms in the ' 116 patent. The claim construction issues also have been extensively briefed. Currently before the Court are Plaintiffs' Opening Claim Construction Brief , Defendants'Claim Construction Brief , Plaintiffs'Reply Claim Construction Brief , and Defendants' Surreply Claim Construction Brief . The Court' s construction of the disputed claim is set forth below.
The ' 116 patent, entitled "Method for Treating and Preventing Secondary Hyperparathyroidism," describes a method for preventing loss of bone mass or bone mineral content in persons suffering from secondary hyperparathyroidism using certain vitamin D analogs. In particular, the claimed invention relates to the treatment of patients having hyperparathyroidism secondary to end-stage renal disease ("ESRD"), a condition which results in a loss of bone mass. Claim 7 of the ' 116 patent -- the only that claim the parties have asked the Court to construe -- is directed to a method for the treatment of such patients using 1α-OH-vitamin D2 (which reads: one-alpha-hydroxy-vitamin D two).
Active vitamin D is essential to maintaining normal calcium and phosphorous levels in the body. In healthy people, vitamin D is activated in the kidney. When a healthy individual's calcium levels fall below normal, the parathyroid glands secrete parathyroid hormone ("PTH"), which causes two things to happen to restore the proper balance. First, PTH signals the bones to release calcium into the blood. Second, PTH signals the kidney to produce active vitamin D, which in turn signals the intestine to absorb more calcium into the blood. ESRD patients' kidneys are not able to produce sufficient active vitamin D. When a person with ESRD has low calcium levels, the kidneys cannot help to restore the balance. As a result, PTH secretion increases (a condition known as "hyperparathyroidism") and the bones release too much calcium, which leads to a loss of bone mass. The ' 116 patent "provides a method for treating or preventing hyperparathyroidism secondary to end stage renal disease by lowering (or maintaining low) serum parathyroid hormone levels in a patient suffering from the disease." ' 116 patent, col. 3, ll. 46-50.
In a patent infringement case, the court must engage in a two step analysis. Markman v. Westview Instruments, Inc., 52 F.3d 967, 976 (Fed. Cir. 1995) (en banc), aff'd, 517 U.S. 370 (1996). First, the court determines the meaning and scope of the asserted patent claims. Id. Second, the court concludes whether the accused product or device infringes on the properly construed claims. Id. The first step -- claim construction -- is a legal determination to be made by the court. Markman v. Westview Instruments, Inc., 517 U.S. 370, 391 (1996). The Federal Circuit has explained that "'
[t]he construction of claims is simply a way of elaborating the normally terse claim language in order to understand and explain, but not to change, the scope of the claims.'
" Terlep v. Brinkmann Corp., 418 F.3d 1379, 1382 (Fed. Cir. 2005).
Claims must be construed through the eyes of "the person of ordinary skill in the field of the invention." Multiform Desiccants, Inc. v. Medzam, Ltd., 133 F.3d 1473, 1477 (Fed. Cir. 1998); see also Phillips v. AWH Corp., 415 F.3d 1303, 1313 (Fed. Cir. 2005) ("The inquiry into how a person of ordinary skill in the art understands a claim term provides an objective baseline from which to begin claim interpretation."). With that mindset, courts "look to the intrinsic evidence, including the claim language, written description, and prosecution history, as well as to extrinsic evidence" in construing claims. TIP Sys., LLC v. Phillips & Brooks/Gladwin, Inc., 529 F.3d 1364, 1369 (Fed. Cir. 2008).
The Federal Circuit has directed courts to "look first to the intrinsic evidence of record, i.e., the patent itself, including the claims, the specification and, if in evidence, the prosecution history." Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996). The analysis begins with the words of the claims themselves, which generally are given their ordinary and customary meaning. Id. "[T]he ordinary and customary meaning of a claim term is the meaning that the term would have to a person of ordinary skill in the art in question at the time of the invention." Phillips, 415 F.3d at 1313.
The second place to which a court looks in construing claims is the specification, in part to determine whether the inventor has redefined any claim terms. Vitronics, 90 F.3d at 1582. The Federal Circuit has explained that, because claims "are part of ' a fully integrated written instrument,'* * * [they] 'must be read in view of the specification of which they are a part.'
" Phillips, 415 F.3d at 1315 (quoting Markman, 52 F.3d at 978-79). Therefore, "the specification is always highly relevant to the claim construction analysis." Vitronics, 90 F.3d at 1582. Indeed, the Federal Circuit has advised that the specification "is the single best guide to the meaning of a disputed term," and, therefore, "[u]sually, it is dispositive." Id.
Nevertheless, while "the claim language must be examined in light of the written description," the Federal Circuit repeatedly has admonished courts not to read "limitations * * * into the claims from the written description." Prima Tek II, L.L.C. v. Polypap, S.A.R.L., 318 F.3d 1143, 1148 (Fed. Cir. 2003). In the same vein, the Federal Circuit "has cautioned against limiting the claimed invention to preferred embodiments or specific examples in the specification." Texas Instruments, Inc. v. United States Int'l Trade Comm'n, 805 F.2d 1558, 1563 (Fed. Cir. 1986). The line between reading a claim in light of the specification, and reading limitations into the claim from the specification is a fine one. Comark Commc'ns, Inc. v. Harris Corp., 156 F.3d 1182, 1186 (Fed. Cir. 1998). To "discern[ that line] with reasonable certainty and predictability[,] * * * the court' s focus [must] remain on understanding how a person of ordinary skill in the art would understand the claim terms." Phillips, 415 F.3d at 1323.
The third type of intrinsic evidence that the Court may consider, if it is available, is the prosecution history. Phillips, 415 F.3d at 1323. However, the Federal Circuit has recognized that, "because the prosecution history represents an ongoing negotiation between the PTO and the applicant, rather than the final product of that negotiation, it often lacks the clarity of the specification and thus is less useful for claim construction purposes." Id. at 1317.
If, after reviewing the intrinsic evidence, ambiguity remains regarding the meaning of disputed claim terms, the court may consider extrinsic evidence, including dictionaries, treatises, and expert testimony. Phillips, 415 F.3d at 1317; see also Vitronics, 90 F.3d at 1584 ("[o]nly if there [is] still some genuine ambiguity in the claims, after consideration of all available intrinsic evidence, should the trial court * * * resort to extrinsic evidence"). However, extrinsic evidence generally is considered to be "less reliable" than intrinsic evidence and "unlikely to result in a reliable interpretation of patent claim scope unless considered in the context of the intrinsic evidence." Phillips, 415 F.3d at 1318-19.
The sole claim that the parties have asked this Court to construe is claim 7, which provides:
A method for lowering or maintaining lowered serum parathyroid hormone in human patients suffering from hyperparathyroidism secondary to end stage renal disease, comprising: administering to said patients an effective amount of 1α-OH-vitamin D2 to lower and maintain lowered serum parathyroid hormone levels.*fn1 The parties offer conflicting constructions of five claim terms: (i) "lowering or maintaining lowered serum parathyroid hormone;" (ii) "in human patients suffering from;" (iii) "hyperparathyroidism;" (iv) "end stage renal disease;" and (v) "an effective amount of 1α-OH-vitamin D2 to lower and maintain lowered serum parathyroid hormone levels." The parties also dispute the proper definition of a person of ordinary skill in the art ("POSA") for purposes of the ' 116 patent.
The parties offer relatively similar characterizations of a POSA. Plaintiffs define a POSA as a person working in the field of kidney diseases and, specifically, someone with a medical degree who was Board certified in nephrology or endocrinology; or someone having a Ph.D. in biochemistry and at least two years of experience in the field of vitamin D drug discovery. Defendants define a POSA along the same lines, except that they contend that a POSA is someone with both a medical degree and a Ph.D. During the claim construction hearing, counsel for both sides indicated that their disagreement regarding the definition of a POSA should not affect the Court' s claim construction decision, in that each party maintains that their construction is correct regardless of which definition of a POSA the Court ultimately employs. Therefore, the Court need not determine at this stage whether a POSA must possess both a medical degree and a Ph.D. For purposes of claim construction, the Court will employ the lower of the two proposed thresholds, and will define a POSA as a person working in the field of kidney diseases who either possesses a medical degree and was Board certified in nephrology or endocrinology, or possesses a Ph.D. in biochemistry and has at least two years of experience in the field of vitamin D drug discovery.
B. Lowering or Maintaining Lowered Serum Parathyroid Hormone
Defendants contend that the phrase "lowering or maintaining lowered serum parathyroid hormone" is sufficiently straightforward, and need not be construed by the Court. Plaintiffs propose construing the phrase as "reducing elevated blood concentrations of parathyroid hormone (PTH) or maintaining blood concentrations of PTH at reduced levels." Plaintiffs' proposed claim construction does three things: (1) it replaces "lowering" and "lowered" with "reducing" and "reduced;" (2) it replaces "serum parathyroid hormone" with "blood concentrations of parathyroid hormone"; and (3) it adds that the reduction pertains to elevated concentrations of PTH.
With respect to Plaintiffs'first two proposals, the parties agree that Plaintiffs' terms are synonyms for the claim terms (i.e., that "lower" and "reduce" are synonymous, and substituted that "serum parathyroid hormone" and "blood concentrations of parathyroid hormone" are synonymous). They simply debate the usefulness of Plaintiffs' proposed substitutions.
The Court declines to construe the terms "lowering" and "lowered." The Federal Circuit has recognized that "district courts are not (and should not be) required to construe every limitation present in a patent' s asserted claims." O2 Micro Intern. Ltd. v. Beyond Innovation Technology Co., Ltd., 521 F.3d 1351, 1362 (Fed. Cir. 2008); see also Biotec Biologische Naturverpackungen GmbH & Co. KG v. Biocorp, Inc., 249 F.3d 1341, 1349 (Fed. Cir. 2001) (finding no error in refusal to construe claim term); Mentor H/S, Inc. v. Med. Device Alliance, Inc., 244 F.3d 1365, 1380 (Fed. Cir. 2001) (finding no error in court' s refusal to construe "irrigating" and "frictional heat"). The purpose of claim construction is to resolve "disputed meanings and technical scope, to clarify and when necessary to explain what the patentee covered by the claims, for use in the determination of infringement." U.S. Surgical Corp. v. Ethicon, Inc., 103 F.3d 1554, 1568 (Fed. Cir. 1997). Where the construction of a claim term does nothing to clarify or explain the patentee's invention, the court is under no obligation to construe the claim. See id. (claim construction "is not an obligatory exercise in redundancy"). The Court recognizes that "[w]hen the parties present a fundamental dispute regarding the scope of a claim term," it has a "duty to resolve it." O2 Micro Intern. Ltd., 521 F.3d at 1362. But here Plaintiffs do not contend that construing "lowering" and "lowered" as "reducing" and "reduced" ...