Orange Book Blog

GPhA Files Amicus Brief in Appeal of "Baseless Paragraph IV Certification" Case; Warns of Chilling Effect on Future Patent Challenges

Takeda v. Mylan and Alphapharm, Nos. 2007-1269, -1270 (Fed. Cir.)

In February 2006, the U.S. District Court for the Southern District of New York determined that Takeda's patent on pioglitazone, the active ingredient in ACTOS, is neither invalid for obviousness nor unenforceable due to inequitable conduct.  In the court's 124-page opinion, the court remarked, "The length of this Opinion is occasioned by the need to address the many iterations of the defendants' arguments, as they searched for a viable theory to attack the '777 patent."

Later in 2006, the court awarded $16.8 million in attorney fees to Takeda ($5.4 million from Alphapharm; $11.4 million from Mylan), finding this to be an exceptional case under 35 U.S.C. § 285.  In a 51-page opinion, the court explained that "Alphapharm and Mylan each filed baseless Paragraph IV certifications attacking the validity of the '777 Patent," in violation of the "duty of due care" ANDA filers are held to under the Hatch-Waxman Act.  Moreover, according to the court, they "each engaged in other litigation misconduct," including (by Alphapharm), "constantly shifting its theory of obviousness," in bad faith; attempting at trial to insert "entirely frivolous" arguments of inequitable conduct; and ignoring a court order and offering an untimely advice of counsel defense; and (by Mylan), acting "without a reasonable basis and in bad faith in pursuit of its inequitable conduct claim."

Alphapharm and Mylan appealed both decisions to the Federal Circuit.  In June of last year, the Federal Circuit affirmed the decision on the merits of the patent case, which will keep any generic versions of ACTOS off the market until at least 2011, when the '777 patent expires.  The appeal of the attorney fees decision has now proceeded to the briefing stage.  And, signaling that it has a "critical interest" in the case, GPhA has weighed in with its own amicus brief.

GPhA's brief asserts that the district court "placed too much weight on Mylan's and Alphapharm's decision to take the case to trial on grounds other than the particular theories of invalidity that they had stated in their respective pre-suit notice letters."  According to GPhA, "such an evolution of a defendant's litigating position is unexceptional.  Reversal is vital because this aspect of the district court's ruling will undermine the efficacy of the Hatch-Waxman scheme by deterring future ANDA filings by many companies, keeping generic drugs off the market and increasing the cost of drugs to the consumers who depend on them."  GPhA's brief addresses only this aspect of the district court decision.

Alphapharm's and Mylan's opening briefs are available below.  Takeda's opposition brief is due May 23rd; reply briefs will be due in June; and oral argument is expected to be scheduled for late fall.

More:

• Alphapharm's opening brief
• Mylan's opening brief
• 2006 article about baseless paragraph IV certifications, authored by lead counsel for Takeda

OBB News Briefs

• Last Thursday, FDA Law Blog reported on the Lupin v. Abbott case scheduled for oral argument at the Federal Circuit on Wednesday.  The case concerns a very unusual situation, where Abbott obtained two patent term extensions under 35 U.S.C. § 156 for a single drug product.
• In what is being reported as a setback for the prospects of a biosimilars industry in the United States, the FDA recently denied Genzyme's request to change the manufacturing site of its drug Myozyme.  For more: Boston Globe, Pharmalot, WSJ Health Blog.
• The L.A. Times published an interesting op-ed last week about safety concerns with biotech drugs.
• The New York Times reported last week on a lobbying fight between the brand-name and generic drug industries over inequitable conduct provisions in patent reform legislation.
• FDA Law Blog recently updated their coverage of two interesting cases: Teva vs. FDA, concerning 180-day exclusivity on Risperdal, in which Apotex filed a motion to intervene; Nu-Pharm v. FDA, Nu-Pharm's ANDA for generic Depakote, in which the D.C. Circuit summarily affirmed the district court's decision in favor of FDA.
• On April 16, a district court denied Perrigo's motion for summary judgment that its generic version of Olux (clobetasol propionate foam), a treatment for scalp psoriasis, does not infringe Connetics' U.S. Patent No. 6,126,920.
• On March 19, a district court denied Ranbaxy's motion for summary judgment that Roche's patent on Valcyte (valganciclovir HCl), U.S. Patent No. 6,083,953, is invalid due to incorrect inventorship.  Numerous other summary judgment motions are still outstanding in the case.

Barr and Caraco Win Summary Judgment that Ortho-McNeil's Formulation Patent on Ultracet is Invalid

Ortho-McNeil Pharm. v. Kali Labs., No. 06-CV-3533 (DMC)

          by Robert S. Dailey

In a decision released April 17th, the U.S. District Court for the District of New Jersey granted summary judgment that certain claims of U.S. Patent No. RE39,221 are invalid as obvious. The '221 patent claims combinations of acetaminophen and tramadol, marketed by Ortho-McNeil (OMI) as Ultracet.  Barr and Caraco are challenging the patent.

OMI had previously asserted U.S. Patent No. 5,336,691 (the predecessor patent to RE39,221) against Barr and Kali. In early 2007, the district court granted summary judgment that the asserted claims of the '691 patent were invalid as anticipated and obvious.

While the litigation over the '691 patent was pending, OMI surrendered the '691 patent and requested a reissue from the USPTO. When the '691 patent reissued in 2006 as the '221 patent, OMI filed suit against Kali, Barr, Par and Caraco.  By that time, several of the defendants were already selling generic versions of Ultracet.

As part of the reissue, OMI obtained new claims that were less likely to be found invalid or not infringed. Therefore, it was unclear whether the generic companies would be able to knock out the claims of the '221 reissue patent.  In July 2007, Par and Kali decided not to take that risk, and settled their litigation with OMI, agreeing to cease selling their generic products by November of last year.  Barr and Caraco remained in the litigation.

The asserted claims of the '221 patent are directed to a formulation "consisting essentially of" a tramadol-to-acetaminophen ratio that ranges from about 1:5 to about 1:19. Ultracet has a ratio of 1:8.67.

This month's decision largely draws from the 2007 summary judgment that invalidated the claims of the '691 patent as obvious and anticipated. Both opinions rely on U.S. Patent No. 3,652,589, which discloses various embodiments of a four-agent tablet that includes acetaminophen and tramadol as two of the active ingredients. In particular, the '589 patent discloses formulations where the acetaminophen-to-tramadol ratio falls within the ratio range claimed in the '221 patent.

Nevertheless, the '589 patent uses "consisting of" language in its description of the pharmaceutical formulations. In an anticipation context, this "consisting of" language would prevent the '589 patent's four-agent formulations from reading on the two-agent formulations claimed in the '221 patent. But what effect should this linguistic choice have in the context of obviousness?

OMI argued that the "consisting of" language in the '221 patent would not have instructed a person of ordinary skill in the art to combine only acetaminophen and tramadol into a two-agent tablet.  The court, however, was not persuaded, concluding that "[h]ere, a person of ordinary skill in the art would not be misled by the 'consisting of' language."

Essentially, OMI appears to have argued that the "consisting of" language is an instance of "teaching away" from the two-agent formulations claimed in the '221 patent.  But is it? Does one of skill in the relevant art have knowledge of patent lingo, such as the distinction between "comprising" and "consisting of"? If not, then the district court may be correct. This does pose an interesting question, though. "Teaching away," after all, is evaluated from the perspective of one of skill in the relevant art, and not from the perspective of a patent lawyer having ordinary skill in the relevant art.

The court also cited another piece of prior art that disclosed a three-agent formulation that included acetaminophen and tramadol in ratios similar to those claimed in the '221 patent. No "teaching away" appeared in this second reference. Thus, the Federal Circuit could affirm the judgment without having to consider whether "consisting of," as recited in the '589 prior art patent, can constitute teaching away.

District Court Upholds Validity of Takeda's Patents on Prevacid, Rejecting Teva's Obviousness Arguments

Takeda Pharma. v. Teva Pharms. USA, No. 06-033-SLR (D. Del. 2008)

Following a week-long bench trial held last year, the U.S. District Court for the District of Delaware released an opinion on March 31st stating that Takeda's patents on Prevacid (lansoprazole) are valid and that Teva's ANDA for a generic version of Prevacid capsules infringes one of the patents.  Prevacid, a treatment for acid reflux, heartburn and stomach ulcers, had $3.4 billion in U.S. sales last year.

Takeda asserted U.S. Patent Nos. 4,628,098, covering the lansoprazole compound, and 5,045,321, covering a pharmaceutical composition of lansoprazole, against Teva.  Teva conceded that its generic drug product infringes the '098 patent, though it contested infringement of the '321 patent.  Moreover, Teva argued that the '098 and '321 patents are invalid for obviousness and unenforceable due to inequitable conduct.

Lansoprazole is a member of a class of drugs known as proton pump inhibitors, or PPIs, which prevent stomach cells from pumping acid into the gastrointestinal tract.  The first PPI was timoprazole, which was disclosed and claimed in a patent in 1977.  Timoprazole is the basic molecular skeleton upon which every subsequent successful PPI has been based, including omeprazole and lansoprazole.  Teva asserted that the lansoprazole compound would have been obvious in view of the prior art disclosure of the timoprazole backbone and the methyl and trifluoroethoxy fluorinated substituents in lansoprazole.

The district court began its analysis of Teva's obviousness argument by citing KSR: "Teva must identify some reason that would have prompted a person of ordinary skill in the relevant field to combine these elements to yield the claimed compounds."  The court found that while a person "would have started with a timoprazole skeleton and focused on the four key locations on the skeleton," Teva failed to prove there would have been a motivation "to substitute the trifluoroethoxy substituent, found previously on the benzimidazole ring in the compounds of the [prior art] patent, onto the 4-position of the pyridine ring to form lansoprazole . . . or would have had any reasonable expectation of success in doing so."  Thus, the court rejected Teva's argument that the '098 patent would have been obvious.

The court also rejected Teva's argument that the '321 patent, which claims a lansoprazole formulation comprising a basic inorganic salt (to stabilize the active ingredient), would have been obvious.  However, the court found that the lansoprazole and magnesium carbonate in Teva's product are not "in contact . . . evenly," as required by the claims, and therefore Teva does not infringe the '321 patent.

Finally, the court found Teva's inequitable conduct arguments to be meritless.

Teva immediately announced plans to appeal the district court decision to the Federal Circuit.  If the decision is upheld on appeal, Teva will have to wait until at least May 2009, when the '098 patent expires, to market its generic version of Prevacid capsules.

RELATED READING:

• Bloomberg

OBB News Briefs

• Last Monday, the Federal Circuit affirmed a district court decision in McNeil-PPC v. Perrigo, concerning a generic version of Pepcid Complete.  The decision was affirmed without an opinion, under Rule 36.
• Tuesday, AstraZeneca and Ranbaxy announced a settlement of their patent litigation over generic Nexium (esomeprazole), with Astra granting Ranbaxy exclusive rights to sell a generic version of Nexium in 2014, six months before the first patent expires.  Teva and Dr. Reddy's plan to continue challenging Astra's patents.  Astra press release; Ranbaxy press release; AP; Bloomberg; Pharmalot; WSJ Health Blog.
• In a very surprising decision, a D.C. district court recently ruled in favor of Teva in a case in which Teva alleged that the FDA wrongfully delisted a patent on Risperdal (risperidone) from the Orange Book, depriving Teva of 180-day exclusivity.  FDA Law Blog has a full report.
• Earlier this month, Depomed announced a settlement of patent litigation against Teva over generic Glumetza (metformin HCl).  Depomed press release; AP story.
• Pharmalot recently had two interesting posts about biosimilars: the first suggested, based on a report about the Food and Drug Law Institute's annual meeting, that biosimilars legislation may actually be passed this year; the second reported on lobbying for a biosimilars bill.
• FDA Law Blog recently updated their coverage of the generic Depakote (divalproex sodium) litigation between Nu-Pharm (a former subsidiary of Apotex) and FDA, in which Nu-Pharm is seeking an injunction requiring FDA to grant final approval to its divalproex ANDA.
• Pharmalot posted a summary of a recent article in the Seattle Post-Intelligencer about a citizen petition that has stymied Nastech Pharmaceutical's bid to market a generic version of Miacalcin (calcitonin), a treatment for postmenopausal osteoporosis.
• Takeda announced earlier this month that on March 31, the Supreme Court denied Alphapharm's cert petition from the Federal Circuit's decision last year in the Actos (pioglitazone) litigation.

Federal Circuit Finds Declaratory Judgment Jurisdiction Despite Covenant Not to Sue

Caraco Pharm. Labs. v. Forest Labs., No. 2007-1404 (Fed. Cir. 2008)

In a 2-1 decision, the Federal Circuit held today that an ANDA applicant's declaratory judgment action for noninfringement meets Article III's "case or controversy" requirement notwithstanding that the patentee has granted the applicant a covenant not to sue.  Today's decision will likely bring a flood of new declaratory judgment claims by generic drug companies seeking a clear path to the market.  In addition, it may solve the "bottleneck problem" created when an innovator settles litigation with a first ANDA applicant but refuses to sue subsequent applicants.

The case involves Lexapro (escitalopram oxalate), Forest Labs' antidepressant drug with over $2 billion in annual sales.  Forest owns two Orange Book-listed patents on Lexapro:  U.S. Patent Nos. RE34,712 and 6,916,941.  The '712 patent claims substantially pure escitalopram, and expires in 2012; the '941 patent claims crystalline particles of escitalopram of a particular size range, and expires in 2023.

The first ANDA applicant to file paragraph IV certifications to the '712 and '941 patents was Ivax Pharmaceuticals (since acquired by Teva).  Accordingly, Ivax is entitled to 180 days of market exclusivity, which will begin either on the day it begins marketing its drug or on the day a court determines that both the '712 and '941 patents are invalid or not infringed, whichever comes first.  (This is a pre-MMA case.)  Forest sued Ivax on the '712 patent but not the '941 patent.  Last year, the Federal Circuit affirmed a district court decision that the '712 patent is valid and infringed.  Thus, Ivax is enjoined from marketing its generic Lexapro until 2012, and all subsequent ANDA applicants are blocked by Ivax's 180-day exclusivity.

After Ivax's ANDA filing, Caraco (a subsidiary of Sun Pharma) filed its own ANDA with paragraph IV certifications to the '712 and '941 patents.  Forest sued Caraco on the '712 patent but not the '941 patent.  Caraco then filed a complaint seeking a declaratory judgment that its generic version of Lexapro does not infringe the '941 patent.  Forest moved to dismiss under FRCP 12(b)(1) on the grounds that the action did not present a "case" or "controversy" as required by Article III of the Constitution.  Then, following the Federal Circuit's decision in Teva v. Novartis, Forest unilaterally granted Caraco an irrevocable covenant not to sue for infringement of the '941 patent.  Due to the covenant not to sue, the district court dismissed Caraco's complaint for lack of jurisdiction.

In reversing the district court's dismissal of the case, the Federal Circuit cited the Supreme Court's decision last year in MedImmune v. Genentech, where the Court "framed the justiciability inquiry as 'whether the facts alleged, under all the circumstances, show that there is a substantial controversy, between parties having adverse legal interests, of sufficient immediacy and reality to warrant the issuance of a declaratory judgment.'"  The Federal Circuit applied "the Supreme Court's three-part framework for determining whether an action presents a justiciable Article III controversy":  whether (1) the plaintiff has standing; (2) the issues presented are ripe for judicial review; and (3) the case is not rendered moot at any stage of the litigation.

The court determined that Caraco has standing for three reasons.  First, according to the court, Caraco alleges a judicially cognizable injury-in-fact:  "it is being excluded from selling a non-infringing product because Forest has taken actions that delay the FDA from approving Caraco's ANDA."  Second, Caraco's injury is traceable to Forest:  "Forest's listing of the '712 and '941 patents in the Orange Book effectively denies Caraco an economic opportunity to enter the marketplace unless Caraco can obtain a judgment that both those patents are invalid or not infringed by its generic drug."  Third, Caraco's injury is redressible by a favorable judgment:  "If Caraco obtains a favorable judgment that the drug described in its ANDA does not infringe Forest's '941 patent, then it will only need a judgment of invalidity or noninfringement on Forest's '712 patent in order to activate Ivax's exclusivity period and obtain FDA approval as swiftly as possible."

Interestingly, the Federal Circuit stated, in a footnote:

Although we do not so decide, it appears that if Forest would submit to a consent decree that the drug described in Caraco's ANDA does not infringe the '941 patent, such a decree would redress Caraco's alleged injury-in-fact just as well as any other court judgment.  Thus, if Forest's objective in granting the covenant not to sue on the '941 patent was to avoid costly litigation with Caraco, this might be the best approach to resolve the controversy between the parties.

The Federal Circuit further determined that the issues are ripe and the case is not moot.  Accordingly, the court held that Caraco's action presents an ongoing Article III case and controversy, reversed the district court's decision dismissing the case, and remanded the case for a decision on the merits.

Given the importance of today's decision (and the split vote--J. Friedman dissented), it would not be surprising to see the Federal Circuit review the case en banc.

RELATED READING:

• Reuters article

Federal Circuit Affirms Topamax Decision in Favor of Ortho-McNeil and Against Mylan and Cobalt

Ortho-McNeil v. Mylan, No. 2007-1223 (Fed. Cir. 2008); Ortho-McNeil v. Cobalt, Nos. 2007-1258, -1259 (Fed. Cir. 2008)

U.S. Patent No. 4,513,006 is listed in the Orange Book as protecting Topamax (topiramate), Ortho-McNeil's blockbuster anticonvulsant for the treatment of migraines and epilepsy.  Mylan and Cobalt seek to market generic versions of Topamax before the '006 patent expires in September.  Last year, a district court construed the claims of the '006 patent and, on summary judgment, rejected Mylan's inequitable conduct, obviousness, and non-enablement arguments.  The Federal Circuit affirmed those decisions today.

Claim 1 of the '066 patent is drafted in a form typical of chemical compound claims.  Specifically, it is directed to a "sulfamate of formula (I) . . . wherein . . . R2, R3, R4 and R5 are independently hydrogen or lower alkyl and R2 and R3 and/or R4 and R5 together may be a group of formula (II) . . . ."  Mylan argued that the district court improperly construed the term "and" to mean "or" and, under the proper construction, the claim does not cover topiramate.  The Federal Circuit disagreed, reasoning, among other things, that "and appears in conjunction with the adverbs independently and together . . . [signaling] that and links alternatives that occur under the different conditions of independence or togetherness."

With respect to invalidity, the district court decision, released last February (before KSR), relied fairly heavily on the "teaching-suggestion-motivation" ("TSM") test to find the claims of the '066 patent invalid as obvious.  Accordingly, one might think this decision would be ripe for reversal.  Nevertheless, the Federal Circuit affirmed the decision, noting that "a flexible TSM test remains the primary guarantor against a non-statutory hindsight analysis such as occurred in this case."

According to the court's opinion, Ortho-McNeil scientist Dr. Bruce Maryanoff invented topiramate during a search for new antidiabetic drugs, when he "unexpectedly" . . . discovered that the compound had "powerful anticonvulsant properties."  In support of its obviousness position, Mylan argued "that a person of ordinary skill in the art faced with finding a diabetes drug (as Dr. Maryanoff was) would necessarily design an FBPase inhibitor."  The Federal Circuit found, however, that "even if an ordinarly skilled artisan sought an FBPase inhibitor, that person would not have chosen topiramate."  According to the court, "Mylan's expert, Dr. Anderson, simply retraced the path of the inventor with hindsight, discounted the number and complexity of the alternatives, and concluded that the invention of topiramate was obvious."

The Federal Circuit also affirmed the district court court's conclusion of no inequitable conduct, finding that Ortho-McNeil did not misrepresent certain prior art references to the patent office, as Mylan argued, but instead "accurately characterize[d] the references."  In addition, the court affirmed the district court's conclusion that the '066 patent is not invalid for lack of enablement, finding that the claim term "anticonvulsively effective amount" is not unclear and its determination would not require undue experimentation.

In a separate decision, released concurrently, the Federal Circuit affirmed the district court's decision against Cobalt, another ANDA filer for generic Topamax, who stipulated that it would be bound by the district court's decision in the litigation against Mylan.  Cobalt retained its rights to appeal to the Federal Circuit, but stipulated that such an appeal would be based on the record in the Mylan case.  Accordingly, the Federal Circuit rejected Cobalt's "indefiniteness" argument, raised in its appeal brief, because it was not presented to the district court.

RELATED READING:

• Reuters article

Eisai Wins Preliminary Injunction Against Teva's Generic Aricept

Eisai Co. v. Teva Pharms. USA, No. 05-5727 (D.N.J. 2008)

Eisai Co., Ltd., the Japanese manufacturer of Aricept (donepezil hydrochloride), has won a preliminary injunction against Teva Pharmaceuticals USA, Inc., keeping Teva's generic version of Aricept off the market for the time being.  Aricept, which accounts for $1.6 billion in annual U.S. sales, is reportedly the world's most prescribed treatment for Alzheimer's disease.

In the decision, released Friday, the district court found that Eisai is likely to succeed on its claim of infringement because Teva's sole defense, that U.S. Patent No. 4,895,841 is unenforceable for inequitable conduct, lacks substantial merit.  Initially, Teva also asserted that the '841 patent is invalid for obviousness.  However, in December, Teva acknowledged that it had dropped its obviousness defense.  Teva stipulated to infringement of claims 8, 10 and 13 of the '841 patent, which are directed to the active ingredient in Aricept, donepezil hydrochloride, pharmaceutical compositions thereof, and a method for treating Alzheimer's disease by administering the compound.

Teva asserted that the '841 patent is unenforceable for inequitable conduct due to Eisai's failure to disclose two references during prosecution: a co-pending patent application owned by Eisai, now known as the '431 patent; and a 1984 article in the Journal of Medicinal Chemistry, authored by Richard A. Kenley.  According to Teva, had Eisai informed the Examiner of the '431 patent application and the Kenley article, the Examiner likely would have rejected the '841 patent application for obviousness-type double patenting over the '431 patent.  Donepezil is an acetylcholinesterase ("AChE") inhibitor.  The '431 patent is directed to AChE inhibitor compounds that are structurally related to donepezil, while the Kenley article focuses on restoring activity to already-inhibited AChE enzymes.

The court determined that "Eisai's co-pending '431 patent was material enough that it should have been disclosed," noting that "both patent applications were largely aimed at treating the same disease, Alzheimer's, and both patent applications stemmed from research by at least nine common inventors at Eisai."  However, after carefully comparing the chemical structures of donepezil and the compounds disclosed by the '431 patent, the court concluded that the materiality of the '431 patent is "very low."  Meanwhile, the court concluded that the materiality of the Kenley article is "almost non-existent."  Dr. Kenley himself submitted a declaration in support of Eisai.

With respect to the other prong inequitable conduct, the court stated: "there can be no punishable intent to deceive where there is no substantial likelihood that a reasonable patent examiner would have considered the undisclosed information important to deciding whether to allow the application to issue as a patent."  Accordingly, the court concluded that Eisai is likely to succeed on the merits of its case at trial.  The court treated the remaining elements of the preliminary injunction analysis in summary fashion.

A trial date in the case has not been set.  The '841 patent is set to expire November 25, 2010.  Assuming that Teva holds the 180-day exclusivity rights for generic Aricept, Teva will likely proceed to trial (and appeal, if necessary), hoping for a decision declaring the '841 patent unenforceable at least six months prior to then.

RELATED READING:

• Bloomberg article
• Eisai press release
• Teva press release

District Court Upholds Validity of P&G's Actonel Patent, Rejecting Teva's Obviousness Arguments

Proctor & Gamble v. Teva Pharms. USA, No. 04-940 (D. Del. 2008)

Late last month, the U.S. District Court for the District of Delaware (J. Farnan) upheld the validity of Proctor & Gamble's U.S. Patent No. 5,583,122, which claims risedronate sodium, the active ingredient in Actonel.  Teva had challenged the '122 patent in a paragraph IV certification in its ANDA.  P&G's U.S. sales of Actonel, which is indicated for the prevention and treatment of osteoporosis, were approximately $1 billion last year.

Teva alleged that the '122 patent is invalid as obvious in light of U.S. Patent No. 4,761,406, entitled "Regimen for Treating Osteoporosis."  Alternatively, Teva alleged that the '122 patent is invalid for obviousness-type double patenting in view of the '406 patent.  Specifically, Teva argued that the structural similarities between risedronate, claimed in the '122 patent, and 2-pyr EHDP, disclosed and claimed in the '406 patent, render claims 4, 16 and 23 of the '122 patent obvious.

The district court's opinion relies heavily on the Federal Circuit's decision last year in Takeda v. Alphapharm:

The Federal Circuit has held that "structural similarity between claimed and prior art subject matter, proved by combining references or otherwise, where the prior art gives reason or motivation to make the claimed compositions, creates a prima facie case of obviousness."  Takeda.  In addition to structural similarities, the Federal Circuit has also required a showing of "adequate support in the prior art" for the change in structure.  Id.  Clarifying these principals further, the Federal Circuit has held that a prima facie case of unpatentability requires a "showing that the prior art would have suggested making the specific molecular modifications necessary to achieve the claimed invention."  Id.

Reviewing the evidence adduced at trial in light of these legal principles, the Court concludes that Teva has not established by clear and convincing evidence that "the prior art would have suggested making the specific molecular modifications necessary" to achieve risedronate.  To begin, the Court is unpersuaded that a person of ordinary skill in the art would have selected 2-pyr EHDP as the "lead compound" out of the numerous compounds disclosed in the '406 patent.

The court further concluded, "even if Teva can establish a prima facie case of obviousness, Proctor & Gamble has demonstrated sufficient evidence of unexpected results regarding resedronate's potency and toxicity to rebut such a prima facie showing."  Finally, the court determined that Teva had not proven double patenting, as "the same type of analysis is used for an obviousness-type double patenting inquiry as for a Section 103 obviousness inquiry."

The '122 patent won't expire until December 2013.  Teva immediately announced its intention to appeal the district court's decision to the Federal Circuit.

RELATED READING:

• Business Week
• P&G press release
• Teva press release

Federal Circuit Invalidates Pfizer's Latest-Expiring Patent on Celebrex, for Double Patenting

Pfizer v. Teva Pharms. USA, No. 2007-1271 (Fed. Cir. 2008)

Pfizer owns three Orange Book-listed patents protecting its blockbuster arthritis drug Celebrex (celecoxib): U.S. Patent Nos. 5,466,823; 5,563,165; and 5,760,068.  As we previously reported, last year a district court held that Teva's ANDA infringes all three patents, and enjoined Teva from marketing its generic version of Celebrex until 2015, when the '068 patent expires.  (There is also a fourth, later-expiring, patent listed in the Orange Book for Celebrex, No. 5,972,986, but presumably Teva filed a section viii statement on it).

On Friday, the Court of Appeals for the Federal Circuit held that the '068 patent, claiming methods of use, is invalid for double patenting in view of the '165 patent, claiming compositions.  The decision effectively results in a loss of one and a half years of patent protection on Celebrex.

The primary issue in the case appears to be one of first impression: whether 35 U.S.C. § 121 applies not only to divisional patent applications, but also to continuation-in-part ("CIP") applications.  35 U.S.C. § 121 provides, in part, as follows:

A patent issuing on an application with respect to which a requirement for restriction under this section has been made, or on an application filed as a result of such a requirement, shall not be used as a reference either in the Patent and Trademark Office or in the courts against a divisional application or against the original application or any patent issued on either of them, if the divisional application is filed before the issuance of the patent on the other application.

Thus, section 121 provides a "safe harbor" to divisional applications from obviousness-type double patenting rejections.  Teva contended that section 121 applies exclusively to divisional applications, and that because the '068 patent issued on a CIP rather than a divisional application, the '068 patent is not entitled to the protections of the statute.  According to the Federal Circuit's opinion, Pfizer argued "that the terms 'divisional' and 'continuation-in-part' are merely labels used for the administrative convenience, and that accordingly, although the '068 is termed a CIP, it is in effect a divisional for purposes of section 121."

The Federal Circuit sided with Teva.  The court reviewed the text of section 121 (which refers exclusively to divisional applications), the statute's legislative history, and case law, concluding that "the protection afforded by section 121 to applications (or patents issued therefrom) filed as a result of a restriction requirement is limited to divisional applications."  Moreover, because "[t]he claims at issue of the '068 merely recite methods of administering a 'therapeutically-effective amount' of the compositions found in claim 5 of the '165 patent," the court found them not patentably distinct over the claims of the '165 patent, and therefore invalid for obviousness-type double patenting.

Although the Federal Circuit invalidated the '068 patent, the court upheld the validity of the '823 and '165 patents, rejecting Teva's arguments that they are invalid for failure to disclose the best mode and unenforceable for inequitable conduct.  Thus, Celebrex will remain protected until at least May 30, 2014, when pediatric exclusivity attached to the '165 patent expires.

RELATED READING:

• Patent Docs
• Pfizer press release
• Reuters
• Wall St. Journal