CURRENT ISSUES OF IMPORTANCE TO THE GENERIC INDUSTRY Patent Validity Issues

As part of the approval process, an ANDA applicant must make a certification addressing each patent listed in the Orange Book that claims the drug (53). The ANDA applicant must certify that (I) no such patent information has been submit-ted to the FDA; (II) the patent has expired; (III) the patent is set to expire on a certain date; or (IV) the patent is invalid or will not be infringed by the manufacture, use, or sale of the new generic drug for which the ANDA is submitted (54). These are commonly referred to as paragraph I, II, III, and IV certifications.

When an ANDA contains a paragraph IV certification, the ANDA applicant must give notice to the patentee and the NDA holder and provide a detailed basis for its belief that the patent is not infringed, invalid, or unenforceable (55). Further, in order to obtain the 180-day exclusivity afforded by the Hatch–Waxman Amend-ments, the ANDA applicant generally must prevail on these issues in court.

Accordingly, it is essential that a successful generic competitor have a work-ing understandwork-ing of patent validity, unenforceability, and infrwork-ingement concepts.

These concepts are discussed later.

Validity in General

Proving that a patent is invalid (or even unenforceable) is a very difficult challenge.

Patent claims are presumed to be valid (56). This presumption can be overcome only by clear and convincing evidence (57).

In order for a court to uphold the validity of a patent claim, the claim must meet the statutory requirements of Title 35 of the United States Code. A patent claim may be held invalid in litigation if the claimed invention fails to satisfy the novelty and/or nonobvious subject matter conditions for patentability set forth in the patent laws, namely 35 USC§§102 and 103 or if it fails to satisfy the require-ments of adequacy of description, “enablement,” “best mode,” or “definiteness” of 35 USC§112.

Patent Claims Are Not Valid If They Are Anticipated Or Obvious

One of the first steps in evaluating a potential generic drug project should be an extensive investigation and review of the development of the technology, which is the context of the particular drug in question. As a first step, a comprehensive prior art “search” should be conducted (as well as a complete investigation of potential

“prior art” activities, such as public disclosure, public uses, and the general con-text of the development of the drug). The goal is to uncover prior art which would potentially render the relevant patent(s) invalid and/or unenforceable by reason,

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among other things, of “anticipation” or “obviousness.” Both of these concepts are, necessarily, legalistic, and are discussed in detail later. Additionally, the patent itself and its history should be thoroughly studied to determine compliance with other requirements, also discussed later.

Anticipation

Anticipation under 35 USC§102 requires the disclosure in a single piece of prior art (this can be a “publication” or an “event”) of each and every limitation of a claimed invention (58). If the prior art does not anticipate (exactly disclose) the claimed invention, in a single reference, the question of whether the prior art renders the claimed invention obviously remains. “Obviousness” is discussed in more detail later.

Obviousness

The determination of obviousness under§103 is a question of law (59). Specifically,

§103 provides, in pertinent part, that:

A patent may not be obtained though the invention is not identically disclosed or described as set forth in§102 of this Title, if the differences between the sub-ject matter sought to be patented and the prior art are such that the subsub-ject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which the subject mat-ter pertains. Patentability shall not be negatived by the manner in which the invention was made.

The language of§103 requires that the evaluation of obviousness be from the perspective of a hypothetical person “of ordinary skill in the art at the time that the invention was made” (60). The proper approach to making a determination of obvi-ousness was first described by the Supreme Court in Graham v. John Deere Co (61).

Specifically, it was stated that: Under§103, the scope and content of the prior art are to be determined; differences between the prior art and the claims at issue are to be ascertained; and the level of ordinary skill in the pertinent art is to be resolved.

Against this background, the obviousness or nonobviousness of the subject matter is determined (62).

Other evidence of nonobviousness such as long-felt but unsolved need, com-mercial success, failure of others, copying, and unexpected results must also be con-sidered in a determination of obviousness (63).

The Supreme Court has recently elaborated on this approach (64). An obvious-ness analysis requires “an expansive and flexible approach” with “a broad inquiry [that] invites courts, where appropriate, to look at any secondary considerations that would prove instructive” (65). “The combination of familiar elements accord-ing to known methods is likely to be obvious when it does no more than yield predictable results” (66). “[A]ny need or problem known in the field of endeavor at the time of invention and addressed by the patent can provide a reason for com-bining the elements in the manner claimed” (67). For example, obviousness may be proved by noting that there existed at the time of invention a known problem for which there was an obvious solution encompassed by the patent’s claims (obvious to try). Specifically, “[w]hen there is a design need or market pressure to solve a problem and there are a finite number of identified, predictable solutions, a person of ordinary skill has good reason to pursue the known options within his or her

technical grasp. If this leads to the anticipated success, it is likely the product not of innovation but of ordinary skill and common sense” (68).

Patent Claims Must Also Satisfy the Requirements of 35 USC§112

35 USC§112, first and second paragraphs, sets forth essentially three requirements for a patent: (i) the “written description” and “enablement” requirements, (ii) the

“best mode” requirement, and (iii) the requirement of distinct claiming.

The Written Description Requirement

What is recited in the claims of a patent must be supported by a “written descrip-tion” thereof in the specification. To fulfill the written description requirement, a patent specification must describe the invention and do so in sufficient detail that one skilled in the art can clearly conclude that “the inventor invented the claimed invention” (69).

Enablement

35 USC§112, first paragraph, requires the patent specification to have an enabling disclosure. Specifically,§112, first paragraph, provides in pertinent part that:

The specification shall contain a written description of the invention and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same. . . .

The specification need only be enabling to a person “skilled in the art to which it pertains, or with which it is most nearly connected” (70). In determining whether a patent has an adequate disclosure, it is necessary to bear in mind that “[p]atents are written for those skilled in the relevant art, and thus, an applicant need to not divulge every piece of information which a lay person would need to operate the invention most effectively” (71). The Federal Circuit has recently determined that the issue of whether a claimed invention is enabled by the specification is a matter of law (72).

In determining whether a disclosure is adequate under 35 USC§112 the ques-tion is “whether the disclosure is sufficiently definite to guide those skilled in the art to its successful application. . . some experimentation, provided it is not an undue amount, is permissible. However, nothing must be left to speculation or doubt” (73).

The specification must provide more than “an invitation to experiment in order to determine how to make use of [the inventor’s] alleged discovery. . . the law requires that the disclosure in the application shall inform them how to use, not how to find out how to use for themselves” (74).

Best Mode

35 USC§112 requires that the patent applicant set forth the best mode of practicing the invention known to the applicant at the time the application for patent is filed.

A best mode analysis has two components: the first inquiry focuses on whether the inventor knew of a mode of practicing his invention at the time he filed his patent application which he considered to be better than any other. If he did have a best mode, the next question is whether the inventor disclosed it and did so adequately to enable one of ordinary skill in the art to practice the best mode (75).

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Distinct Claiming

35 USC§112, second paragraph, states that:

The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.

Under this statute, the general requirement is that the claims, read in light of the specification, reasonably apprise those skilled in the art of the scope of the inven-tion (76). A decision as to whether a claim is invalid under the second paragraph of§112 requires a determination whether those skilled in the art would understand what is claimed (77).

“Double Patenting” Is Prohibited

An inventor is only entitled to a single patent for a patentable invention. This is reflected in 35 USC§101 which states that:

Whoever invents or discovers any new and useful process, machine, manufac-ture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefore. . ..

This prohibition is referred to as “statutory double patenting.” In addition to statutory double patenting, the doctrine of “judicially created” or nonstatutory ble patenting has been propounded. “[n]on-statutory, or ‘obviousness-type,’ dou-ble patenting is a judicially created doctrine adopted to prevent claims in separate applications or patents that do not recite the ‘same’ invention, but nonetheless claim inventions so alike that granting both exclusive rights would effectively extend the life of patent protection” (78).

The True Inventors Must Be Named

A patent is invalid if more or fewer than the true inventors are named (79). Because a patent is presumed valid under 35 USC§282, there follows a presumption that the named inventors on a patent are the true and only inventors (80).

When two or more persons jointly invent, they must jointly apply for a patent (81). Coinventors must so apply “even though . . . they did not physically work together or at the same time,. . . each did not make the same type or amount of contribution, or. . . each did not make a contribution to the subject matter of every claim of the patent” (82). Because conception is the touchstone of inventorship, each

“joint inventor must contribute in some significant manner to the conception of the invention” (83). “Conception is the formation in the mind of the inventor, of a defi-nite and permanent idea of the complete and operative invention, as it is hereafter to be applied in practice” (84). “An inventor may solicit the assistance of others when perfecting the invention without ‘losing’ any patent rights” (85).

Because coinventors need not contribute to the subject matter of every claim of the patent, inventorship is determined on a claim-by-claim basis (86).

Practical Application

As a practical matter, an initial goal is often to locate and identify “anticipatory”

prior art, as defined earlier. However, such a “smoking gun” is rare, and so resort must be had to other prior art, or other attacks on validity, also outlined earlier.

Thus, it is often necessary to acquire and piece together a mosaic of informa-tion which tells the whole story of the context and development of the drug, as well as activities “behind the scenes,” which could give rise to meaningful, credible attacks on the patent.

Thus, in the context of the true facts surrounding the development of the drug, the alleged “invention” may be merely an obvious combination of old elements. Or the invention may have been the next (and obvious) progression of ideas which have long existed.

In conducting such an investigation, care should be taken to keep all of the foregoing requirements in mind. Thus, an inventor’s (or company’s) own patents and publications can be “prior art” with respect to the patent in question. And the award of more than one patent to a particular inventor or company may also give rise to prohibited “double patenting” (discussed earlier), thus invalidating the patent on those grounds.

Other bases for proving invalidity and/or unenforceability, such as failure to comply with the “best mode” requirement, inequitable conduct (“fraud”) and inventorship issues are often only developed as a result of the “discovery” process which takes place after litigation has started.

Patent Infringement Issues

In view of requirement that a “paragraph IV” ANDA applicant make the certifi-cation discussed earlier (and eventually obtain a judgment of noninfringement and the award of 180-day market exclusivity), it is also essential that a successful generic competitor have a working understanding of patent infringement concepts. These concepts are discussed later.

General Infringement Concepts

Patent infringement involves the violation of the rights of the owner (or licensee) of the patent. Ownership of a patent confers the right to exclude others from mak-ing, usmak-ing, sellmak-ing, or offering for sale the invention within the United States, or importing the invention into the United States (87). Infringement of a patent is the unauthorized use of a patent owner’s exclusive rights as defined by the claims of the patent (88). Thus, acts such as the unauthorized making, using, or selling of the claimed invention, or importing or offering the claimed invention for sale, can constitute infringement.

The claims are the specific part of the patent (found at that portion of the patent with the heading “Claims” or “What is claimed is”) that define the patent grant and set its boundaries, that is, they establish the patentee’s legal rights (89).

Thus, claims must be construed or interpreted to ascertain what they cover.

Construction of Claims

In determining the meaning and scope of the claims, it is first necessary to analyze the relationship of the claims to the specification and prosecution history of the subject patent (90).

In construing a claim, claim terms are given in their ordinary and accustomed meaning, unless examination of the specification, prosecution history, and other claims indicate that the inventor intended otherwise (91). The best source for inter-preting a technical term used in a claim is the specification from which it arose and guided, as needed, by the prosecution history (92). The evolution of restrictions in

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the claims, during the course of examination in the PTO, reveals how those closest to the patenting process—the inventor and the patent examiner—viewed the subject matter (93).

With regard to scope, in construing a claim, care should be taken to avoid a construction that reads on the prior art. [C]laims should be read in a way that avoids ensnaring prior art if it is possible to do so (94). Also with regard to scope, [w]hether or not claims differ from each other, one cannot interpret a claim to be broader than what is contained in the specification and claims as filed (95).

Moreover, [b]ecause the applicant has the burden to “particularly point out and distinctly claim the subject matter which the applicant regards as his invention”

(96), if a claim is susceptible to both a broader and a narrower meaning, and the narrower one is clearly supported by the intrinsic evidence while the broader one raises questions of whether it is “supported,” courts will adopt the narrower of the two (97).

Closed, Partially Closed, and Open Terminology

When evaluating the scope of a particular claim, care should be taken to ascer-tain whether “closed,” “partially closed,” or “open” terminology is employed in the claim. Such terminology is almost always indicated by the use of certain key terms. In this regard, “consisting of” indicates a “closed claim,” the use of “con-sisting essentially of” indicates a partially closed claim, while the use of “compris-ing” indicates an open claim. “Closed” claims are not open to the inclusion of addi-tional elements beyond what is recited in the claim. Thus, a “closed” claim reciting a composition “consisting of” components A, B, and C would not be infringed by a composition containing A, B, C, and D. Conversely, an “open” claim reciting a com-position “comprising” elements A, B, and C would be infringed by a comcom-position containing A, B, C, and D. The use of “consisting essentially of” presents a gray area.

Such claims are open to infringement by matter having an additional element, if the additional element does not alter the “basic and novel” character of the invention.

Infringement

A proper infringement analysis requires that the question of infringement be eval-uated both literally and under the doctrine of equivalents.

For literal infringement to exist, an accused product must fall clearly within the literal language of the claim(s) in question (98). Every element of the claim must be present in the accused matter for literal infringement to be properly found (99).

All Elements Rule

A patent claim cannot be infringed if any limitation of the claim, or its substantial equivalent, is not present in the accused matter (100). The claim is compared with the proposed or accused matter on an element-by-element basis (101). However, two physical components of an accused device may be viewed in combination to serve as an equivalent of one element of a claimed invention, as long as no claim limitation is thereby wholly vitiated (102).

Doctrine of Equivalents

Even when a claim is not literally infringed, such a claim may be infringed under the doctrine of equivalents. Infringement under the doctrine of equivalents is appropri-ately applied in situations in which no literal infringement has taken place, but in

which an alleged infringer has only made unimportant and insubstantial changes or substitutions in the patented subject matter which, though adding nothing, would be enough to otherwise evade the reach of law (103).

Although the determination of equivalence involves a determination of whether the accused product embodies only an insubstantial change from the patented invention, the essential inquiry remains: Does the accused product or process contain elements identical or equivalent to each claimed element of the patented invention? (104). Thus, a determination of equivalence needs to be made, as an objective inquiry, and on an element-by-element basis (105).

Prosecution History Estoppel

The prosecution history of the patent is of great importance in interpreting the scope of the claims, because equivalence will not be found if it is limited by prosecution history estoppel or if the equivalent item is in the public domain (106). Prosecution history estoppel applies as a limitation to the doctrine of equivalents after the claims have been properly interpreted and no literal infringement is found (107). As the Court of Appeals for the Federal Circuit has repeatedly held, other players in the marketplace are entitled to rely on the record made in the Patent Office [sic.] in determining the meaning and scope of the patent (108).

The prosecution history of the patent is of great importance in interpreting the scope of the claims, because equivalence will not be found if it is limited by prosecution history estoppel or if the equivalent item is in the public domain (106). Prosecution history estoppel applies as a limitation to the doctrine of equivalents after the claims have been properly interpreted and no literal infringement is found (107). As the Court of Appeals for the Federal Circuit has repeatedly held, other players in the marketplace are entitled to rely on the record made in the Patent Office [sic.] in determining the meaning and scope of the patent (108).