Patent Baristas

Ortho-McNeil kept it’s exclusivity on topiramate after a district court blocked Mylan Labs from infringing Ortho-McNeil’s U.S. Patent No. 4,513,006 covering Topomax® (topiramate), an anticonvulsive drug used to treat epilepsy. The trial court also reset the effective approval date for Mylan’s Abbreviated New Drug Application (ANDA).

The United States Court of Appeals for the Federal Circuit affirmed the district court rulings on claim construction, inequitable conduct, obviousness, and enablement. Ortho-Mcneil Pharmaceutical v. Mylan Laboratories (07-1223).

Mylan filed an ANDA with the FDA with a paragraph IV certification asserting that Ortho-McNeil’s ‘006 patent is invalid or not infringed. Ortho-McNeil sent the usual congratulatory note (a lawsuit), triggering a 30-month stay on approval of Mylan’s ANDA.

After a Markman proceeding to decide what words mean what in the patent, the district court rejected Mylan’s position that the ‘006 patent doesn’t cover topiramate. The court then ruled against Mylan’s affirmative defenses of unenforceability due to inequitable conduct and invalidity based on obviousness and non-enablement.

Mylan argued that the district court improperly construed the word and to mean or in independent claim 1, and under the proper (Mylan’s) construction, the claim does not cover topiramate.

Claim 1 of the ‘006 patent is for a sulfamate of the following formula (I):

wherein X is oxygen; R1 is hydrogen or alkyl; and R2, R3, R4 and R5 are independently hydrogen or lower alkyl and R2 and R3 and/or R4 and R5 tgether may be a group of the following formula (II):

wherein R6 and R7 are the same or different and are hydrogen, lower alkyl or are alkyl and are joined to form a cyclopentyl or cyclohexyl ring.

In the molecule topiramate, R2 and R3 and R4 and R5 together are a group of formula (II), wherein R6 and R7 are methyl. Mylan argued that the use of the term and precludes the claim from encompassing topiramate. In context, the term and falls between several R group recitations: 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) (emphasis added).

Mylan argued that the phrase contains two independent claim limitations: (1) that “R2, R3, R4, and R5 are independently hydrogen or lower alkyl” and (2) that “R2 and R3 and/or R4 and R5 together may be a group of formula (II).” Under Mylan’s construction, both of these limitations must be met in order for a compound to infringe. Both of these limitations are not met in topiramate. None of the R2, R3, R4, and R5 subunits are hydrogen or lower alkyl because both R2 and R3 and R4 and R5 together are a group of formula (II).

Au contraire, mon amie. The court said that the claim language depicts two subsets of compounds, but does not require their simultaneous existence:

In one subset of compounds covered by claim 1, the groups R2, R3, R4, and R5 are independent of one another, in which case, according to the claim, they are either hydrogen or lower alkyl. In a second subset of compounds covered by claim 1, the R2 through R5 groups are not independent, but rather R2 and R3 are together, and/or R4 and R5 are together, to form either one or two groups of formula (II). Topiramate is an example of this type of compound. In it, R2 and R3 are arranged together in a group, as are R4 and R5. Thus, as used in this claim, and conjoins mutually exclusive possibilities.

The claim also does not use and in isolation but in a larger context that clarifies its meaning. Specifically, and appears in conjunction with the adverbs independently and together. As the district court explained, these terms signal that and links alternatives that occur under the different conditions of independence or togetherness. In context, it is clear that one of the subunits (R2, R3, R4, or R5) does not always have to be either a hydrogen or lower alkyl.

The court said that it did not need to look at extrinsic evidence but did anyway:

Nonetheless, this court notes that dictionary definitions of and, while most often listing the additive sense as the most common usage of the term, also show usage of the term to connote alternatives. Webster’s Third New International Dictionary (2002). In the circumstances of this case, the use of and to express alternatives was chosen and adequately expressed by the applicant. Thus, extrinsic evidence too offers support for the district court’s reading of the disputed term.

In light of the plain language of independent  claims, the specification, and the extrinsic evidence, the court decide that claim 1’s use of the term and means or.

Good news for Ortho-McNeil. Sales of topiramate exceed $1 billion annually.