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Federal Circuit Upholds Patent Term Extensions in LEVAQUIN and METVIXIA Cases

By Aaron Barkoff

Ortho-McNeil and Daiichi Sankyo v. Lupin, No. 2009-1362 (Fed. Cir. 2010)

Photocure v. Kappos, No. 2009-1393 (Fed. Cir. 2010)

In separate cases decided today, the Federal Circuit upheld two patent term extensions under 35 U.S.C. § 156--one relating to LEVAQUIN (levofloxacin) and the other relating to METVIXIA (methyl aminolevulinate).  The cases were argued on the same day last year to the same three-judge panel, and Judge Newman authored both of today's opinions.

In the LEVAQUIN case, the Federal Circuit affirmed a district court decision sustaining the term extension of U.S. Patent No. 5,053,407, assigned to Daiichi and exclusively licensed to Ortho-McNeil, and enjoining Lupin from infringement during the extended term of the patent.  The '407 patent claims levofloxacin, which is the levorotatory enantiomer of racemate ofloxacin.  Levofloxacin and ofloxaxin are both antibiotics.

In the METVIXIA case, the Federal Circuit reversed a decision of the USPTO that denied a term extension of U.S. Patent No. 6,034,267, owned by Photocure.  The '267 patent claims methyl aminolevulinate ("MAL"), the methyl ester of the known drug aminolevulinic acid ("ALA").  MAL and ALA are both indicated for the treatment of actinic keratoses--precancerous cell growths on the skin.

Under § 156, the term of a patent which claims a drug product, a method of using a drug product, or a method of manufacturing a drug product may be extended by up to five years if the drug product was subject to FDA regulatory review prior to its commercial marketing or use.  The Federal Circuit explained the policy behind § 156:

The Patent Term Extension statute was enacted in recognition of the lengthy procedures associated with regulatory review of a new drug product, for the patent term continues to run although the product cannot be sold or used until authorized by the Food and Drug Administration (FDA).  The statute was designed to restore a portion of the patent life lost during the period of regulatory review, in order to preserve the economic incentive for development of new therapeutic products.

A key feature of § 156 is that only one patent term extension is allowed per drug product.  This is reflected in the statutory language: "the permission for the commercial marketing or use of the [drug] product after such regulatory review period [must be] the first permitted commercial marketing or use of the [drug] product."  In turn, the statute defines a "drug product" as the active ingredient of a new drug, antibiotic drug or human biological product (as those terms are used in the Federal Food, Drug, and Cosmetic Act and the Public Health Service Act).

The issue in both of the cases decided today was whether the FDA approval sought for each drug was for the "first permitted commercial marketing or use" of the drug.  In the levofloxacin case, Lupin argued that the enantiomer levofloxacin was an "active ingredient" of the previously-marketed racemate ofloxacin, levofloxacin is therefore the same "drug product" as ofloxacin, and therefore levofloxacin is not eligible for a patent term extension.  Similarly, in the MAL case, the PTO argued that "active ingredient" means "active moiety," MAL, as the methyl ester of ALA, is the same product as ALA because the "underlying molecule" of MAL is ALA, and therefore MAL is not eligible for a patent term extension.   But the Federal Circuit rejected these arguments.

In the levofloxacin case, the court agreed with Ortho that "an enantiomer has consistently been recognized, by the FDA and the PTO, as a different 'drug product' from its racemate."  The court further observed that, in this case, "levofloxacin was viewed by the FDA as a new product requiring full regulatory approval, and that levofloxacin was viewed by the PTO as separately patentable."

The Federal Circuit applied similar reasoning in the MAL case:

[A]s the '267 patent illustrates, the pharmacological properties of MAL differ from those of ALA, supporting the separate patentability of the MAL product.  MAL hydrochloride is a different chemical compound from ALA hydrochloride, and it is not disputed that they differ in their biological properties, warranting separate patenting and separate regulatory approval, although their chemical structure is similar.

Thus, separate regulatory review and separate patentability are important factors in determining whether a pharmaceutical is the same "drug product" as one that was previously approved, and therefore whether it is eligible for patent term extension under § 156.

Full post as published by Orange Book Blog: At the Intersection of Patent Law and FDA Law on May 11, 2010 (boomark / email).