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New and Improved Drug Product Eligible for Patent Term Extension Pursuant to 35 U.S.C. § 156

May 10, 2010
Del Monaco, Anthony D.

Decision icon Decision

Last Month at the Federal Circuit - June 2010

Judges: Newman (author), Rader, Linn

[Appealed from: E.D. Va., Judge O’Grady]

In Photocure ASA v. Kappos, No. 09−1393 (Fed. Cir. May 10, 2010), the Federal Circuit affirmed the district court’s reversal of the PTO’s denial of Photocure ASA’s (“Photocure”) request for a patent term extension pursuant to 35 U.S.C. § 156.  In so doing, the Court considered the applicability of § 156 to a drug product having as its active ingredient the chemical compound methyl aminolevulinate hydrochloride (“MAL hydrochloride”), brand name Metvixia®. 

Metvixia® is used in photochemotherapy or photodynamic therapy to treat actinic keratoses, which are precancerous growths on the skin.  MAL hydrochloride was a new chemical compound that was patented in U.S. Patent No. 6,034,267 (“the ’267 patent”) on the basis of improved therapeutic properties as compared with the known compound aminolevulinic acid hydrochloride (“ALA” hydrochloride).  MAL is the methyl ester of ALA.  ALA hydrochloride had previously received FDA approval for the same therapeutic use as MAL hydrochloride, but the ’267 patent specification discusses and exemplifies the biological and physiological advantages of the MAL hydrochloride product over the ALA hydrochloride product.  Patentability of the MAL hydrochloride product was not disputed. 

Because MAL hydrochloride was considered a “new drug” pursuant to 21 U.S.C. § 321(p), it required full FDA approval.  The clinical and other tests to demonstrate MAL hydrochloride’s safety and efficacy took four and a half years.  Upon completion of the tests, Photocure applied to the PTO for an extension of the term of the ’267 patent. 

The PTO consulted with the FDA regarding Photocure’s request for patent extension.  Despite MAL hydrochloride having received regulatory approval for the designated use, the FDA stated that the proposed requirements of 35 U.S.C. § 156(a)(5)(A) were not met because MAL hydrochloride is an ester of the previously FDA−approved ALA hydrochloride.  The PTO then denied the patent term extension, interpreting the term “active ingredient” in 35 U.S.C. § 156(f)(2) to mean the “active moiety” of the product, not the product that was approved by the FDA.  Indeed, the PTO determined that MAL hydrochloride is the same product as ALA hydrochloride because the underlying molecule of MAL is ALA.  As such, the PTO held that since a drug product containing ALA hydrochloride was previously approved by the FDA, the FDA’s marketing approval of the MAL hydrochloride product was not the first commercial marketing or use of that product, as required by 35 U.S.C. § 156(a)(5)(A).  Photocure appealed the PTO’s decision.

On appeal, the district court held that the PTO’s ruling was “not in accordance with law,” and that the patent on MAL hydrochloride is subject to term extension.  Slip op. at 2 (citing PhotoCure ASA v. Dudas, 622 F. Supp. 2d 338 (E.D. Va. 2009)).  In reversing the PTO, the district court considered the separate chemical composition of MAL hydrochloride and held that (1) it is the active ingredient of a new drug product that required FDA approval under 35 U.S.C. § 156(f)(2)(A); (2) the MAL hydrochloride product was subject to a full regulatory review period before commercial marketing and use was permitted, pursuant to 35 U.S.C. § 156(a)(4); (3) this review permitted the first commercial marketing and use of the MAL hydrochloride product (see U.S.C. § 156(a)(5)(A)); and (4) the statutory requirements for term extension were therefore met.

The PTO appealed, arguing that the term “active ingredient” in 35 U.S.C. § 156(f)(2) means only the “active moiety” of the product, i.e., the part responsible for the pharmacological properties.  The Federal Circuit agreed, stating that the ’267 patent illustrates that the pharmacological properties of MAL hydrochloride differ from those of ALA hydrochloride, supporting the separate patentability of the MAL hydrochloride product.  The Federal Circuit further concluded that MAL hydrochloride is a different chemical compound from ALA hydrochloride and that the differences in their biological properties warrant separate patenting and separate regulatory approval.  Relying on Glaxo Operations UK Ltd. v. Quigg, 894 F.2d 392, 393 (Fed. Cir. 1990), the Federal Circuit affirmed that MAL hydrochloride and ALA hydrochloride are “different products” with different “active ingredients,” as the terms are used in 35 U.S.C. § 156, agreeing with the district court that “a compound can only qualify as the ‘active ingredient’ of a drug if that compound itself is present in the drug.”  Slip op. at 5.

The PTO attempted to distinguish Glaxo, arguing that Glaxo did not address the term “active ingredient.”  The PTO instead relied on Pfizer Inc. v. Dr. Reddy’s Laboratories, Ltd., 359 F.3d 1361 (Fed. Cir. 2004), in which the underlying issue was whether infringement of an extended patent was avoided by changing the salt.  The Federal Circuit in Pfizer held that the changed salt had no effect on the activity of the product, for the “active moiety” of the product was unchanged.  In the instant matter, the Federal Circuit concluded that Pfizer did not apply, as the Pfizer court did not hold that extension is not available when an existing product is substantively changed in a way that produces a new and separately patentable product having improved properties and requiring full FDA approval.

Finally, the PTO argued that even if the Court did not accept the PTO’s reading of Pfizer, the agency’s interpretation is entitled to deference in accordance with the persuasiveness of the agency’s reasoning, citing Skidmore v. Swift & Co., 323 U.S. 134 (1944).  In the district court, the PTO also cited Chevron, U.S.A., Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837 (1984), for the contention that, when a statute is ambiguous, courts should defer to the interpretation of the agency charged with administering the statute.  The Federal Circuit disagreed with both contentions, holding that Skidmore deference is not warranted because the PTO’s interpretation is neither persuasive nor consistent and Chevron does not apply because the statute is unambiguous.


Summary authored by Anthony D. Del Monaco, Esq.