Bayer Pharma AG v. Watson Labs., Inc.

Subsequent patent teaching a formulation of specific dosage amounts was not invalid for general or double-patenting obviousness when the specific dosages produced unexpected results contrary to the knowledge of one of ordinary skill at the time of patenting.

October 25, 2016

GENERICally Speaking

Case Name: Bayer Pharma AG v. Watson Labs., Inc., Case No. 12-1726-LPS, 2016 U.S. Dist. LEXIS 96267 (D. Del. July 18, 2016) 

Drug Product and Patent(s)-in-Suit: Natazia® (estradiol valerate / dienogest); U.S. Patent No. 8,071,577 (“the ’577 patent”)

Nature of the Case and Issue(s) Presented: Bayer holds a series of patents related to its oral contraceptive drug, Natazia. Natazia’s formulation, disclosed in the ’577 patent, requires a specific, multiphasic dosage regimen of estradiol valerate (“EV”) and dienogest (“DNG”). The ’577 patent calls for administration of EV and DNG in specific dosage levels, varying over the course of the user’s menstrual cycle. Notably, the ’577 patent formulation includes much lower levels of EV relative to DNG than was known in the art at the time. Bayer also holds U.S. Patent Number 6,884,793 (“the ’793 patent”), which also teaches an oral contraceptive formulation of EV and DNG. Unlike the ’577 patent, however, the ’793 patent does not claim specific amounts of EV and DNG during each administration phase.

Bayer sued Watson for infringing the ’577 patent. Watson argued that the ’577 patent was invalid for two reasons. First, in light of the ’793 patent, Watson asserted that the ’577 patent was invalid for obviousness-type double patenting. Second, Watson argued that the ’577 patent was invalid as obvious. After a bench trial, the court found the ’577 patent valid.

Why Bayer Prevailed: Although there was significant overlap between the claims of the ’577 patent and the ’793 patent, the ’577 patent describes a precise recipe of EV and DNG with low levels of EV. The court determined that those differences between the claims were patentably distinct for a number of reasons. First, at the time of patenting, it was believed that oral contraceptives needed to be “estrogen dominant”—consisting of significantly more EV than DNG—to be effective. Although this ultimately proved not to be true, as evidenced by Natazia’s effectiveness, one of ordinary skill in the art would have deferred to the “estrogen dominant” model. Thus, the specific, low EV doses of the ’577 patent would not have been obvious at the time of patenting, nor would they have been considered an “effective amount” of EV. Since the ’793 patent claimed a formulation with an “effective amount” of EV, the claims of the patents were distinct. Further, the ’577 patent’s formulation satisfied a long-felt need as the first and only low-estrogen oral contraceptive. Accordingly, the secondary considerations of non-obviousness also spoke to the non-obviousness of the ’577 patent claimed invention.

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