Bayer Schering Pharma v. Barr Labs
By Aaron Dulles – Edited by Evelyn Breithaupt
Bayer Schering Pharma AG and Bayer Healthcare Pharm., Inc. v. Barr Labs., Inc., No. 2008-1282 (Fed. Cir. Aug. 5, 2009)
On August 5, 2009, a Federal Circuit panel affirmed the decision of the District of New Jersey, which had found Bayer’s U.S. Patent No. 6,787,531 (“’531 Patent”) invalid because of obviousness. The ’531 Patent concerns a formulation of the well-known contraceptive drug drospirenone. The patent previously protected Bayer’s formulation of a daily oral contraceptive product, marketed as the drug Yasmin. When Barr Labs sought approval from the FDA to market a generic version of Yasmin, Bayer filed a patent infringement suit. The district court found that under KSR International Co. v. Teleflex Inc., 550 U.S. 398 (2007), the formulation of drospirenone in the Yasmin product was obvious. The sole issue of appeal was obviousness, and by a 2-1 vote the Federal Circuit affirmed the district court’s decision.
Passino PLLC suggests that the majority’s application of the In re O’Farrell, 853 F.2d 894 (Fed. Cir. 1988) standards was too rigid, and thus appeared to go against warnings in KSR concerning rigid application of tests. Patent Docs agreed, asserting that the judges both at the trial and appellate levels disregarded important evidence and emphasizing that the “common sense” of obviousness is that of the practitioner, not the judge. AboutLawSuits.com noted the ruling, but focused on known potential negative side effects of the drospirenone-based contraceptives such as Yasmin.
Drospirenone had been a well-known contraceptive. In formulating the drug as a daily oral pill, however, Bayer ran into two problems: it is hydrophobic, resisting dissolution in water; and it is acid-sensitive, isomerizing (changing shape but not composition) in acids such as those found in the stomach, thereby losing certain important qualities. While the usual solution of “micronization” for hydrophobic chemicals ordinarily may have seemed to be a clear solution, that process was known to worsen acid sensitivities. Bayer scientists considered certain protective coatings for a time, but during experimentation they found that drospirenone’s bioavailability – its crucial ability to be absorbed into the bloodstream to work – could be assured by micronization and without any protective coatings. Yasmin was formulated as such, and in prosecuting the ’531 Patent, Bayer relied on the fact that prior art had pointed against micronization due to the isomerization problem.
Writing for the majority, Mayer, J., applied the KSR standard to the micronization, first examining whether a person of ordinary skill would have attempted the formulation. Citing In re O’Farrell, the Court considered two identifiers of non-obviousness: first, a solution may be non-obvious where there is not a limited and relatively small set of solutions that may be investigated; and second, a solution may be non-obvious where prior art is vague and does not give clues about future courses of study.
In considering the obviousness of micronization, the Court relied in large part on the text of a pharmacology textbook that gave clues as to why a formulator would nevertheless consider micronization. The Court further cited prior art that pointed towards micronization, as well as the testimony of a Bayer expert who stated that micronization would generally be a first-choice solution.
Bayer argued foregoing the coating was non-obvious because certain prior art points towards using the coating, while Barr argued that other prior art points against using the coating. The Court noted that the parties’ disagreement neatly proved that a drug formulator would have been presented with options to investigate, thus avoiding the first indicator of non-obviousness in O’Farrell. Moreover, the inconclusive prior art on coating of drospirenone would clearly have indicated a topic for exploration.
Dissenting, Newman, J., emphasized that ex post bias may have caused the Bayer formulation to appear obvious to the majority. Citing the same textbook, the dissent showed that it also advised against micronization of acid-sensitive drugs. Moreover, the prevailing knowledge available showed that drospirenone was sensitive to acids, and so a formulator would not ordinarily contemplate direct exposure to stomach acids without a protective coating. Interestingly, the dissent characterized the district court’s finding on micronization – that it was viable but uncertain – as insufficient to find obviousness, stating that predictability was a more important factor than such fortuitous experimentation.