Intellectual Property Law

Federal Circuit Affirms Invalidity of Bayer Patent on Yasmin

By Aaron Barkoff

Bayer Schering v. Barr Labs, No. 2008-1282 (Fed. Cir. 2009)

A divided panel of the Federal Circuit today affirmed a district court decision holding Bayer's U.S. Patent No. 6,787,531 invalid due to obviousness.  The '531 patent, which claims pharmaceutical compositions of drospirenone and ethinyl estradiol, protects Bayer's popular birth-control pill Yasmin.  In today's decision, the majority (Judges Mayer and Friedman) held that "the invention would have been obvious to try."  Judge Newman dissented.

Drospirenone is an acid-sensitive and poorly soluble compound.  The use of drospirenone with ethinyl estradiol was known in the prior art, but, according to Bayer, formulations of micronized drospirenone in a normal (not enteric coated pill) would not have been obvious, especially since the prior art taught that an enteric coating is necessary to protect drospirenone from the acidic environment of the stomach.

The majority, however, disagreed.  Citing KSR, the majority stated that a person having ordinary skill in the art would have chosen

In dissent, Judge Newman argued that the actual experience of the Bayer scientists should be dispositive.  They testified, without contradiction, "that it was not reasonably expected that uncoated micronized drospirenone would be 99+% effective as an oral contraceptive when ingested into the acid stomach, when it was known to degrade rapidly in acid."  According to Judge Newman, "the exercise of judicial expertise to override the clear evidence of how persons of skill in this field actually behaved, is inappropriate."

RELATED READING:

• Bloomberg article
  
• Teva press release
• OBB post on district court decision

Full post as published by Orange Book Blog: At the Intersection of Patent Law and FDA Law on August 06, 2009 (boomark / email).