Until recently, generic pharmaceutical manufacturers were without any type of real roadmap when trying to invalidate a compound patent as being obvious under 35 U.S.C. § 103. The Federal Circuit recently affirmed an obviousness finding in a lead compound case. Bristol-Myers Squibb Co. v. Teva Pharms. USA, Inc., --- F.3d ----, 2014 WL 2609924 (Fed. Cir. June 12, 2014). In the opinion, the Federal Circuit provided at least one way of proving lead compound obviousness in the structure of a fourpart test.

The Four-Part Test

The factors that the Federal Circuit considered were:

  1. Is there structural similarity between the product-at-issue and the lead compound?
  2. What are the teachings of secondary references?
  3. Would the modification to the lead compound be a “small, conservative change?”
  4. What are the teachings (i.e., motivation and expectation of success) of the totality of the prior art with respect to the lead compound?

How The Four-Part Test Was Applied

Under this test, the BMS Court found that (1) there was structural similarity between the claimed compound and the lead compound, and both had similar antiviral properties; (2) secondary references demonstrated that modification to a certain atom of a compound yielded superior efficacy; (3) modifying the lead compound per the secondary references would have been a “small, conservative change” to that structure; and (4) the totality of the prior art taught that there was motivation and a reasonable expectation of success that modifying the lead compound (a compound more potent than others on the market) would produce a product with similar properties for use in treating the same types of diseases.

Secondary Consideration Insufficient

BMS countered with an unexpected results argument. The Federal Circuit did not agree, holding that while there may have been unexpected results, those results were not sufficient to overcome the clear and convincing evidence of obviousness. In support, the Court cited to its own recent decision, Hoffmann-La Roche Inc. v. Apotex Inc., --- F.3d ---, 2014 WL 1394948, at *7 (Fed. Cir. Apr. 11, 2014): “The evidence of superior efficacy does nothing to undercut the showing that there was a reasonable expectation of success with the 150 mg monthly dose, even if the level of success may have turned out to be somewhat greater than would have been expected.”

Import of the Case

This case serves as guidance for generic pharmaceutical manufacturers when seeking to invalidate compound patents as being obvious in order to get their generic products on the market for the benefit of consumers. In knowing what the courts are specifically looking for in these analyses, generic pharmaceutical manufacturers should be able to properly focus their case on a lead compound obviousness strategy that can prove successful.