Obviousness olf a Compound Does not Hinge on Structural Similarity Alone

Eli Lily and Company v. Zenith Goldline Pharmaceuticals, Inc., [05-1396, -1429, -1430](December 26, 2006)[RADER, Schall, Gajarsa] The Federal Circuit affirmed the district’s holding that Lily’s patent on a composition to treat schizophrenia was valid and infringed.
BRIEF: LOF: Anticipation is a question of fact, including whether or not an element is inherent in the prior art. To anticipate a prior art reference must place the inventive compound or composition in the possession of the public. Thus the prior art reference must disclose each and every feature of the claimed invention, either explicitly or inherently. The Chakrabarti reference disclosed millions of compounds considering all of the proposed alternative substituents, and listed several preferred compounds and substituents, none of which resembled the claimed compound. While the reference did disclose a similar general structural formula, not possible combination of the preferred substituents would lead to the claimed compound. The Federal Circuit noted that to make claimed compound one would have to depart from the teaching of the reference, and recombine the components of specific illustrative compound with hindsight. The Federal Circuit concluded that the Chakrabarti reference did not place the claimed compound in the possession of the public. As to obviousness, the Federal Circuit said that for a chemical compound, a prima facie case of obviousness require structural similarlity between the claimed and prior art subject matter, where the prior art gives reason or motivation to make the claimed composition. The Federal Circuit agreed with the district court that the prior art taught away from the substitution required to arrive at the claimed compound. The Federal Circuit said that patentability does not hinge on structural similarity alone. Where the claimed properties differ from the prior art, and if those difference are unexpected and significant, the differences may lead to nonobviousness. Moreover, there was no evidence that a person of ordinary skill in the art would have selected the asserted prior art as a lead compound in view of the teachings of the prior art. The Federal Circuit also found that Lily had shown strong secondary considerations, including longfelt but unmet need, failure of others, industry acclaim, and unexpected results.
Regarding public use, the Federal Circuit held that such use as there was, was experimental, identifying six relevant factual inquiries: 1. the length of the test period; 2. existence of confidentiality agreements; 3. records of testing; 4. monitoring and control of test results; 5. the number of tests; 6. the length of testing compared to testing of similar inventions.
The Federal Circuit also affirmed the finding of no inequitable conduct.