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September 11, 2007

Obvious Viper

Aventis sued Lupin for infringing 5,061,722 after Lupin filed an FDA drug application (ANDA). '722 goes to a blood medication, Altace. District court summary judgment found infringement under the doctrine of equivalents, and a pre-KSR bench trial rendered the patent "not invalid," as the appeals court backhandedly put it. Which is to say, on appeal, the CAFC took the double negative out, finding the patent "would have been obvious." KSR strikes again.

Aventis Pharma Deutschland GMBH and King Pharmaceuticals v. Lupin (CAFC 2006-1530, -1555)

Ramipril originated from viper venom extract.

Ramipril is one of a family of drugs known as “Angiotensin-Converting Enzyme inhibitors,” or “ACE inhibitors.” ACE inhibitors inhibit a biochemical pathway that constricts blood vessels and therefore are useful for treating high blood pressure. The earliest ACE inhibitors, dating back to the late 1960s, were based on the venom of the Brazilian Viper, which was known to reduce blood pressure. The active compound isolated from viper venom, known as BPP5a, has six stereocenters, all of which are in the S configuration. Synthetic ACE inhibitors have been developed by making structural modifications to this venom and to successive generations of ACE inhibitors.

The district court had found motivation in the prior art lacking, but especially post-KSR, motivation for improvement is inherent. Structural similarity of chemicals provides a presumption of obviousness. If there is some "desirable property" of a mixture, or if even if there is "reason to believe that this is so," the mixture is obvious, "without an explicit teaching." Concentrating or purifying a mixture is just "common sense." But if a purified compound is discovered meaningful, or the purification process itself novel, it may be "of patentable weight in itself."

In the chemical arts, we have long held that “structural similarity between claimed and prior art subject matter, proved by combining references or otherwise, where the prior art gives reason or motivation to make the claimed compositions, creates a prima facie case of obviousness.” Takeda Chem. Indus., Ltd. v. Alphapharm Pty., Ltd., No. 06-1329, slip op. at 9 (Fed. Cir. June 28, 2007) (quoting In re Dillon, 919 F.2d 688, 692 (Fed. Cir. 1990) (en banc)); see also In re Papesch, 315 F.2d 381 (C.C.P.A. 1963). The “reason or motivation” need not be an explicit teaching that the claimed compound will have a particular utility; it is sufficient to show that the claimed and prior art compounds possess a “sufficiently close relationship . . . to create an expectation,” in light of the totality of the prior art, that the new compound will have “similar properties” to the old. Dillon, 919 F.2d at 692; see also In re Wilder, 563 F.2d 457, 460 (C.C.P.A. 1977) (“[O]ne who claims a compound, per se, which is structurally similar to a prior art compound must rebut the presumed expectation that the structurally similar compounds have similar properties.”). Once such a prima facie case is established, it falls to the applicant or patentee to rebut it, for example with a showing that the claimed compound has unexpected properties. Dillon, 919 F.2d at 692.

The analysis is similar where, as here, a claimed composition is a purified form of a mixture that existed in the prior art. Such a purified compound is not always prima facie obvious over the mixture; for example, it may not be known that the purified compound is present in or an active ingredient of the mixture, or the state of the art may be such that discovering how to perform the purification is an invention of patentable weight in itself. However, if it is known that some desirable property of a mixture derives in whole or in part from a particular one of its components, or if the prior art would provide a person of ordinary skill in the art with reason to believe that this is so, the purified compound is prima facie obvious over the mixture even without an explicit teaching that the ingredient should be concentrated or purified.

Ordinarily, one expects a concentrated or purified ingredient to retain the same properties it exhibited in a mixture, and for those properties to be amplified when the ingredient is concentrated or purified; isolation of interesting compounds is a mainstay of the chemist’s art. If it is known how to perform such an isolation, doing so “is likely the product not of innovation but of ordinary skill and common sense.” KSR, 127 S. Ct. at 1742.

Posted by Patent Hawk at September 11, 2007 2:31 PM | Prior Art


What happens to issued patents after KSR? Would many of them become invalid, and does anyone have an estimate of how many are now invalid for obviousness?
Also how does getting a patent in the US compare to getting one in Europe now? Would a marginal patent in Europe (i.e. just good enough to get granted) be likely to be granted in the US or is the standard in the US now higher than Europe?

Posted by: MJC at September 21, 2007 2:26 AM

Depending upon the art area, many to the vast majority of issued patents are unenforceable, as they would be found obvious. Because the numbers are so large, and yet each patent is individual, it is difficult to have any sense of percentage. Patent Hawk, whose bread-and-butter is invalidating patents via prior art, kills over 60% of those assigned using 102. Most Patent Hawk work is in the fields of business methods, software, electronics, and semiconductor. Add in the ease of 103(a) invalidity post-KSR, and over 90% of patents in those areas are likely to be fodder for invalidity via obviousness. The pre-KSR strategy of incremental invention created a historical library that now acts as a falling-domino set for obviousness hindsight reasoning that the courts for decades shunned, but now embrace, thanks to the unlawful SCOTUS KSR decision.

Posted by: Patent Hawk at September 23, 2007 1:01 PM

What happens then if this decision is reversed later, and inventors have had their patents invalidated then revalidated?

Posted by: MJC at September 26, 2007 10:59 PM

Patents are invalidated either through reexamination or attempted enforcement. There is no resurrection for invalidated patents, unless, through a sibling, in freakish circumstance, a continuation exists when the case law, or statutory law, changes; then, an invention that would have been doomed may be redeemed.

Most now-unenforceable patents will languish unenforced. Attrition, in the form of not paying maintenance fees, will take many. Hope dies hard sometimes, and worthless patents sustained, maintenance fees paid as a breath of wistful anticipation that fortune may change.

Posted by: Patent Hawk at September 26, 2007 11:23 PM

It may not be as bad as you say if this patent survived:


Posted by: MJC at September 28, 2007 8:38 PM