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March 11, 2009

Up in Smoke

Robert Chapman (11/391,897) followed on the heels of Michael Casner (7,153,966) in his formulation for a synthetic opioid, oxycodone. In a USPTO interference, Casner knocked out the upstart Chapman on obviousness. On a spiteful appeal, Chapman tried comeuppance.

Robert Chapman et al v. Michael Lawrence Casner et al (CAFC 2008-1427, -1428) non-precedential

The fight was mistakenly over creation of a particular form of stereoisomer, which is an isomer where the atoms are in the same order, but a different arrangement.

Oxycodone is a synthetic analgesic opioid used to relieve pain. Typically, one prepares oxycodone by first oxidizing thebaine. This step converts thebaine into two types of compounds: 14-hydroxycodeinone ("14-hydroxy") and the 8,14-dihydroxy-7,8-dihydrocodeinones (collectively, "8,14-dihydroxys"). The 14-hydroxy is converted via hydrogenation into oxycodone, which is then treated with acid during a final "salting" step to yield pharmaceutical grade oxycodone. Any 14-hydroxy remaining at the end of the reaction is problematic, as the compound is potentially toxic.

The 8,14-dihydroxys created during the initial oxidation step are stereoisomers--there are two forms, designated "8α" and an "8β," that differ only by the relative orientation of a hydroxyl group. Chapman claims that prior to the '897 application, persons of ordinary skill in the art did not know that 8α formed during the reaction. Instead, they believed that thebaine oxidized to form 14-hydroxy and 8α, and that any 14-hydroxy remaining at the end of the reaction was leftover, unreacted 14-hydroxy. In fact, during the salting step at least one of the 8,14-dihydroxys reacts with acid to form "new" 14-hydroxy; this 14-hydroxy can then, of course, undergo hydrogenation to become additional oxycodone.

Chapman argues that he was the first to recognize that additional 14-hydroxy is created from 8α during the reaction's salting step, and that the "new" 14-hydroxy can therefore yield additional oxycodone. Chapman purports to claim this method of eliminating the "new" 14-hydroxy in claim 96. The claim does not, however, differentiate between the 8α and 8β forms of 8,14-dihydroxy, nor does the claim language specifically disclose which conditions are "suitable" for promoting the desired reaction from 8,14-dihydroxy to 14-hydroxy.

In short, lack of careful claiming and argument -

Chapman has not identified any statement before the Board that explicitly differentiated between the invention and the prior art based on stereochemistry.

[P]rior art references that disclose either the 8α or 8β form of 8,14-dihydroxy converting to 14-hydroxy, or disclose any reaction condition (whether "commercial" or not) that promotes the conversion of 8á or 8â to 14-hydroxy, may render the claim obvious. See In re May, 574 F.2d 1082, 1088-89 (C.C.P.A. 1978) ("[The reference] expressly discloses . . . a species within the genus of claim 1. Therefore, [the reference] is a technical anticipation of claim 1. Appellants' assertions to the contrary notwithstanding, this finding does not constitute a new ground of rejection; lack of novelty is the epitome of obviousness."); cf. Medichem, S.A. v. Rolabo, S.L., 353 F.3d 928, 934-35 (Fed. Cir. 2003) (concluding that first step of an interference-in-fact inquiry was satisfied where two method claims had a genus/species relationship, since "'[i]t is . . . an elementary principle of patent law that when, as by a recitation of ranges or otherwise, a claim covers several compositions, the claim is "anticipated" if one of them is in the prior art.'" (quoting Titanium Metals Corp. v. Banner, 778 F.2d 775, 782 (Fed. Cir. 1985)); Eli Lilly & Co. v. Barr Labs., Inc., 251 F.3d 955, 971 (Fed. Cir. 2001) (in context of an obviousness-type double patenting analysis, noting that "[t]he only other difference between [the two method claims] is that the former is directed to humans while the latter is directed to animals," and "[o]ur case law firmly establishes that a later genus claim limitation is anticipated by, and therefore not patentably distinct from, an earlier species claim.").

Given that claims directed to the genus (methods for eliminating 8,14-dihydroxys) can be anticipated or rendered obvious by references disclosing the species (methods for eliminating either the 8α or 8β form of 8,14-dihydroxy), we agree with the Board that the method described in claim 96 would have been obvious.

Chapman's attempt to smoke Casner failed. PBAI ruling affirmed.

Posted by Patent Hawk at March 11, 2009 3:52 PM | Prior Art

Comments

The IPBiz blog has picked up and is running with this case, and its owner is interested in the way the EPO handles obviousness. But as an anonymity, I can't post to IPBiz, so I'll post here instead.

The Rader dissent in this "Chapman" case detects what in Europe we call a "problem invention". But that doesn't provide any indication that Rader favours the European "Problem and Solution Approach" to obviousness. Probably, like nearly everybody else, he hasn't begun to ponder whether it is worth looking at, from the point of view of adopting it. Instead, Rader finds support in old domestic US jurisprudence for recognising the non-obviousness of a "problem invention".

Posted by: MaxDrei at March 13, 2009 8:18 AM