prima facie case of obviousness can be based upon implicit teaching supported by expert witness evidence about understanding at time of invention
In Alza Corporation v. Mylan Laboratories, Case No. 06-1019 (Fed. Cir. Sept. 6, 2006), the Federal Circuit upheld a district court’s decision that plaintiff-appellant Alza’s patent (6,124,355) was invalid and was not infringed by defendant-appellee Mylan’s generic version of an extended release anti-incontinence drug, oxybutynin.
The court upheld the finding that the patent was invalid as obvious while primarily discussing the “motivation-suggestions-teaching” doctrine. The court defended the motivation requirement as flexible because the motivation need not be found explicitly in the prior art so long as there is evidence in the record as to why, at the time of the invention, one skilled in the art would make the asserted combination. While an explicit motivation to combine is one way to meet this test, the Federal Circuit held that the broader inquiry rests “on the unremarkable premise that legal determinations of obviousness, as with such determinations generally, should be based on evidence rather than on mere speculation or conjecture.” Moreover, in meeting the prima facie burden for obviousness, “where the testimony of an expert witness is relevant to determining the knowledge that a person of ordinary skill in the art would have possessed at a given time, this is one kind of evidence that is pertinent to our evaluation of a prima facie case of obviousness.” Thus, it is sufficient for the record show some evidence demonstrating that, at the time of the invention, information was available which would lead one skilled in the art to make the combination.
In applying this test, the court held that the motivation to combine oxybutynin and the time-release pill delivery system existed to the person of ordinary skill in the art in 1995 (the time of the ‘355 patent filing) based upon expert witness testimony. Plaintiff argued that two prior art references demonstrated that, in 1995, no one knew that oxybutynin would be well-absorbed in the colon and thus would not be motivated to create a time release pill form factor. The court found that both references in fact implied that drugs such as oxybutynin would be well-absorbed in the colon, and that the expert witness testimony on the knowledge of persons in the art at the time of the invention was sufficient to meet a prima facie burden for obviousness purposes. The Federal Circuit held that the Plaintiff had failed to rebut this prima facie burden since the applied references did not undercut the witness’ testimony and no other evidence contradicted the testimony or otherwise showed that the expectations were other than that set forth by the expert witness, and found the claims invalid under 35 U.S.C. §103.
The court upheld the finding of non-infringement because Alza failed to submit evidence sufficient to demonstrate that Mylan’s formulation met the time-release characteristics claimed in the ‘355 patent. Alza submitted profiles of the amount of drug in a subject’s blood for both Alza’s and Mylan’s formulation, and similarly submitted evidence of similar release times in laboratory apparatus for the two formulations. However, since the ‘355 patent claimed the rate of in vivo dissolution in the gastrointestinal tract, and since Alza declined to link its two studies to the rate of in vivo dissolution, the court found that the Mylan formulation did not infringe the ‘355 patent.