Alza Loses Appeal of Ditropan XL Case to Mylan
The Court of Appeals for the Federal Circuit recently affirmed a lower court's determination that Alza's patent on Ditropan XL, a controlled-release formulation of oxybutinin, is invalid due to obviousness. Ditropan XL is a treatment for incontinence, with annual sales of $380 million.
In the opinion, written by Judge Gajarsa, a unanimous panel of the Federal Circuit concluded that the controlled-release formulation of oxybutinin claimed in Alza's U.S. Patent No. 6,124,355 would have been obvious. Alza argued that one of ordinary skill in the art would not have believed that oxybutinin could be absorbed in the colon, and therefore would not have believed that a controlled-release formulation would have been effective, and therefore there was no motivation to make the claimed oxybutinin formulation. The court rejected Alza's argument based on Mylan's expert testimony.
The Federal Circuit used this case, like it has used other recent cases, to defend its "teaching, suggestion, motivation" test of obviousness, which is under assault in the KSR v. Teleflex case currently pending before the Supreme Court. The Federal Circuit stated:
As an initial matter, it is essential to recognize that, as we have explained above, under our non-rigid "motivation-suggesting-teaching" test, a suggestion to combine need not be found in the prior art. . . . Accordingly, 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.
The district court decision, written by Judge Irene M. Keeley of the U.S. District Court for the Northern District of West Virginia, found that Alza's patent was both invalid and not infringed by Mylan. Because the Federal Circuit affirmed the obviousness finding, it did not address the infringement issue.
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