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On January 20, 2015, Bristol-Myers Squibb petitioned for certiorari in Bristol-Myers Squibb v. Teva Pharmaceutical, asking whether an assessment of obviousness should "consider post-filing evidence showing the actual differences between a patented invention and the prior art." The district court had found patent claims directed towards Entacavir (an anti-hepatitis drug) obvious in view of structural similarity between the drug and a prior art compound, in spite of the fact that the prior art compound was highly toxic and therefore not a viable candidate for use as a human drug. A Federal Circuit panel affirmed the district court's decision to disregard the toxicity of the prior art compound because that toxicity was unknown at the time the patent application was filed, reasoning that since the relevant timeframe for assessing the obviousness of invention is prior to the filing of the application, toxicity data generated after the filing date is not probative of nonobviousness. While perhaps plausible on its face, this approach runs contrary to a well-established body of Federal Circuit case law standing for the proposition that post-filing evidence can be used to establish the nonobviousness of an invention. Although the Supreme Court denied certiorari, the question remains of great importance, particularly for the pharmaceutical industry. This short article reviews the status of this unsettled area of law, summarizing relevant precedent and the positions taken by amici representing the biotechnology and pharmaceutical sectors, and also considering the divergent views of several Federal Circuit judges who have weighed in on the issue.

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Biotechnology Law Report