Obviousness of Chemical Compounds: Navigating the Lead Compound Test at the Patent Office
The outcomes of inter partes review petitions and final written decisions have differed dramatically for claims in pharmaceutical patents, compared to other technologies, particularly for obviousness challenges of claims to chemical compounds. In its final written decisions of Orange Book-listed patents, the Patent Trial and Appeal Board (“PTAB”) has found claims unpatentable 35% of the time, in contrast to a 73% unpatentability rate in final written decisions across all technologies. Likewise, in its institution decisions, the PTAB has granted 70% of petitions for inter partes review, but only 57% of petitions concerning pharmaceutical patents, and only 30% of petitions raising obviousness challenges of chemical compounds.
As emphasized by these statistics, alleging obviousness of a chemical compound involves a particularly complex analysis with numerous pitfalls for petitioners and patent owners alike. In the article linked below, I analyzed PTAB opinions from ex parte examination appeals and in inter partes review proceedings on prima facie obviousness of chemical compounds to gain insight into how the PTAB is handling these cases. From this analysis, methodological inconsistencies were uncovered between PTAB decisions in ex parte appeals and inter partes proceedings, with the PTAB seeming to apply a more strict “lead compound analysis” in inter partes review proceedings. By analyzing these decisions, the article identifies pitfalls and practice pointers for navigating the fact-intensive chemical obviousness analysis at the Patent Office.
For a link to the full article, please click here.
Mr. Shackelford is an associate in the chemical patent and biotechnology / pharmaceutical practice groups, where he maintains an active patent prosecution and litigation practice.
Prior to joining Sughrue Mion, Mr. Shackelford served as Intellectual Property Fellow at Illinois Institute of Technology Chicago-Kent College of Law, where he taught IP courses for LL.M. and J.D. students and conducted research into patent claim construction. During law school, Mr. Shackelford worked as a patent prosecution law clerk at the U.S. Department of Energy, evaluating invention disclosures, responding to Office Actions, and drafting patent applications. Prior to law school, Mr. Shackelford worked at the Midwest Center for Structural Genomics as an Associate Research Scientist, where he conducted and helped develop techniques for high-throughput cloning, expression, and crystallization of target proteins.
Mr. Shackelford earned his J.D. from the IIT Chicago-Kent College of Law, where he was a member of the Moot Court Honor Society and Law Review. He received his B.S. in Biochemistry from the University of Missouri-Columbia and M.S. in Chemistry and Chemical Biology from the University of California, San Francisco. As an undergraduate and graduate research scientist, Mr. Shackelford focused his research in the area of protein chemistry, studying protein superfamilies to identify mechanisms of enzymatic function and routes through which enzymes develop new functionality.
Admitted in Illinois only. Not a member of the DC Bar. Practice limited to certain matters before federal agencies and courts.
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