July 25, 2014

Obviousness-Type Double Patenting Requires a Reason to Modify with a Reasonable Expectation of Success

Addressing the issue of obviousness-type double patenting, the U.S. Court of Appeals for the Federal Circuit reaffirmed its earlier rulings that obviousness must be judged by whether the differences in subject matter between the new claim and the earlier claim are patentably distinct.  Eli Lilly and Co. et al. v. Teva Parenteral Medicines et al., Case Nos. 11-1561, -1562 (Fed. Cir., Aug. 24, 2012) (Lourie, J.). 

The appeal arose from the filing of an Abbreviated New Drug Application (ANDA) by Teva for regulatory approval of the anticancer agent pemetrexed.  At trial, Teva conceded infringement of U.S. Patent No. 5,344,932, but argued that the patent was invalid for obviousness-type double patenting based on two parent references—a predecessor to pemetrexed shown in U.S. Patent Nos. 5,028,608 and an intermediate in making pemetrexed shown in U.S. Patent No. 5,248,775.  The district court found the patent was not invalid, ruling that one of ordinary skill in the art would not have been motivated to change the portion of pemetrexed that differed from the compound shown in the ’608 and ’775 references and that, because the ’932 patent did not claim the use of the ’775 patent’s compound, the teachings of the ’775 patent were irrelevant to an obviousness-type double patenting analysis.

On appeal, the Federal Circuit affirmed the district court, ruling that proof of obviousness-type double patenting requires identifying some reason that would have led a chemist to modify the earlier compound with a reasonable expectation of success.  The Federal Circuit found that the district court’s factual findings in this regard with respect to the predecessor compound showed no clear error.  With respect to the precursor intermediate, the Court rejected Teva’s argument that because the precursor claimed in the ’775 patent is used to make pemetrexed, the ’932 patent claims a previously disclosed use for a patented compound.  Holding that for an obviousness-type double patenting analysis, only the claims of the prior art reference may be considered, not the specification itself, the court distinguished earlier holdings in In re Byck and Sun Pharmaceutical Industries, by finding that those cases involved situations in which the patentee attempted to claim a method of using a composition after disclosing the use in an earlier patent claiming the composition itself.  Here, the ’775 patent never claimed pemetrexed, only an intermediate along the path to synthesizing pemetrexed, and therefore Byck and its progeny did not apply. 

Finally, the panel rejected the district court’s refusal to examine secondary indicia of non-obviousness, finding that such evidence applied to an obviousness-type double patenting analysis as equally as any other obviousness argument.

© 2014 McDermott Will & Emery

About the Author


Christopher L. May is an associate in the law firm of McDermott Will & Emery LLP and is based in the Firm’s Washington, D.C., office.  He focuses his practice on patent and trademark litigation.  Christopher is also an adjunct professor at Michigan State University where he teaches a course on general intellectual property. 


Boost: AJAX core statistics

Legal Disclaimer

You are responsible for reading, understanding and agreeing to the National Law Review's (NLR’s) and the National Law Forum LLC's  Terms of Use and Privacy Policy before using the National Law Review website. The National Law Review is a free to use, no-log in database of legal and business articles. The content and links on are intended for general information purposes only. Any legal analysis, legislative updates or other content and links should not be construed as legal or professional advice or a substitute for such advice. No attorney-client or confidential relationship is formed by the transmission of information between you and the National Law Review website or any of the law firms, attorneys or other professionals or organizations who include content on the National Law Review website. If you require legal or professional advice, kindly contact an attorney or other suitable professional advisor.  

Some states have laws and ethical rules regarding solicitation and advertisement practices by attorneys and/or other professionals. The National Law Review is not a law firm nor is  intended to be  a referral service for attorneys and/or other professionals. The NLR does not wish, nor does it intend, to solicit the business of anyone or to refer anyone to an attorney or other professional.  NLR does not answer legal questions nor will we refer you to an attorney or other professional if you request such information from us. 

Under certain state laws the following statements may be required on this website and we have included them in order to be in full compliance with these rules. The choice of a lawyer or other professional is an important decision and should not be based solely upon advertisements. Attorney Advertising Notice: Prior results do not guarantee a similar outcome. Statement in compliance with Texas Rules of Professional Conduct. Unless otherwise noted, attorneys are not certified by the Texas Board of Legal Specialization, nor can NLR attest to the accuracy of any notation of Legal Specialization or other Professional Credentials.

The National Law Review - National Law Forum LLC 4700 Gilbert Ave. Suite 47 #230 Western Springs, IL 60558  Telephone  (708) 357-3317 If you would ike to contact us via email please click here.