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Sun Pharmaceuticals v. Eli Lilly: obviousness-type double patenting in the pharmaceutical context

By Jason Rantanen

Sun Pharmaceutical Industries, Ltd. v. Eli Lilly and Company (Fed. Cir. July 28, 2010)

By Jason Rantanen

Double-patenting issues arise when two commonly owned applications cover the same or similar inventions.  The issues in this appeal revolved around an earlier patent claiming a composition of matter and describing a method for using that composition, and a later patent claiming that method of use. 

Both of the patents in this case, Patent No. 4,808,614 (the '614 patent) and Patent No. 5,464,826 (the '826 patent) relate to gemcitabine, the active ingredient of Lilly's Gemzar® product.  The '614 patent claims both gemcitabine itself, as well as a method of using it to treat viral infections.  In addition, the '614 patent's specification discloses using gemcitabine to treat cancer.  The '826 patent claims a method treating cancer comprising administering a therapeutically effective amount of gemcitabine.  The difference was important: the '614 patent expired on May 15, 2010, while the '826 patent does not expire until November 7, 2012.

Note: The applications leading to both the '614 and '826 patents were filed on the same day, December 4, 1984.  The '614 was a continuation-in-part of application No. 473,883 ("the '883 application"), which did not disclose using gemcitabine to treat cancer.  That information was added as part of the continuation-in-part. 

After filing an Abbreviated New Drug Application ("ANDA") for a generic version of Gemzar®, Sun Pharmaceuticals, sought a declaratory ruling that the '826 patent was invalid and not infringed.  Lilly counterclaimed for infringement of the '826 and '614 patents.  The '614 patent was not at issue in this appeal.

Obviousness-type double patenting applies
Applicants are barred from obtaining multiple patents covering the same invention by the doctrine of double patenting.  There are two types of double patenting: statutory double patenting, which prohibits a later patent from covering the identical invention, and obviousness-type double patenting, which prevents a later patent from covering a slight variation of an earlier patented invention.

On appeal, the panel agreed with the district court and Sun that the latter type of double patenting occurred here, thus invalidating the asserted claims of the '826.  The basis for the court's decision were two prior opinions, Geneva v. GlaxoSmithKline, 349 F.3d 1373, and Pfizer v. Teva, 518 F.3d 1353.  In Geneva, the earlier patent claimed a compound and the specification disclosed its effectiveness for inhibiting beta-lactamase.  The later patent claimed a method of using the compound to affect beta-lactamase inhibition.  Similarly, in Pfizer, the earlier patent claimed several compounds and the specification disclosed their use in treating inflamation; the later patent claimed a method of using these compounds for treating inflammation.  In both cases, the court ruled that the claims were not "patentably distinct," and thus the latter claims were invalid for obviousness-type double patenting.  

While Lilly argued that Geneva and Pfizer did not apply because "the specification of the earlier patent disclosed a single use for the claimed compound, which was an essential part of the patented invention and thus necessary to patentability," Slip Op. at 8, the court rejected that argument for two reasons.  First, the court disagreed that the specification in Pfizer disclosed more than one utility for the claimed compound.  In addition, the court read the rule of Pfizer as simply that "obviousness-type double patenting encompasses any use for a compound that is disclosed in the specification of an earlier patent claiming the compound and is later claimed as a method of using that compound.  Pfizer never implies that its reasoning depends in any way on the number of uses disclosed in the specification of the earlier patent."  Slip Op. at 10. 

The court also rejected Lilly's argument that the specification of an earlier application should have been consulted, as opposed to the specification of the '614 patent.  Drawing upon its claim construction precedent, the court noted that the specification is relevant to determining the coverage of the claims, which is at the heart of the obviousness-type double patenting analysis.  The court further noted that "consulting the specification of the issued patent, as opposed to an earlier version, is consistent with the policy behind double patenting," which rests "on the fact that a patent has been issued and later issuances of a second patent will continue protection, beyond the date of expiration of the first patent of the same invention or an obvious variation thereof."  Slip Op. at 14-15.

Full post as published by Patently Obvious on August 02, 2010 (boomark / email).