Duhaime's Law Dictionary

Double Patenting Definition:

An attempt by a patentee to receive two consecutive patents on essentially the same invention thus extending the term of exclusivity.

Related Terms: Patent

Double-patenting is prohibited.

In Takeda, Chief Justice Randall Rader of the United States Court of Appeals (Federal Circuit) wrote:

"Double patenting generally prevents a patentee from receiving two patents and extending the term of exclusivity for a single invention.

"The proscription against double patenting takes two forms: statutory and non-statutory.

"Statutory, or same invention double patenting finds its origin in the statutory grant of a patent for any new and useful invention.

"Non-statutory, or obviousness-type double patenting is a judicially created doctrine designed to foreclose claims in separate applications or patents that do not recite the same invention, but nonetheless claim inventions so alike that granting both exclusive rights would effectively extend the life of patent protection.

"In other words, the double patenting doctrine is designed to prevent unjustified timewise extension of the right to exclude. For instance, the doctrine bars an applicant from obtaining separate patents with separate terms for both a product and process for making that product, unless the product and process are patentably distinct....

"[D]ouble patenting is not sustainable when the product can be fabricated by processes other than that secured by the issued process patent....

"[A] product and its process are patentably distinct if the product as claimed can be made by another materially different process."

In Sanofi-Synthelabo, Justice Sidney Stein of the United States District Court added, in regards to non-statutory double-patenting:

"The judicial doctrine of obviousness-type double-patenting prevents a patent claim from validly issuing when it "is obvious over, or anticipated by a claim in an earlier patent.

"It is a judge-made criterion adopted out of necessity where the courts were faced with a situation in which claims in two applications or patents were not drawn precisely to the same invention, but were drawn to inventions so very much alike as to render one obvious in view of the other and to effectively extend the life of the patent that would have had the earlier of the two issue dates."


  • Bayer AG v. Dr. Reddy's Laboratories, Ltd., 518 F. Supp. 2d 617 (2007)
  • Sanofi-Synthelabo v. Apotex Inc., 492 F. Supp. 2d 353 (2007)
  • Takeda Pharmaceutical Co., Ltd. v. Doll, 561 F. 3d 1372 (2009)

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