Under US patent law, an inventor is entitled to only one patent for an invention. Thus, the US Patent Office can reject a patent application based on double-patenting. Note also that double-patenting can be used as a defense to a claim of patent infringement. Essentially, the defendant can argue that the patent allegedly infringed is invalid based on double patenting. See, for example, Perricone v. Medicis Pharm. Corp., 267 F.Supp.2d 229 (D.Conn.2003) aff’m on the double patenting issue, 432 F. 3d 1368 (Federal Circuit 2005).

This article addresses options for responding to a rejection by the US Patent Office based on double patenting.

Note that with respect to double patenting, the issue applies only to an inventor with more than one patent. When considering double patenting as a basis for rejection — or invalidity — the focus is between an earlier patent and a later patent or application owned or submitted by the same inventor.

Two types of double patenting

There are two types of prohibited double patenting: statutory and non-statutory. The first involves patent claims that are identical between the two patents. This is prohibited by §101 of the Patent Act. As such, this is called statutory double-patenting. If your patent application is rejected for statutory double patenting, essentially, there are only three options:

• Cancel or abandon your application
• Modify the claims in the pending application or
• Dispute the rejection and potentially litigate

The final option might be viable if the Patent Examiner is wrong. Rejection for statutory double patenting will be forthcoming if the patent claims are word-for-word the same. But, if there is a slight variation in the wording, that variation might be sufficient to avoid a rejection for double-patenting.

Non-statutory double patenting is often designated as “obviousness-type” double patenting. That is, the two patent claims are not worded the same, but nonetheless are so alike that granting the application would effectively be granting two patents. With non-statutory double patenting, the public policy purpose is to disallow an inventor from extending the life of the patent protection provided by the earlier patent. If your patent application is rejected for non-statutory double patenting, the three options from above are available.

A fourth  option for non-statutory double patent rejection is to file a “Terminal Disclaimer.” Essentially, this is an inventor’s agreement that the term of the second patent’s protection will not exceed the term of the earlier patent. As an example, the term of protection for a utility patent is 20 years. If a Terminal Disclaimer is filed, the Patent Office will also require that the patents be owned by the same person/entity during the relevant time period. By its terms, a Terminal Disclaimer is binding upon the inventor and any successors or assigns.

For more information or if you have an invention that you want to patent, contact the patent lawyers at Revision Legal at 231-714-0100.