Bottom line: By filing a string of continuing patent applications and not claiming priority for the continuing patent applications back to a common parent application, the patent owner may be able to extend patent protection for its product.
Under U.S. patent laws, an inventor can file a series of successive child patent applications. This is commonly referred to as continuation practice as each application is a “continuation” of the earlier application. With some limitations, each successive child patent application can claim priority back to a different parent application in its lineage. Moreover, since a patent’s term is calculated from the date of the earliest priority parent application, it is possible to have two related patents sharing at least one common patent application in its lineage but having different patent terms, and thus effectively extend patent protection. However, the two related patents should be filed in response to a restriction requirement, as discussed further below, so that they are “divisional” applications rather than “continuation” applications.
Continuation practice may be beneficial to the patent owner in order to maintain pendency of the subject matter disclosed in the patent application. Doing so allows the patent owner to craft new claims at a later date to try and cover competitors trying to design around the base patent. If a competitor designs around the initial patent, then the continuation patent application can be used as a vehicle to introduce new claims crafted specifically for that competitor’s product. The following case illustrates one way that the life of a patent can be ‘extended’ through continuation practice beyond the term of the first patent – but in this case the claims were improperly extend and found invalid.
In AbbVie Inc. v. Kennedy (Fed. Cir. 2014), the patent owner (Kennedy) filed a string of patent applications from 1992 to 2005. Kennedy obtained U.S. Pat. No. 6,270,766 (‘766 Patent) that expired in 2012. Kennedy obtained a $100 million royalty from AbbVie as a licensee to sell the product Humira. Thereafter, Kennedy also obtained U.S. Pat. No. 7,846,442 (‘442 Patent) which would expire in 2018.
Referring to the diagram below, the ‘766 patent issued from a patent application filed on August 1, 1996 and claimed priority back to a patent application filed on in 1992. The ‘442 patent matured from a patent application filed in 2005 and claimed priority back to the patent application which matured into the ‘766 patent so that the ‘442 patent had a priority date of August 1, 1996.
The patent term or life for a patent is calculated based on a number of factors. The basic calculation for patent term is twenty years from the earliest priority date. Using this priority date the ‘442 patent would expire after the expiration of the ‘766 patent even though they share a common lineage because the earliest priority date for the ‘442 patent is later than the earliest priority date for the ‘766 patent. Kennedy was able to file the patent application maturing into the ‘442 patent without claiming priority all the way back to the earliest priority patent application of the ‘766 patent. In this way, Kennedy was able to extend patent protection for its product six years beyond that of the ‘776 patent.
After Kennedy secured AbbVie as a licensee of the ‘776 patent and obtained $100 million dollar for the license of the ‘766 patent, Kennedy requested additional royalties for a license on the ‘442 patent. AbbVie was unwilling to pay further royalties for the right to sell the same product. Litigation ensued. AbbVie attacked the validity of the ‘442 patent based on obviousness-type double patenting. Although Kennedy was successful at the USPTO in extending the term of patent protection for its product, Kennedy was unsuccessful in defending validity of the ‘442 patent. AbbVie was successful in convincing the court that the claims of the ‘442 patent was obvious in light of the claims of the ‘776 patent. This is called a double patenting rejection. The courts do not want multiple patents having similar claims with different patent terms.
Although Kennedy was unsuccessful in defending its patent during litigation, the technique to extend patent protection employed by Kennedy could have been successful if it was done in response to a restriction requirement.
A restriction requirement is a requirement from the examiner finding that the applicant has claimed more than one independent and distinct invention, and requiring that the applicant elect one invention out of two or more inventions recited in the claim set. One common scenario in which the examiner might classify the claims as being directed to two different inventions is in relation to an apparatus claim and a claim directed to the method of using the apparatus. This is a typical method / apparatus restriction requirement. If a restriction requirement was involved between the ‘442 patent and the ‘766 patent, then AbbVie could not have invalidated the ‘766 patent by way of double patenting. Rather, such obviousness type double patenting arguments based on the claim sets of two related patents are precluded by statute. Kennedy would have successfully defended its patents, and thus extend patent protection. On the other hand, a divisional application has to be filed before the patent issues in which the restriction requirement is imposed. Doing so in Kennedy’s case would have resulted in filing the patent several years sooner and shortening its life. But it would still have offered the possibility of demanding a second royalty from AbbVie.
Thus, another lesson from this case is that if you are taking a license under a patent, make sure the license covers future patents on the same subject matter that is being licensed.
I invite you to contact me with your patent questions at (949) 433-0900. Please feel free to forward this article to your friends. As an Orange County Patent Attorney, I serve Orange County, Irvine, Los Angeles, San Diego and surrounding cities.