Source: https://www.fdalawblog.net/2009/12/pto-rules-on-the-availability-of-multiple-interim-patent-term-extensions/
Timestamp: 2019-04-26 11:48:30+00:00

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A recent decision from the Patent and Trademark Office (“PTO”) in which the Office granted an interim Patent Term Extension (“PTE”) for U.S. Patent No. 5,407,914 but denied interim extensions for U.S. Patent Nos. 5,260,273 and 5,789,381 covering the drug product SURFAXIN appears to be the first time in which the PTO has had to address the issue of the availability of multiple interim PTEs. The PTO has previously ruled that multiple PTEs are available, under certain circumstances, once a drug product has been approved (see our previous posts here and here).
There are two types of interim patent extensions under the PTE statute (35 U.S.C. § 156): (1) interim patent extensions granted during the “review phase” of the statutory “regulatory review period” (35 U.S.C. § 156(d)(5)); and (2) interim patent extensions granted during the PTO’s review of an application for a PTE (35 U.S.C. § 156(e)(2)).
The PTO may grant an interim patent extension while an NDA is undergoing FDA review if the patent owner (or his agent) “reasonably expects” that the applicable statutory “regulatory review period” will extend beyond the expiration of a patent that claims the drug product under review at FDA. The patent owner (or his agent) must submit to the PTO an application “during the period beginning 6 months, and ending 15 days, before such [patent] term is due to expire.” If the PTO determines that, except for receipt of FDA’s permission to market or use a product commercially, the patent would be eligible for a statutory extension of the patent term under 35 U.S.C. § 156, then the PTO publishes a notice in the Federal Register announcing the interim patent extension for the particular product, and issues to the applicant a certificate of interim patent extension for a period of not more than one year. The applicant may apply for additional interim patent extensions for the patent; however, the PTO generally limits subsequent applications for a particular patent to four one-year interim patent extensions (thus, a total of five years).
The PTO may also extend (either on its own initiative or upon the application of a patent owner) the term of a patent for up to one year if the time necessary to process and review an application for patent term extension might result in a patent expiring while the application is under review at the PTO.
The cumulative patent time granted under either type of interim patent extension cannot exceed the PTE that a company might obtain under regular patent extension provisions. That is, interim patent extensions cannot exceed what the PTO might ultimately determine is the correct PTE for which a particular patent claiming a drug product is eligible. The PTO reviews each application requesting an interim patent extension to ensure that a patent will not be extended for more time than that for which it is eligible under the law.
The explicit language of section 156, in many instances, states that it is the term of "a patent" which shall be extended. Additionally, the statute provides for "an extension of the term of a patent." See § 156(d)(1). This is not the first time that the USPTO has been required to interpret the language "a patent." It is a long-standing interpretation of the USPTO that "a patent" means one patent. In the context of double patenting, the USPTO's Manual of Patent Examining Procedure (MPEP) clearly explains a "'same invention' type double patenting rejection [is] based on 35 U.S.C. 101 which states in the singular that an inventor 'may obtain a patent.'" See MPEP 804 (emphasis added). . . .
Based on the language of the statute, as a whole, and the plain meaning of "a patent," the statute only contemplated that a single patent is entitled to have the term extended for the same (single) regulatory review period. Similarly, the explicit language of section 156(d)(5)(C) makes clear that interim extension is applicable only for "a patent," stating, "[t]he owner of record of a patent, or its agent, for which an interim extension has been granted under subparagraph (b), may apply for not more than 4 subsequent interim extensions under this paragraph . . . ." The plain language of obtaining "an extension" for "a patent" delineates that the patent term extension statute contemplates that only one patent may be granted an interim extension. Furthermore, the language of § 156 distinguishes "interim extension" from "extension" by referring throughout subsection 156(d)(5) that the extension is "an interim extension." See e.g., § 1 56(d)(5)(F) indicating that the rights derived are "during the period of interim extension." (emphasis added).
With respect to cases in which a company might ultimately be eligible for multiple PTEs once a drug product is approved, the PTO’s interim PTE decision leaves the door open for multiple interim patent extensions. Specifically, the PTO’s statement that “only a single interim PTE is available for the same (single) regulatory review period,” means that when separate NDAs, each with its own “regulatory review period,” might be approved on the same first day, more than a single patent might qualify for an interim patent extension.

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