Patent term extension (PTE)

The patent must claim a product, a method of using a product, or a method of manufacturing a product, and the product must have been subject to a regulatory review period before its commercial marketing or use¹.

• Covered products. A product is a drug product, or any medical device, food additive or color additive subject to regulation under the Federal Food, Drug, and Cosmetic Act. A drug product is the active ingredient of a new drug, antibiotic drug or human biological product, or of a new animal drug or veterinary biological product not primarily made by recombinant DNA and similar techniques, including any salt or ester, alone or in combination (35 U.S.C. 156(f))¹.
• Conditions. The patent's term must not have expired before the application is submitted, and must never have been extended under section 156(e)(1). The application must be submitted by the owner of record or its agent in accordance with section 156(d). The permission for commercial marketing or use after the regulatory review period must be the first permitted commercial marketing or use of the product under the law under which the review occurred, subject to exceptions for certain recombinant DNA manufacturing patents and certain animal drugs (35 U.S.C. 156(a))¹.
• One patent per review period. In no event may more than one patent be extended for the same regulatory review period for any product (35 U.S.C. 156(c)(4))¹.
• Active ingredient. For human drugs, FDA says the product is the active ingredient, which is not the same as the active moiety. A new ester or salt of a previously approved acid is eligible, and a new acid of a previously approved salt or ester is not⁵.
• Devices. The USPTO says a regulatory review period under section 510(k) of the Federal Food, Drug, and Cosmetic Act does not give rise to eligibility for extension⁴.

1. ApplicationThe owner of record of the patent or its agent submits an application to the Director of the USPTO¹. With limited exceptions set out in the statute, it may only be submitted within the 60-day period beginning on the date the product received permission, under the law governing the regulatory review period, for commercial marketing or use¹. It must identify the approved product, the patent and each claim that claims the product or a method of using or manufacturing it, and the activities undertaken during the regulatory review period¹.
2. Regulatory review period determinationWithin 60 days of the application the Director notifies the Secretary of Health and Human Services, for patents claiming a drug product, medical device, food additive or color additive subject to the Federal Food, Drug, and Cosmetic Act¹. Not later than 30 days after receipt, the Secretary reviews the dates, determines the applicable regulatory review period and publishes a notice in the Federal Register¹. FDA says its role is to assist the USPTO with eligibility and the regulatory review period, and that the USPTO determines the period of extension⁵.
3. Due diligence challengeA petition may be submitted to FDA not later than 180 days after publication of the determination, on the ground that the applicant did not act with due diligence during the regulatory review period¹. Any period in which the applicant did not act with due diligence reduces the extension¹.
4. Certificate of extensionThe Director may determine that a patent is eligible solely on the basis of the representations in the application. If the patent is eligible and the application requirements are met, the Director issues a certificate of extension, which is recorded in the official file and is part of the original patent¹.
5. Interim extensionsIf the patent would expire before a certificate of extension is issued or denied, the Director extends its term for periods of up to one year if the patent is eligible¹. Separately, an owner who reasonably expects the approval phase of the regulatory review period to extend beyond the patent's expiry may apply for an interim extension in the period beginning 6 months, and ending 15 days, before the term expires¹.

• Basis. The extension equals the regulatory review period for the approved product that occurs after the patent issued, reduced by any period in which the applicant did not act with due diligence (35 U.S.C. 156(c)(1))¹.
• Half the testing phase. After that reduction the extension includes only one-half of the time remaining in the first of the two periods that make up a regulatory review period (35 U.S.C. 156(c)(2))¹. For a human drug FDA calls these the testing phase, from the effective date of the investigational exemption to the initial submission of the marketing application, and the approval phase, from submission to approval⁵.
• Five-year cap. For a patent issued after the date of enactment of section 156, the extension may not exceed five years. For a human drug product, medical device, food additive or color additive that date is September 24, 1984 (35 U.S.C. 156(g)(6)(A), (f)(7))¹.
• Fourteen-year cap. If the term remaining after approval, added to the revised regulatory review period, exceeds fourteen years, the extension is reduced so that the total does not exceed fourteen years (35 U.S.C. 156(c)(3))¹. FDA says a product whose patent life after approval is 14 or more years is not eligible⁵.
• Starting point. The extension runs from the original expiration date of the patent, which includes any patent term adjustment (35 U.S.C. 156(a))¹.
• Scope of rights. During the extension, rights under a patent claiming a product are limited to uses approved for the product, and rights under a method-of-use patent are limited to uses claimed by the patent and approved for the product. Rights under a method-of-manufacture patent are limited to the method as used to make the approved product (35 U.S.C. 156(b))¹.

Both lengthen a US patent's term, but for different reasons and under different statutes^1,3. See also Supplementary protection certificate.

The Federal Register notice below is an FDA determination of a regulatory review period, made after an extension application reached the USPTO. It is shown for how the period is stated, and says nothing about the applicant or the patents beyond the record.

FDA determined a regulatory review period of 3,292 days for a human drug product: 2,990 days in the testing phase and 302 days in the approval phase. The notice says this is the maximum potential length of an extension, because the USPTO applies statutory limitations, and records that the applicant seeks 1,136 days6.