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2756 Correspondence Between the USPTO and the Regulatory Agency [R-11.2013]

It is the Director’s responsibility to decide whether an applicant has satisfied the requirements of the statute and whether the patent qualifies for patent term extension. The regulatory agency possesses expertise and records regarding some of the statutory requirements and has certain direct responsibilities under 35 U.S.C. 156 for determining the length of the regulatory review period. Consequently, to facilitate eligibility decisions and permit the regulatory agency and the Office to carry out their responsibilities under 35 U.S.C. 156, both the Food and Drug Administration and the Department of Agriculture have entered into an “agreement” of cooperation with the Office. Memorandum of Understanding Between the Patent and Trademark Office and the Food and Drug Administration, 52 FR 17830 (May 12, 1987); Memorandum of Understanding Between the Patent and Trademark Office and the Animal and Plant Health Inspection Service, 54 FR 26399 (June 23, 1989); 1104 OG 18 (July 11, 1989). The agreements establish the procedures whereby the regulatory agency assists the Office in determining a patent’s eligibility for patent term extension under 35 U.S.C. 156. It also establishes procedures for exchanging information between the regulatory agency and the Office regarding regulatory review period determinations, due diligence petitions and informal regulatory agency hearings under the law. The patent term extension applicant receives a copy of all correspondence between the Office and the regulatory agency.

The Animal and Health Inspection Service of the Department of Agriculture is responsible for assisting the Office in determining the eligibility of patent claiming a veterinary biological product that has been subject to the Virus-Serum-Toxin Act (21 U.S.C. 151-59) and for determining the regulatory review period of the veterinary biological product. The Secretary of Health and Human Services of the Food and Drug Administration is responsible for assisting the Office in determining the eligibility of patents claiming any other product for which regulatory review gives rise to eligibility for patent term extension. 21 CFR 60.10.


If the Office has no clear reason to deny eligibility for patent term extension (even if there are questions concerning eligibility), or if the applicant has been notified of any informalities and it is anticipated that the informalities will be corrected or explained, a first letter is sent to the regulatory agency to request information regarding eligibility. The letter is accompanied by a copy of the patent term extension application. This letter does not request the determination of the applicable regulatory review period.

The regulatory agency reply is usually in the form of a written response:

  • (A) verifying whether the product has undergone a regulatory review period within the meaning of 35 U.S.C. 156(g) prior to commercial marketing or use;
  • (B) stating whether the marketing permission was for the first permitted commercial marketing or use of that product, or, in the case of recombinant DNA technology, whether such commercial marketing or use was the first permitted under the process claimed in the patent;
  • (C) informing the Office whether the patent term extension application was submitted within sixty days after the product was approved for marketing or use; and
  • (D) providing the Office with any other information relevant to the Office determination of whether a patent related to a product is eligible for patent term extension.

While the Office has primary responsibility for the eligibility determination, the regulatory agency often possesses information which is not readily available to the Office. The assistance on the part of the regulatory agency enables both the Office and the agency to process applications efficiently and to conserve resources.


Upon receipt of a reply from the regulatory agency to the first letter from the Office requesting assistance on determining eligibility, a preliminary eligibility decision (not the final decision) is made as to whether the patent is eligible for an extension of its term. As noted above, the reply from the regulatory agency will usually inform the Office as to whether the permission for commercial marketing and use of the product on which the application for patent term extension is based is the first such approval for that product. Furthermore, the regulatory agency usually provides information regarding the date of product approval to permit a determination as to whether the application was filed within the sixty-day statutory period. The information provided by the regulatory agency is then compared with the related information from the application. If no major discrepancies are found and the patent is determined to be eligible for patent term extension, a second letter requesting a determination of the length of the regulatory review period of the product is mailed to the regulatory agency not later than sixty (60) days after the Office receipt date of the reply from the regulatory agency. In the interest of efficiency, if the patent is determined to be ineligible for patent term extension, the Office will dismiss the application rather than request a determination of the regulatory review period. In re Allen & Hansbury, Ltd., 227 USPQ 955, 960 n. 9 (Comm’r Pat. & Tm. 1985). The second letter states that, subject to final review, the patent is considered eligible for patent term extension and requests a determination of the applicable regulatory review period.



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Last Modified: 01/24/2018 17:19:01