A U.S. patent term runs for 17 years from the patent's issue date or 20 years from the date of the patent's first filing. However, product testing, development, and compliance with federal marketing requirements can consume some of this patent term and thus reduce the marketing time during which the patent holder can recover research and development costs.
On September 24, 1984, President Reagan signed the Drug Price Competition and Patent Term Restoration Act (Public Law 98-417) into law. This Act has been described as the one of the most important pieces of legislation affecting the drug industry.
Title II of the Act, the patent term restoration or patent term extension portion, gave certain patent holders the opportunity to extend the terms of patents claiming human drug products, including antibiotics and biologics, medical devices, food additives and color additives. By giving inventors a portion of the patent term lost to federal regulatory review, Congress sought to:
restore to our domestic drug companies some of the incentive for innovation which has weakened as Federal pre-market approval requirements have become more expensive and time consuming. That incentive will produce both the investment and the commitment to research and development that will again place the United States in unquestioned leadership in the field. And it will generate an increase in the number of important new drugs, among the most vital causes for this century's dramatic increase in the length and quality of life.
On November 16, 1988, the Generic Animal Drug and Patent Term Restoration Act (Public Law 100-670) provided the same benefits to animal drug products (excluding those derived from recombinant DNA technology).
A maximum of 5 years can be restored to the patent. However, if the patent was issued before September 24, 1984 and the product's regulatory review period began before that date, then the limit is 2 years. For animal drug products whose regulatory review periods began before November 16, 1988, the limit is 3 years. In all cases, the total patent life for the product cannot exceed 14 years from the product's approval date, or, in other words, 14 years of marketing time.
In the patent term restoration program, FDA works with the Patent and Trademark Office (PTO). The Office of Health Affairs' (OHA) Health Assessment Policy Staff (HAPS) is responsible for FDA's obligations.
Statutory and Regulatory Citations
The patent term restoration statute can be found at 35 U.S.C.ß 156 et seq. PTO published its regulations on March 24, 1987. These regulations can be found at 37 C.F.R. Part 1. FDA published its regulations on March 7, 1988. These regulations can be found at 21 C.F.R. Part 60. FDA published a Memorandum of Understanding governing information exchanges and cooperation between the two agencies in the May 12, 1987 Federal Register (52 Fed. Reg. 17,830).
Eligibility Assistance on Applications
To obtain patent term extension, an application must satisfy certain eligibility criteria, including:
- the patent has not expired,
- the patent has never been extended,
- the application is submitted by the patent owner or its agent,
- the product has been subject to a regulatory review period with FDA or USDA before its commercial marketing or use, and
- the permission for commercial marketing or use represents the first permitted commercial marketing or use of the product under the provision of law under which the regulatory review occurred (but for products produced using recombinant DNA technology, excluding animal drug products, the product can be the first permitted commercial marketing or use of a product produced under that technology), or if the product is a veterinary drug product, the product cannot be claimed in any other patent which has been extended and, if previously approved for use in non-food producing animals, must not have received patent term extension for that use.
[Please note that medical devices approved under section 510k of the Federal Food, Drug, and Cosmetic Act are NOT eligible for patent term restoration.]
In addition, the patent term restoration application must be submitted within 60 days of the product's approval. FDA regulations interpret product approval as being the date on which FDA sends letters notifying the marketing applicant that the marketing application has been approved, the product development protocol completed, or the effective date of the notice listing the food or color additive for use. The day after approval is counted as the first day, and the application for patent term extension must be received by PTO on the sixtieth day or the next business day after the sixtieth day if this day falls on a weekend or holiday.
PTO is responsible for eligibility determinations, but because some of the eligibility criteria depend upon information in FDA's records, PTO sends a copy of the application to FDA and requests eligibility assistance. When this happens, FDA processes the application by sending a copy of the application to the appropriate Center (i.e., Center for Drug Evaluation and Research (CDER), Center for Biologics Evaluation and Research (CBER), Center for Devices and Radiological Health (CDRH), Center for Food Safety and Nutrition (CFSAN), or CVM (Center for Veterinary Medicine)).
The Center will provide the following information: the date the product was approved by the FDA and the FDA license number, whether the product was approved under the Federal Food, Drug, and Cosmetic Act (FFD&C Act) or the Public Health Service (PHS) Act, the active ingredient(s) of the product and whether other products with the same active ingredient(s) or a salt or ester of the active ingredient(s) has been previously approved, and other relevant dates for regulatory review determination (i.e., the date an investigational exemption was granted and when the product was initially submitted for FDA review). The Center also lists any discrepancies it noted between the application and its records.
Based on the information received from the Center, HAPS prepares a letter to PTO, notifying PTO whether the application is eligible for patent term extension based on this preliminary review of FDA files.
Generally, the issuance of the eligibility assistance letter ends FDA's involvement in eligibility. At this point, PTO either determines that the patent is ineligible (at which point the patent term extension process ends) or proceeds to request a regulatory review period determination.
Regulatory Review Period Determinations
The regulatory review period is the basis for the patent term extension. Basically, a regulatory review period is composed of two parts: a testing phase, and an approval phase. The testing phase is the period between the effective date of an investigational product exemption (such as an Investigational New Drug Application (IND) or Investigational Device Exemption (IDE)) and the initial submission of a marketing application (such as an NDA, Product License Application (PLA) or Pre-market Approval Application (PMA)). The approval phase is the period between the submission and approval of the marketing application. FDA has 30 days by law to determine the regulatory review period for a product.
Based on the dates obtained from the Center previously, FDA determines the regulatory review periods. HAPS then prepares two documents. The first is a letter addressed to the "Assistant Secretary of Commerce and Commissioner of Patents and Trademarks," which informs the Commissioner of the regulatory review period determination. In brief, this letter sets forth the testing and approval phases, the dates used to determine such periods, and explanations of any discrepancies between the applicant's information and FDA's records. The second document that HAPS prepares is a Federal Register notice for the product, which contains essentially the same information as the letter, as well as other required information for publishing the notice. Both documents are signed by the Associate Commissioner for Health Affairs.
Once the Federal Register notice has been published, a copy of the notice is sent to:
Deputy Assistant Commissioner for Patent Policy and Projects
Office of the Assistant Commissioner for Patents
U.S. Patents and Trademark Office.
The publication triggers a 60-day comment period in which parties can request revisions to the regulatory review period determination. The expiration of the 60-day comment period marks the end of the regulatory review period stage.
Due Diligence Determinations and Hearings
The statute gives any person 180 days from the publication of the Federal Register notice to challenge the review period on the grounds that the marketing applicant did not exercise "due diligence" while seeking marketing approval and, therefore, should not get credit for the "non-diligent" time. A due diligence petition must contain sufficient information to justify a FDA investigation, and FDA regulations require such a petition to be filed in accordance with 21 C.F.R. ß 10. FDA regulations also state that the petition must claim a period of time that will materially affect the extension. For example, if the regulatory review period was 1,000 days, an allegation that the marketing applicant was not diligent for 500 days would be material; an allegation that it was not diligent for 10 days would not be material and would be ignored.
Once the 180-day due diligence period has expired, HAPS informs PTO whether any due diligence petitions are still pending. If there are none, HAPS then notifies PTO that FDA considers the regulatory review period determination to be final.
This event marks the end of FDA's involvement in the patent term restoration application.
Certificate of Extension
PTO calculates the length of the extension which it can grant, giving half-credit to the testing phase, full credit to the approval phase, and no credit for any non-diligent review time or any time before the patent was issued. PTO issues a Notice of Final Determination and, later, a Certificate of Extension to the patent holder after the regulatory review period determination is final. PTO sends copies of these documents to FDA.