Patent Term Extensions for Drug Products: How Do They Work?
For drugs that are subject to FDA approval, patent holders can obtain extensions of their patent terms if the drug is still being reviewed by the FDA when the patent issues. This type of patent term extension for regulatory review was added to the Patent Act two decades ago as part of the Drug Price Competition and Patent Term Restoration Act of 1984, which is commonly known as the Hatch-Waxman Act.
In order to obtain a patent term extension under the Hatch-Waxman Act, the patent holder must apply for an extension after the patent issues but before the patent expires. There are provisions allowing for interim extensions if the patent expires before the regulatory review has been completed. The application for an extension must be submitted within 60 days after the date on which the product receives FDA approval for commercial marketing or use.
The patent term extension is calculated as follows: first, the regulatory review period is broken down into a “testing period” and an “FDA approval period,” and the number of days in each period is counted. If any part of the testing period or the FDA approval period occurred before the patent issued, then those days are subtracted. If the applicant did not act with due diligence during the testing period or the FDA approval period, then those days are subtracted as well. Second, the number of days in the testing period is reduced by half and added to the full number of days in the FDA approval period. This figure is then added to the original term of the patent.
If the addition of this “restoration” period to the patent term results in the patent term being extended by more than 14 years after the date of FDA approval, then the restoration period is decreased so that the patent term is not extended by more than 14 years from the date of FDA approval. Similarly, if the addition of this “restoration” period to the patent term results in the patent term being
extended by more than 5 years after the expiration of the original patent term, then the restoration period is reduced so that the patent term is not extended by more than 5 years from the original patent expiration date.
Only one extension is allowed per “active ingredient,” and only one extension can be afforded per patent. This means that if more than one patent covers the same active ingredient, only one extension will be allowed, and if a patent covers more than one active ingredient, only one extension will be allowed. If a patent covers more than one drug product or use, then the extension will only apply to the particular product or use that was approved by the FDA after the patent issued; all other drug products or uses covered by the same patent will be subject to the original patent term. For this reason, the patent, during the period of its extension, may not be as broad as it was during the prior period.
An extension will not be afforded unless the FDA approval is for the first commercial marketing or use of the product. In this context, the term “product” is equated with “active ingredient.” Thus, if the FDA previously approved a drug containing the same active ingredient, the patent holder will not be entitled to a patent term extension. If the formulation of the drug evolves during the testing period but the active ingredient remains the same, then calculation of the testing period will begin on the date on which the first testing of a product containing that active ingredient occurred.
As is apparent from the above discussion, calculation of patent term extensions for drug products is extremely complicated. Although holders of patents for drug products should be aware that these provisions exist, the author strongly recommends consultation with a qualified patent attorney to ensure that the maximum benefit is obtained from your patent. Similar patent term extensions are available for medical devices, food additives, color additives, and animal drug and veterinary biological products.