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The Hatch-Waxman Act provides certain market exclusivities for new drug applicants based on two factors:

  • Patent
  • Non-patent

The patent related exclusivities are part of the discussion and we will learn further in this article.


The innovator typically obtains patent protection for their approved drugs and have a period of exclusivity that prevents unlicensed third parties from making, using, offering for sale, selling or importing the patented invention.

An NDA holder must provide the FDA with the patent number and expiration date of any patent that claims either:

  • the drug, including the active ingredient and the formulation for the active ingredient.
  • a method of using the drug, but not other inventions such as:
    • metabolites;
    • synthetic intermediates; or
    • methods of making the drug.

For patents claiming methods of using the drug, the applicant must submit a use code, which is a description of the approved method.

When the FDA approves the NDA, the FDA publishes the patent information in the FDA’s Approved Drug Products with Therapeutic Equivalence Determinations (the Orange Book) publication.

The Orange Book also lists any non-patent exclusivity concerning the RLD and is publicly available on the FDA’s website.


The first-filer of an ANDA with a Paragraph IV certification rewarded with the 180-days of market exclusivity, during which the FDA will not approve any other ANDAs having a Paragraph IV certification for a generic version of the same RLD and may enter the market.

A Section 505(b)(2) applicant is not entitled to this 180-day exclusivity. However, a Section 505(b)(2) applicant still may be entitled to NCE, a new chemical study or orphan drug and paediatric exclusivity.


The term “first-ANDA filer” refers to all of the applicants who submits substantially complete ANDAs with Paragraph IV certifications on the same day that is earlier than any other ANDA.

A substantially complete application is one that:

  • on its face is sufficiently complete to permit substantive FDA review.
  • contains all information statutorily required in an ANDA.


Most US patents have a 20-year term measured from the original application’s filing date. Since the application process for most patents typically takes about three years, a patent’s effective life is usually about 17-years from its issuance. This term is subject to patent term adjustment for US Patent and Trademark Office (USPTO).

Virtually all RLDs are covered by one or more patents. The useful term for patents covering a RLD is typically much shorter than 17-years because the time-consuming FDA approval process typically occurs during part of the patent term.

As a partial remedy, the Hatch-Waxman Act provides a patent term extension for patents covering certain products and methods, including human drug products that are subject to FDA approval. The patent’s term can be extended by a maximum of five years or 14 years of effective patent life, whichever is less. Specifically, the patentee is entitled to a credit for the time the FDA was reviewing the first drug application. Only one extension can be granted in connection with a particular product, and it must be for a patent that claims either a:

  • drug product, which means the active ingredient and an approved drug using that active ingredient.
  • method of using a drug product.
  • method of manufacturing a drug product.

on June 8, 1995, or any patent application pending at that time would get the term of twenty years from the time of filing or seventeen years from the time of grant, whichever was longer. The difference between those two dates was referred to as the “Delta Period“.

Commencing Litigation and Approval Stays

The patentee has the right to sue the generic drug applicant immediately on receipt of the Notice Letter. However, the generic drug applicant cannot file a declaratory judgment action against the NDA holder for 45 days after the date of the Notice Letter (45-day period).

The generic drug company may include with its Notice Letter an offer to the NDA holder to allow it to confidentially review the ANDA. The generic drug company may redact irrelevant information and place other restrictions on the review.

If the patentee sues within the 45-day period, the FDA may not grant final approval of the generic application for 30 months from the NDA holder and patentee’s receipt of the Notice Letter (30-month stay). However, if the RLD has NCE exclusivity, the 30-month stay does not begin to run until the NCE exclusivity expiration. This 30-month stay is intended to:

  • allow for parallel resolution of the patent case and the FDA’s review of the ANDA.
  • provide certainty for the innovator because the generic player cannot launch the generic during this period while there is ongoing litigation.

Proof of Infringement:

Proof of infringement is slightly different in a Hatch-Waxman Act case than in a typical patent case. Typically, however, the generic drug company has not actually marketed a product by the time the case has reached trial. If the ANDA is not determinative, the court determines infringement just as in any other patent litigation.

Delisting Counterclaim:

If sued, the generic drug company may bring a counterclaim alleging that a patent was wrongly listed in the Orange Book because it does not claim the RLD or a method of using the RLD.

Safe Harbor:

The Hatch-Waxman Act includes a safe harbor provision that allows a generic drug company to conduct certain activities to develop its product without significant risk of patent infringement liability. This safe harbor provides immunity from infringement liability for acts reasonably related to the development and submission of any information to the FDA, including the development of a generic drug application.

Exclusivity Forfeiture:

A generic player/first-filer may forfeits its 180-day exclusivity if it fails to market the generic drug:

  1. seventy-five days after the date on which
    1. approval of its application is effective, or
    1. thirty months after its application was submitted, whichever is earlier;
  • seventy-five days after the date on which
    • a court has found the patent invalid or not infringed,
    • a court has signed a settlement order or consent decree finding the patent invalid or not infringed, or
    • the patentee has withdrawn the patent information pertaining to the approved NDA.
    • the first-filer amends or withdraws the Paragraph IV certification that qualified it for exclusivity;

In addition, a first-filer forfeits its exclusivity if fails to obtain tentative approval within 30-months of the filing of its application, unless either its:

  • failure to obtain approval was caused by a change or review of approval requirements imposed after the application’s filing.
  • approval was delayed by a citizen petition.

Additionally, exclusivity is forfeited if the first-filer

  1. withdraws its application or the application is considered withdrawn for failing to meet the requirements for approval;
  2. amends or withdraws its paragraph IV certifications that qualified it for exclusivity;
  3. fails to obtain tentative approval of its application within thirty months after it was filed (unless that failure was caused by a change in requirements for approval after the application was filed);
  4. enters into an agreement with another ANDA applicant, the NDA holder, or a patent holder, and the Federal Trade Commission (FTC) or a court finds that the agreement violates antitrust laws; or
  5. does not begin its exclusivity before all the patents as to which it filed a paragraph IV certification have expired.

Key note and Final Takeaways:

For the patentee, the primary reward for winning a Hatch-Waxman Act patent litigation is continued enjoyment of any unexpired exclusivity. The typical remedies for a prevailing patentee are:

  • An order directing the FDA not to approve the ANDA before the expiration of the relevant patents and any other exclusivity.
  • An injunction against future infringement.

In addition,

  • The 30-month stay provides an opportunity for the parties to resolve the litigation before the generic drug can enter the market.
  • Some generic drug companies will agree to stay off the market and not launch at risk during the pendency of the litigation even if it lasts more than 30 months.

For a generic drug company, the primary reward for victory is the ability to enter the market before patent expiration without patent infringement liability. A first filer also enjoys its 180-days of exclusivity against other Paragraph IV-certifying generic drug companies.

Finally, where all first-filers forfeit the 180-day exclusivity period, no exclusivity exists and the FDA will not delay the effective approval of any subsequent ANDAs and generics are immediately able to enter the market.

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