What is Patent Term Extension?

Key Facts

• Statute: 35 U.S.C. § 156 and 37 C.F.R. §§ 1.710 to 1.791
• Application deadline: Within 60 days of FDA approval of the product, counted from the approval date itself; there is no extension or revival
• Maximum extension: 5 years
• Total cap: Remaining term plus extension cannot exceed 14 years from the FDA approval date
• One patent per product: Only one patent may be extended for each regulatory review period, chosen by the patent owner
• Who decides: The USPTO determines eligibility and the FDA certifies the length of the review period

Who Qualifies

A patent is eligible if it claims the approved product, a method of using it, or a method of manufacturing it, and:

• The patent has not expired before the application is filed
• The patent has not previously been extended
• The product was subject to a regulatory review period before its first commercial marketing
• The application is filed by the patent owner or its agent within the 60-day window

Eligible products include human drugs, biologics, animal drugs, medical devices requiring premarket approval, and food or color additives.

How the Extension Is Calculated

The regulatory review period has two parts. The testing phase runs from the effective date of the investigational new drug exemption (or device equivalent) to the submission of the marketing application; half of this time counts. The approval phase runs from submission to approval; all of this time counts. Any period in which the applicant failed to act with due diligence is subtracted. The result is then capped at five years and at the fourteen-year ceiling.

Interim Extensions

If the original patent will expire before FDA approval is granted, the owner can request one-year interim extensions under § 156(d)(5) to keep the patent alive until the final decision. These must be requested during the six months before the patent would otherwise expire.

PTE vs PTA

Patent term adjustment is automatic, applies to every utility patent, and compensates for USPTO delay. PTE must be applied for, applies only to regulated products, and compensates for FDA delay. A patent may receive both, and the PTE is added to the term as already adjusted by PTA. Where a terminal disclaimer exists, courts have held that PTE can extend beyond the disclaimed date while PTA cannot.

For pharmaceutical portfolios the choice of which patent to extend is one of the highest-stakes docketing decisions in the company, since the extended patent is typically the one that defines the end of market exclusivity.