Q.01

How long do drug patents last?

In the US, a drug patent normally lasts 20 years from the date the application was filed, not from approval. Because much of that time passes during development and FDA review, the US allows the term to be extended by up to 5 years. In the EU, a supplementary protection certificate (SPC) can add up to 5 years, plus 6 months for medicines studied in children.

United States (35 U.S.C. 154 and 156, from the USPTO's patent examining manual, the MPEP)

  • Base term: the term runs "20 years from the date on which the application for the patent was filed in the United States," or from an earlier related US application if one is claimed. Foreign priority claims do not lengthen it (MPEP 2701).
  • Patent term adjustment (154(b)): applications filed on or after June 8, 1995 may get extra time to make up for USPTO delays. A terminal disclaimer can make the term shorter (MPEP 2701).
  • Patent term extension (156): this is for products that needed premarket approval, including human drugs, animal drugs and veterinary biologics. You must apply within 60 days of marketing approval. During the extra time, the patent only protects the approved active ingredient, or its salt or ester (MPEP 2750). How the length is worked out (MPEP 2758):
    • The formula is: regulatory review period, minus time before the patent was granted, minus any time without due diligence, minus half of the testing phase.
    • 14-year cap: the extension is reduced if the patent time left after approval, plus the extension, would go past 14 years.
    • Maximum extension: 5 years for patents granted after September 24, 1984, and 2 years for older patents where the product was approved after that date.
  • For veterinary biologics, the USDA's APHIS works out the regulatory review period and checks that the 60-day deadline was met (9 CFR 124.1, 124.10) [1][2].

European Union

  • SPC (Regulation (EC) No 469/2009): the European Commission says "An SPC can extend a patent right for a maximum of five years." A further six months is available under Regulation (EC) No 1901/2006 when the SPC covers a medicine for children (European Commission, SPCs). I couldn't open the Regulation's own text on EUR-Lex, so I haven't checked how Article 13 calculates the SPC length.
  • Base term of European patents: I couldn't open Article 63 of the European Patent Convention on the EPO site, so this is not confirmed here.
  • Data protection is separate from patents, but often matters as much: under Directive 2001/83/EC Article 10, a generic company can rely on the originator's data only once the reference medicine has been authorised for 8 years. The generic "shall not be placed on the market until ten years have elapsed" from the first authorisation. This becomes up to 11 years if, within the first 8 years, the company gets a new indication with significant clinical benefit [3].

If you tell me the jurisdiction or the product, I can look up its listed patents and exclusivities.

Approach: I searched the US 9 CFR Part 124 rules and the consolidated Directive 2001/83/EC, then used official USPTO and European Commission pages for the patent statutes. The US and EU patent laws themselves aren't in the datasets I can search, and EUR-Lex and the EPO pages wouldn't open.

Q.02

How does FDA exclusivity affect generic entry?

FDA exclusivity holds back generics in two ways. Five-year new chemical entity (NCE) exclusivity stops a generic application (ANDA) or 505(b)(2) application from even being submitted for 5 years, or 4 years if it challenges a patent. Other exclusivities let FDA review the generic but not approve it until the period ends. FDA approves a generic only on the latest of all the dates set by patents and exclusivities. [4][5]

What protects the brand-name (reference) drug

ExclusivityEffect on a genericLength
NCE (21 CFR 314.108(b)(2); FD&C Act 505(j)(5)(F)(ii))For a drug with a new active moiety, "no person may submit" an ANDA or 505(b)(2) application for the same active moiety. A generic that challenges a patent (paragraph IV certification) may be submitted after 4 years5 years from the brand's approval [4]
NCE plus patent suit (314.108(b)(3), 314.107(b)(3)(i)(B))If the brand sues in the year starting 4 years after approval, the generic's approval waits until 7½ years after the brand's approval7½ years [5][6]
3-year "new clinical investigation" (314.108(b)(4)-(5))Applies to a new application or supplement that needed new clinical studies (not bioavailability studies) run or sponsored by the applicant. FDA "will not approve" a generic for those conditions of approval or that change. The generic can still be submitted and reviewed3 years [4]
Orphan drug (FD&C Act 527)FDA "may not approve another application" for "the same drug for the same disease or condition" by anyone else. Exceptions: the holder cannot supply enough of the drug, or the holder consents7 years [7]
Pediatric (FD&C Act 505A)Earned by completing pediatric studies that FDA asked for in writing. It adds time to every exclusivity above and to patent-based blocks (5 → 5½ years, 4 → 4½, 7½ → 8, 3 → 3½, orphan 7 → 7½). It also adds 6 months after a listed patent expires, or after a court finds a paragraph IV patent valid and infringed. It cannot be granted if FDA accepts the studies later than 9 months before the period would expire+6 months [8]
QIDP/GAIN (FD&C Act 505E)For qualified infectious disease products. Adds 5 years to the NCE, 3-year or orphan period, on top of any pediatric extension+5 years [9]

How exclusivity combines with patents

  • 21 CFR 314.107(d): FDA "will also delay" approval where 314.108, the orphan rules (section 527 / 316.31), the pediatric rules (505A) or the QIDP rules (505E) require it. The generic is then approved "on the latest of the days specified" [5].
  • When a generic challenges a patent (paragraph IV) and the brand sues within 45 days of being notified, approval is stayed for 30 months, unless a court decides earlier or the patent owner consents [5].
  • While a block is still running, FDA can only give tentative approval. A tentatively approved drug "is not an approved drug" and cannot be marketed [6][5].

Exclusivities that go to generic companies

  • 180-day exclusivity (505(j)(5)(B)(iv)): the "first applicant" is the company that files the first substantially complete paragraph IV ANDA. Later ANDAs become effective only 180 days after any first applicant starts selling commercially. Under 21 CFR 314.107(c), the period cannot run past the expiry of the patent it is based on, and the first applicant must tell FDA within 30 days that it has started marketing [6][5].

  • Losing (forfeiting) the 180 days (505(j)(5)(D)): this happens if the first applicant:

    • fails to market within the deadlines (75 days, 30 months or 75 days after the patents are resolved);
    • withdraws its application, or amends or withdraws its patent certification;
    • does not get tentative approval within 30 months;
    • signs an agreement that is finally found to break antitrust law;
    • or if all the qualifying patents expire.

    If every first applicant forfeits, nobody gets the 180 days. FDA can also approve later applicants straight away if a first applicant "is not actively pursuing approval" [6][5].

  • Competitive generic therapy (505(j)(5)(B)(v)): this is for drugs with no unexpired patents or exclusivities listed when the application is submitted. The first approved applicant gets 180 days, and loses it if it does not market within 75 days of approval [6].

Biologics work differently. Under PHS Act 351(k)(7), a biosimilar application cannot be submitted until 4 years after the reference product was first licensed, and approval cannot take effect until 12 years after that date (FDA, Purple Book background).

Approach: I used 21 CFR Part 314 as currently published on the eCFR and the 2023 US Code text of the FD&C Act (21 U.S.C. 355, 355a, 355f, 360cc), plus FDA's Purple Book page for biologics. I couldn't open 21 CFR 316.31 (how far orphan exclusivity reaches) on the eCFR site or the full text of 42 U.S.C. 262, so the biologics periods above come from FDA's summary only.

If you name a product, I can pull its listed patents and exclusivity dates from the Orange Book or Purple Book.

Q.03

What about drug patent protection in the UK?

In the UK a patent lasts 20 years from the filing date (Patents Act 1977, s.25(1)), provided renewal fees are paid. A supplementary protection certificate (SPC) can add up to 5 more years, or 5½ years with the paediatric reward. Separately, the Human Medicines Regulations 2012 stop a generic being sold until 10 or 11 years after the reference product's UK authorisation, and give orphan medicines 10 to 12 years of market exclusivity.

1. Patent term (Patents Act 1977, s.25)

  • Term: a patent "shall continue in force until the end of the period of 20 years beginning with the date of filing the application for the patent" (IPO Manual of Patent Practice, s.25).
  • Renewal fees: these are due every year after the fourth year. If one is not paid on time, the patent "shall cease to have effect." It can be restored if the fee is paid within six months (s.25(3)-(4)).

2. SPCs (Regulation (EC) No 469/2009, kept in UK law and amended after Brexit)

  • How long: the SPC starts when the basic patent ends. Its length is the time between filing the patent and the first marketing authorisation "in the area comprising the European Economic Area and the United Kingdom," minus five years. It "may not exceed five years" (Art. 13(1)-(2)).

  • 15-year cap: in practice the SPC ends at whichever comes first: 15 years from the first UK or EEA authorisation, or 5 years after it takes effect (SPM 13.04). If the first authorisation came within five years of the patent filing, the SPC has no effective term (SPM 13.05) (IPO manual, SPCs).

  • Paediatric extension: the periods "shall be extended by six months" where regulation 58A of the Human Medicines Regulations applies (Art. 13(3)). The extension follows the territory of the authorisation it is based on:

    • a UK authorisation gives it across the UK;
    • a GB authorisation gives it in England, Wales and Scotland only;
    • an NI authorisation gives it in Northern Ireland only (Art. 13(5)).

    Extensions must be requested before the two-year deadline in Art. 7(4) (SPM 13B.03).

  • Deadline: you apply within six months of the authorisation (SPM 7.01).

  • Northern Ireland: an SPC can be widened to cover later first authorisations in GB or NI. The holder must notify the IPO on Form SP6 within six months of that grant; if not, protection "shall not extend" to the extra territory (Art. 13A).

  • Manufacturing waiver (since 1 July 2019): other companies may make SPC-protected medicines for export, and may build up stock during the last six months of the SPC. They must notify the SPC holder and the IPO at least three months before they start (GOV.UK, SPCs).

3. Data and market protection for generics (Human Medicines Regulations 2012, reg. 51B, UK-wide authorisations)

  • Data protection (8 years): a generic applicant may leave out the pre-clinical and clinical results only if the reference product "is or has been authorised for not less than eight years" (reg. 51B(1)).
  • Market protection (10 years): the generic "must not be sold or supplied, or offered for sale or supply, in the United Kingdom before the expiry of ten years" from the reference product's UK authorisation (reg. 51B(6)).
  • Extra year: the 10 years become 11 if, within the first eight years, the holder gets a new indication that brings "a significant clinical benefit" (reg. 51B(7)).
  • New indication for a well-established substance: if significant studies supported it, others may not refer to those studies for one year (reg. 51B(8)) [10].
  • Northern Ireland-only authorisations: a generic follows Article 10 of Directive 2001/83/EC and may not be sold in Northern Ireland before the time that Article allows (reg. 51) [11].

4. Orphan and paediatric rewards

  • Orphan market exclusivity: for 10 years after an orphan marketing authorisation is granted, the MHRA "must not" grant or vary an authorisation for a similar medicine for the same indications (reg. 58D(1)).
    • This can be cut to 6 years if, at the end of year five, the orphan criteria are no longer met (reg. 58D(4)).
    • It rises to 12 years if the paediatric reward applies (reg. 58D(5)).
    • It does not block a competitor if the holder consents, cannot supply enough, or the competitor's product is safer, more effective or clinically superior (reg. 58D(6)) [12].
  • Orphan criteria: the medicine is for a life-threatening or chronically debilitating condition, and either the condition affects "not more than five in 10,000 persons in the United Kingdom" or the medicine is unlikely to make enough return. There must also be no satisfactory authorised method, or the product must offer significant benefit (reg. 50G(2)) [13].
  • Paediatric reward: compliance with an agreed paediatric investigation plan (PIP) gives the patent or SPC holder a six-month SPC extension (reg. 58A(3)). The rewards don't stack:
    • no SPC extension if the holder already gets the one-year 51B(7) extension for a new paediatric indication (58A(4));
    • for orphans, the reward is the 12-year exclusivity instead of the SPC extension (58A(5));
    • a paediatric-use marketing authorisation (PUMA) gets the reg. 51B(1) and (6) data and market periods (58A(8)) [14].

Approach: I used the current Human Medicines Regulations 2012 from legislation.gov.uk in the datasets, and the IPO's Manual of Patent Practice and SPC guidance on GOV.UK for the Patents Act and the UK SPC Regulation. The Patents Act and the SPC Regulation aren't in the datasets, and the legislation.gov.uk pages for s.25 and Article 13 wouldn't open, so their wording is taken from the IPO manual's reproduction.

If you name a product, I can check whether it holds a UK orphan marketing authorisation or a PIP compliance statement.

Q.04