Generic entry timeline

Tembexa generics — when can they launch?

Tembexa (BRINCIDOFOVIR) · Emergent Biodefense · 6 active US patents · 0 expired

Earliest patent expiry
2031-08-31
5 years remaining
Full patent estate to
2034-10-10
complete protection through 2034
FDA approval
2021
Emergent Biodefense

Where Tembexa sits in the generic timeline

Mid-term cliff: earliest active US patent for Tembexa expires in 2031 (~5 years). Generic developers typically begin ANDA bioequivalence studies 3-4 years ahead of this date. Paragraph IV filings + Hatch-Waxman 30-month stays may shift the effective entry by another 18-36 months.

Under US Hatch-Waxman, a generic enters via an ANDA (Abbreviated New Drug Application) and may file with one of four Paragraph IV certifications attacking the brand's listed patents. If the brand sues within 45 days, a 30-month FDA approval stay is triggered. First Para IV filer typically gets 180-day market exclusivity.

Patent estate by type — active patents

Method-of-use patents only carve out specific indications; generics can launch with a "skinny label" omitting those uses. Composition-of-matter patents block the molecule itself.

  • Method of Use — 4 patents
  • Formulation — 1 patent
  • Composition of Matter — 1 patent

FDA U-codes carved out by Tembexa patents

Method-of-use patents are listed against specific FDA Patent Use Codes ("U-codes") representing carved-out indications. Generics can launch with a label that omits these uses.

U-codeDescription
U-3165(no description)

Sample patent estate

Showing 6 of 6 active US patents. View full estate on the Tembexa drug page →

  • US9303051 Method of Use · expires 2031-08-31
    This patent protects methods of synthesizing phosphonate ester derivatives, including preferred methods for large-scale preparation with high purity.
    USPTO title: Phosphonate ester derivatives and methods of synthesis thereof
  • US9303051 Method of Use · expires 2031-08-31
    This patent protects methods of synthesizing phosphonate ester derivatives, including preferred methods for large-scale preparation with high purity.
    USPTO title: Phosphonate ester derivatives and methods of synthesis thereof
  • US9371344 Formulation · expires 2034-10-10
    This patent protects methods of synthesizing phosphonate ester compounds and their morphic forms, allowing for large-scale preparation with high purity and stability.
    USPTO title: Morphic forms of hexadecyloxypropyl-phosphonate esters and methods of synthesis thereof
  • US10112909 Method of Use · expires 2034-10-10
    This patent protects methods of synthesis for phosphonate ester compounds, including those with high purity and stability, and their morphic forms.
    USPTO title: Morphic forms of hexadecyloxypropyl-phosphonate esters and methods of synthesis thereof
  • US10487061 Method of Use · expires 2034-10-10
    This patent protects methods of synthesis for phosphonate ester compounds, including those with high purity and stability, and their morphic forms.
    USPTO title: Morphic forms of hexadecyloxypropyl-phosphonate esters and methods of synthesis thereof
  • US8962829 Composition of Matter · expires 2034-10-10
    This patent protects methods of synthesizing phosphonate ester compounds and their morphic forms, allowing for large-scale preparation with high purity and stability.
    USPTO title: Morphic forms of hexadecyloxypropyl-phosphonate esters and methods of synthesis thereof

Sources

Patent term extensions (PTR, pediatric exclusivity), Hatch-Waxman 30-month stays, and FDA regulatory exclusivity (NCE/ODE/PED) may shift the effective generic entry date. Not legal advice.

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