Skelaxin generics — when can they launch?
Skelaxin (METAXALONE) · Pfizer · 1 active US patent · 1 expired
Where Skelaxin sits in the generic timeline
Long-dated protection: earliest active US patent for Skelaxin extends to 2039 (~13 years out). Generic competition is at least 4 years away. Lifecycle moves (new formulations, label extensions, combination filings) typically execute 18-36 months ahead of cliff.
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.
- Formulation — 1 patent
Sample patent estate
Showing 1 of 1 active US patents. View full estate on the Skelaxin drug page →
-
This patent protects oral dosage forms of metaxalone with improved bioavailability, including those that use a reduced dose.USPTO title: Reduced dose metaxalone formulations
Sources
- FDA Orange Book — patents listed against Skelaxin (NDA filed 1962)
- Skelaxin drug profile — full patent estate, indications, clinical trials, pricing
- Pfizer patent portfolio
- Patent cliff 2039 — every drug losing US exclusivity that year
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.
Get generic entry alerts
Free Pharma CI alerts on Skelaxin — get notified the moment an ANDA Paragraph IV certification is filed, a 30-month stay is triggered, or a generic launches. First 2 drugs free.
Subscribe free →