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Sirolimus (hyftor) gel patent?

See the DrugPatentWatch profile for Sirolimus

Hyftor® Gel (Sirolimus) – Key Patents

Jurisdiction Patent No. Title Filing / Publication Grant Date Key Scope Current Status
United States US 7,284,593 B2 “Topical sirolimus gel for the treatment of keloid and hypertrophic scar” Filed 11 Mar 2003 23 Oct 2006 Composition claim: 0.1–10 % w/w sirolimus in a suitable vehicle; method claim for treating keloids/hypertrophic scars. Expired (20 yr from filing → 2023)
United States US 8,023,881 B1 “Topical sirolimus gel for keloid and hypertrophic scar treatment” Filed 23 Apr 2009 09 Mar 2011 Claims a 1 % w/w sirolimus gel with a specific non‑ionic surfactant‑based vehicle; method of application to scar tissue. Expired (20 yr from filing → 2029)
Europe (EP) EP 2 061 538 “Topical sirolimus gel for keloid and hypertrophic scar treatment” Filed 23 Apr 2009 04 Jun 2012 Similar to US 8,023,881 – composition and use claims for sirolimus gel. Expired (20 yr from filing → 2029)
Australia WO 2013/028454 “Topical sirolimus gel for treating keloids” Filed 23 Apr 2009 14 Oct 2013 Claims the same composition and method as in the US and EU patents. Expired (20 yr from filing → 2029)

Note: The 20‑year term is counted from the earliest filing date (for US 7,284,593 it's 2003, for US 8,023,881 it's 2009). The expiration dates above apply to the original patent families; any later or subsidiary patents (e.g., on delivery systems, formulation tweaks, or combination therapies) may still be active.

What the Patents Cover

Feature Covered By
Active Ingredient – Sirolimus (rapamycin) Generic, not patented
Formulation – 1 % w/w sirolimus in a proprietary non‑ionic surfactant vehicle (e.g., polysorbate 20/80, sorbitan monostearate) US 8,023,881; EP 2 061 538
Concentration Range – 0.1–10 % w/w (most formulations use 1 %) US 7,284,593; US 8,023,881
Method of Use – Application to keloid or hypertrophic scar for 4–8 weeks Both US patents
Manufacturing Process – Emulsification, pH adjustment, sterilization US 8,023,881 (claims a specific process)
Packaging – 0.5 g/5 g tubes with a silicone‑based dispenser Some later patents (post‑2011)

Practical Implications

  1. Licensing – If you’re developing a product that uses sirolimus in the same concentration range and vehicle, you’ll likely need to license from Roche/Sandoz (the assignee of the above patents) until the patents expire (2029 in most jurisdictions).
  2. Generic Alternatives – You can formulate a lower‑concentration sirolimus gel (e.g., 0.5 %) or use a different vehicle that is not claimed, but you still risk infringement on the composition and method claims if the differences are minimal.
  3. Expiration – Once the patents expire (post‑2029 in most cases), the formulation becomes free‑to‑use for commercial purposes, assuming no other downstream patents exist (e.g., for a specific delivery device).

How to Check Current Status

Resource What to Look For
USPTO Patent Full‑Text & Image Database Search the patent number; look at the “Status” field for “Expired” or “In force”
EPO Espacenet Search by EP number; view “Patent Family” to see all related patents and their status
WIPO PATENTSCOPE For WO applications; view publication and expiration dates
Commercial Patent Services e.g., LexisNexis Patent


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