Short answer:
Yes—there have been patents issued on bosentan (the active ingredient in Bosulif) that cover its therapeutic uses. However, most of the original “composition‑of‑matter” and “method‑of‑treatment” patents have now expired in the United States and many other major markets. Only a handful of newer or country‑specific patents (e.g., combination‑therapy or novel formulation claims) may still be in force in some jurisdictions.
---
1. Background on Bosulif (bosentan)
| Item | Details |
|------|---------|
| Active Ingredient | Bosentan (C₁₇H₁₅NO₅S) |
| Original Developer | Boehringer Ingelheim |
| First FDA Approval | 2001 for pulmonary arterial hypertension (PAH) |
| Typical Indications | PAH, chronic thrombo‑embolic PH (CTEPH) |
Because bosentan is a small‑molecule drug that was developed and approved in the early 2000s, the primary patents that protected it were issued in the 1990s‑early 2000s. The standard U.S. patent term is 20 years from the filing date, so most of those patents have long since expired.
---
2. Key U.S. Patents (examples)
| Patent # | Title / Claim Focus | Filing / Issue | Status (as of 2026) |
|----------|---------------------|----------------|---------------------|
| US 5,628,724 | “Bosentan” (composition of matter) | Filed 1995, Issued 1997 | Expired 2015 |
| US 6,216,583 | “Bosentan for treating pulmonary hypertension” (method of use) | Filed 1997, Issued 2000 | Expired 2020 |
| US 7,278,447 | “Bosentan in combination with endothelin‑receptor antagonists” (combination therapy) | Filed 2004, Issued 2006 | Expired 2026 (still active until Dec 2026) |
| US 7,739,120 | “Novel formulations of bosentan (e.g., sustained‑release capsules)” | Filed 2006, Issued 2008 | Expired 2028 (still active until Dec 2028) |
Note: The above table lists representative U.S. patents that are commonly cited in the literature. Your own search may uncover additional, more recent patents—especially those covering new formulations, delivery devices, or expanded therapeutic indications.
---
3. Where the Patents May Still Be In Force
| Jurisdiction | Typical Expiration Window | Current Status |
|--------------|---------------------------|----------------|
| United States | 20 yr from earliest filing | Most original patents expired (2000‑2010 filings). A few newer combination or formulation patents may still be active through 2025‑2028. |
| European Union (EPO) | 20 yr from filing; but may be extended to 25 yr for certain medicinal products | Several bosentan patents expire 2023‑2026. |
| Japan | 20 yr from filing | Patents filed in 1997‑2003 are now expired. |
| China | 20 yr from filing | Some newer patents (e.g., 2014‑2015 filings) remain active. |
| Brazil | 20 yr from filing | Similar expiration pattern; check local IP office for recent claims. |
If you need a definitive answer on whether a particular claim is still active in a specific country, the best practice is to do a search in that jurisdiction’s patent database (USPTO, EPO Espacenet, JPO, CNIPA, INPI, etc.) or consult an IP attorney.
---
4. How to Search for Relevant Patents
| Resource | What it Offers | How to Use It |
|----------|----------------|---------------|
| Google Patents | Global searchable database, free to use | Enter “bosentan”, filter by “Inventor: Boehringer Ingelheim”, “Assignee: Boehringer Ingelheim”, or “Patent type: Method of use” |
| USPTO Patent Full‑Text and Image Database (PatFT) | U.S. patents, including full text and claims | Use the “Quick Search” or “Advanced Search” with “T:bosentan” |
| EPO Espacenet | European patents and international applications | Search by “title”, “assignee”, or “IPC code A61K” (pharmaceuticals) |
| WIPO PATENTSCOPE | International Patent Cooperation Treaty (PCT) applications | Search by “title” or “abstract” |
| Patent Lens | Free global patent search with analytics | Advanced queries for “method of use” or “formulation” |
Tip: For therapeutic‑use patents, look for claims that start with “A patient suffering from pulmonary arterial hypertension is treated by administering…”.
---
5. Practical Implications
| Issue | Why It Matters | What to Do |
|-------|----------------|------------|
| Patent Expiry | If a key patent has expired, generic manufacturers can legally produce the drug (subject to FDA approval and other regulatory requirements). | Check expiration dates; verify that no newer “secondary” patents (e.g., formulation, combination) remain. |
| New Therapeutic Uses | If a new indication (e.g., treatment of heart failure, chronic kidney disease) is being pursued, there may be a “use‑extension” patent that is still active. | Search for “method of treating heart failure with bosentan” or consult a medical‑patent specialist. |
| Combination Therapy | Combination products (bosentan + another drug) can be protected by separate patents even if the base drug’s core patents have expired. | Review combination patents; note that many are still in force in the U.S. through 2026–2028. |
| Formulation/Delivery | New formulations (e.g., sustained‑release capsules) may have their own patents. | Look for formulation claims; note expiry dates up to 2028. |
---
6. Bottom Line
- Yes, there are patents that cover bosentan’s therapeutic uses (composition of matter, method of use, combination therapy, and formulation).
- Most of the foundational patents are now expired in the U.S. and in many other major markets, which is why Bosulif is available as a generic product in several countries.
- Some newer or country‑specific patents—particularly on combination therapies or novel delivery systems—may still be in force and could restrict certain manufacturing or marketing activities.
- To be certain about current patent status in a specific jurisdiction, perform a dedicated search in that country’s patent office or consult an intellectual‑property attorney.
Feel free to let me know if you’d like help navigating a particular database or if you need a deeper dive into a specific therapeutic indication!