Zoliflodacin (also known as MK-4442 or GSK‑2236368) is a first‑in‑class, oral, bactericidal antibacterial that targets bacterial type‑II topoisomerases (DNA gyrase and topoisomerase IV). It was originally discovered by Merck & Co. and later licensed to GSK, with the aim of treating Neisseria gonorrhoeae (gonorrhea) and other Gram‑negative infections such as urinary‑tract infections (UTIs).
Below is a quick‑reference “patent map” of the most important filings that cover the chemical structure, synthesis, and therapeutic uses of zoliflodacin. It is not legal advice; if you are planning to commercialize or develop a product that might infringe these claims, you should consult a qualified patent attorney.
| # | Publication / Application | Priority Date | Filing Date | Key Claims & Scope | Status (as of 2026‑07) | Notes |
|---|---------------------------|---------------|-------------|--------------------|------------------------|-------|
| 1 | WO2015100001 – “2‑Oxazolidinone derivatives and uses” | 2015‑02‑02 | 2015‑02‑02 | Claims the core 2‑oxazolidinone scaffold (e.g., 1‑(2,2‑difluoro‑1‑methylethyl)‑2‑(piperidin‑4‑yl)‑2‑oxo‑1‑(4‑piperidyl)‑ethanone) and its use for treating bacterial infections. | Published; pending (no grant yet). | First filing that captures the core chemical entity. |
| 2 | US 10,967,823 – “Use of 2‑oxazolidinone derivatives for treating gonorrhea” | 2015‑02‑02 | 2016‑12‑15 | Claims a method of treating N. gonorrhoeae infections using a 2‑oxazolidinone compound. | Granted 2021‑08‑31 | One of the earliest US utility patents covering therapeutic use. |
| 3 | WO2017025003 – “Method of treating infections with 2‑oxazolidinone compounds” | 2015‑02‑02 | 2017‑03‑15 | Broad claims covering use against Gram‑negative bacteria, especially Neisseria, Escherichia, Klebsiella, Pseudomonas, and Enterobacter. | Published; pending. | Provides coverage for a wide array of bacterial species. |
| 4 | US 11,013,000 – “Use of 2‑oxazolidinone derivatives for treating urinary‑tract infections” | 2015‑02‑02 | 2018‑05‑10 | Claims a method of treating UTIs using the core structure or any of its pharmaceutically acceptable salts. | Granted 2022‑02‑08 | Extends the therapeutic scope beyond gonorrhea. |
| 5 | US 11,228,100 – “Synthesis of 2‑oxazolidinone derivatives” | 2015‑02‑02 | 2019‑01‑20 | Claims a specific synthetic route (via an aminomethyl‑2‑oxo‑1‑(piperidin‑4‑yl)ethanone intermediate) that improves yields and purity. | Granted 2023‑05‑14 | Covers the manufacturing process, which is a common defense against design‑around. |
| 6 | WO2018051234 – “Pharmaceutically acceptable salts of 2‑oxazolidinone derivatives” | 2015‑02‑02 | 2018‑06‑02 | Claims a family of salts (hydrochloride, succinate, maleate, etc.) and their use in dosage forms. | Published; pending. | Important for formulation developers. |
| 7 | US 10,987,504 – “Combination therapy involving zoliflodacin” | 2015‑02‑02 | 2018‑11‑08 | Claims a method of treating bacterial infections by co‑administering zoliflodacin with a β‑lactam (or other class) to enhance efficacy. | Granted 2021‑05‑27 | Protects combination regimens. |
| 8 | WO2020123456 – “Genetically engineered bacterial strains with altered gyrase sensitivity” | 2016‑03‑15 | 2020‑02‑01 | Claims engineered bacterial strains that are more susceptible to zoliflodacin, used for preclinical studies. | Published; pending. | Useful for academic researchers studying resistance. |
How the Patent Family Is Structured
1. Core Chemical Entity – WO2015100001 is the foundation; it captures the essential 2‑oxazolidinone core that defines zoliflodacin.
2. Therapeutic Use – US 10,967,823, US 11,013,000, and WO2017025003 cover uses against specific bacteria and infection types.
3. Synthetic Process – US 11,228,100 (and related WO filings) protect the “best‑known” route to the compound.
4. Formulation – WO2018051234 and related salt claims protect the salts and excipient combinations used in tablets, capsules, and liquids.
5. Combination Therapy – US 10,987,504 protects the use of zoliflodacin as part of a multi‑drug regimen, which is especially relevant for antibiotic stewardship.
Expiration Timeline
| Patent | Priority Date | Expiration (approx.) | Comments |
|--------|----------------|----------------------|----------|
| WO2015100001 | 2015‑02‑02 | 2035‑02‑02 (if it becomes a patent) | Priority dates set the clock; actual expiration depends on grant and maintenance fees. |
| US 10,967,823 | 2015‑02‑02 | 2033‑02‑02 | 17 years from grant (2021‑08‑31). |
| US 11,013,000 | 2015‑02‑02 | 2035‑02‑02 | 17 years from grant (2022‑02‑08). |
| US 11,228,100 | 2015‑02‑02 | 2035‑02‑02 | 17 years from grant (2023‑05‑14). |
| US 10,987,504 | 2015‑02‑02 | 2035‑02‑02 | 17 years from grant (2021‑05‑27). |
Note: The U.S. and many other jurisdictions grant 17 years from the date of grant, not from the priority date. The priority date is only relevant for determining whether a later filing is “new” or “novel” relative to earlier filings.
Freedom‑to‑Operate (FTO) Considerations
- Core Chemical Scope: If you intend to develop a compound that is structurally identical to the core 2‑oxazolidinone scaffold, you are likely infringing WO2015100001 and all derivative patents that claim the same structure.
- Analogues: Minor modifications (e.g., changing the side chain or adding a substituent that is not present in the claims) may still fall under the doctrine of “inherently similar” or “design‑around” if the changes are not obvious. A detailed novelty search and claim‑by‑claim analysis is required.
- Synthetic Route: Using a different synthetic route that is not covered by US 11,228,100 may be a potential design‑around, but you must ensure you’re not infringing on other process claims.
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