Last updated: February 27, 2026
What are the core facts of the case?
Anacor Pharmaceuticals filed a patent infringement lawsuit against Lupin Limited in the District of Delaware on May 31, 2018. The complaint alleges that Lupin infringed U.S. Patent Nos. 9,632,202 and 9,512,018 based on proposed generic versions of Anacor's topical non-steroidal anti-inflammatory drug, crisaborole, used to treat atopic dermatitis. The patents cover specific formulations and methods of use of crisaborole.
Lupin responded with a paragraph IV certification, asserting that the patents are invalid or will not be infringed. The case revolves predominantly around patent validity challenges and potential infringement by Lupin’s proposed generic.
What are the key legal issues?
- Patent Validity: Whether the '202 and '018 patents meet the requirements of novelty, non-obviousness, and utility under U.S. patent law.
- Infringement: Whether Lupin’s generic formulations infringe the asserted patents.
- Notice of Paragraph IV Certification: The timing of Lupin’s notice and whether it triggers certain statutory procedures.
The litigation is typical of Hatch-Waxman patent disputes involving first-to-file generic challengers.
What procedural developments occurred?
- Filing Date: Complaint lodged on May 31, 2018.
- Lupin’s Response: On July 16, 2018, Lupin filed an ANDA paragraph IV certification, asserting non-infringement and/or invalidity of the patents.
- Automatic Stay: Court proceedings follow a typical course under the Hatch-Waxman Act, with potential for settlement, patent challenges, or court rulings.
No settlement agreements or dismissals are publicly reported as of the latest update.
What are the relevant legal precedents or statutes?
- 35 U.S.C. § 271(e)(2): Provides for infringement liability upon filing an ANDA containing a paragraph IV certification.
- 35 U.S.C. § 272: Statutory framework for patent litigation involving generic drug applications.
- Patent Resolutions: Courts often decide on patent validity and infringement simultaneously, especially for patents with complex formulations.
What could be the potential outcomes?
- Patent Validity Upheld: If courts find patents valid, Lupin’s market entry is delayed until patent expiry or a license is negotiated.
- Patent Invalidated: Anacor may be forced to modify claims or settle.
- Infringement Confirmed: A ruling confirming infringement could lead to preliminary or permanent injunctions.
- Invalidity or Non-infringement: Could enable Lupin to launch a generic product.
Legal timelines suggest potential court rulings within 12-24 months, depending on motions, discovery, and trial settings.
What is the strategic significance?
For Anacor, the litigation aims to protect market exclusivity on crisaborole. For Lupin, proceedings delay generic entry, with the risk of significant patent-related damages or injunctions. Market consequences hinge on the validity of the patents; a ruling invalidating them could open a large commercial market for Lupin.
Key Data Summary
| Item |
Details |
| Case Number |
1:18-cv-01606-RGA |
| Court |
U.S. District Court, District of Delaware |
| Filed |
May 31, 2018 |
| Parties |
Anacor Pharmaceuticals, Inc. (Plaintiff) vs. Lupin Limited (Defendant) |
| Patent Numbers |
9,632,202 and 9,512,018 |
| Subject |
Patent infringement and validity regarding crisaborole formulations |
Key Takeaways
- The case centers on patent rights associated with crisaborole, a treatment for atopic dermatitis.
- Lupin’s early paragraph IV certification indicates an intent to challenge patent validity or non-infringement.
- Legal proceedings follow the typical Hatch-Waxman escalation, with potential for settlement or patent invalidation.
- A final ruling could significantly impact market access for generic crisaborole.
FAQs
1. What are the patents involved in this lawsuit?
The patents are Nos. 9,632,202 (covering formulations) and 9,512,018 (covering methods of use). Both are filed by Anacor to extend exclusivity for crisaborole.
2. How does paragraph IV certification impact the case?
It triggers a30-month stay of regulatory approval for the generic, unless settled or dismissed earlier. It also starts the legal process for patent litigation.
3. What are the chances of the patents being invalidated?
Based on prior patent challenges in similar topical drug formulations, courts often scrutinize obviousness and novelty. The outcome depends on the strength of prior art and claim construction.
4. When could a final ruling be expected?
Typically 12 to 24 months post-filing, considering court schedules, motions, and potential appeals.
5. What market implications does this case hold?
If the patents hold, Lupin’s entry is delayed, protecting Anacor’s market share. If invalidated, Lupin can launch, competing on price and availability.
References
- U.S. District Court, District of Delaware. (2018). Anacor Pharmaceuticals, Inc. v. Lupin Limited, Case No. 1:18-cv-01606-RGA.
- U.S. Patent and Trademark Office. (2023). Patent Statutes and Regulations.
- Hatch-Waxman Act, 21 U.S.C. §§ 355, 355(j).
