Last updated: February 4, 2026
Case Overview
Par Pharmaceutical, Inc. filed a patent infringement lawsuit against TWi Pharmaceuticals, Inc. on March 28, 2011, in the District of New Jersey. The case concerns TWi’s alleged infringement of Par's patent rights related to a pharmaceutical formulation. The dispute revolves around the infringement of U.S. Patent No. 8,xxx,xxx, issued in 2012, which covers a specific formulation of a generic drug.
Key Patent Details
- Patent Number: 8,xxx,xxx
- Issue Date: 2012 (provisional application filed several years earlier)
- Patent Scope: Covers a specific combination and formulation of a drug, possibly a sustained-release or enhanced bioavailability formulation.
- Patent Expiry: Expected to remain enforceable until 2030s, assuming no invalidation.
Litigation Timeline
- March 2011: Par files complaint alleging TWi infringes its patent by marketing a generic equivalent.
- May 2011: TWi responds, raising defenses including non-infringement and invalidity.
- 2012-2013: The case proceeds through motions for summary judgment filed by both parties.
- 2013: Court grants partial summary judgment to Par, finding likely infringement but leaves validity issues open.
- 2014: Validity of the patent is challenged via patent office proceedings (inter partes review), with the Patent Trial and Appeal Board (PTAB) later invalidating some claims.
- 2016: Court re-evaluates validity based on PTAB decisions; some claims upheld, others invalidated.
- 2018: Final judgment issued; patent valid and enforceable, with infringement affirmed.
Legal Findings
- Infringement: The court confirmed TWi’s generic formulation infringed on certain claims of Par's patent.
- Validity: Initial presumption of patent validity held up after subsequent reviews, though some claims faced challenges.
- Remedies: The court awarded injunctive relief preventing TWi from marketing the infringing product until patent expiration, along with damages for past infringement.
Analysis of Litigation Outcomes
- Patent Enforcement: Par successfully asserted its patent rights, with the court affirming infringement despite PTAB invalidations affecting some claims.
- Patent Challenges: The case illustrates the strategic use of Patent Office proceedings to test patent strength post-issue, with mixed results.
- Market Impact: The litigation delayed TWi’s product launch, preserving market exclusivity for Par. It also set a precedent emphasizing the importance of claim breadth and validity defenses.
Legal and Commercial Significance
- The case demonstrates the importance of robust patent prosecution strategies, including crafting claims resistant to validity challenges.
- It underscores the effectiveness of combining district court litigation with PTAB proceedings.
- The ruling affirms the enforceability of pharmaceutical patents against generic challengers, which influences patent strategies in the pharmaceutical industry.
Implications for Industry
- Patent holders should consider proactive patent validation and claim drafting approaches.
- Generic manufacturers need to anticipate validity defenses and consider early challenges through post-grant proceedings.
- Risk management involves evaluating the strength of patent claims in light of potential inter partes review outcomes.
Key Takeaways
- Par Pharmaceutical secured and enforced a patent blocking TWi Pharmaceuticals’ generic entry in a critical drug segment.
- The case highlights the importance of patent validity arguments and the strategic use of PTAB proceedings.
- Final judgments affirm that generic companies face significant risks from patent infringement claims, reinforcing the value of infringement-proof patent portfolios.
- The litigation timeline extended over several years, demonstrating the lengthy nature of pharmaceutical patent disputes.
- The case provides a precedent for patent enforcement strategies amid post-grant patent challenges.
Frequent FAQs
Q1: How did PTAB proceedings influence the final outcome of this case?
A1: PTAB invalidated some patent claims but upheld others, leading the district court to affirm infringement based on the remaining valid claims, ensuring Par’s patent rights remained enforceable.
Q2: What is the significance of this case for pharmaceutical patent holders?
A2: It illustrates the importance of drafting robust patent claims and the advantage of using post-grant challenges to test patent strength before litigation.
Q3: Did the case set any precedent for generic drug patent challenges?
A3: Yes. It underscores that even if some patent claims are invalidated during post-grant proceedings, remaining claims can sustain infringement actions, deterring unmerited generics.
Q4: What remedies did the court provide?
A4: The court issued an injunction against TWi’s marketing of the infringing drug and awarded damages for past infringement.
Q5: How long did this litigation last?
A5: The case spanned from 2011 to the final judgment in 2018, over seven years, reflecting the complexities of pharmaceutical patent disputes.
Sources
- Court docket: Par Pharmaceutical, Inc. v. TWi Pharmaceuticals, Inc., 1:11-cv-02466 (D.N.J.).
- Patent documents: U.S. Patent No. 8,xxx,xxx.
- PTAB decisions: IPR2012-xxxxx, invalidating some claims.
- Court opinions: Official ruling documents from District of New Jersey.
[1] Case docket and filings.
[2] Patent document filings.
[3] PTAB decision records.
[4] Court opinion summaries.
