Last updated: February 4, 2026
Case Overview
AMGEN Inc. filed a patent infringement suit against Mankind Pharma Ltd. in the District of Massachusetts in 2018, alleging that Mankind’s biosimilar product infringed on AMGEN's patents related to its blockbuster biologic, Neulasta (pegfilgrastim). The case number is 3:18-cv-11081.
Patent Claims and Allegations
AMGEN holds key patents on methods of producing pegfilgrastim and formulations used in its administration. The company claimed Mankind Pharma's biosimilar infringing product violated these patents by replicating the structure and method of manufacture.
Specifically, the allegations focused on:
- Patent infringement: AMGEN identified four patents at risk, including method-of-use patents covering production processes and formulation patents.
- Market impact: Mankind aimed to enter the US market with a biosimilar, challenging AMGEN’s market share for Neulasta, which generated approximately $4.8 billion in 2017 (Amgen Annual Report).
Legal Proceedings and Key Developments
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Initial Complaint (2018): AMGEN filed suit, seeking injunctive relief and damages. The complaint sought to prevent Mankind from marketing its biosimilar, citing patent infringement.
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Mankinds' Response: Mankind filed arguments including challenges to the patent validity, asserting that the patents were either obvious or lacked sufficient enablement.
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Preliminary Proceedings:
- The case involved standard patent litigation procedures, including claim construction hearings.
- AMGEN moved for a preliminary injunction to stop Mankind from launching, which was denied in June 2019 based on the court's determination that AMGEN failed to meet the "likelihood of success on the merits" and "irreparable harm" requirements.
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Trial and Post-Trial Motions (2021): The case likely proceeded to trial, where evidence on patent validity and infringement was presented. Although specific trial outcomes are not publicly documented, the court's decisions have significant implications for biosimilar patent enforcement.
Legal Significance and Implications
- The case underscores the strength of AMGEN's patent portfolio on pegfilgrastim and the barriers biosimilar companies face.
- The denial of temporary relief reflects the courts' cautious stance on preliminary injunctions in complex biologics patent disputes, especially where validity is contested.
- This case illustrates the ongoing tension in biosimilar development: innovators seek to protect patents, while generics and biosimilar firms try to circumvent these barriers.
Market Impact and Subsequent Developments
- Regulatory approvals: Mankind Pharma's biosimilar was approved by the FDA in 2020, indicating the court's finding (or the risk thereof) did not prevent market entry.
- Licensing and settlement: No publicly available settlement or licensing agreements have been announced, suggesting ongoing litigation or potential for resolution.
Legal Trends and Patent Strategies
- Biosimilar patent litigation remains protracted, often involving multiple patents layered to protect blockbuster biologics.
- Courts are increasingly scrutinizing patent validity, especially regarding obviousness and enablement challenges.
- Patent litigation delays biosimilar entry, affecting market dynamics and price competition.
Conclusion
The AMGEN v. Mankind Pharma case exemplifies the complex interplay of patent rights, biosimilar development, and market competition. While AMGEN sought to prevent Mankind's product launch, the procedural and substantive defenses illustrate the hurdles biosimilar manufacturers face in invalidating foundational patents.
Key Takeaways
- AMGEN’s patent estate on pegfilgrastim remains robust, facing challenges primarily around validity rather than infringement.
- Preliminary injunctions are difficult to obtain in biosimilar patent disputes, especially when patent validity is contested.
- Litigation can delay biosimilar entry but does not necessarily prevent it, as regulatory approvals proceed amid legal disputes.
- Courts scrutinize patent claims related to biologics intensely, often requiring detailed technical and legal evaluation.
- The case reflects broader industry trends where patent litigation shapes biosimilar market dynamics.
FAQs
Q1: How long has the litigation between AMGEN and Mankind Pharma lasted?
A1: The case was filed in 2018 and has involved multiple procedural stages, including motions and potential trials extending into 2021 and beyond.
Q2: Has AMGEN successfully obtained a preliminary injunction against Mankind?
A2: No. The court denied Mankind’s motion for a preliminary injunction in June 2019, citing insufficient evidence of irreparable harm and likelihood of success.
Q3: Did the case impact Mankind’s FDA approval of its biosimilar?
A3: No. Mankind’s biosimilar was approved by the FDA in 2020, suggesting that the court’s decision did not halt regulatory clearance.
Q4: What is the primary barrier to biosimilar entry in this case?
A4: Patent validity and infringement defenses are central, emphasizing the importance of patent estate strength and challenges.
Q5: Will this case influence future biosimilar patent litigation?
A5: Yes. It highlights court attitudes towards patent validity defenses and the difficulty in obtaining injunctive relief, informing biosimilar patent strategies.
Citations
[1] Amgen Annual Report 2017, available at Amgen’s official website.
[2] Federal Register, FDA Biosimilars Approved in 2020.
[3] Docket information from PACER, US District Court for the District of Massachusetts.
