Last updated: February 26, 2025
Here is a summary and analysis of the patent litigation between Vifor Fresenius Medical Care Renal Pharma Ltd. and Annora Pharma Private Limited:
Background
This case involves a patent infringement lawsuit filed by Vifor Fresenius Medical Care Renal Pharma Ltd. and Vifor Fresenius Medical Care Renal Pharma France S.A.S. (collectively "Vifor Fresenius") against Annora Pharma Private Limited and Hetero Labs Limited (collectively "Annora") in the U.S. District Court for the District of Delaware.
Key Details
- Plaintiffs: Vifor Fresenius Medical Care Renal Pharma Ltd. and Vifor Fresenius Medical Care Renal Pharma France S.A.S.
- Defendants: Annora Pharma Private Limited and Hetero Labs Limited
- Case Number: 1:18-cv-01996
- Filed: December 17, 2018
- Court: U.S. District Court for the District of Delaware
- Judge: Leonard P. Stark
- Nature of Suit: Patent - Abbreviated New Drug Application (ANDA)
Key Issues
The lawsuit stems from Annora seeking FDA approval to market a generic version of Vifor Fresenius's Velphoro® product, which is a phosphate binder used to treat hyperphosphatemia in patients with chronic kidney disease on dialysis[1].
Vifor Fresenius alleges that Annora's proposed generic product would infringe U.S. Patent No. 9,561,251 ('251 patent), which covers Velphoro®[4]. Specifically, Vifor Fresenius claims that Annora's Abbreviated New Drug Application (ANDA) and proposed generic product would directly infringe claims of the '251 patent[4].
Legal Claims
The key legal claims in the lawsuit include:
- Direct patent infringement by Annora
- Inducement of patent infringement by Hetero Labs
Vifor Fresenius is seeking:
- A judgment that Annora's ANDA product would infringe the '251 patent
- An injunction to prevent Annora from commercially manufacturing, using, selling or importing the generic product before patent expiration
- Damages if Annora engages in commercial manufacture, use, sale or importation before patent expiration
Key Arguments
Vifor Fresenius argues that:
- Annora's proposed generic is bioequivalent to Velphoro® and would necessarily infringe the '251 patent claims[4]
- Hetero Labs induced infringement by directing Annora to file the ANDA[4]
Annora likely argues that:
- Its generic product does not infringe the '251 patent claims
- The '251 patent is invalid and/or unenforceable
Procedural History
- Complaint filed on December 17, 2018
- Multiple stipulations to extend time for defendants to respond
- Pro hac vice motions filed for plaintiffs' attorneys
Analysis
This case follows a typical pattern for ANDA patent litigation, with the brand drug manufacturer (Vifor Fresenius) suing the generic applicant (Annora) for patent infringement based on the ANDA filing. Key issues likely to be litigated include:
- Claim construction of the '251 patent
- Whether Annora's proposed generic would infringe under the proper claim construction
- Validity challenges to the '251 patent
- Whether Hetero Labs can be held liable for inducement
The 30-month stay of FDA approval for Annora's ANDA expires on May 30, 2021, so the parties and court will likely aim to resolve the case before then[3]. If Vifor Fresenius prevails, Annora would be blocked from launching its generic until patent expiration in 2030, absent an appeal or settlement[3]. If Annora prevails, it could potentially launch its generic product upon receiving FDA approval.
This case highlights the ongoing tensions between brand and generic drug manufacturers in the pharmaceutical industry, with billions of dollars often at stake in these patent disputes. The outcome will impact market exclusivity for Velphoro® and patient access to a lower-cost generic alternative.
"This obviousness issue comes down to weighing competing facts – particularly competing expert testimony," the Court explicitly "found Plaintiff's experts to be more credible" than Teva's experts and that "Defendant's obviousness arguments suffer from significant and improper hindsight bias."[1]
Key Takeaways
- Patent litigation is a critical strategy for brand drug makers to protect market exclusivity
- ANDA filings by generics frequently trigger infringement lawsuits
- Courts must weigh complex scientific and legal issues in these cases
- Outcomes significantly impact drug pricing and market dynamics
- Expert testimony often plays a crucial role in patent validity challenges
FAQs
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What is an ANDA?
An Abbreviated New Drug Application (ANDA) is an application for a U.S. generic drug approval for an existing licensed medication or approved drug.
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What is the 30-month stay in ANDA litigation?
The 30-month stay is a period during which the FDA cannot give final approval to an ANDA if a patent owner files an infringement suit within 45 days of receiving notice of the ANDA filing.
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What does it mean for a generic to be bioequivalent?
Bioequivalence means the generic has the same active ingredient, dosage form, strength, and route of administration as the brand drug, and is absorbed by the body at the same rate and extent.
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What is inducement of patent infringement?
Inducement occurs when a party actively encourages or aids another party in directly infringing a patent.
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How long do pharmaceutical patents typically last?
In the U.S., pharmaceutical patents generally last for 20 years from the date of filing, but the effective patent life is often shorter due to the time required for drug development and FDA approval.
