US Federal Judge Dismisses Class Action Suit Targeting Zoetis’ Canine OA Drug Librela®

In one of the Major Legal Victories for Zoetis, US Federal Judge dismissed Class Action Suit against Librela of Zoetis. Next, Zoetis awaits outcome of yet another class action suit by its select shareholders.

In a landmark decision for the veterinary pharmaceutical industry, U.S. District Judge Susan D. Wigenton of the U.S. District Court for the District of New Jersey granted Zoetis Inc.’s motion to dismiss a nationwide class action lawsuit regarding its blockbuster canine osteoarthritis (OA) therapy, Librela® (bedinvetmab injection).

The lawsuit (Hartney et al. v. Zoetis, Inc., Case No. 2:24-cv-09698), brought forward by eight named dog owners, alleged that Zoetis misrepresented Librela’s safety profile, failed to adequately warn pet owners and veterinarians about severe adverse events, and marketed a defectively designed biological product.

In her ruling, Judge Wigenton concluded that the plaintiffs’ claims suffered from fatal legal deficiencies under the New Jersey Product Liability Act (NJPLA) and state consumer protection statutes, primarily invoking the Learned Intermediary Doctrine and federal preemption principles.

Key Legal Findings: Why the Court Dismissed the Complaint

The court’s 15-page opinion systematically dismantled the plaintiffs’ core legal theories, establishing critical precedents regarding pharmaceutical manufacturer liability in veterinary medicine.

1. Application of the Learned Intermediary Doctrine

Under the Learned Intermediary Doctrine, a prescription drug manufacturer fulfills its legal duty to warn by providing adequate safety risk information to the prescribing medical professional (in this case, licensed veterinarians), who then exercises clinical judgment when advising clients.

• Failure to Prove Reliance: The court highlighted that the complaint failed to identify specific affirmative misrepresentations or omissions that prescribing veterinarians relied upon when choosing to administer Librela®.

• Presumption of Label Adequacy: Under the NJPLA, FDA-approved package inserts carry a rebuttable presumption of warning adequacy. The court ruled that the plaintiffs failed to show that Zoetis deliberately concealed or withheld post-approval safety data from regulatory authorities or veterinary clinicians.

2. Deficiencies in Consumer Protection Claims

The plaintiffs brought claims under state consumer fraud statutes across California, Illinois, Missouri, Texas, and Virginia. However, Judge Wigenton ruled that the complaint failed to specify any affirmative advertising statement that individual plaintiffs personally viewed and relied upon prior to consenting to treatment.

3. Dismissal of Design Defect Claims

The plaintiffs contended that bedinvetmab was defectively designed because safer therapeutic alternatives exist. The court dismissed this claim on two distinct grounds:

• Federal Preemption: Because the FDA approves specific monoclonal antibody formulations, federal law prohibits manufacturers from unilaterally altering a drug’s molecular design once approved.

• Failure to Propose Alternative Design: Plaintiffs failed to demonstrate a feasible, safer alternative design that would meet FDA regulatory approval or prove that Librela’s inherent risks outweighed its clinical therapeutic benefits.

Case Overview & Claims Comparison

Clinical Context: Librela® and the Science of Anti-NGF Therapies

Approved by the U.S. FDA in May 2023, Librela® (bedinvetmab injection) represents the first monoclonal antibody therapy cleared in the United States to control pain associated with canine osteoarthritis.

Monoclonal antibodies targeting Nerve Growth Factor (NGF) function by binding to circulating NGF, preventing it from attaching to tropomyosin receptor kinase A (TrkA) receptors on peripheral sensory nerves. This target-specific mechanism halts pain signal transmission without the gastrointestinal or renal systemic toxicity frequently associated with traditional non-steroidal anti-inflammatory drugs (NSAIDs)

Safety Monitoring and Label Updates

As with all biological products introduced to large patient populations, post-market pharmacovigilance surveillance collects field observations from practicing veterinarians. In early 2025, Zoetis and the FDA updated Librela’s U.S. prescribing information and issued routine veterinarian communications to expand post-approval safety disclosures—including observations of ataxia, paresis, and injection-site reactions—ensuring clinicians maintain complete risk-benefit visibility.

In response to the legal proceedings, Zoetis reaffirmed its clinical confidence in the medication, emphasizing that over 18 million doses have been safely administered globally to improve the mobility and life quality of aging dogs suffering from chronic arthritic pain.