Patent Suits Trigger 30-Month FDA Stay and Extend EXPAREL’s Exclusivity
Pacira BioSciences has opened a new front in its long effort to protect EXPAREL, filing two patent-infringement lawsuits in the U.S. District Court for the District of Delaware against The WhiteOak Group and Qilu Pharmaceutical following submissions of ANDAs referencing its flagship non-opioid analgesic. The challenge signals the increasing commercial value of long-acting local anaesthetics in the perioperative pain-management market, and Pacira is positioning itself for a drawn-out patent defence that could determine the trajectory of its core franchise.
The complaints allege that both companies seek approval to market generic liposomal bupivacaine prior to the expiration of 21 Orange Book-listed patents tied to EXPAREL’s multivesicular liposome technology. Those patents span two families and stretch well into the next decade, with expirations ranging from January 22, 2041 to as late as July 2, 2044. Pacira argues that the submissions of the ANDAs and their accompanying Paragraph IV certifications constitute infringement, setting up a classic Hatch-Waxman confrontation with high stakes for the U.S. non-opioid infiltration anaesthesia market.
What You Need To Know
- Pacira filed dual patent-infringement lawsuits in Delaware against WhiteOak and Qilu after both companies submitted ANDAs referencing EXPAREL.
- The legal action triggered a 30-month FDA stay that blocks any final approval of the generics while litigation proceeds.
- EXPAREL is protected by 21 Orange Book patents spanning two families, with expirations running from 2041 to 2044.
- Pacira positions the move as a defense of its core non-opioid anesthesia franchise amid growing generic interest in complex liposomal products.
Under the Hatch-Waxman Act, Pacira’s decision to sue immediately triggered a 30-month statutory stay that halts the FDA from granting final approval of the two ANDAs unless a court decision arrives earlier. That stay, which can meaningfully delay generic entry, offers Pacira time to contest the scientific, technical, and chemical arguments that typically underpin generic liposome challenges. In the world of complex drug products, bioequivalence is notoriously difficult to demonstrate, and Pacira’s formulation is one of the more intricate in the sector.
In its announcement, Pacira emphasized that it will defend the intellectual property protecting EXPAREL vigorously and that the product’s long-term exclusivity is foundational to the company’s growth narrative. With EXPAREL continuing to serve as the company’s primary revenue driver, the legal strategy reflects a familiar playbook, use a dense patent estate, technical formulation complexity, and multi-year litigation timelines to preserve market leadership. The company’s IP coverage extends across composition of matter, manufacturing processes, release kinetics, and structural characteristics of the multivesicular liposomes.
The threat posed by would-be generic entrants is not limited to litigating claims. Even if challengers prevail on some patent arguments, manufacturing a liposomal anaesthetic at scale that meets stability, release-profile, and particle-size requirements is a major barrier. The FDA has historically taken a conservative stance with complex generics, often requiring extensive evidence that goes beyond standard bioequivalence comparisons. Pacira’s patents describe highly specific structural and functional properties of the vesicles, further elevating the evidentiary bar for any generic developer attempting to match the physicochemical attributes of EXPAREL.
Pacira’s stance also fits squarely within a broader strategy of reinforcing the brand’s value amid growing demand for opioid-sparing perioperative pain solutions. Hospitals facing heightened scrutiny over opioid stewardship have increasingly prioritized non-opioid analgesics that can support ERAS pathways. As operating volumes continue a steady post-pandemic normalization, demand for consistent, long-acting analgesia options is drifting upward. Pacira has positioned EXPAREL as a premium, durable asset in this shift, which amplifies the relevance of long-term exclusivity.
The lawsuits also come at a moment when large health systems are re-evaluating cost structures and labor dynamics, often seeking predictable recovery profiles and reduced need for postoperative pain-related interventions. Pacira has frequently argued that EXPAREL reduces downstream clinical burden by lowering opioid exposure, potentially mitigating complications or readmissions. Protecting exclusivity is therefore not just a legal matter; it plays directly into the product’s economic value proposition in an increasingly outcomes-driven reimbursement environment.
For WhiteOak and Qilu, the move reflects a growing appetite among generics manufacturers to challenge complex injectables previously considered insulated from routine competition. The commercial payoff of cracking a high-value specialty injectable like EXPAREL could be considerable, but the regulatory and technical path is far from straightforward. Several past examples in the liposomal and complex-generic space illustrate how litigation, FDA manufacturing questions, or CMC obstacles can stretch development timelines far beyond initial assumptions.
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Pacira, meanwhile, continues to diversify across its non-opioid portfolio, including iovera and ZILRETTA. But EXPAREL remains the anchor asset, and the company’s messaging makes it clear that any challenge to its patent estate will be met aggressively. The dual lawsuits consolidate that posture, adding new legal proceedings to a docket that could define the competitive landscape of the franchise through the early 2040s.
As the cases proceed, the market will watch closely for early signals: preliminary injunction rulings, claim-construction battles, or any settlement overtures that might outline a potential entry date. For now, the 30-month stay buys Pacira time, locks out near-term generic disruption, and sets the stage for a multi-year dispute cantered on one of the most commercially consequential pain-management drugs in the U.S. hospital ecosystem. In a market where payers and providers are tightening around cost and outcomes, the durability of EXPAREL’s exclusivity may dictate how much leverage Pacira maintains as the perioperative care model continues to evolve.
For media inquiries or to share perspectives on access and evidence policy, email editor@synopulse.com.
