Arrowhead’s Subsidiary Visirna Transfers Greater China Rights to Plozasiran to Sanofi in Strategic $395 Million Deal Amid Regulatory Milestone in Hypertriglyceridemia
In a move poised to reshape the therapeutic landscape for patients with severe lipid disorders in China, Arrowhead Pharmaceuticals, Inc. (NASDAQ: ARWR) announced a significant asset transfer agreement on August 1, 202 5, involving its majority-owned subsidiary Visirna Therapeutics and global pharmaceutical giant Sanofi. The agreement centers around the investigational RNA interference (RNAi) therapy, plozasiran, which targets apolipoprotein C-III (APOC3) and is under development for the treatment of familial chylomicronemia syndrome (FCS) and severe hypertriglyceridemia (SHTG).
This agreement represents a high-profile regional divestiture that not only highlights the growing strategic interest in RNAi therapies within Asia’s pharmaceutical market but also reflects the maturing capabilities of China-based biotech ecosystems in bringing novel modalities through advanced clinical development and into the regulatory pipeline.
Background: Visirna’s Origin and Arrowhead’s China Strategy
Visirna Therapeutics was established in 2022 as a China-based joint venture and majority-owned subsidiary of Arrowhead Pharmaceuticals, created to focus on the development and commercialization of select RNAi therapeutic candidates within Greater China. Arrowhead, headquartered in Pasadena, California, and a recognized leader in RNAi therapeutics, seeded Visirna with four of its investigational cardiometabolic assets, with plozasiran being the most advanced program in the pipeline.
By launching Visirna, Arrowhead aimed to harness the power of localized expertise, regulatory familiarity, and market access in China while continuing to retain value through a strategically structured partnership. This structure allowed for clinical progress in China to proceed largely independently, even as the parent company advanced the same assets globally through separate regulatory pathways.
“Greater China has long been seen as a critical growth market in biopharma, and when we founded Visirna in 2022, we recognized that our RNAi platform had the potential to make a meaningful impact on cardiometabolic disease there,” said Christopher Anzalone, Ph.D., President and CEO of Arrowhead. “We strategically created Visirna to ensure we had boots on the ground—partners who understood the local landscape and could execute clinical development, regulatory engagement, and eventually commercialization. The team has done remarkable work, and we’re excited to now bring in Sanofi, a partner with global scale and deep roots in the region.”
The Deal: Sanofi Acquires Greater China Rights to Plozasiran
Under the terms of the transaction, Sanofi will acquire full development and commercial rights to plozasiran in Greater China, which includes mainland China, Hong Kong, Macau, and Taiwan. This includes the rights to pursue additional indications beyond the initial focus on familial chylomicronemia syndrome. In return, Sanofi will pay Visirna an upfront consideration of $130 million.
Furthermore, Visirna is entitled to receive up to $265 million in milestone payments based on the successful approval of plozasiran for multiple indications within mainland China. Arrowhead, through its existing licensing arrangement with Visirna, which was partially assigned to Sanofi under the current agreement, will also be eligible to receive royalties on net product sales generated from plozasiran in Greater China.
The deal is one of the more notable regional licensing transactions involving an RNAi therapeutic in 2025 and aligns with Sanofi’s ongoing efforts to build out its cardiometabolic portfolio, particularly in markets with high unmet medical need and a growing burden of metabolic disease.
“This agreement gives us the opportunity to advance a first-in-class RNAi therapeutic that directly targets the root cause of dangerously high triglyceride levels,” said Wayne Shi, President of Sanofi Greater China. “China has one of the highest burdens of cardiometabolic disease in the world, and plozasiran has already demonstrated impressive clinical efficacy. We believe our established presence in the region will enable us to swiftly bring this innovation to patients who need it most.”
Plozasiran: A First-in-Class RNAi Therapy Targeting APOC3
Plozasiran (formerly ARO-APOC3) is Arrowhead’s investigational RNAi-based therapeutic targeting the hepatic production of apolipoprotein C-III (APOC3), a key regulator of triglyceride metabolism. Elevated levels of APOC3 are strongly associated with hypertriglyceridemia and increased cardiovascular risk, particularly in rare inherited disorders such as FCS and in broader populations with severe hypertriglyceridemia.
Through the mechanism of RNA interference, plozasiran silences the expression of the APOC3 gene in hepatocytes, leading to a sustained reduction in serum APOC3 levels and, consequently, a profound lowering of circulating triglycerides. The therapeutic candidate is delivered using Arrowhead’s proprietary TRiM™ platform, which facilitates liver-targeted delivery and minimizes off-target effects.
Arrowhead is currently conducting multiple Phase 3 and late-stage studies of plozasiran outside China, including trials targeting FCS, SHTG, and mixed dyslipidemia in collaboration with regulatory bodies in the U.S., Europe, and elsewhere.
Clinical Progress and Regulatory Milestones in China
The agreement follows a string of major clinical and regulatory milestones achieved by Visirna in China. Most notably, the company successfully completed a Phase 3 clinical trial evaluating plozasiran in Chinese patients diagnosed with familial chylomicronemia syndrome (Clinical Trial ID: CTR20231418 / NCT05902598). The study met its primary efficacy endpoint, demonstrating a statistically significant and clinically meaningful reduction in fasting triglyceride levels, and also achieved all key secondary endpoints.
Based on this positive dataset, Visirna submitted a New Drug Application (NDA) for plozasiran to the National Medical Products Administration (NMPA) in China in late 2024. The application was formally accepted in January 2025. Notably, the Chinese NMPA granted plozasiran Breakthrough Therapy Designation for the treatment of FCS and designated the NDA for Priority Review—recognition that underscores the significant unmet need in this ultra-rare and potentially life-threatening lipid disorder.
As FCS is characterized by extremely high triglyceride levels—often exceeding 880 mg/dL—patients suffer from recurrent episodes of pancreatitis, severe abdominal pain, and other complications. Currently, there are few approved therapies that adequately address the underlying pathophysiology of the disease, and no approved RNAi therapeutics for lipid disorders are yet commercially available in China.
The expedited review timeline associated with the Priority Review designation suggests that the NMPA may reach a regulatory decision by the end of 2025 or early 2026, depending on final data evaluation and manufacturing inspections.
Strategic Implications for Sanofi and Arrowhead
The acquisition of Greater China rights to plozasiran is consistent with Sanofi’s broader cardiometabolic and rare disease strategy, which has gained new momentum in recent years following its push to rejuvenate the pipeline under CEO Paul Hudson. Sanofi has particularly emphasized its commitment to RNAi, gene therapy, and other cutting-edge modalities, as evidenced by its partnerships with companies like Alnylam, Kymera, and now, through this deal, Arrowhead/Visirna.
For Arrowhead, the deal is emblematic of a strategic model that leverages geographic specialization. By spinning out regionally focused subsidiaries like Visirna and licensing selective territorial rights to global players, Arrowhead is able to maintain upside exposure to key markets without overextending operationally. The structure also allows for quicker regulatory and commercial action in localized markets, where domestic partners often possess superior regulatory knowledge and stakeholder access.
Additionally, the deal reinforces the value of Arrowhead’s RNAi platform, as it marks yet another major pharmaceutical partner—following Takeda, Amgen, and Horizon Therapeutics—willing to invest heavily in Arrowhead’s therapeutic candidates.
The transaction remains subject to customary closing conditions, including any applicable regulatory approvals. Gibson, Dunn & Crutcher LLP and Sidley Austin LLP served as legal counsel to Arrowhead for the deal, advising on cross-border intellectual property assignments, licensing rights, and regulatory considerations specific to biopharmaceutical asset transfers in China.
While the financial details are specific to Greater China rights only, the broader implications of the agreement are global. The transaction underscores the increasing strategic interest in RNAi therapies, the globalization of clinical development, and the emerging role of China as a key market for innovative biologics and genetic medicines.
With regulatory review now underway in China and Sanofi stepping into the commercialization role, expectations are high that plozasiran could become one of the first RNAi therapies approved for a cardiometabolic indication in China. If approved, the drug would mark a milestone not only for Arrowhead and Sanofi but also for the broader Chinese biotech and regulatory ecosystem, which has rapidly matured to support global-class innovation.
Moreover, the successful execution of this agreement may serve as a template for future regional deals in emerging markets, particularly as Western biopharmaceutical companies seek to expand access to innovative therapies without compromising operational focus or resource allocation.
As the biopharma landscape becomes increasingly decentralized and innovation continues to emerge from cross-border partnerships, the Arrowhead-Visirna-Sanofi agreement provides a clear illustration of how smart structuring, regulatory agility, and scientific excellence can converge to deliver promising new therapies to patients worldwide—starting with those in Greater China.
