Sanofi Expands China Presence with $395M Arrowhead Deal for Rare Metabolic Disease Treatment

Sanofi has struck a $395 million deal with Arrowhead Pharmaceuticals for the China rights to plozasiran, a promising RNA interference (RNAi) therapeutic for rare metabolic diseases. The agreement, announced on August 1, 2025, marks another significant step in Sanofi's expansion strategy in the Chinese pharmaceutical market.

Deal Structure and Financial Details

The French pharmaceutical giant will pay $130 million upfront to Visirna Therapeutics, Arrowhead's China-focused subsidiary. The deal includes potential milestone payments of up to $265 million, contingent on plozasiran securing regulatory approvals in China for familial chylomicronemia syndrome (FCS) and other indications. Arrowhead is set to receive royalties on sales from the greater China region as part of its licensing arrangement with Visirna.

Plozasiran: Mechanism and Clinical Success

Plozasiran is designed to lower the production of apolipoprotein C-III (APOC3), a key component in triglyceride metabolism. By reducing APOC3 levels, the drug aims to decrease triglycerides and normalize lipid levels in patients with rare metabolic disorders.

The treatment has already demonstrated impressive results in clinical trials. In a phase 3 study completed last year, plozasiran showed significant efficacy in FCS patients:

• 25-mg dose: 80% reduction in triglycerides at 10 months
• 50-mg dose: 78% reduction in triglycerides at 10 months

These positive outcomes have positioned plozasiran as a strong contender in the treatment of rare metabolic diseases, particularly in the Chinese market where Visirna Therapeutics has already submitted an approval request to regulators.

Strategic Implications for Sanofi and Arrowhead

This collaboration aligns with Sanofi's ongoing efforts to strengthen its presence in China's pharmaceutical landscape. Wayne Shi, president of Sanofi Greater China, emphasized the strategic fit of the deal, stating, "We are pleased to have concluded this agreement to enable us to advance plozasiran in Greater China where Sanofi has deep roots and a proud heritage of serving people living with a wide range of diseases."

For Arrowhead, the partnership represents a significant milestone in its expansion into the Chinese market. Christopher Anzalone, Ph.D., CEO of Arrowhead, commented on the deal's importance: "When we founded Visirna in 2022, we believed that Greater China represented an important potential future market for multiple programs in Arrowhead's pipeline of investigational RNAi-based candidates for cardiometabolic diseases."

The agreement with Sanofi follows Arrowhead's strategic decision to establish Visirna Therapeutics, leveraging local expertise to navigate China's complex clinical, regulatory, and commercial environment. This approach has already yielded results, with plozasiran progressing through clinical studies and into the regulatory review process in China.