Sanofi grabs Chinese rights to Arrowhead rare disease drug

The importance of China as a growth market for pharma multinationals is underlined by the news that Sanofi has paid $130 million upfront for Chinese rights to an Arrowhead Pharma drug under review for a disease associated with elevated triglyceride levels.

The deal with Arrowhead's Visirna Therapeutics subsidiary – which also includes $265 million in milestones tied to potential Chinese approvals – is focused on gene-silencing drug plozasiran, which generated positive results in rare disease familial chylomicronaemia syndrome (FCS) last year.

Sanofi has rights to the apoC-III inhibitor in FCS and follow-up indication severe hypertriglyceridaemia (SHTG). Plozasiran has also advanced into phase 3 trials in SHTG on the back of encouraging results in the phase 2b SHASTA-2 study, also reported last year.

In the phase 3 PALISADE trial, plozasiran, given as a subcutaneous injection every three months, achieved an 80% reduction in fasting triglyceride levels after 10 months of follow-up, accompanied by a sharp fall in the rate of acute pancreatitis, a serious complication of the ultra-rare disorder, compared to placebo.

One potential rival is Ionis and its olezarsen candidate, which is already on the market in the US as Tryngolza after getting the go-ahead from the FDA in FCS towards the end of last year. So far, however, Ionis has not filed for approval of the drug in China.

Plozasiran has been granted breakthrough therapy designation and a priority review by China's National Medical Products Administration (NMPA), so it should have a swift review there. Meanwhile, Arrowhead is waiting to hear from the FDA in November on its filing for the drug in FCS and is waiting for results of phase 3 studies in SHTG in mid-2026.

Arrowhead set up Visirna in 2022 as a joint venture with Vivo Capital to take forward plozasiran and three other RNAi-based cardiometabolic medicines in the Greater China market, which also covers Hong Kong, Macau, and Taiwan.

Arrowhead's chief executive, Christopher Anzalone, said China is an important market for those candidates, adding that the Visirna team "understand the intricacies of China's clinical, regulatory, and commercial environment and have done impressive work moving plozasiran through clinical studies and into the regulatory submission and review process."

He added: "We now look forward to working with Sanofi and believe they are extremely well-positioned as a global company with a strong presence in China," which is now the second-largest pharma market in the world after the US.

The Chinese market accounted for €687 million out of Sanofi's near-€10 billion in total sales in the second quarter of this year, rising by 1.8% in a declining market that has been affected in the last few years by a slowing economy, changes to the national reimbursement policy for medicines, and rising competition.