(Yicai) Oct. 8 -- Shares of Chinese innovative drug maker Allist Pharmaceuticals plummeted by the daily limit today, following disappointing results in an overseas Phase III clinical trial for its flagship product, lung cancer treatment Firmonertinib.

Allist [SHA: 688578] closed down 20 percent at CNY89.26 (USD13.32) today, cutting its market capitalization to CNY40.2 billion (USD6 billion). Firmonertinib accounts for nearly 99 percent of the Shanghai-based firm’s revenue.

The trial was co-conducted with the company’s US partner ArriVent BioPharma, which in 2021 acquired the rights to develop the drug outside China. The trial failed to show that Firmonertinib offered a meaningful delay in disease progression compared with standard chemotherapy, the firms revealed yesterday. 

The two partners said they are now evaluating the complete dataset from the trial to determine their follow-up plan. Pennsylvania-headquartered ArriVent announced the failure a day earlier than Allist, as markets were closed in China for the National Day holiday. ArriVent [NASDAQ: AVBP] slumped 47 percent on the news on Oct. 6, but rebounded 11.9 percent to USD16.89 yesterday.

Firmonertinib is a small molecule targeted drug used to treat non-small cell lung cancer caused by epidermal growth factor receptor mutations. The drug was approved for the market in China in March 2021 and quickly became a mainstream lung cancer treatment drug in the country. Last year, its sales reached CNY5.1 billion (USD761 million), accounting for 98.7 percent of Allist’s total revenue for 2025.

In order to expand overseas, Allist reached a cooperation agreement with ArriVent in July 2021, granting it the rights to develop and sell Firmonertinib in markets outside China. The deal gave Allist a down payment of USD40 million and potential future earnings of up to USD765 million as well as a stake in ArriVent.

The trial is one of two conducted for Firmonertinib by the two firms, and it enrolled 398 patients worldwide, with research centers in the US, Europe, Japan, and China.

The other international multicenter clinical trial targeting EGFR PACC mutations has also entered Phase III, with the first patient enrolled in December last year. EGFR PACC mutation is a rare subtype of EGFR mutations, accounting for about 12 percent of NSCLC patients who have EGFR mutations. As yet, there are no approved targeted drugs for it globally.

Editors: Dou Shicong, Tom Litting