(Yicai) July 1 -- Hybio Pharmaceutical’s shares surged after the Chinese drugmaker said US regulators have accepted for review its filing for generic versions of tirzepatide and revealed it is challenging Eli Lilly’s patent on the blockbuster weight-loss drug, which has 10 more years to run, making it the first company to publicly announce such a step.

Hybio [SHE: 300199] closed at CNY23.93 (USD3.30) per share in Shenzhen today, up 8.4 percent after surging by as much as 9.1 percent intraday. The benchmark ChiNext Index fell 1.9 percent. The stock has gained almost 34 percent in value since the end of last year.

Hybio filed abbreviated new drug applications for two generic versions of tirzepatide injection with the US Food and Drug Administration and has received official acceptance notices, the Shenzhen-based company said yesterday.

The company also said it has begun a Paragraph IV patent challenge against Lilly under the US Hatch-Waxman Act, a move that is likely to trigger a patent infringement lawsuit, according to analysts. If Hybio were to prevail in court, the firm could launch its generics before Lilly’s patent expires and receive 180 days of generic market exclusivity.

Hybio said it has developed proprietary synthesis technology and large-scale manufacturing capabilities for tirzepatide's active pharmaceutical ingredients, adding that it was the first supplier whose tirzepatide API drug master file passed the FDA's completeness review.

Developed by Indianapolis-based Lilly, tirzepatide is a once-weekly injectable dual glucagon-like peptide-1 receptor and glucose-dependent insulinotropic polypeptide receptor agonist. It is marketed as Mounjaro for adults with Type 2 diabetes and as Zepbound for chronic weight management in overweight or obese adults. No generic version has yet been launched anywhere in the world.

The drug's main US compound patent is scheduled to expire on Jan. 5, 2036, while various secondary patents expire at different times, with the latest extending to 2041, according to publicly available information.

The global craze for weight-loss therapies has made tirzepatide one of Lilly's biggest income drivers. According to its 2025 annual report, global sales of tirzepatide reached USD36.51 billion last year, including almost USD23 billion from Mounjaro and USD13.54 billion from Zepbound. US sales were about USD32 billion, accounting for roughly 88 percent of global revenue.

Editor: Emmi Laine