(Yicai) Aug. 18 -- Shares of China's Betta Pharmaceuticals plunged by the daily limit today after its US partner EyePoint said a late-stage trial of their jointly developed eye disease drug Duravyu failed to show it worked at least as well as an existing treatment.

Chinese innovative drug developer Betta Pharma [SHE: 300558] closed at CNY55.72 (USD8.20), down 20 percent. The shares are still 14 percent higher than in early January.

EyePoint [Nasdaq: EYPT], an American ophthalmic drug company, tumbled 67 percent yesterday after announcing the results of Lugano, the first of two pivotal Phase III trials of Duravyu for wet age-related macular degeneration, a condition that can cause severe vision loss in older adults.

EyePoint said the Lugano trial failed to show that Duravyu was as effective as aflibercept, an existing treatment for the disease. Developed by Bayer and Regeneron Pharmaceuticals, aflibercept is a widely used wet AMD drug and the benchmark against which Duravyu was tested, with annual sales nearing USD10 billion at their peak.

However, EyePoint said Lugano produced encouraging results on other measures. Duravyu reduced the need for additional treatments by 42 percent, while 54 percent of patients did not need supplemental injections through week 56. The drug also showed a favorable safety profile and helped keep the disease under control.

Betta Pharma told Yicai that Duravyu's second parallel Phase III trial is ongoing, with topline results expected in the fourth quarter. The registration pathway for Duravyu can only be determined after considering the results of both trials and discussions with regulators, the Hangzhou-based company added.

Duravyu, formerly known as EYP-1901, combines Betta Pharma’s vorolanib with EyePoint’s Durasert technology to gradually release the drug inside the eye, potentially reducing the need for frequent injections. Vorolanib (CM082) is also used in an oral treatment for advanced kidney cancer that was approved in China in 2023.

Betta Pharma licensed Duravyu to EyePoint in 2020 for development and commercialization outside China for USD1 million upfront, plus milestone payments and royalties, while retaining exclusive rights in China.

Editors: Tang Shihua, Emmi Laine