The board of directors of Simcere Pharmaceutical Group Limited announce that on January 28, 2023, the innovative drug XIANNUOXIN (Simnotrelvir Tablets/Ritonavir Tablets (co-packaged)), which was jointly developed by the Group with Shanghai Institute of Materia Medica and Wuhan Institute of Virology (the ‘WIV'), Chinese Academy of Sciences (the ‘CAS'), has been conditionally approved for marketing in China by the National Medical Products Administration of China (NMPA) with urgent review and approval under Special Examination and Approval of Drugs (Approval No. H2 0230001). XIANNUOXIN TM will be used for the treatment of adult patients infected with mild to moderate COVID-19 and its recommended dosage is 0.750g of Simnotrelvir (0.375g×2 tablets) in combination with 0.1g of Ritonavir (0.1g×1 tablet) orally for every 12 hours for 5 consecutive days.

A multi-centered, randomized, double-blind, placebo-controlled phase II/III clinical study in China (the ‘Study') to evaluate the efficacy and safety of XIANNUOXIN TM met the pre-specified primary efficacy endpoint. The study randomized 1,208 adult patients with symptomatic mild to moderate COVID-19. The results showed that XIANNUOXIN TM was effective in accelerating recovery from symptoms and shortening the duration of disease compared to placebo: a significant reduction of the time to first occurrence of sustained recovery of 11 target COVID-19 symptoms by approximately 1.5 days, with a significant reduction of approximately 2.4 days for the subgroup population with at least one high risk factor for progression to severe COVID-19, while the data suggest superior efficacy of XIANNUOXIN TM with early use.

XIANNUOXIN TM also demonstrates significant antiviral effects: viral load reduced rapidly and significantly after dosing; viral load reduced up to over 96%(treatment difference in change from baseline 1.43 log 10 copies/mL) compared to placebo on day 5 after dosing; and nucleic acid conversion time shortened by approximately 2.2 days. Safety data show that XIANNUOXIN TM is safe and well tolerated for Chinese patients infected with mild to moderate COVID-19. Detailed data of the Study are expected to be released in academic journals or conferences in the future.

The results of the Study demonstrated that XIANNUOXIN TM is safe and effective to adult patients infected with mild-moderate COVID-19 and is of extensive clinical values. As the first 3CL target anti-SARS-CoV-2 innovative drug with independent intellectual property rights in China, the successful marketing of XIANNUOXIN TM is expected to bring patients in China with a more effective treatment option.