Ascletis Announces Notice of Issuance of the U.S. Patent for Oral Viral Polymerase Inhibitor ASC10 and Its Derivatives

--The issue date of the patent will be January 3,2023 by the United States Patent and Trademark Office (USPTO). The patent number is 11,541,071

-- The issued patent covers ASC10 and its derivatives,and their uses to treat virus infections including SARS-CoV-2,monkeypox virus and respiratory syncytial virus (RSV)

-- Ascletis is the first Chinese biotech company which has been granted a patent by the USPTO for its in-house developed oral viral polymerase inhibitor and its derivatives. The issuance of the U.S. patent further strengthens Ascletis' patent portfolio in viral diseases

HANGZHOU and SHAOXING,China,Dec. 19,2022 -- Ascletis Pharma Inc. (HKEX: 1672,"Ascletis") today announces that it has received the Notice of Issuance from the United States Patent and Trademark Office (USPTO) for the patent application of oral viral polymerase inhibitor ASC10 and its derivatives,and their uses to treat multiple virus infections including SARS-CoV-2,monkeypox virus and respiratory syncytial virus (RSV). The issue date of the patent will be January 3,2023 by the USPTO and the patent title is Nucleoside Derivatives and Methods of Use Thereof (U.S. patent number: 11,071).

ASC10 is an orally bioavailable double prodrug which has a new and differentiated chemical structure from the single prodrug molnupiravir. After oral administration,both ASC10 and molnupiravir are rapidly and completely converted in vivo into the same active drug ASC10-A,also known as β-D-N4-hydroxycytidine (NHC) or EIDD-1931. ASC10 was discovered and developed in-house.

With this issue notification,Ascletis has become the first Chinese biotech company which has been granted a patent by the USPTO for its in-house developed oral viral polymerase inhibitor and its derivatives. The patent issuance will extend commercial protection for ASC10 and its derivatives,and their uses until 2042.

"The issuance of the U.S. patent for our oral viral polymerase inhibitor ASC10 and its derivatives,and their uses further strengthens our patent portfolio in viral diseases. ASC10 has a broad spectrum of antiviral activity,and is expected to unleash more potential in addressing the challenges of multiple viruses. I'm looking forward to advancing the clinical studies to benefit more patients." said Dr. Jinzi J. Wu,Founder,Chairman and CEO of Ascletis.

About Ascletis

Ascletis is an innovative R&D driven biotech listed on the Hong Kong Stock Exchange (1672.HK),covering the entire value chain from discovery and development to manufacturing and commercialization. Led by a management team with deep expertise and a proven track record,Ascletis focuses on three therapeutic areas with unmet medical needs from a global perspective: viral diseases,non-alcoholic steatohepatitis (NASH) and oncology. Through excellent execution,Ascletis rapidly advances its drug pipeline with an aim of leading in global competition. To date,Ascletis has three marketed products,i.e. ritonavir tablets,GANOVO®and ASCLEVIR®,and 22 drug candidates in its R&D pipeline. The most advanced drug candidates include ASC22 (HBV functional cure),ASC10 and ASC11(oral small molecules for COVID-19 treatment),ASC40 (recurrent glioblastoma),ASC42 (PBC,primary biliary cholangitis),and ASC40 (acne).

For more information,please visit www.ascletis.com.