Ascletis Expands Ritonavir Oral Tablet Production and Announces Oral Direct-Acting Antiviral Pipeline Against SARS-CoV-2 Virus

- Ritonavir oral tablet annual production capacity has been expanded to 100 million tablets and can be further rapidly expanded based on market demand

- ASC10 is an oral direct-acting antiviral drug candidate targeting RNA dependent RNA polymerase (RdRp) to treat SARS-CoV-2 infection

- ASC11 is an oral direct-acting antiviral drug candidate targeting 3-chymotrypsin like protease (3CLpro),combined with ritonavir oral tablets,to treat SARS-CoV-2 infection

HANGZHOU and SHAOXING,China,Jan. 3,2022 -- Ascletis Pharma Inc. (HKEX: 1672) today announces the expansion of the production of ritonavir oral tablets and oral direct-acting antiviral R&D pipeline for the treatment of SARS-CoV-2 infection. The Company's COVID-19 pipeline currently includes (i) ritonavir oral tablet (100mg),an authorized product,(ii) ASC10,an oral RNA dependent RNA polymerase (RdRp) inhibitor and (iii) ASC11,an oral 3-chymotrypsin like protease (3CLpro) inhibitor.

The Company owns the only authorized ritonavir oral tablet in China,which passed bioequivalence study. The Company's ritonavir oral tablet was approved in September,2021 by China National Medical Products Administration (NMPA). As a pharmacokinetic booster of multiple antiviral protease inhibitors,a low dose ritonavir oral tablet (100mg)is a component of oral direct-acting antiviral drug Paxlovid (Nirmatrelvir+ritonavir). The Company applied the sophisticated formulation technology to significantly increase the human bioavailability of ritonavir which has a very poor solubility and successfully achieved human bioequivalence with the ritonavir oral tablets produced by the Originator,AbbVie. The Company is planning to file generic drug applications for registrations in multiple countries in the world. Ritonavir oral tablet annual production capacity has been expanded to 100 million tablets and can be further rapidly expanded based on market demand.

ASC10 is an oral direct-acting antiviral drug candidate targeting RdRp. In vitro data showed significant activity against SARS-CoV-2. ASC10 is an in-house discovered drug candidate with the global intellectual property and commercial rights. Compared to RdRp-targeted Molnupiravir which was approved by US Food and Drug Administration (FDA),ASC10 has a new and differentiated chemical structure. The Company has filed multiple compound and use patent applications. The data from animal studies demonstrated that ASC10 has higher bioavailability when compared to Molnupiravir. The Company plans to submit investigational drug applications (INDs) for clinical trials in China,USA etc. in the first half of 2022.

ASC11 is an oral direct-acting antiviral drug candidate targeting 3CLpro,in combination with the authorized ritonavir oral tablets produced by the Company,to treat SARS-CoV-2 infection. ASC11 is an in-house discovered drug candidate with the global intellectual property and commercial rights. Compared to 3CLpro-targeted Nirmatrelvir which was approved by US FDA,ASC11 has a new and differentiated chemical structure. The Company has filed the compound and use patent applications. The Company plans to submit INDs for clinical trials in China,USA etc. in the second half of 2022. The Company has extensive R&D experience in viral protease inhibitors and successfully developed and commercialized oral HCV protease inhibitor GANOVO® in combination with ritonavir oral tablets for the treatment of chronic hepatitis C.

"At the beginning of COVID-19 in 2020,based on its antiviral platform and R&D experience,the Company made the firm and rapid decision to invest in oral direct-acting antivirals R&D against RdRp and 3CLpro of SARS-CoV-2. Meanwhile,the Company accelerated the development effort to obtain the approval of ritonavir oral tablets in China and successfully achieved the authorization by China NMPA for ritonavir oral tablets," said Dr. Jinzi J. Wu,Founder,Chairman and CEO of Ascletis,"The Company has tremendous experience in antiviral oral protease inhibitors and successfully developed the fixed-dose combination ASC09F (ASC09+ritonavir) to treat HIV infection,in addition to launching GANOVO®/Ritonavir combination for chronic hepatits C."