HANGZHOU and SHAOXING, China, May 4, 2021 /PRNewswire/ -- Ascletis Pharma Inc. (HKEX:1672) today announces the positive Phase IIa clinical results of ASC22 (Envafolimab), which is a first-in-class, subcutaneously administered PD-L1 antibody for chronic hepatitis B (CHB) functional cure.
ASC22Phase IIa clinical trial is a single dose escalation study of three subcutaneously administered doses (0.3, 1.0 and 2.5 mg/kg, three patients per dose) with 12-week follow-up to explore the safety and preliminary efficacy of ASC22 in CHB patients (ClinicalTrials.gov Identifier: NCT04465890). The primary efficacy endpoint is HBsAg reduction during 12-week follow-up after the single dose administration. Median baseline HBsAgof nine CHB patients enrolled was 3.0 log10 IU/mL.
The phase IIa data indicated that there is a trend of dose dependent HBsAg reduction after single dose administration of 0.3, 1.0 or 2.5 mg/kg ASC22. Eight out of nine patients treated with ASC22 exhibited some decline in HBsAg at the end of 12-week follow-up. Among three patients receiving 2.5 mg/kg dose, one patient achieved a maximum HBsAg reduction of 1.2 log10 IU/mL during the 12-week follow-up.
ASC22 is safe and well tolerated at all three dose levels with only grade 1 adverse effects. There were no grade 2 or above adverse effects observed during 12-week follow-up. Single dose administrations up to 2.5 mg/kg ASC22 did not affect alanine aminotransferase (ALT) and aspartate aminotransferase (AST)levels (all below upper limit of norm) during 12-week follow-up.
On January 12, 2019, Ascletis entered an exclusive licensing agreement for PD-L1 antibody ASC22 (KN035) with Suzhou Alphamab Co., Ltd. (Alphamab). Under the terms of the agreement, Ascletis has an exclusive license from Alphamab to develop and commercialize ASC22 (KN035) for all viral diseases including Hepatitis B and HIV in Greater China. For ASC22 (KN035) in viral indications worldwide outside Greater China, Ascletis will be eligible to share certain economics such as upfront, milestone payments and royalties, depending on the development and regulatory status of ASC22 (KN035) inside Greater China.