Ascletis' ASC37 shows 88% greater weight loss than tirzepatide

HONG KONG, July 27, 2026 /PRNewswire/ -- Ascletis Pharma Inc. (HKEX: 1672, "Ascletis") announces that ASC37, a next-generation GLP-1R/GIPR/GCGR^[1] triple peptide agonist, demonstrated superior weight loss to tirzepatide in a diet-induced obese (DIO) mouse model. Following 11-day administration of ASC37 and tirzepatide at the same dose of 1 nmol/kg in DIO mice, ASC37 had statistically significant 88% greater relative body weight reduction compared to tirzepatide (Table 1). Furthermore, ASC37 demonstrated up to 41.5% weight loss in a dose-dependent fashion in the DIO mice (Table 1).

Table 1. ASC37 demonstrated statistically and significantly more weight loss than tirzepatide in DIO mice following 11-day administration

Note: DIO mice: diet-induced obese mice; SQ: subcutaneous; QD: once daily.

ASC37 was engineered to have 41 alpha amino acids, which qualifies it as a biologic. The Investigational New Drug (IND) application of both ASC37 once-monthly subcutaneous (SQ) formulation and oral formulation will be submitted in the third quarter of 2026. Biologics license applications (BLAs) for both ASC37 once-monthly SQ formulation and oral formulation will be submitted to the FDA after Phase III completion. ASC35, a next-generation GLP-1R/GIPR dual peptide agonist, also has 41 alpha amino acids and will be submitted as a BLA as well.

Compared to retatrutide, another triple peptide agonist, in non-human primate (NHP) studies, ASC37 SQ Self Assembly Lipid Depot (SALD) formulation had an average observed half-life of approximately 17 days compared to 2.5 days for retatrutide. This approximately 7-fold longer half-life for ASC37 confirms once-monthly or less dosing frequency.

"Based on these encouraging preclinical data, we believe ASC37 has the potential to be a first-in-class once-monthly SQ triple peptide agonist for people living with severe obesity, also with the added advantage of being submitted under the BLA regulatory process," said Jinzi Jason Wu, Ph.D., Founder, Chairman and CEO of Ascletis. "Qualification of ASC37 as a biologic offers a number of benefits, including longer statutory exclusivity periods and extended protection from government price negotiation compared to small molecules."

Under the Inflation Reduction Act, biologics benefit from a longer exemption period of 13 years following FDA approval, instead of nine years for small molecules, before being subject to government price negotiations. There is also no regulatory path for biologics to be compounded by third-party pharmacies. This limits the ability of compounding pharmacies from potentially offering a lower-price version of ASC37 and ASC35.

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