Adagene gets NMPA clearance for HER2xCD3 bispecific ADG138

Adagene Inc. said on September 22, 2026 that China's National Medical Products Administration approved the company's investigational new drug application for ADG138, a double-masked HER2×CD3 bispecific T cell engager built on Adagene's proprietary SAFEbody precision masking technology.¹

Adagene expects to initiate a first-in-human Phase 1 study of ADG138 for the treatment of advanced solid tumors in the fourth quarter of 2026.¹ That open-label study is designed to evaluate the safety and preliminary efficacy of ADG138 in patients with advanced solid tumors and to determine the recommended dose for Phase 2.¹

On the science, Adagene said ADG138 covalently links masking peptides to both the HER2- and CD3-binding arms of the molecule, so that in its inactivated state it minimally binds HER2-expressing cancer cells and T cells, with activation occurring within the tumor microenvironment to selectively kill HER2-expressing tumor cells while limiting off-target toxicity.¹

Citing preclinical data presented at AACR in 2022, the company said double-masked ADG138 achieved approximately 220-fold and greater than 1,000-fold reductions in binding to HER2 and CD3, respectively, while driving regression in HER2-high and HER2-low tumor models, including one refractory and/or resistant to Enhertu (DS-8201), and showing synergistic activity in combination with anti-CTLA-4, anti-PD-1, or anti-CD137 antibodies.¹ The company also reported that ADG138 was tolerated at doses over 300-fold higher than an unmasked T-cell engager, with markedly reduced cytokine release and a longer apparent half-life and higher systemic exposure than the parental molecule.¹

Adagene's lead clinical program remains muzastotug (ADG126), which the company described as a masked, anti-CTLA-4 SAFEbody with FDA Fast Track designation currently in Phase 1b/2 and Phase 2 studies in combination with anti-PD-1 therapy, focused on microsatellite stable metastatic colorectal cancer.¹