JSKN033

JSKN033 is a first-in-class, high-concentration subcutaneous co-formulation that combines an anti-HER2 bispecific antibody-drug conjugate (ADC, known as JSKN003) with the PD-L1 immune checkpoint inhibitor envafolimab (also referred to as KN035). The ADC component targets two non-overlapping epitopes of the HER2 extracellular domain and delivers a topoisomerase I inhibitor directly to HER2-expressing tumor cells. Envafolimab is a humanized anti-PD-L1 single-domain antibody fused to an IgG1 Fc fragment, approved in China as the first subcutaneously injectable PD-(L)1 inhibitor. By integrating these two modalities, JSKN033 aims to enhance antitumor efficacy through both direct cytotoxicity against HER2-positive cancer cells and immune system activation via PD-L1 blockade. The formulation’s high concentration allows for rapid subcutaneous injection, improving patient convenience and potentially enabling home-based administration. Currently in Phase I/II clinical trials in Australia for advanced or metastatic solid tumors with HER2 expression, JSKN033 has demonstrated promising safety and early efficacy signals.

Other names

JSKN003 + KN046 co-formulation