JSKN033 (Alphamab Oncology)

JSKN033 is a first-in-class, high-concentration subcutaneous co-formulation developed by Alphamab Oncology for the treatment of advanced metastatic malignant tumors. It consists of two active components: JSKN003, a bispecific antibody-drug conjugate (ADC) targeting two non-overlapping epitopes of the HER2 extracellular domain, and envafolimab, a humanized anti-PD-L1 single-domain antibody (sdAb) Fc fusion protein. JSKN003 utilizes a cleavable linker and a topoisomerase I inhibitor payload to induce targeted tumor cell death. By combining the direct cytotoxic effects of the ADC with the immune checkpoint inhibition provided by envafolimab, JSKN033 leverages a dual mechanism of action to enhance anti-tumor efficacy. It is currently being evaluated in Phase I/II clinical trials for HER2-positive and PD-L1-expressing solid tumors, including cervical cancer and non-small cell lung cancer.