AMX-818, also known as SAR446309, designed with the PRO-XTEN masking platform, is a novel prodrug HER2-XPAT TCE exhibiting potent T cell activation and is being evaluated in a phase 1/2 study (NCT05356741) for patients with locally advanced or metastatic HER2-expressing cancers (20). Here, ERBB2 is linked to cancer.