ARX305

ARX305 is a next-generation antibody-drug conjugate (ADC) developed to target CD70, a protein overexpressed in various solid and hematologic tumors, including renal cell carcinoma, nasopharyngeal cancers, multiple myeloma, non-Hodgkin’s lymphoma, and acute myeloid leukemia. The drug consists of a proprietary humanized anti-CD70 antibody site-specifically conjugated to AS269—a potent microtubule inhibitor—using stable oxime chemistry and a non-cleavable PEG linker. Upon binding to CD70 on tumor cells, ARX305 is internalized and releases its cytotoxic payload (pAF-AS269), which inhibits cellular proliferation by disrupting microtubules. Preclinical studies have demonstrated selective cytotoxicity against CD70-expressing tumor cells, strong anti-tumor activity in renal cell carcinoma models, increased survival in multiple myeloma models, high serum stability with a long terminal half-life (~16.5 days), and favorable tolerability in non-human primates[1][4][5][6][7][8].