VLS-101 structure and its HIC profile. (A) VLS-101 is composed of the anti-ROR1 antibody, UC-961, conjugated to the antimicrotubule cytotoxic agent MMAE by a proteolytically cleavable mc-vc-PAB linker. (B) DAR of VLS-101, as analyzed by HIC, displaying an average DAR of 4 and a distribution from 0 to 8. DAR, drug-antibody ratio; HIC, hydrophobic interaction chromatography; mc-vc-PAB, maleimidocaproyl-valine-citrulline-para-aminobenzoate.