Abstract 2436: AGS-16M8F is a novel antibody drug conjugate (ADC) for treating renal and liver cancers

AGS-16 is a novel transmembrane antigen discovered by Agensys using transcription profiling and is expressed in kidney, liver and other cancers. A fully human IgG 2 k monoclonal antibody that binds to AGS-16 with high affinity was conjugated to the anti-microtubulin drug monomethyl auristatin F (MMAF) via a noncleavable maleimidocaproyl (mc) linker to yield the antibody drug conjugate, AGS-16M8F. AGS-16M8F was evaluated for binding affinity, species cross reactivity and cell cytotoxicity in vitro. Its’ anti-tumor activity was investigated using multiple established patient-derived and cell line models of renal clear cell carcinomas. The pharmacokinetics (PK) of AGS-16M8F was evaluated in mice. In addition, the expression of AGS-16 protein in patient kidney and liver cancer specimens was confirmed using IHC. AGS-16M8F bound with high affinity (Kd = 0.3 nM) to both human and cynomolgus monkey AGS-16 orthologs. Following cell surface binding, AGS-16M8F was internalized and trafficked to lysosomes leading to catabolism and release of active drug metabolite. AGS-16M8F mediated potent cell cytotoxicity in vitro and led to significant and prolonged growth inhibition or complete eradication of multiple established renal cancer xenograft models, including those grown orthotopically. Pharmacokinetic analysis of AGS-16M8F in mice demonstrated ADC stability. IHC analysis confirmed that AGS-16 was highly expressed in over 80% of renal clear cell cancers and 33% of hepatocellular carcinomas. When considered together these data indicate that AGS-16M8F is a promising therapeutic ADC for the treatment of renal and other AGS-16 expressing cancers. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2436.