Abstract 1274: SLITRK6, the target of a novel antibody drug conjugate AGS15E, is expressed in bladder and other cancers

SLITRK6, a member of the SLITRK family of neuronal transmembrane proteins, was discovered by Agensys using suppressive subtractive hybridization on biopsies from bladder cancer patients. Immunohistochemical (IHC) analysis of SLITRK6 expression was evaluated in various human cancers including bladder, using a SLITRK6-specific antibody M15-68(2)22. This mouse monoclonal antibody was raised to a peptide contained within the extracellular domain of SLITRK6 and was selected as a suitable IHC reagent by screening on RNA positive and negative cell lines and xenografts. Subsequent analysis of SLITRK6 expression in human cancer tissue microarray samples, utilizing M15-68(2)22, showed positive staining in 90% of 452 cases of bladder transitional cell carcinoma, including in situ, advanced primary and metastatic tumors. A subset of lung primary and metastatic cancers, breast cancers and glioblastomas also expressed SLITRK6. In normal tissues SLTRK6 expression is highly restricted to limited epithelia, including transitional epithelium, and some mast cells. In view of the restricted expression in normal tissues and the high expression in bladder transitional cell carcinoma, SLITRK6 constitutes an excellent target for antibody drug conjugate therapy for bladder transitional cell carcinoma and, potentially, for other cancer indications. Citation Format: Peng YANG, Jeffrey Coleman, Ying Li, Yi Zhang, Candice Junge, Kendall Morrison, Fernando Donate, David Stover, Karen Morrison. SLITRK6, the target of a novel antibody drug conjugate AGS15E, is expressed in bladder and other cancers. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1274. doi:10.1158/1538-7445.AM2013-1274