How successful checkpoint inhibitors and chimeric antigen receptor (CAR) T cells will be at revolutionizing oncology hangs largely on whether it will be possible to curb their on-target but off-tissue toxicities. CytomX Therapeutics Inc. is using its Probody platform to restrict activity to tumors by capitalizing on enzymes unique to the tumor microenvironment. The company believes that by improving safety, its technology can expand the range of targets, indications and therapeutic combinations possible in cancer immunotherapy.
Over the past eight weeks, CytomX has presented the first data on its Probody platform for three different types of cancer immunotherapies - checkpoint inhibitors, antibody-drug conjugates (ADCs) and T cell-engaging bispecific antibodies (TCBs) - and announced a new partnership on a fourth, CAR-NK cells.
"Probodies are designed to bind tumors to protect healthy tissue. The rationale is that antibody therapeutics, particularly the recent wave of highly potent oncology modalities, come with significant side effects that can limit utility," said CytomX CEO Sean McCarthy.
At the September meeting of the American Association for Cancer Research (AACR), Cancer Research Institute (CRI), Association for Cancer Immunotherapy (CIMT) and European Academy of Tumor Immunology (EATI), CytomX presented preclinical data showing its lead candidate CX-072, an anti-PD-L1 probody, decreased tumor growth as effectively as standard antibodies, but without the autoimmune toxicities.