IDO Pathway Inhibitors
NewLink’s IDO pathway platform is focused on developing small molecule drugs that disrupt mechanisms by which tumors evade a patient’s immune system. IDO pathway inhibitors are another class of immune checkpoint inhibitors akin to the recently developed antibodies targeting CTLA-4 and PD-1 that are potential breakthroughs in cancer therapy. NewLink’s IDO pathway inhibitors are orally administered small molecules that can be used in combination with other cancer therapeutics.
The IDO pathway regulates immune response by suppressing T-cell function and enabling local tumor immune escape. Recent studies have demonstrated that the IDO pathway is active in many cancers, both within tumor cells as a direct defense against T-cell attack, and also within antigen presenting cells in tumor draining lymph nodes resulting in peripheral tolerance to tumor associated antigens (TAAs). Cancers may use the IDO pathway to facilitate survival, growth, invasion and metastasis of malignant cells expressing TAAs that might otherwise be recognized and attacked by the immune system.
NewLink is actively developing two IDO pathway inhibitors. The most advanced is indoximod, which is being studied in various chemotherapy and immunotherapy combination clinical studies. The second IDO pathway inhibitor, NLG919, has shown promising preclinical results and is expected to enter clinical trials by the end of 2013.