Nadine Jahchan, BSc, PhD, Pionyr Immunotherapeutics, San Francisco, CA, describes the development of PY159, an anti-triggering receptor expressed on myeloid cells 1 (TREM-1) monoclonal antibody. Initial studies on human blood and dissociated tumor cells indicate successful anti-tumor activity by binding to TREM-1 and stimulating anti-inflammatory activity. Measuring TREM-1 expression was additionally carried with biomarkers and technologies such as multiplex immunohistochemistry. Dr Jahchan also comments on the Phase Ia/Ib dose-escalation trial of PY159 (NCT04682431). This interview took place during the 36th Society for Immunotherapy of Cancer (SITC) Annual Meeting in Washington, D.C.