Alicia Levey, BA, PhD, Pionyr Immunotherapeutics, San Francisco, CA, gives an overview of Pionyr Immunotherapeutics and its ongoing work in developing antibody-based therapeutics for modulating myeloid cells present in the tumor microenvironment to enhance anti-tumor immunity. Following on, Vladi Juric, PhD, Pionyr Immunotherapeutics, San Francisco, CA, gives an overview of the pre-clinical assessment of PY159, an anti-TREM1 monoclonal antibody, for the treatment of solid tumors. TREM1 is a pro-inflammatory cell surface receptor expressed on normal and tumor-associated myeloid cells, where it plays a role in immunosuppression. PY159 is currently being evaluated in a Phase Ia clinical trial in patients resistant and refractory to standard of care therapies (NCT04682431). This interview took place at the virtual 8th Immunotherapy of Cancer Conference (ITOC) 2021.