CD8A and cancer: NCT05737706, a phase 1/2 trial assessing MRTX1133 in patients with advanced solid tumors, is ongoing.227 MRTX1133 treatment induces changes in the TME, notably an increase in the number of CD8-positive effector T cells, a decrease in the number of neutrophils and myeloid cells, and the reprogramming of cancer-associated fibroblasts (CAFs) and the overall TME.