Dynamics Of Activated Cd8+T-Cells And Decreased Osteoclasts In The Tumor Microenvironment Are Associated With Clinical Efficacy Of Anti-Pd-L1 And Anti-Cd38 Combination Treatment In Relapsed Or Refractory Multiple Myeloma

Introduction: Immune checkpoint inhibition targeting the PD-1/PD-L1 pathway is insufficient to induce clinical response in relapsed or refractory (R/R) multiple myeloma (MM). We postulated that combining atezolizumab (A; anti-PD-L1) with daratumumab (D; anti-CD38), which targets myeloma cells and has immunomodulatory activity, may alter the tumor microenvironment (TME) to favor cytotoxic T-cell activation and clinical activity. To assess the immunologic efficacy of this combination, we studied changes in CD8+ T cells in D-naïve and D-refractory pts from a Phase Ib study (GO29695; NCT02431208).