Enrique M. Ocio, MD, PhD, Marqués de Valdecilla University Hospital, Santander, Spain, shares the findings of the GEM-Pembresid trial (NCT02636010) of pembrolizumab as a consolidation strategy in patients with multiple myeloma. The trial enrolled patients who achieved a very good partial response or higher with previous therapy but had persistent measurable disease. Of 17 evaluable patients, 1 improved response was achieved. Analyses of immune system characteristics were conducted to look for potential predictive biomarkers, revealing significantly lower PD-1 expression in CD8 T-cells in early progressors. Pembrolizumab was also shown to decrease the percentage of NK cells. This interview took place during the 7th World Congress on Controversies in Multiple Myeloma (COMy), 2021.