Pidilizumab in the treatment of diffuse large B-cell lymphoma

Introduction: The programmed death-1 (PD-1) immune checkpoint pathway is an emerging target in the treatment of hematologic malignancies. Pidilizumab is an mAb that binds to PD-1 and is a safe and well-tolerated therapy. Recent data have shown clinical activity utilizing this strategy in diffuse large B-cell lymphoma (DLBCL). Areas covered: The role of PD-1 expression in hematologic malignancies is explored. Recent clinical trials including the results of a Phase I trial in hematologic malignancies and a Phase II trial of pidilizumab following autologous hematopoietic stem-cell transplant (AHSCT) are reviewed. Expert opinion: We review data that suggest that PD-1 is a promising target in the treatment and management of DLBCL. Changes in immune subsets following administration of pidilizumab are felt to represent on-target responses. The improvement in progression-free survival (PFS) following AHSCT supports a response to therapy. Importantly, the improvement in PFS for patients with positive FDG-PET/CT following AHSCT indicating residual disease further supports direct activity of pidilizumab in DLBCL.