Treatments targeting Hodgkin’s lymphoma microenvironment—a review of immune checkpoint inhibitors

Hodgkin lymphoma (HL) is still considered a rare cancer, which originates from B lymphocytes in lymphoid tissues. About 90% of patients with early disease and 70% of patients with advance disease achieve long term complete remission. In relapsed/refractory disease, high dose chemotherapy (HDC) and autologous stem cell transplant (ASCT) is only effective in 50% of the cases. In classical Hodgkin’s lymphoma (cHL), Hodgkin Reed-Sternberg cells (HRS) exploit programmed death-1 (PD-1) pathway, which allow for increase in the abundance of PD-1 ligands, PD-L1 and PD-L2. Even though classical HL responds well to a combination of chemotherapy and radiation, a number of patients relapse and become refractory to standard therapy. Recently the FDA approved nivolumab, a PD-1 blocking antibody in patients with classical HL, who have relapsed after ASCT and post transplantation brentuximab vedotin (BV). This review article aims to understand the efficacy of novel immune checkpoint inhibitors and to further assess the future of HL in the context of immunotherapy with nivolumab and pembrolizumab.