The Landscape of Checkpoint Inhibition in the Management of Hematological Malignancies

The programmed-death 1 (PD-1) and cytotoxic T-lymphocyte associated protein 4 (CTLA-4) pathways are inhibitory immune checkpoints involved in the escape of cancer cells from the immune system. Inhibition of these immune checkpoints can lead to the induction of body’s immune response to these cancer cells. To activate the immune system against the tumor cells, various monoclonal antibodies targeting these pathways have been developed. Many of such antibodies have been approved for therapy in solid tumor malignancies and now some hematological malignancies. Here, we review the available data regarding the response to PD-1 and CTLA-4 pathway blockade in hematological malignancies including Hodgin lymphoma, non-Hodgkin lymhoma, multiple myeloma and myeloid neoplasms as well as before and after hematopoietic cell transplantation. We also discuss the specific concerns and differences related to their use in hematological malignancies (HMs) as compared to solid tumors.