T-cell-based Immunotherapies for Haematological Cancers, Part A: A SWOT Analysis of Immune Checkpoint Inhibitors (ICIs) and Bispecific T-Cell Engagers (BiTEs).

Haematology has been at the vanguard of cancer immunotherapy. Immune checkpoint inhibitors (ICIs), bispecific T-cell engagers (BiTEs), allogeneic haematopoietic stem cell transplantation (allo-HSCT) and donor lymphocyte infusion (DLI), as well as adoptive T-cell therapies outside the setting of allo-HSCT, have been approved for distinct haematologic malignancies producing durable responses in otherwise untreatable patients. Despite recent advances, immunotherapies do not benefit most patients, due to resistance or lack of response, and are only approved in specific settings. Moreover, immunotherapies are expensive and may produce severe immune related adverse reactions. Combination therapy complicates the picture and requires further evaluation. This review considers the current status and future perspectives of ICIs and BiTEs approved for haematological malignancies by analysing their strengths, weaknesses, opportunities and threats (SWOT). The biological rationale for anti-cancer mechanisms, clinical data for specific haematological cancers, efficacy, toxicity, response and resistance profiles, novel strategies to improve these characteristics as well as the potential targets to enhance or expand the application of ICIs and BiTEs are also discussed.