Therapy of Relapsed/Refractory Acute Lymphoblastic Leukemia Today and Tomorrow.

Background: New diagnostics and treatments, including the use of new drugs, have advanced considerably the treatment of acute lymphoplastic leukemia (ALL) in the past few years. Monoclonal antibodies and immunoconjugates targeting antigens CD19 and CD22 show greater efficacy and more favourable toxicity profiles than standard salvage chemotherapeutic protocols. Two of these drugs - blinatumomab and inotuzumab ozogamicin - have already made their way into clinical practice. Ponatinib and other new generation tyrosine kinase inhibitors allow dose reduction of intensive cytostatic regimens in Ph-positive ALL patients and slowly start to overshadow the importance of allogeneic hematopoietic cell transplants. For the time being, their use is reserved for relapsed/refractory ALL, but they are already available as a first line therapy in clinical trials. An entirely new group of living drugs is emerging for the treatment of ALL - chimeric antigen receptor T-cells produced by genetic modification of native human cells. Chimeric antigen receptor T-cells can be looked upon as in vitro trained professional blast killers. They show an efficacy never seen before for the treatment of relapsed/refractory ALL. On the other hand, this treatment still presents significant risks, mainly due to cytokine release syndrome. Ruxolitinib, mTOR inhibitors, bortezomib, and other drugs for targeted treatment of ALL are currently being evaluated in clinical trials.

Purpose: The article focuses on current options and news in the field of relapsed and refractory ALL treatment. This work was created at Masaryk University as part of the project “New Approaches in Research, Diagnostics and Therapy of Hematological Malignancies VI”, number MUNI/A/1105/2018, supported by Czech Ministry of Education, Youth and Sports in 2019.  The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 28. 8. 2018 Accepted: 10. 1. 2019.