Tocilizumab for Cytokine Release Syndrome Prophylaxis in Haploidentical Transplantation

Cytokine release syndrome (CRS) is a common and potentially severe toxicity associated to haploidentical peripheral blood (PBSC) hematopoietic stem cell transplantation (Haplo-HSCT), which was described previously in the context of immunotherapies for acute lymphoblastic leukemia such as chimeric antigen receptor T-cells and blinatumomab.

CRS is characterized by immune system activation with a high level of circulating inflammatory cytokines including IL-6. Haplo-HSCT recipients have a high incidence of post-transplant fever, with elevated IL-6 in absence of documented infection. CRS occurs more frequently when using PBSC, and severe cases have been associated to delayed engraftment, increased transplant-related mortality and lower survival.

Tocilizumab an IL-6 receptor-targeted monoclonal antibody has been effectively used to treat CRS in several scenarios, including Haplo-HSCT. Therefore, there is considerable interest for the development of a successful strategy for CRS prevention with tocilizumab, potentially eliminating complications. However, it is currently unknown whether the use of this monoclonal antibody can adversely affect the outcome of Haplo-HSCT recipients.

Inclusion criteria

• Haploidentical transplant recipients
• Informed consent signature
• Previous diagnosis of any neoplastic, metabolic or autoimmune disease

Exclusion criteria

• History of immune deficiency virus infection
• Hepatitis C or B virus infection
• Documented bacterial of fungal infection prior to tocilizumab infusion
• Previous use of tocilizumab