The treatment landscape for Relapsed Refractory B Acute Lymphoblastic Leukaemia (ALL)

The last eight years have seen a rapid expansion of salvage options for patients with relapsed refractory (RR) acute lymphoblastic leukemia (ALL). The efficacy of targeted approaches with blinatumomab and Inotuzumab ozogamicin (InO), outweigh that of conventional chemotherapeutic regimens, and the reduced toxicity profile has also translated into higher transplant realization rates. Factors influencing the sequential use of these two antibodies include the preference for InO in those with high disease burden, while blinatumomab is a superior agent for attaining MRD responses in low disease burden groups. InO should not be used first in those with significant liver disease. Most impressive is the advent of chimeric antigen receptor cell therapy (CAR-T), a curative therapy in a significant proportion of younger patients with RR-ALL. Careful consideration is now required in the selection of relapse therapies; this review summarizes current available strategies and how to navigate the treatment landscape for RR ALL.

Immunotherapeutic options for management of relapsed or refractory B-cell acute lymphoblastic leukemia: how to select newly approved agents?

Recently, immunotherapeutic agents such as inotuzumab ozogamicin (INO), blinatumomab (BLIN), and tisagenlecleucel (TISA) have been approved for treatment of relapsed or refractory (R/R) acute lymphoblastic leukemia (ALL). No head to head trials have compared these agents. Thus, various factors influence the decision to choose an appropriate treatment for R/R ALL. INO may be preferred in patients with high tumor burden; BLIN is preferred in patients with low tumor burden or to eradicate minimal residual disease (MRD). Both INO and BLIN, compared to standard chemotherapy, increase the probability of receiving subsequent hematopoietic stem cell transplant (HSCT). TISA, approved for patients ≤25 years of age, is effective regardless of tumor burden or prior receipt of HSCT and can be used as a definite treatment in some patients. Further studies comparing the efficacy, safety, and other outcomes related to different immunotherapeutic options in combination with other treatment modalities and among themselves are needed.