Treatment will depend on the timing of relapse, location of relapse (isolated bone marrow relapse, isolated extramedullary relapse, combined relapse), immunophenotype in ALL (B-cell vs T-cell), previous management, response to salvage therapy (including MRD response in ALL), number of previous relapses and the patient’s preferences.

CAYA with relapsed ALL are often eligible for enrolment in clinical trials for relapsed disease. These typically involve systemic chemotherapy, newer targeted agents and/or immunotherapy, together with HSCT for selected patients.

In relapsed AML, achieving rapid remission via systemic chemotherapy, targeted therapies and/or immunotherapy followed by HSCT is currently the most effective curative strategy.

Immunotherapy or immune effector cell therapy is used in certain relapsed acute leukaemia patients. Current examples of immunotherapy used in acute leukaemia include BiTEs (e.g. blinatumomab), antibody drug conjugates (e.g. gemtuzumab, inotuzumab) and CAR T-cells (e.g. tisagenlecleucel).

A number of additional immunotherapies are currently under investigation in CAYA acute leukaemia.

Access to new therapies that have not yet been approved by the Pharmaceutical Benefits Scheme may sometimes be challenging. This highlights the importance of enrolling CAYA with relapsed/ refractory disease onto clinical trials wherever possible.

The potential goals of treatment should be discussed, respecting the patient’s cultural values. Wherever possible, written information should be provided.