Case Report: Precision medicine target revealed by in-vitro modelling of relapsed, refractory ALL from a child with neurofibromatosis

Children with neurofibromatosis have a higher risk of developing juvenile myelomonocytic leukaemia and acute myeloid leukaemia, but rarely develop B-cell acute lymphoblastic leukaemia (B-ALL). Through in-vitro modelling, a novel NF1 p.L2467 frameshift (fs) mutation identified in a relapsed/refractory Ph-like B-ALL patient with neurofibromatosis demonstrated cytokine independence and increased RAS signalling, indicative of leukaemic transformation. Furthermore, these cells were sensitive to the MEK inhibitors trametinib and mirdametinib. Bi-allelic NF1 loss of function may be a contributing factor to relapse and with sensitivity to MEK inhibitors, suggests a novel precision medicine target in the setting of neurofibromatosis patients with B-ALL.EGA study EGAS00001006187