Two studies describe distinct mechanisms of resistance to anti-CD19 chimeric antigen receptor (CAR) T cell therapy in relapsed leukaemia patients

Orlando et al. and Ruella, Xu, Barrett et al. identified distinct mechanisms of resistance to anti-CD19 chimeric antigen receptor (CAR) T cell therapy in relapsed leukaemia patients, based on loss of CD19 surface expression.

The approval of blinatumomab based on achievement of undetectable minimal residual disease (MRD) in patients with B cell acute lymphoblastic leukaemia in complete remission is the first of its kind and raises important considerations. This drug might improve outcomes in this setting, although considerable evidence is needed to validate the performance of MRD as a surrogate end point and confirm the hypothesis.