BCR-ABL1 Molecular Remission After 90y-Epratuzumab Tetraxetan Radioimmunotherapy In CD22+Ph+B-ALL: A Potential New Treatment Paradigm

Targeted therapies are increasingly becoming treatment options for many hematological diseases. While immuno/chemoimmunotherapy is a recent area of research in acute lymphoblastic leukemia (ALL) (Raetz, JCO, 2008; Advani, Blood, ASH Meeting 2012, abstract 2603), we are unaware of any published studies in ALL using radioimmunotherapy (RAIT), where a potent radionuclide conjugated to an antibody can deliver radiation selectively to the tumor. CD22 is highly expressed in B-ALL. As such, the anti-CD22 humanized antibody, epratuzumab (Immunomedics, Inc., Morris Plains, NJ), which has been studied extensively in non-Hodgkin lymphoma, is also under active investigation in adult and pediatric ALL (see references above). Here we report a patient with Ph+B-ALL who presented in third relapse and who received RAIT with 90yttrium (90Y)-labeled anti-CD22 epratuzumab tetraxetan, resulting in an outstanding response.