Long term outcome of a patient with relapsed refractory early thymic precursor acute lymphoblastic leukemia treated with daratumumab.

The prognosis of patients with relapsed Early Thymic Precursor acute lymphoblastic leukemia (ETP-ALL) remains poor. Unlike B cell Precursor-ALL (BCP-ALL), there are no approved targeted therapies for ETP-ALL. Recent studies have identified a consistent expression of CD38 on the blasts of patients with T-ALL (both ETP-ALL and non ETP-ALL). Pre-clinical studies indicate that CD38 expression persists on the blasts of T-ALL even after receipt of conventional chemotherapy. These findings make CD38 an attractive targetable surface protein for patients with relapsed refractory T-ALL. We were the first to describe the clinical use of daratumumab in a patient of ETP-ALL, with relapsed disease post allogeneic transplant. We describe here the long term outcome of this patient more than 3 years after starting single agent daratumumab.