JALSG T-ALL213-O: Nelarabine combined chemotherapy in newly diagnosed T-ALL

Development of monoclonal antibody- or CAR-based immunotherapies for T-ALL remains challenging due to life-threatening T-cell immunodeficiency and fratricide of CAR-T cells resulting from shared target antigen expression between normal and malignant T cells.¹ Nelarabine, a DNA-terminating nucleoside prodrug, preferentially accumulates in T lymphoblasts and has shown antitumor activity in patients with R/R T-ALL.¹

The single-arm, multicenter phase II JALSG T-ALL213-O trial (UMIN-CTR UMIN000010642) investigated nelarabine combined chemotherapy (nelarabine in the second induction for patients without CR after first induction, and incorporated into C3 and C5 consolidation phases) in patients with newly diagnosed T-ALL.¹ 28 patients were enrolled and 24 received the first cycle of induction. The primary end point was EFS at 3 years after registration, defined as the time from registration to failure to achieve CR, relapse, death, or the last visit. Results were published by Hayakawa et al.¹ in Cancer Science. Findings were compared with the previous T-ALL202-O study (UMIN-CTR C000000063) of high-dose methotrexate consolidation therapy for ALL without nelarabine.¹