Efficacy and Toxicity of Intrathecal Liposomal Cytarabine in First-line Therapy of Childhood Acute Lymphoblastic Leukemia

We investigated efficacy and toxicity of replacing conventional triple (cytarabine, methotrexate, and hydrocortisone) intrathecal therapy (TIT) with liposomal cytarabine during maintenance therapy among 40 acute lymphoblastic leukemia patients. Twenty-eight of 29 patients in the TIT arm received TIT and 9/11 in the liposomal cytarabine arm received liposomal cytarabine. Arachnoiditis occurred in all initial 5 patients given liposomal cytarabine and intrathecal prednisolone succinate. Subsequently liposomal cytarabine was given with systemic dexamethasone. Neurotoxicity occurred at 6/27 liposomal cytarabine administrations with concomitant dexamethasone (22%). More liposomal cytarabine-treated patients experienced neurotoxicity in relation to intrathecal therapy during at least 1 cycle compared with TIT-treated patients (6/9 [67%] vs. 3/28 [11%], P=0.002). Apart from intermittent lower extremity sensory pain in 1 liposomal cytarabine-treated patient, no permanent adverse neurological sequelae were observed. In intention-to-treat analysis, projected 5-year event-free survival (pEFS-5y) was borderline higher for patients in the liposomal cytarabine arm compared with the TIT arm (1.0 vs. 0.69, P=0.046). However, pEFS-5y and projected 5-year relapse-free survival did not differ signficantly between patients treated with liposomal cytarabine or TIT (1.0 vs. 0.73, P=0.10; 1.0 vs. 0.76, P=0.12). Larger prospective trials are needed to explore whether liposomal cytarabine should be used as first-line prevention of relapse.