Impact of triple intrathecal prophylaxis in acute lymphoblastic leukemia adults receiving HyperCVAD: A COVID-19 practice change.

Treatment of acute lymphoblastic leukemia (ALL) requires both systemically and locally directed therapies to prevent central nervous system (CNS) recurrence. In response to restrictions brought on by the COVID-19 pandemic, our institution adopted triple intrathecal (IT) chemotherapy for CNS prophylaxis during HyperCVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone alternating with high-dose methotrexate and cytarabine). We retrospectively reviewed records of newly diagnosed adult all patients who were consecutively treated with HyperCVAD between January 2011 and July 2022. Outcomes of patients who received triple IT chemotherapy and standard of care (SOC) CNS prophylaxis were compared. The primary endpoint was CNS relapse-free survival (RFS) while secondary endpoints included cumulative incidence of relapse, overall survival, number of outpatient, and total ITs per patient, and CNS treatment-related toxicities. A total of 37 patients including 21 in the triple IT and 16 in the SOC cohorts were evaluated. There were no differences between the triple IT and SOC cohorts with respect to CNS-RFS (89.6% vs. 80.4%; HR, 1.55; 95% CI, 0.45-5.39; p = .49), cumulative incidence of relapse (8.9% vs. 19.6%; HR, 1.14; 95% CI, 0.3-5.3; p = .87), and overall survival (89.6% vs. 85.7%; HR, 0.91; 95% CI, 0.20-4.21; p = .90) at 2-years. Significantly fewer IT doses were administered in the triple IT cohort (p = .011) and the number of additional outpatient appointments to administer IT chemotherapy were markedly reduced as 98.6% of IT doses were administered during scheduled admissions compared to 76.8% (p < .001). The adoption of triple IT chemotherapy did not increase CNS treatment-related toxicities but rather, the inverse was observed. Triple IT chemotherapy during HyperCVAD represents a feasible alternative to SOC CNS prophylaxis, especially during times of resource restriction and when minimization of patient exposures is desired.