At the end of induction, the complete response rate was 69% in the CNS-intensive group and 51% in the CNS-conservative group (P = .16). Primary refractory disease was observed in 19% and 38% of patients, respectively (P = .07).
The CNS was the most common site of relapse or progression (n = 28). CNS progression or relapse occurred in 25% of the CNS-intensive group and 49% of the CNS-conservative group (P = .03).
The 2-year progression-free survival rate was 50% for the CNS-intensive group and 31% for the CNS-conservative group (P = .006). The 2-year overall survival rate was 54% and 44%, respectively (P = .037).
When patients were matched for induction outcomes, consolidative transplant did not improve survival.
“The most significant factor affecting survival was the ability to control the CNS disease, which was improved by the addition of IV cytarabine to [high-dose methotrexate],” the researchers wrote.
“Whilst the younger age and more intensive systemic treatment of the CNS-intensive group may have contributed to the improved survival, it is clear that CNS disease control was substantially improved by the addition of cytarabine with lower rates of CNS relapse/progression observed.”
The researchers noted that “adequate control of the CNS disease is paramount and is best achieved by intensive CNS-directed induction.”
There was no formal funding for this study, and the researchers did not provide financial disclosures.
SOURCE: Wight JC et al. Br J Haematol. 2019 Jun 24. doi: 10.1111/bjh.16064.