Long-term update confirms advantage of ATRA-ATO in APL
The randomized trial APL0406 has recently demonstrated that the chemotherapy-free combination of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) is at least non-inferior to the combination of ATRA with chemotherapy, with improved outcome and reduced myelotoxicity. Therefore, ATRA/ATO is now the new standard of care for patients with non-high risk acute promyelocytic leukemia (APL). At the EHA congress, Dr Laura Cicconi (University Tor Vergata, Rome, Italy) presented the long-term outcome of an extended cohort of 276 patients in the APL0406 study with a median follow-up of 66.4 months.
The current intention-to-treat analysis included 266 evaluable patients with newly diagnosed, non-high risk APL. At 72 months the event-free survival (EFS) rate was 96.6% with ATRA-ATO versus 77.4% with ATRA-chemotherapy. In the ATRA-ATO group four events occurred in total, compared to 29 events in the ATRA-chemotherapy group. Relapses later than 48 months only occurred in the ATRA-chemotherapy group. Treatment with ATRA-ATO resulted in a higher disease-free survival rate (DFS; 96.6% versus 79.8%) and lower cumulative incidence of relapse (CIR; 1.7% versus 15.5%). The OS rate at 72 months significantly improved as well with ATRA-ATO (98.3% versus 89.8%; p=0.004).
“The present update shows increasing advantage over time of ATRA-ATO compared to ATRA-chemotherapy with respect to both efficacy and safety”, Cicconi concluded.