The early addition of arsenic trioxide versus high-dose arabinoside is more effective and safe as consolidation chemotherapy for risk-tailored patients with acute promyelocytic leukemia: multicenter experience

The purpose of the study was to evaluate event-free survival (EFS), overall survival (OS) and safety for early addition of arsenic trioxide (As₂O₃) as frontline consolidation therapy compared to high-dose arabinoside (HiDAC) in adult patients with de novo acute promyelocytic leukemia (APL). 271 patients (aged 17–65 years) received consolidation therapy containing As₂O₃ (two 21-day courses) or HiDAC regimen. EFS at 5 years was 75% versus 54% (P < 0.001), and OS at 5 years was 83% versus 71% (P = 0.002) in As₂O₃ and HiDAC treatment arms. 139 patients treated with As₂O₃, EFS at 5 years reached 79% versus 56% (P = 0.014), but OS at 5 years was 77% versus 84% (P = 0.32) in low-risk (WBC ≤ 10 × 10⁹/L) and high-risk (WBC > 10 × 10⁹/L) cohorts. Further, patients treated with As₂O₃ rarely incurred agranulocytosis (1.4%, P < 0.001), or severe infection (0.7%, P < 0.001). It is still very well tolerated compared to HiDAC. We confirmed that As₂O₃ as a first-line consolidation regimen provided significant benefits of OS to patients with APL. The As₂O₃ regimen made low-risk patients gain more EFS benefits than high-risk group. The high-risk cohort receiving As₂O₃ overcame the negative impact, yielding OS similar to that for with the low-risk patients treated with As₂O₃.