ATRA plus ATO for low- to intermediate-risk disease

In a phase III, randomized controlled, multicenter trial in patients with APL classified as low-to-intermediate risk (WBC count, ≤10 × 109/L) ATRA plus chemotherapy was compared with ATRA plus ATO.[4]

In a phase III, randomized controlled, multicenter trial in patients with APL classified as low-to-intermediate risk (WBC count, ≤10 × 109/L) ATRA plus chemotherapy was compared with ATRA plus ATO.[4]

CR rates were equally high for both groups. CR occurred in all 77 patients (100%) who could be evaluated in the ATRA plus ATO group and in 75 of 79 patients (95%) in the ATRA plus chemotherapy group (P = .12).

In a phase III, randomized controlled, multicenter trial in patients with APL classified as low-to-intermediate risk (WBC count, ≤10 × 109/L) ATRA plus chemotherapy was compared with ATRA plus ATO.[4]

With a median follow-up of 34.4 months, the 2-year OS rate was 99% (95% confidence interval [CI], 96%−100%) in the ATRA plus ATO group, and 91% (95% CI, 85%−97%) in the ATRA plus chemotherapy group (P = .02).

In a phase III, randomized controlled, multicenter trial in patients with APL classified as low-to-intermediate risk (WBC count, ≤10 × 109/L) ATRA plus chemotherapy was compared with ATRA plus ATO.[4]

The 2-year cumulative incidence of relapse was similarly low in both groups, 1% (95% CI, 0%−4%) in the ATRA plus ATO group and 6% (95% CI, 0%−11%) in the ATRA plus chemotherapy group (P = .24).

In a phase III, randomized controlled, multicenter trial in patients with APL classified as low-to-intermediate risk (WBC count, ≤10 × 109/L) ATRA plus chemotherapy was compared with ATRA plus ATO.[4]

The primary end point was event-free survival (EFS) (defined as no achievement of hematologic CR after induction therapy, no achievement of molecular CR after three consolidation courses, molecular relapse, hematologic relapse, or death). The 2-year EFS rate was 97% for the ATRA plus ATO group and 85% in the ATRA plus chemotherapy group (P < .001 for noninferiority).

The results of this chemotherapy-free regimen for low- to intermediate-risk APL were confirmed in a second, phase III, randomized controlled trial.[5][Level of evidence A1]