Autologous stem cell transplantation (ASCT) for acute myeloid leukemia in patients in first complete remission after one versus two induction courses: A study from the ALWP of the EBMT

BACKGROUND: Achieving complete remission (CR) is the main goal in AML treatment and a prerequisite for successful autologous stem cell transplantation (ACT). METHODS: Comparing results of peripheral blood ACT in patients with AML in CR1 attained following 1 versus 2 chemotherapy courses transplanted in 2000–2019. RESULTS: Patients 1532 (84%) with one and 293 (16%) patients with two induction chemotherapies courses (a total of 1825 patients) were included in the study. Follow‐up was 7.9 (95% CI: 7.4–8.4) and 7.7 (95% CI: 7.0–8.6) years (p = 0.8). Time from diagnosis to ACT was 4.7 (range, 3.9–5.8) versus 5.7 (range, 4.7–7.1) months (p < 0.001), respectively. Leukemia free survival (LFS) and overall survival (OS) at 5 years were inferior for patients achieving CR1 with 2 versus 1 course of chemotherapy: 26.6% versus 41.7% (HR = 1.42 [95% CI: 1.22–1.66], p < 0.001) and 36.2% versus 53.3%, (HR = 1.48 [95% CI: 1.25–1.75], p < 0.001), and 5‐year relapse incidence (RI) was higher: 67.2% versus 52.3%, (HR = 1.46 [95% CI: 1.25–1.72], p < 0.001). Five‐year non‐relapse mortality (NRM) was 6.2% versus 6.0% for patients with 2 versus 1 chemotherapy courses, and did not differ significantly (HR = 1.31 [95% CI: 0.81–2.10], p = 0.27). CONCLUSIONS: LFS and OS were inferior and relapse rate was higher in AML patients who received two inductions chemotherapy courses to reach CR1 before being autografted. AML patients who required 2 induction courses to achieve remission, may be offered allogeneic transplantation rather than an autologous one in an attempt to reduce their high RI and improve outcomes.