Acute leukemia arising from myeloproliferative or myelodysplastic/myeloproliferative neoplasms: A series of 372 patients from the PETHEMA AML registry

Treatment of acute myeloid leukemia (AML) evolving from myeloproliferative (MPN) or myelodysplastic/myeloproliferative neoplasms (MDS/MPN) is challenging. We evaluated disease characteristics, treatment patterns and outcomes in 372 patients diagnosed with AML after MPN or MDS/MPN over a 27-year period. Frontline treatment was intensive chemotherapy (38%), hypomethylating agents [HMAs] (17%), non-intensive chemotherapy (14%), and supportive care (31%). Median overall survival was 4.8 months, with a 5-year survival rate of 4%. Median survival was 2.8, 3.9 and 8.3 months for the 1992-2010, 2011-2015 and 2016-2019 periods, respectively (test for trend p < 0.001). Complete response (CR) rate was higher with intensive chemotherapy (43%) than with non-intensive chemotherapy (12%) or HMAs (8.5%) [p < 0.001], but responses were short-lived without allogeneic hematopoietic cell transplantation. Patients treated with intensive chemotherapy or HMAs had superior survival than those receiving non-intensive chemotherapy (median: 8.5 vs. 8.6 vs. 4.2 months, respectively). No differences in treatment response or survival were observed according to prior disease subtypes. Patients undergoing transplantation in CR had better survival than those transplanted in other response categories (3-year survival rate of 64% vs. 22%, p = 0.002). Our results support the use of intensive chemotherapy followed by transplant whenever possible, and the preferential use of HMAs over attenuated chemotherapy regimens in unfit patients. In spite of the survival improvement in recent years, this subset of AML constitutes an unmet medical need and deserves systematic incorporation in clinical trials.