Azacytidine for the treatment of retrospective analysis from the Gruppo Laziale for the study of Ph-negative MPN

• Azacytidine is active in patients with blastic evolution of MPN (complete response 26.3%).
• The treatment is safe with an acceptable hematologic and extra-hematologic toxicity.
• The overall survival of AZA patients is improved compared to historical controls.

To highlight the role of azacytidine (AZA) in patients with myeloproliferative neoplasms developing blast phase (MPN-BP), we evaluated retrospectively 19 patients [M/F 15/4, median age 71.3 years, interquartile range (IQR) 64.5–77.7] reported in the database of our cooperative group. Median time from diagnosis to BP evolution was 52.7 months (IQR 11.2–181.8). All patients were treated with AZA at the standard dosage of 75 mg/m2. Two patients died early after 5-AZA initiation from pulmonary fungal infection and respiratory failure respectively, 4 patients had a disease progression, 4 patients a stable disease, 3 patients had an hematological improvement, 1 patient a partial response and 5 pts (26.3%) a complete response (CR) after 4, 4, 4, 5, and 12 months. The median cumulative survival from BP evolution was 9.9 months (95%CI 6.6–13.1): the comparison with an historical cohort of 72 patients with MPN-BP treated with approaches other than AZA (median cumulative survival 3.1 months, 95%CI 1.1–5.0) showed a significant advantage for patients treated with AZA (p = 0.02). Our data confirm the relative efficacy and safety of AZA in this group of patients with otherwise dismal prognosis, underlining the possible achievement of long-lasting responses in a sizeable portion of them.