Azacitidine In The Treatment Of Ph- Myeloproliferative Neoplasms In Blastic Phase: The Experience Of Gruppo Laziale For The Study Of Ph- SMPC

To highlight the role of 5-AZA in this subset, we evaluated retrospectively 16 patients (M/F 12/4, median age 63.5 years, range 51 - 81) with MPN-BP according to standard definition (Mascarenhas J et al., Leuk Res. 2012 Dec;36(12):1500-4) treated with 5-AZA in the last 3 years and reported in the database of Gruppo Laziale for the study of Ph- SMPC. Primitive MPN diagnosis was Essential Thrombocythemia in 5 cases, Primary Myelofibrosis in 6, Polycythemia Vera in 1 and MDS/MPN in 4; the JAK-2 V617F mutation was present in 7/14 patients tested (50%); all, but 1, patients received a previous treatment during chronic myeloproliferative phase [12 patients with Hydroxyurea (HU) alone, 1 with HU + Anagrelide, 1 with HU + Pipobroman and 1 with Melphalan + Allogeneic bone marrow transplantation]. Median time from diagnosis to BP evolution was 47 months (range 12 - 317). All patients were treated with 5-AZA at the dosage of 75 mg/m²: as to the schedule, 13 patients received a 7-day schedule and 3 patients a 5-day schedule every 28 days. At the time of evolution, median WBC value was 17.1 x 10⁶/L (range 5.0–89.5), median Hb level 9.9 g/dl (range 6.6–12.7) and median PLT value 155 x 10⁶/L (range 7–434). 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, 2 patients(14%) had an hematological improvement and 4 pts (28.5%) a complete response after 4, 4, 5, and 12 months; median survival of patients in CR is 19.6 months. The overall survival from BP evolution was 8.1 months (range 1–49.5 months) and 3/4 patients in CR are still alive after 15, 24 and 49.5 months, respectively.

Our data confirm the relative efficacy and safety of 5-AZA in this group of patients with otherwise dismal prognosis, underlining the possible achievement of long-lasting responses in a sizeable portion of them.

Off Label Use: Bendamustine.