DP126 | REAL-LIFE STUDY ON VERY ELDERLY PATIENTS WITH POLYCYTHEMIA VERA: EXPERIENCE FROM THE NPM PH-NEGATIVE LATIAL GROUP

Background With increasing life expectancy, there has been a progressive rise in the proportion of patients (pts) aged ≥80 years diagnosed with myeloproliferative neoplasms (MPNs). However, data specifically focusing on very elderly pts with polycythemia vera (PV) remain limited. Aim: To describe the clinical characteristics and disease course of PV in a real-life cohort of pts aged ≥80 years. Methods: Between 1/2000 and 06/2024, 125 consecutive pts aged ≥80 years were diagnosed with PV across nine hematology centers. These pts were enrolled in the retrospective and prospective databases of the Latial group for Ph-negative MPNs. Diagnoses were reviewed according to WHO 2022 criteria. Results: Main characteristics at diagnosis are shown in the Table. Bone marrow (BM) biopsy was performed in 18 of 114 evaluable pts (15.8%). Median JAK2 V617F allele burden was 38.8% (IQR 11.4–65). At diagnosis, symptoms were reported in 24 of 81 evaluable pts (29.6%), with pruritus present in 10 (41.6%). A history of thrombotic events was found in 33 pts (26.4%). Hydroxyurea (HU) was initiated in 121 pts, typically within one month from diagnosis (IQR 0.1–3.8). HU was discontinued in 23 pts (18.8%), mainly due to intolerance (16/23). Of these, only 3 pts (13%) received ruxolitinib as 2nd line therapy, while 13 (56.6%) received no further cytoreductive treatment. During follow-up, thrombotic events occurred in 11 pts (8.8%), and disease progression to fibrotic or blastic phase was observed in 4 cases. At the last follow-up, 34 pts had died, 33 were lost to follow-up, 58 were alive. The 60- and 120-month cumulative overall survival (OS) rates were 71% (95%CI 82.2–59.8) and 31.9% (95%CI 49.2–14.6), respectively. Conclusion: This real-life cohort study of very elderly PV patients reveals key insights into current clinical practice. BM biopsy was infrequently performed, and nearly all pts received HU promptly after diagnosis. However, there was a noticeable hesitancy in initiating 2nd line therapy with ruxolitinib following HU discontinuation. The high rate of pts lost to follow-up, likely due to challenges in accessing care, limits the robustness of survival analysis. Nevertheless, the observed OS was comparable to that of the general population in the same age group.