C006 | EFFICACY AND SAFETY OF AVATROMBOPAG IN 203 PATIENTS WITH CHRONIC IMMUNE THROMBOCYTOPENIC PURPURA: RESULTS OF THE ITALIAN MULTICENTER STUDY AVA-01-CE

Introduction: Chronic immune thrombocytopenia (ITP) is a bleeding disorder characterized by a persistently low platelet count lasting 12 months or longer. First-line treatments include corticosteroids or intravenous immunoglobulin (IVIG). In relapsed, refractory, or poorly adherent patients (pts), second-line therapies are required, including thrombopoietin receptor agonists (TPO-RAs) such as Romiplostim, Eltrombopag, and Avatrombopag (Ava), or immunosuppressive agents like Rituximab, Azathioprine, Mycophenolate mofetil, or Ciclosporin. Splenectomy is considered a last resort. Aim of the Study: To evaluate the efficacy and safety of Ava in real-world pts with chronic ITP, focusing on outcomes based on prior exposure to other TPO-RAs. Results: A total of 203 ITP pts treated with Ava between 1 June 2022 and 31 October 2024 were enrolled in the AVA-01-CE study across 20 Italian hematology centers. The median age at treatment initiation was 60.4 years (range 17.6–92.3), with a female predominance (61.6%). Pts had received a median of two prior therapies (range 0–10), and 117 pts (57.6%) had been treated with at least one other TPO-RA. At baseline, the median platelet count (available for 192 pts) was 15 × 10⁹/L (range 2–49). Eleven additional pts switched to Ava due to intolerance to prior TPO-RAs, without a washout period, and had baseline counts >86 × 10⁹/L. The median time to achieve platelet counts >50 × 10⁹/L (among 157/192 pts) was 14 days (range 3–742) (Fig. 1A). At a median follow-up of 11.5 months (range 0.3–32.0), 144 patients (70.9%) remained on treatment, with a median platelet count of 132 × 10⁹/L (range 8–618) (Fig. 1B). Thrombotic events occurred in 14 pts (6.9%), and bleeding events in 22 pts (10.8%), but only five events (four thrombotic, one bleeding) led to treatment discontinuation. Eight deaths were recorded: four due to COVID-19 infection, one from acute renal failure, one from subdural hematoma, and two from unrelated causes. Conclusions: This is the largest real-world experience reported in Italy regarding Ava use in ITP. Ava demonstrated high efficacy even in heavily pretreated pts, including those previously exposed to other TPO-RAs. The safety profile was acceptable, with few adverse events leading to discontinuation. Our findings align with previous clinical trials and real-world studies. Longer follow-up is needed to evaluate the durability of response.