Background/objectives: Fostamatinib is a spleen tyrosine kinase (SYK) inhibitor approved for the treatment of adult patients with chronic immune thrombocytopenia (ITP). There is little information about dose tapering and sustained remission after discontinuation in ITP. In this retrospective multicenter study, we evaluated efficacy and safety of fostamatinib in adult patients with ITP before, during, and after tapering/discontinuation (T/D). Methods: T/D was performed on subjects who achieved complete platelet response (CR) with progressive, conditional dose reduction every four weeks. Results: Sixty-one patients were included from 14 reference centers between October 2021 and May 2023. In subjects that completed T/D (n = 9), the median time from treatment initiation to response was 21 days (IQR: 7.5–42), median time from treatment initiation to CR was 28 days (IQR: 28–42), median time from treatment initiation to the start of tapering was 116 days (IQR: 42–140), and duration of tapering was 112.5 days (IQR: 94.5–191). The median platelet count was 232 × 10⁹/L (IQR: 152–345 × 10⁹/L) at tapering and 190 × 10⁹/L (IQR: 142.5–316.5 × 10⁹/L) at discontinuation. With a median follow-up since discontinuation of 263 days (IQR: 247–313 days), only two patients have relapsed (at 63 and 73 days). Fostamatinib was restarted, achieving a new CR. Platelet counts higher than 100 × 10⁹/L in week 12 were the only positive predictive factors for successful tapering and discontinuation. Conclusions: Sustained response in patient with ITP treated with fostamatinib could be developed. The prognostic factors and recommended scheme of tapering still have to be evaluated.

Fostamatinib is a spleen tyrosine kinase (SYK) inhibitor approved for the treatment of adult patients with chronic immune thrombocytopenia (ITP). There is little information about dose tapering and sustained remission after discontinuation in ITP. In this retrospective, multicenter study we evaluated efficacy and safety of fostamatinib in adult patients with ITP before, during and after tapering/discontinuation (T/D). T/D was performed in subjects who achieved complete platelet response (CR) with progressive, conditional dose reduction dose every 4 weeks. Sixty-one patients were included at 14 reference centers between October 2021 and May 2023. In subjects that completed T/D (n=9), median time from treatment initiation to response was 21 days (IQR:7.5-42), time to CR 28 days (IQR:28-42), time to start tapering 116 days (IQR: 42-140), duration of tapering 112.5 days (IQR 94.5-191). Median platelet count at tapering was 232×10⁹/L (IQR 152-345×10⁹/L) and at discontinuation 190×10⁹/L (IQR 142.5-316.5×10⁹/L). With a median follow-up since discontinuation of 263 days (IQR: 247-313 days), only two patients have relapsed (at 63 and 73 days. Fostamatinib was restarted, achieving a new CR. Platelet counts higher than 100x10⁹/L at week 12 was the only positive predictive factors for successful tapering and discontinuation.

Platelet transfusion is essential in hematology but remains characterized by practice variability, uneven certainty of evidence across clinical settings, short component shelf life and clinically relevant adverse effects. This narrative review integrates evidence on efficacy, thresholds and dosing, safety, and implementation of platelet-specific patient blood management (PBM). In stable non-bleeding therapy-induced thrombocytopenia, a restrictive prophylactic threshold of 10 × 10⁹/L is supported by randomized evidence and contemporary guidelines, whereas higher thresholds increase exposure without consistent clinical benefit. Therapeutic-only strategies reduce utilization but are not equally safe across populations, particularly in acute leukemia. Platelet PBM should therefore combine indication-specific protocols, a single-adult-dose policy with reassessment, audit and feedback, post-transfusion response monitoring, refractoriness management, inventory stewardship and multidisciplinary governance. The objective is not simply fewer transfusions, but fewer unnecessary transfusions with preserved hemostatic safety.