Immune Thrombocytopenia Onset and Relapse During the COVID-19 Pandemic. A Monocenter Study.

Background And Objectives: Several infections and vaccinations can provoke immune thrombocytopenia (ITP) onset or relapse. Information on ITP epidemiology and management during the Covid-19 pandemic is scarce. In a large monocenter ITP cohort, we assessed the incidence and risk factors for: 1) ITP onset/relapse after Covid19 vaccination/infection; 2) Covid19 infection. Methods: Information on the date/type of anti-Covid-19 vaccine, platelet count before and within 30 days from the vaccine, and date/grade of Covid-19 was collected via phone call or during hematological visits. ITP relapse was defined as a drop in PLT count within 30 days from vaccination, compared to PLT count before vaccination that required a rescue therapy OR a dose increase of an ongoing therapy OR a PLT count <30 ×109/L with ≥20% decrease from baseline. Results: Between February 2020 and January 2022, 60 new ITP diagnoses were observed (30% related to Covid-19 infection or vaccination). Younger and older ages were associated with a higher probability of ITP related to Covid19 infection (p=0.02) and vaccination (p=0.04), respectively. Compared to Covid-19-unrelated ITP, Infection- and vaccine-related ITP had lower response rates (p=0.03) and required more prolonged therapy (p=0.04), respectively. Among the 382 patients with known ITP at the pandemic start, 18.1% relapsed; relapse was attributed to Covid-19 infection/vaccine in 52.2%. The risk of relapse was higher in patients with active disease (p<0.001) and previous vaccine-related relapse (p=0.006). Overall, 18.3% of ITP patients acquired Covid19 (severe in 9.9%); risk was higher in unvaccinated patients (p<0.001). Conclusions: All ITP patients should receive ≥1 vaccine dose and laboratory follow-up after vaccination, with a case-by-case evaluation of completion of the vaccine program if vaccine-related ITP onset/relapse and with tempest initiation of antiviral therapy in unvaccinated patients.

Ruxolitinib in cytopenic myelofibrosis: Response, toxicity, drug discontinuation, and outcome.

BACKGROUND: Patients with cytopenic myelofibrosis (MF) have more limited therapeutic options and poorer prognoses compared with patients with the myeloproliferative phenotype. AIMS AND METHODS: Prognostic correlates of cytopenic phenotype were explored in 886 ruxolitinib-treated patients with primary/secondary MF (PMF/SMF) included in the RUX-MF retrospective study. Cytopenia was defined as: leukocyte count <4 × 109 /L and/or hemoglobin <11/<10 g/dL (males/females) and/or platelets <100 × 109 /L. RESULTS: Overall, 407 (45.9%) patients had a cytopenic MF, including 249 (52.4%) with PMF. In multivariable analysis, high molecular risk mutations (p = .04), intermediate 2/high Dynamic International Prognostic Score System (p < .001) and intermediate 2/high Myelofibrosis Secondary to Polycythemia Vera and Essential Thrombocythemia Prognostic Model (p < .001) remained associated with cytopenic MF in the overall cohort, PMF, and SMF, respectively. Patients with cytopenia received lower average ruxolitinib at the starting (25.2 mg/day vs. 30.2 mg/day, p < .001) and overall doses (23.6 mg/day vs. 26.8 mg/day, p < .001) and achieved lower rates of spleen (26.5% vs. 34.1%, p = .04) and symptom (59.8% vs. 68.8%, p = .008) responses at 6 months compared with patients with the proliferative phenotype. Patients with cytopenia also had higher rates of thrombocytopenia at 3 months (31.1% vs. 18.8%, p < .001) but lower rates of anemia (65.6% vs. 57.7%, p = .02 at 3 months and 56.6% vs. 23.9% at 6 months, p < .001). After competing risk analysis, the cumulative incidence of ruxolitinib discontinuation at 5 years was 57% and 38% in patients with cytopenia and the proliferative phenotype (p < .001), whereas cumulative incidence of leukemic transformation was similar (p = .06). In Cox regression analysis adjusted for Dynamic International Prognostic Score System score, survival was significantly shorter in patients with cytopenia (p < .001). CONCLUSIONS: Cytopenic MF has a lower probability of therapeutic success with ruxolitinib as monotherapy and worse outcome. These patients should be considered for alternative therapeutic strategies.

Sustained response off therapy after fostamatinib: A chronic refractory ITP case report.

Fostamatinib is a SYK-inhibitor drug recently approved by the FDA and EMA for treating chronic immune thrombocytopenia. This drug induces a response in about 40% of patients and has a good toxicity profile. It is known that discontinuing thrombopoietin receptor agonists (TRAs) with the maintenance of sustained response off therapy is possible. On fostamatinib, we do not yet have such information. In this case report, we describe the story of a woman with a multirefractory immune thrombocytopenia (steroids, splenectomy, rituximab, both available TRAs). After 16 years from diagnosis, she started fostamatinib therapy within a clinical trial and achieved a complete response. Grade 1-2 headache and diarrhea occurred during the first months of therapy. These adverse events were resolved with dose reduction of fostamatinib. Despite the dose reduction, the platelet count remained steadily above 80 × 109/L. After 4 years, fostamatinib was gradually reduced and finally discontinued with no drop in platelet count. This is the first case in which fostamatinib discontinuation resulted in a sustained response off therapy.