Background: After discontinuing ruxolitinib, the outcome of patients with myelofibrosis reportedly has been poor. The authors investigated whether disease characteristics before the receipt of ruxolitinib may predict drug discontinuation in patients with myelofibrosis and whether reasons for drug discontinuation, disease phase at discontinuation, and salvage therapies may influence the outcome.Methods: A centralized electronic clinical database was created in 20 European hematology centers, including clinical and laboratory data for 524 patients who received ruxolitinib for myelofibrosis.Results: At 3 years, 40.8% of patients had stopped ruxolitinib. Baseline predictors of drug discontinuation were: intermediate‐2–risk/high‐risk category (Dynamic International Prognostic Score System), a platelet count <100 ×10⁹ per liter, transfusion dependency, and unfavorable karyotype. At last contact, 268 patients (51.1%) had discontinued therapy, and the median drug exposure was 17.5 months. Fifty patients (18.7%) died while taking ruxolitinib. The reasons for discontinuation in the remaining 218 patients were the lack (22.9%) or loss (11.9%) of a spleen response, ruxolitinib‐related adverse events (27.5%), progression to blast phase (23.4%), ruxolitinib‐unrelated adverse events (9.2%), and allogeneic transplantation during response (5.1%). The median survival after ruxolitinib was 13.2 months and was significantly better in the 167 patients who discontinued ruxolitinib in chronic phase (27.5 vs 3.9 months for those who discontinued in blast phase; P < .001). No survival differences were observed among patients who discontinued ruxolitinib in chronic phase because of lack of response, loss of response, or ruxolitinib‐related adverse events. The use of investigational agents and/or ruxolitinib rechallenge were associated with improved outcome.Conclusions: The survival of patients with myelofibrosis after discontinuation of ruxolitinib is poor, particularly for those who discontinue in blast phase. Salvage therapies can improve outcome, emphasizing the need for novel therapies.

Background An increased risk of thrombosis has been reported in primary immune thrombocytopenia (ITP) and with the use of thrombopoietin (TPO) receptor agonists, on the basis of population studies using administrative databases. Objectives To evaluate if the incidence of venous and arterial thrombosis in patients with primary ITP is higher than a clinically significant cut‐off set at of 3% and 6.4%. Patients/Methods We undertook a retrospective multicenter investigation in a large cohort of patients requiring at least one treatment for ITP, enrolled from the major tertiary Italian centers treating ITP. A total of 986 patients were analyzed. Results During a 3888 patient‐year follow‐up, 43 first thrombotic events occurred: 28 arterial and 15 venous, resulting in a cumulative incidence of 3.2% for arterial (95% CI, 2.0–5.0) and 1.4% (95% CI, 0.8–2.5) for venous thrombosis at 5 years. The annualized rates for 100 patient‐years were 1.14 (95% CI, 0.84–1.54), 0.39 (95% CI, 0.23–0.65) and 0.71 (95% CI, 0.49–1.04) for total, venous and arterial thrombosis. Splenectomy, performed in 136 patients (13.7%), increased thrombotic risk (HR = 3.5, 95% CI) compared with non‐splenectomized patients. Age > 60 years, more than two risk factors for thrombosis at diagnosis and steroid use were independently associated with an increased risk of thrombosis. Conclusions In this study, we demonstrate that the 5‐year cumulative incidence of venous and arterial thrombosis in ITP is well below the predefined thresholds. Venous and arterial thromboembolism are not frequent complications in ITP, except in particular settings, such as in splenectomized and elderly patients.

The treatment of choice in steroid-resistant immune thrombocytopenia is still controversial due to the recent advent of new drugs (anti-CD20 antibodies and thrombopoietin mimetics) that have encouraged a generalized tendency to delay splenectomy. Consequently, it is extremely importance to define the efficacy and safety of splenectomy in the long term. We retrospectively analyzed the data of 233 patients affected by immune thrombocytopenia who underwent splenectomy between 1959 and 2001 in 6 European hematologic institutions and who have now a minimum follow up of ten years from surgery. Of the 233 patients, 180 (77%) achieved a complete response and 26 (11%) a response. Sixty-eight of 206 (33%) responsive patients relapsed, mostly (75%) within four years from first response. In 92 patients (39.5%), further treatment was required after splenectomy that was effective in 76 cases (83%). In 138 patients (59%), response was maintained free of any treatment at last contact. No significant association between baseline characteristics and likelihood of stable response was found. Overall, 73 (31%) and 58 (25%) patients experienced at least one infectious or hemorrhagic complication, which was fatal in 2 and 3 patients, respectively. A stable response to splenectomy was associated with a lower rate of infections (P=0.004) and hemorrhages (P<0.0001). Thrombosis developed in 18 patients (8%) and was fatal in 4. Splenectomy achieved a long-term stable response in approximately 60% of cases. Complications mainly affected non-responding patients and were fatal in a minority.

Baseline factors associated with response to ruxolitinib: an independent study on 408 patients with myelofibrosis Baseline factors associated with response to ruxolitinib: an independent study on 408 patients with myelofibrosis

Although infectious complications represent a relevant cause of morbidity and mortality in patients with myelofibrosis (MF), little is known about their incidence, outcome and risk factors. We retrospectively evaluated a cohort of 507 MF patients, diagnosed between 1980 and 2014 in five Italian hematology centers, to define the epidemiology of infections and describe the impact of ruxolitinib (RUX) treatment. Overall, 112 patients (22%) experienced 160 infectious events (grade 3–4, 45%) for an incidence rate of 3.9% per patient‐year. Infections were mainly bacterial (78%) and involving the respiratory tract (52% of cases). Also, viral (11%) and fungal infections (2%) were recorded. Overall, infections were fatal in 9% of the cases. Among baseline features, high/intermediate‐2 IPSS category (HR 1.8, 95%CI:1.2–2.7; P = 0.02) and spleen length ≥10 cm below left costal margin (HR 1.6, 95%CI:1.1–2.5; P = 0.04) were associated with higher infectious risk in multivariate analysis. Overall, the rate of infections was higher in the cohort of 128 RUX‐treated patients (44% vs. 20%, P < 0.001). In conclusion, IPSS‐category and splenomegaly, emerged as the main risk factors for infections in MF. RUX‐treated patients experienced significantly more infection episodes; however, future prospective studies are needed to isolate the confounding contribution of other risk factors such as disease stage. Am. J. Hematol. 92:37–41, 2017.