A Real-world Study Of Ruxolitinib In Myelofibrosis Patients With Thrombocytopenia

Objective:To evaluate the efficacy and safety of ruxolitinib in patients with myelofibrosis with platelet count ≤50×109/L,to explore the influence of ruxolitinib on the grade of myelofibrosis.Methods:A total of eighty myelofibrosis patients who treated with ruxolitinib in The Affiliated Hospital of Qingdao University from September 2017 to June 2022 were enrolled.Patients were divided into platelet count ≤50×109/L group and platelet count>50×109/L group based on platelet count.The clinical data of symptom improvement,spleen shrinkage and adverse reactions were collected.According to the improvement of myelofibrosis grade,the patients were divided into fibrosis grade stable or improvement group and fibrosis progression group,to analyse the influencing factors of myelofibrosis grade.Result:1.A total of 80 patients were enrolled in this study,including 51 males(63.75%)and 29 females(36.25%).The median age was 61.14±9.73 years old,including 56 primary myelofibrosis patients(70.00%),16 Post-PV MF patients(20.00%),and 8 Post-ET MF patients(10.00%).There were 69 patients(86.25%)with JAK2V617F mutation and 11 patients(13.75%)without JAK2V617F mutation.There were 56 patients(70.00%)with MF-2 and 24 patients(30.00%)with MF-3.According to DIPSS stratification,48 patients(60.00%)were low risk/intermediate-1 risk and 32 patients(40.00%)were intermediate-2 risk/high risk.2.The subcostal length of the spleen was shortened after treatment in patients in both the platelet count ≤50×109/L group and the platelet count>50×109/L group(P<0.001).The spleen response rate was 25.00%in the platelet count ≤50×109/L group and 31.25%in the platelet count>50×109/L group,there was no statistical difference in the spleen response rate between the two groups(P=0.855).The physical symptoms of patients were significantly improved after treatment in platelet count≤50×109/L group and platelet count>50×109/L group(P<0.001),and there was no significant difference in the improvement of physical symptoms between the two groups(P=0.664).3.There were no significant differences in white blood cell count and neutrophil count between platelet count ≤50×109/L group and platelet count>50×109/L group before and after treatment(P>0.05).The hemoglobin decreased after treatment in both the platelet count ≤50×109/L group and the platelet count>50×109/L group,and there was no statistically significant difference in hemoglobin changes(P<0.05).Platelets increased after treatment in the platelet count ≤50×109/L group compared with before(P=0.004),and platelets decreased in the platelet count>50×109/L group(P<0.001),there was a statistical difference in platelet count changes before and after treatment in the two groups(P<0.001).4.There was a significant difference in the improvement of myelofibrosis grade between the ruxolitinib dose>10mg bid group and the ruxolitinib dose<10mg bid group(P=0.018).5.The incidences of gastrointestinal bleeding(P=0.005),infection(P=0.032)and fatigue(P=0.003)were higher in platelet count ≤50×109/L group than platelet count>50×109/L group,and there was no significant difference in dizziness and abdominal distension(P>0.05).Conclusion:There was no significant difference in the effectiveness of ruxolitinib in treating patients with platelet count ≤50×109/L and platelet count ≤50×109/L.Platelet count of ≤50×109/L group patients had more adverse reactions such as gastrointestinal bleeding,infection and fatigue,but increased platelet count compared to the previous.Platelet count of ≤50×109/L should not be considered an absolute contraindication for ruxolitinib.Ruxolitinib dose affects improvement in fibrosis grade in patients with myelofibrosis.